The Conversation

Humans have burned 420 billion tonnes of carbon since the start of the industrial revolution. Half of it is still in the atmosphere. Reuters/Stringer

Getting climate change under control is a formidable, multifaceted challenge. Analysis by my colleagues and me suggests that staying within safe warming levels now requires removing carbon dioxide from the atmosphere, as well as reducing greenhouse gas emissions.

The technology to do this is in its infancy and will take years, even decades, to develop, but our analysis suggests that this must be a priority. If pushed, operational large-scale systems should be available by 2050.

We created a simple climate model and looked at the implications of different levels of carbon in the ocean and the atmosphere. This lets us make projections about greenhouse warming, and see what we need to do to limit global warming to within 1.5℃ of pre-industrial temperatures – one of the ambitions of the 2015 Paris climate agreement.

To put the problem in perspective, here are some of the key numbers.

Humans have emitted 1,540 billion tonnes of carbon dioxide gas since the industrial revolution. To put it another way, that’s equivalent to burning enough coal to form a square tower 22 metres wide that reaches from Earth to the Moon.

Half of these emissions have remained in the atmosphere, causing a rise of CO₂ levels that is at least 10 times faster than any known natural increase during Earth’s long history. Most of the other half has dissolved into the ocean, causing acidification with its own detrimental impacts.

Although nature does remove CO₂, for example through growth and burial of plants and algae, we emit it at least 100 times faster than it’s eliminated. We can’t rely on natural mechanisms to handle this problem: people will need to help as well.

What’s the goal?

The Paris climate agreement aims to limit global warming to well below 2℃, and ideally no higher than 1.5℃. (Others say that 1℃ is what we should be really aiming for, although the world is already reaching and breaching this milestone.)

In our research, we considered 1℃ a better safe warming limit because any more would take us into the territory of the Eemian period, 125,000 years ago. For natural reasons, during this era the Earth warmed by a little more than 1℃. Looking back, we can see the catastrophic consequences of global temperatures staying this high over an extended period.

Sea levels during the Eemian period were up to 10 metres higher than present levels. Today, the zone within 10m of sea level is home to 10% of the world’s population, and even a 2m sea-level rise today would displace almost 200 million people.

Clearly, pushing towards an Eemian-like climate is not safe. In fact, with 2016 having been 1.2℃ warmer than the pre-industrial average, and extra warming locked in thanks to heat storage in the oceans, we may already have crossed the 1℃ average threshold. To keep warming below the 1.5℃ goal of the Paris agreement, it’s vital that we remove CO₂ from the atmosphere as well as limiting the amount we put in.

So how much CO₂ do we need to remove to prevent global disaster?

Are you a pessimist or an optimist?

Currently, humanity’s net emissions amount to roughly 37 gigatonnes of CO₂ per year, which represents 10 gigatonnes of carbon burned (a gigatonne is a billion tonnes). We need to reduce this drastically. But even with strong emissions reductions, enough carbon will remain in the atmosphere to cause unsafe warming.

Using these facts, we identified two rough scenarios for the future.

The first scenario is pessimistic. It has CO₂ emissions remaining stable after 2020. To keep warming within safe limits, we then need to remove almost 700 gigatonnes of carbon from the atmosphere and ocean, which freely exchange CO₂. To start, reforestation and improved land use can lock up to 100 gigatonnes away into trees and soils. This leaves a further 600 gigatonnes to be extracted via technological means by 2100.

Technological extraction currently costs at least US$150 per tonne. At this price, over the rest of the century, the cost would add up to US$90 trillion. This is similar in scale to current global military spending, which – if it holds steady at around US$1.6 trillion a year – will add up to roughly US$132 trillion over the same period.

The second scenario is optimistic. It assumes that we reduce emissions by 6% each year starting in 2020. We then still need to remove about 150 gigatonnes of carbon.

As before, reforestation and improved land use can account for 100 gigatonnes, leaving 50 gigatonnes to be technologically extracted by 2100. The cost for that would be US$7.5 trillion by 2100 – only 6% of the global military spend.

Of course, these numbers are a rough guide. But they do illustrate the crossroads at which we find ourselves.

The job to be done

Right now is the time to choose: without action, we’ll be locked into the pessimistic scenario within a decade. Nothing can justify burdening future generations with this enormous cost.

For success in either scenario, we need to do more than develop new technology. We also need new international legal, policy, and ethical frameworks to deal with its widespread use, including the inevitable environmental impacts.

Releasing large amounts of iron or mineral dust into the oceans could remove CO₂ by changing environmental chemistry and ecology. But doing so requires revision of international legal structures that currently forbid such activities.

Similarly, certain minerals can help remove CO₂ by increasing the weathering of rocks and enriching soils. But large-scale mining for such minerals will impact on landscapes and communities, which also requires legal and regulatory revisions.

And finally, direct CO₂ capture from the air relies on industrial-scale installations, with their own environmental and social repercussions.

Without new legal, policy, and ethical frameworks, no significant advances will be possible, no matter how great the technological developments. Progressive nations may forge ahead toward delivering the combined package.

The costs of this are high. But countries that take the lead stand to gain technology, jobs, energy independence, better health, and international gravitas.

Eelco Rohling receives funding from the Australian Research Council and the UK Natural Environment Research Council. Eelco Rohling is also affiliated with the University of Southampton, UK.

Giant sloths: killed by rainy weather? Kamraman/Wikimedia Commons, CC BY-SA

Wet weather at the end of the last ice age appears to have helped drive the ecosystems of large grazing animals, such as mammoths and giant sloths, extinct across vast swathes of Eurasia and the Americas, according to our new research.

The study, published in Nature Ecology and Evolution today, shows that landscapes in many regions became suddenly wetter between 11,000 and 15,000 years ago, turning grasslands into peat bogs and forest, and ushering in the demise of many megafaunal species.

By examining the bone chemistry of megafauna fossils from Eurasia, North America and South America over the time leading up to the extinction, we found that all three continents experienced the same dramatic increase in moisture. This would have rapidly altered the grassland ecosystems that once covered a third of the globe.

The period after the world thawed from the most recent ice age is already very well studied, thanks largely to the tonnes of animal bones preserved in permafrost. The period is a goldmine for researchers – literally, given that many fossils were first found during gold prospecting operations.

Our work at the Australian Centre for Ancient DNA usually concerns genetic material from long-dead organisms. As a result, we have accrued a vast collection of bones from around the world during this period.

But we made our latest discovery by shifting our attention away from DNA and towards the nitrogen atoms preserved the fossils’ bone collagen.

Lead Author Tim Rabanus-Wallace hunts for megafaunal fossils in the Canadian permafrost in 2015. Julien Soubrier Chemical signatures

Nitrogen has two stable isotopes (atoms with the same number of protons but differing number of neutrons), called nitrogen-14 and nitrogen-15. Changes in environmental conditions can alter the ratio of these two isotopes in the soil. That, in turn, is reflected in the tissues of growing plants, and ultimately in the bones of the animals that eat those plants. In arid conditions, processes like evaporation preferentially remove the lighter nitrogen-14 from the soil. This contributes to a useful correlation seen in many grassland mammals: less nitrogen-14 in the bones means more moisture in the environment.

We studied 511 accurately dated bones, from species including bison, horses and llamas, and found that a pronounced spike in moisture occurred between 11,000 and 15,000 years ago, affecting grasslands in Europe, Siberia, North America, and South America.

Alan Cooper inspects ice age bones from the Yukon Palaeontology Program’s collection, Canada, 2015. Julien Soubrier

At the time of this moisture spike, dramatic changes were occurring on the landscapes. Giant, continent-sized ice sheets were collapsing and retreating, leaving lakes and rivers in their wake. Sea levels were rising, and altered wind and water currents were bringing rains to once-dry continental interiors.

The study shows that a peak in moisture occurred between the time of the ice sheets melting, and the invasion of new vegetation types such as peatlands (data shown from Canada and northern United States). http://nature.com/articles/doi:10.1038/s41559-017-0125

As a result, forests and peatlands were forming where grass, which specialises in dry environments, once dominated. Grasses are also specially adapted to tolerate grazing – in fact, they depend upon grazers to distribute nutrients and clear dead litter from the ground each season. Forest plants, on the other hand, produce toxic compounds specifically to deter herbivores. For decades, researchers have discussed the idea that the invading forests drove the grassland communities into collapse.

Our new study provides the crime scene’s smoking gun. Not only was moisture affecting the grassland mammals during the forest invasion and the subsequent extinctions, but this was happening right around the globe.

Extinction rethink

This discovery prompts a rethink on some of the key mysteries in the extinction event, such as the curious case of Africa. Many of Africa’s megafauna — elephants, wildebeest, hippopotamus, and so on — escaped the extinction events, and unlike their counterparts on other continents have survived to this day.

It has been argued that this is because African megafauna evolved alongside humans, and were naturally wary of human hunters. However, this argument cannot explain the pronounced phase of extinctions in Europe. Neanderthals have existed there for at least 200,000 years, while anatomically modern humans arrive around 43,000 years ago.

We suggest instead that the moisture-driven extinction hypothesis provides a much better explanation. Africa’s position astride the Equator means that its central forested monsoon belt has always been surrounded by continuous stretches of grassland, which graded into the deserts of the north and south. It was the persistence of these grasslands that allowed the local megafauna to survive relatively intact.

Our study may also offers insights into the question of how the current climate change might affect today’s ecosystems.

Understanding how climate changes affected ecosystems in the past is imperative to making informed predictions about how climate changes may influence ecosystems in the future. The consequences of human-induced global warming are often depicted using images of droughts and famines. But our discovery is a reminder that all rapid environmental changes — wet as well as dry — can cause dramatic changes in biological communities and ecosystems.

In this case, warming expressed itself not through parched drought but through centuries of persistent English drizzle, with rain, slush and grey skies. It seems like a rather unpleasant way to go.

Alan Cooper receives funding from the Australian Research Council

Matthew Wooller receives funding from US National Science Foundation

Tim Rabanus-Wallace does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.

Wollemia pine pollen cone. Wollemia pines (found in the wild only in Australia) are one of the most ancient tree species in the world, dating back 200 million years. Velela/Wikipedia

They say that trees live for thousands of years. Like many things that “they” say, there is a germ of truth in the saying (even though it is mostly false).

The vast majority of trees that burst forth from seeds dropped on the Australian continent die before reaching maturity, and in fact most die within a few years of germination.

But depending on how you define a tree, a very select few trees can live for an astoundingly long time.

What are the oldest trees?

If we define a “tree” as a single stemmed woody plant at least 2 metres tall, which is what most people would identify as a tree, then the oldest in Australia could be a Huon Pine (Lagarostrobos franklinii) in Tasmania, the oldest stem of which is up to 2,000 years old.

However, the Huon Pine is also a clonal life form – the above-ground stems share a common root stock. If that common root stock is considered to be the base of multi-trunked tree, then that tree could be as old as 11,000 years.

But if you accept a clonal life form as a tree, even that ancient Huon age pales into insignificance against the 43,000-year-old king’s holly (Lomatia tasmanica), also found in Tasmania.

King’s Holly, or Lomatia tasmanica, can form clones nearly 50,000 years old. Natalie Tapson/Flickr, CC BY-NC-SA

Once you accept that a common, genetically identical stock can define a tree, then the absolute “winner” for oldest tree (or the oldest clonal material belonging to a tree) must go to the Wollemi Pine (Wollemia nobilis). It may be more than 60 million years old.

The Wollemi pine clones itself, forming exact genetic copies. It was thought to be extinct until a tiny remnant population was discovered in Wollemi National Park in 1994. The trunk of the oldest above-ground component, known as the Bill Tree, is about 400-450 years old. But the pine sprouts multiple trunks, so the Bill Tree’s roots may be more than 1,000 years old.

There is also substantial evidence that the tree has been cloning itself and its unique genes ever since it disappeared from the fossil record more than 60 million years ago.

How do you date a tree?

If no humans were around to record the planting or germination of a tree, how can its age be determined? The trees themselves can help tell us their age, but not just by looking at their size. Big trees are not necessarily old trees - they might just be very healthy or fast-growing individuals.

A much more reliable way to determine age of a tree is through their wood and the science of dendrochronology (tree-ring dating).

Dendrochronology involves counting tree rings to date a tree. The wider the ring, the more water the tree absorbed in a given year. sheila miguez/flickr, CC BY-SA

Many trees lay down different types of cell wall material in response to seasonal patterns of light, temperature or moisture. Where the cell walls laid down at the beginning of the growth season look different to those laid down at the end of the season, rings of annual growth can be seen in cross-sections of the tree.

This map of growth patterns can also be cross-dated or correlated with major events like multi-year droughts or volcanic eruptions that spewed material into the atmosphere to be incorporated into the wood of the tree. But the cell walls are more than just calendars.

Why so old?

Individual tree stems can live for so long because of the structure of the wood and the tree’s defence mechanisms. The woody cell walls are very strong and resist breakage.

In fact, scientists have recently discovered that these walls contain a structure – nanocrystaline cellulose – that is currently the strongest known substance for its weight.

Wood can, however, be broken down by insects and fungi. Even though there is little nutrition or energy in wood, there is some – and there are plenty of organisms that will try and use it.

But trees are not defenceless, and can fight back with physical barriers or even chemical warfare. When one tree is attacked by these destructive forces, individuals may even signal to other trees to be aware and prepare their own defences to fight off death and decay.

The death of trees

So why don’t all trees live for centuries or millennia, and why do so many die before even reaching maturity?

Adult Wollemi pines in the wild. J.Plaza/Van Berkel Distributors

Seedlings and young trees may die because they have germinated in an area where there’s not enough water, nutrients or light to keep them alive as adults. Young trees also haven’t had much time to develop barriers or defences against other organisms and may be browsed or eaten to death.

Some trees simply fall prey to accidents: wind storms, fires or droughts. This is just as well, because there is a vast number of plants and animals – including humans – which rely on the wood and other components of these dead trees for their food and shelter.

But increasingly we may see trees dying because the environment is changing around them and they may not be able to cope. This is not just due to climate change; urban development and agricultural expansion, pollution and even too much fertiliser acting as a poison – even our most remote environments are subject to these changes.

But that doesn’t necessarily mean we will have no more very old trees. The Wollemi Pine’s genes have already survived over millions of years, multiple ice ages and warming periods and even the fall of the dinosaurs and rise of humans. And now, people have deliberately spread Wollemi Pine trees all around the world so they are living in a wide range of countries and climates, meaning that the risk of them all dying out is substantially reduced.

Maybe we can do the same for other trees, ensuring that trees will outlive us all.

Cris Brack is a member of the Institute of Foresters of Australia and Director National Arboretum, Canberra Foundation.

Matthew Brookhouse does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.

Has carbon capture and storage been tarnished by its association with the coal industry? Peabody Energy/Wikimedia Commons, CC BY-SA

Since the February blackouts in South Australia, the Australian government has increased its interest in carbon dioxide capture and storage (CCS). However, in Australia and elsewhere, CCS is closely associated to so-called “clean coal” technologies. The media sometimes treats them as one and the same thing.

Given the negativity with which the general public, and expert commentators view “clean coal”, this confusion is distracting attention from other sectors where CCS can make a unique and substantial contribution.

CCS is vital for “clean coal”. Even the most efficient coal-fired power plants emit huge amounts of carbon dioxide. Unless these emissions are captured and stored in rock formations thanks to CCS, meeting climate targets with coal power is impossible.

But here’s the thing: carbon dioxide can be captured from any large-scale source. This means that CCS has a valuable role to play in other industrial sectors – as long as clean coal’s bad reputation doesn’t drag CCS down with it.

Other industries

About half of the global potential for CCS by 2050 has been estimated to lie in industry. Some sectors like synthetic fuels and hydrogen production may not grow as predicted. But others such as cement, steel and ammonia, are here to stay.

Several recent UK reports on industrial decarbonisation argue that CCS brings emissions reductions beyond the 50% needed by 2050 required in most sectors and countries.

For cement in the UK, the report argues, efficiency and other measures could deliver a roughly 20% emissions reduction by 2050. But adding CCS could bring this figure to 54%.

Meanwhile, the British steel industry could cut emission reductions by 60% compared to 34% without CCS. For UK chemical manufacturers, these figures are 78.8% versus 34%. These processes often produce a high-purity stream of carbon dioxide that avoids the costly capture methods used for power applications.

So why aren’t industries like these the stars of carbon capture and storage right now?

Money and hype

Unlike the power sector, which is under pressure to reduce emissions, other high-carbon industries currently have little incentive to pay the estimated cost of US$50-150 per tonne of carbon dioxide captured. Carbon pricing has been hard to introduce even far below such levels.

However, if CCS is to be deployed by mid-century, concept demonstration and confirmation of suitable storage sites needs to start now, and on a wide enough scale to deliver useful emissions cuts. Other strategies may be needed to incentivise it.

CCS was first mooted in 1976, but it only caught world leaders’ attention in the mid-2000s. However, over the past decade its popularity seems to have waned, perhaps because of the “clean coal” issue.

In 2005, WWF joined Europe’s CCS platform, and the following year the environmentalist George Monbiot described the technology as crucial.

But over the ensuing ten years, as a “hype process” around CCS for clean coal developed, industrial CCS was largely ignored. At its peak in 2007, proponents announced some 39 CCS power projects, most of them coal-fired, aiming to capture an average per project of 2.2 million tonnes (Mt) of carbon dioxide per year.

Yet by early 2017, only two large-scale power projects have been completed around the world: Boundary Dam, capturing 1Mt per year, and Petra Nova, capturing 1.4Mt per year.

Number of carbon capture and storage projects by type since first concept. Mature refers to projects in sectors in which capture is routinely commercial, such as in natural gas processing. Immature refers to projects in sectors where capture is not the norm, including power generation, steelmaking, and certain chemicals. The share of power generation projects among immature is highlighted.

Cynicism around the technology has grown, with the Australia-founded Global CCS Institute recently being described as a “coal lobby group”. Unfortunately for CCS, the focus has been mostly on the gap between announced and successful “clean coal” projects, rather than on its contribution to industrial emissions reduction.

Last year, Emirates Steel Industries completed its steelmaking CCS project, which now captures 0.8Mt of CO₂ per year.

Australia will soon be host to the world’s largest CCS development, at the Gorgon LNG Project, which will store 4Mt a year from 2018.

Steel, gas-produced ammonia and other industrial products will be fixtures of the 21st century, whereas coal-fired electricity has no such certainty. Economies that aspire to 100% renewable energy will have no room at all for coal, “clean” or otherwise.

Even if our electricity and transport were to become 100% renewables-based, there will be parts of the economy where greenhouse emissions are hard to eliminate. It is important that the unpopularity of “clean coal” does not distract from the importance of CCS in decarbonising other industries.

Alfonso Martínez Arranz does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.

Around 250 million years ago, life on Earth nearly came to an end, in a mass extinction between the Permian and Triassic periods known as the Great Dying. Some 90% of the species in the oceans and 70% of vertebrate families on land were killed, and the great marine life experiment of the Palaeozoic era was brought to a halt.

What does this have to do with nickel? Well, as part of my recent work as a mining geologist, which involves studying the world’s most valuable nickel ore deposits in Siberia, I uncovered evidence of a link between ore genesis – how the nickel got there – and the onset of the Great Dying. These results were recently published in the Proceedings of the National Academy of Sciences.

It was an exceedingly strange world 250 million years ago, and finding the culprits for the world’s worst mass extinction is like putting together a puzzle.

Earth, fire, water

This catastrophic episode was triggered by several different events, which in turn killed the world’s species in different ways: declining oxygen levels in the ocean, massively rising temperatures, and a possible meteor impact.

One of these trigger events involved a major jolt to the carbon cycle, which had dramatic climate effects. Some scientists think the temperature of the upper level of the world’s oceans and rivers increased from 21℃ to 38℃ in the late Smithian era (250.7 million years ago).

This shift in the carbon cycle has been attributed to a major burst of activity of deep marine colonies of Archaea methanosarcina, relatives of bacteria. These colonies had acquired a new way of getting energy from their environment. In much the same way as human bodies get energy from food, producing carbon dioxide in the process, these organisms got energy from transforming organic carbon into methane.

The archaea colonies were normally limited by the amount of nickel in the oceans, but for some reason, 250 million years ago, nickel seems to have been in abundant supply compared with today.

At the same time as the Great Dying, in an area on Earth that we now call Siberia, an astronomical amount of lava generated in the guts of the Earth erupted over an area the size of Europe. This province is the host to the Noril’sk ore deposits, the Earth’s most valuable source of mined nickel.

Scientists previously thought that nickel released into the atmosphere could explain the glut of marine nickel 250 million years ago. But how could nickel get into the air? This is where our work comes in.

Volcanoes and champagne

Let’s take a step back: how do nickel ore deposits form from molten rock (or magma)? Magma rich in nickel needs to come all the way to shallow depths beneath volcanoes, where it becomes enriched with sulfur, and forms liquid sulfide droplets.

The volcanic plumbing system then acts as a smelter. The sulfide liquid droplets scrub the nickel out of the magma. Ore deposits form when the sulphide droplets finally sink and accumulate at the bottom of the magma under the volcanoes. The nickel never reaches the surface – making it hard to explain how so much nickel got into the atmosphere.

A previous paper by our group showed that when liquid sulfide droplets and gas bubbles form together in the same magma they have a strong tendency to stick together. So, if there is a gas present, sulfide droplets can rise to the top of the magma chambers, taking the metals with them.

In a big eruption, like the one that produced the Siberian lava, the pressure drops, and it’s like opening a bottle of champagne. A swarm of bubbles forms and floats to the top. The liquid sulfide droplets hitch a ride like baskets beneath hot air balloons.

We think that this “bubble riding” is how nickel got from the bottom of the Noril’sk magma all the way to the surface and into volcanic gases and aerosols.

During our recent studies of the Noril’sk nickel ores, we found the smoking gun: we used 2D and 3D X-ray imaging to show nickel-rich sulfide droplets physically attached to former gas bubbles, frozen in the ore.

We combined this observation with simple thermodynamic models to show that this transport mechanism greatly increases the amount of nickel content in volcanic aerosols.

The perils of methane

The Noril’sk nickel deposits are unique. They are the only known place where nickel had a direct path to the atmosphere. Explosive eruptions helped to release colossal amounts of gas into the air.

During these massive gas episodes, our sulfide-carrying champagne bubbles transported large amount of nickel and tipped it into the atmosphere to feed the blooming archaea, playing an important role in the Great Dying.

The Noril'sk ores formed in a freak event, but if the broader hypothesis is correct they hold a lesson for life on Earth: release large amounts of methane into the atmosphere at enormous peril.

Under normal circumstances, volcanic eruptions are a relatively minor source of methane in the atmosphere, but lethal time bombs exist in methane frozen into permafrost, much of it, coincidentally, to be found in the tundra wastelands covering the Siberian lava fields. Here, melting of the permafrost releases bubbles of methane into the atmosphere, creating a climate changing feedback loop – to potentially devastating effect.

Margaux Le Vaillant would like to acknowledge the contribution of Steve Barnes, James Mungall and Emma Mungall.

Margaux Le Vaillant does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.

The Australian government plans to target invasive European carp with a herpes virus, leaving hundreds of thousands of tonnes of carp rotting in the river systems that supply our drinking water and irrigate the fruit and vegetables we eat.

The aim of “Carpageddon” is to return Australian aquatic ecosystems to their pre-carp state by eliminating or reducing the serious pest species.

Carp currently make up 83% of the fish biomass in the Murray-Darling Basin in New South Wales. They alter river and lake habitats in a way that reduces habitability for native species, including five threatened species. They also have a major impact on inland fisheries, with an estimated annual economic cost of A$22 million.

This all makes a substantial argument for releasing a carp killing herpes virus. However, dealing with the aftermath could cost A$30 million for NSW alone.

Cleanup costs could be reduced by introducing viruses to discrete populations. However, if the virus escapes into the Murray-Darling Catchment, we will lose control of the virus spread and carp death will be rapid and widespread.

Without a dedicated cleanup effort, the sudden influx of millions of dead fish could permanently pollute our waterways. A potential solution is to recruit nature’s cleaners to do our work for us – scavengers like turtles and crayfish. They could save us from carcass-choked rivers and wetlands, but only if we can protect them from endangerment and extinction.

Turtles and crayfish are our unlikely saviours

Carp carcasses are normally eaten by scavengers, a process that’s vital to the food web (the system of what eats what in a given environment). In fact, the majority of dead fish are consumed by scavengers.

As such, simply removing the carp carcasses may reduce the overall amount of nutrients in the ecosystem. This would destabilise the food web, especially for scavengers such as turtles and crayfish who rely on them.

Instead, these scavenging species can provide crucial biocontrol. They would eat any decomposing flesh in our water systems, particularly in areas we can’t easily access with nets, boats and trucks. They would maintain the quality of our waterways in three ways:

• Slow the spread of bacteria that break down dead fish, keeping water safe to drink and limiting deoxygenation that could devastate native fish species;

• Digest carp directly into basic nutrients (fertiliser) that is more readily absorbed by plants and primary producers;

• Semi-permanently store carp nutrients in their slow to decompose shells and exoskeletons, preventing or limiting toxic algal blooms caused by excess nutrients in water.

Our unlikely saviours are also dying

Threats to crayfish include agricultural and urban expansion, recreational fishing, pollution from surface runoff and insecticides, and introduced species such as trout and cane toads.

Consequently, native crayfish are declining, with nearly 80% of Spiny Crayfish recognised as threatened. However, yabbies have expanded their range.

Turtles on the other hand, are in sharp decline throughout the Murray Catchment and elsewhere in Australia. A recent gathering of turtle experts in Canberra discussed major threats to turtles, and ways to protect them.

The meeting addressed major causes behind the 2% annual mortality rate of adult turtles that is leading the species to rapid extinction. Cars and foxes kill a significant number of adult turtles every year, and foxes destroy more than 95% of turtle nests in the Murray-Darling Basin.

Changes to the hydrology of the Murray Catchment may also impact turtles. Some species require permanent wetlands, while others prefer to move between temporarily flooded wetlands and more permanent waters.

Following modern water management, some temporary wetlands are permanently flooded or gone and some permanent wetlands are dry.

All of these threats together may cause turtles to become functionally extinct in the near future, meaning they cannot play their significant role in the ecosystem anymore.

How can we help conserve the turtle population?

Such a sudden decimation of carp has potentially catastrophic consequences. But it may also be an excellent opportunity to recognise the importance of turtles and prioritise their conservation.

In a recent study, headstarting was named as the only management tool that could protect freshwater turtles from the multiple threats throughout their life cycle and eliminate all risks of extinction.

Headstarting involves rearing eggs or newborn animals in captivity, then releasing them into the wild. It has been controversial for decades, but releasing thousands of little turtles throughout the Murray River just might rescue us from the post-apocalyptic effects of Carpageddon.

Ricky Spencer receives funding from Australian Research Council, North-Central Catchment Management Authority, Yorta Yorta Aboriginal Corporation, Foundation for National Parks and Wildlife, Victorian Department of Land, Environment, Water and Planning, Winton Wetlands, Turtles Australia, Inc. and Save Lake Bonney Group Inc.

Claudia Santori receives funding from the University of Sydney.

James Van Dyke receives funding from Australian Research Council, North-Central Catchment Management Authority, Yorta Yorta Aboriginal Corporation, Foundation for National Parks and Wildlife, Victorian Department of Land, Environment, Water and Planning, Winton Wetlands, Turtles Australia, Inc. and Save Lake Bonney Group Inc.

Michael B. Thompson receives funding from the ARC and the University of Sydney.

Coal mines, such as this one near Bowen, use water for everything from equipment cooling to dust management. CSIRO, CC BY

From accidental water spills into coastal wetlands, to proposed taxpayer-funded loans, Adani’s planned Carmichael coal mine and the associated Abbot Point coal terminal can’t keep out of the news at the moment.

Last week, the granting of an unlimited 60-year water licence to the Carmichael mine, in Queensland’s Galilee Basin, rattled environmentalists, farmers and community groups alike.

In a region experiencing prolonged drought conditions, the provision of unlimited water for one of the largest mining operations in the Southern Hemisphere seems like a commitment at odds with current climate predictions. The decision has also prompted a raft of wider questions about the industry’s water use.

Why do coal mines need so much water?

Underground coal mines rely on water to reduce the hazard of fires or explosion, by using it to cool the cutting surfaces of mining equipment and prevent coal dust from catching fire.

Water also helps to manage dust produced during the processing stage, when coal is crushed and ground. Coal is then transported through pipelines as a water-based slurry for further processing.

Mines also need water for things like equipment maintenance, and for consumption by the mining communities themselves.

In total, about 250 litres of freshwater are required per tonne of coal produced. This freshwater makes up around a quarter of the total water demand during coal production, the rest being “worked” (recycled) water.

What other industries use lots of water?

The Great Artesian Basin is one of the largest underground water reservoirs in the world. It underlies 22% of Australia’s land area, beneath the arid and semi-arid parts of Queensland, New South Wales, South Australia and the Northern Territory.

Its aquifers supply water to around 200 towns or settlements, most of which are allowed to draw between 100 and 500 million litres (ML) per year.

The Great Artesian Basin covers almost a quarter of Australia. Tentotwo/Wikimedia Commons, CC BY-SA

The Great Artesian Basin underpins A$12.8 billion of economic activity annually, according to a 2016 report commissioned by the federal government. Almost all of this is from mining and coal seam gas (A$8 billion) and livestock farming (A$4.7 billion).

In Queensland, mining and industry hold just over 1% (by number) of the water licences linked to the Great Artesian Basin but account for 10% of the water extracted. Coal seam gas accounts for a further 22% of water, with no licensing required. In contrast, livestock production accounts for 88% of water licences but just 46% of the extracted water.

The Carmichael mine’s 12,000ML forecasted use (equivalent to 4% of the water extracted from the Great Artesian Basin in Queensland last year) would put it alongside the biggest annual users of Great Artesian Basin water, such as the Olympic Dam copper and uranium mine in South Australia, which currently draws 10,000ML each year.

Why does Adani need unlimited water anyway?

According to the company’s own modelling, the Carmichael mine’s annual freshwater use is projected to peak at just over 12,000ML – or roughly 13 Olympic swimming pools per day.

Despite these estimates, the water licence granted to Adani puts no limit on the water it can take from the Great Artesian Basin. However, it calls for regular monitoring of water levels, quality and flow in each aquifer that is tapped.

Unlike other controversial Queensland mining projects, such as the New Acland coal mine, Adani’s water licence application was exempted from public scrutiny, courtesy of a November 2016 amendment to the existing laws.

Water licences usually specify the total amount, and/or the daily rate, of groundwater that can be taken. Changes to a water licence to increase the amount of water must be assessed like a new application and pass public scrutiny. But with an unlimited licence, there is no need for Adani to apply for a new licence if they need more water than originally predicted.

What are the environmental effects of industrial-scale water usage on the basin?

Despite a net yearly decrease of 286,000ML in the water stored within the Great Artesian Basin, it is in no danger of running dry. The past 120 years of exploitation have used up less than 0.1% of the water stored.

The real issue is water pressure. Flows from artesian bores are now roughly half what they were in 1915. Since then, the water level in some bores has fallen by as much as 80 metres, and a third of bores have stopped flowing altogether. This directly affects the human, plant and animal communities that rely on artesian water.

Because of their isolation, the natural springs of the Great Artesian Basin are home to many unique plant and animal species. Desert springs are particularly vulnerable to declining water pressure, and many spring habitats have been irreversibly damaged by invasive species, excavation, livestock, industrial activity and even tourists.

An oasis in South Australia’s arid interior. Tandrew/Wikimedia Commons, CC BY-SA

Can mining industries be more water-wise?

Recycled water is an integral part of coal mining, but it contains salt, added in the dust-management stage, which can leave the water unusable for certain processes. Nevertheless, a recent study suggests that Queensland coal mines could cut their freshwater use by 62% simply by using recycled water for processes that are not sensitive to salt levels. Diluting salty recycled water could also reduce freshwater use by 50%, and cut water costs by 40%.

Untreated seawater is perhaps the most sustainable water of all, although transporting it from coast to mine costs energy and therefore money. Its saltiness also creates chemical challenges during coal and uranium processing.

Another option to address climate-induced water challenges might be for mines to share water allocations.

Where do we go from here?

Understandably, there is significant concern that Adani’s unlimited licence will allow the mine to draw more water than predicted. Should the mine go ahead, it is important that the research community continues to scrutinise the regular water quality and usage reports that Adani is required to provide. Water licences can, after all, be revoked.

We should also be concerned about industries like coal seam gas that currently do not require water licensing, but nevertheless use huge amounts of artesian water.

Although water is an important issue, it is vital not to lose sight of the numerous other environmental impacts of the Carmichael mine. For example, an estimated 4.7 billion tonnes of greenhouse gas emissions will result from the mining and burning of Carmichael coal. Climate warming will impact Australia on multiple fronts, including bleaching of the Great Barrier Reef, increasing the intensity of tropical cyclones, causing more heat-related deaths, diseases and droughts.

Ellen Moon works on a project funded by the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment.

AAP/Lukas Coch

Veteran environmental campaigner and former Greens senator Bob Brown has previously pointed to Adani’s proposed Carmichael coal mine as the new Franklin River of environmental protest in Australia. Yet the future of this “climate bomb” hangs in the balance.

The ongoing contest over the mine’s approval is about to get very heated. Some of the final decisions are to be made very soon.

On Wednesday, Prime Minister Malcolm Turnbull declared that native title claims would not impede the approval process, and that Adani would press ahead with its plans to seek A$1 billion in funding for the rail line needed to transport coal to Abbot Point for export.

The consequences of going ahead with the mine are almost incalculable. This is not simply because of the emissions it will produce, but from the fact it promotes and normalises the insanity that coal can still be “good for humanity”.

Here’s my list of the ten most-absurd things about the Adani mine.

1) As the largest coal mine in the Australia when completed, Adani will legitimise the idea of mining all of the coal in the Galilee Basin. If extracted and burnt, this will get the world one-third of the way toward 2℃ of global warming.

The Adani mine alone will see up to 2.3 billion tonnes of coal extracted from an area five times the size of Sydney Harbour over 60 years. This is equivalent to putting out 7.7 billion tonnes of greenhouse gases. The global budget is now less than 500 billion tonnes in order to have an 80% chance of keeping global average temperature rise to less than 2℃.

2) The mine lies adjacent to the Great Barrier Reef. The heaviest risk to the reef’s future is a continued increase in greenhouse gases.

You couldn’t invent a greater insult to the beloved reef than begin mining operations that amount to an affront to those who have begun to mourn for its imminent death.

3) After years of bashing renewables as unviable without government subsidy, contemplating a $1 billion subsidy to the mine by the Turnbull government is quite perverse.

Fossil-fuel companies already receive $2,000 in rebates and subsidies for every $1 they donate to Australia’s major political parties. So, this additional subsidy makes a mockery of any serious attempt to tackle climate change.

4) With climate-change-induced extreme weather events exacting billions of dollars of damage across Australia, and especially in Queensland, the idea that public money would be used to increase these damage bills by injecting even more energy into the world’s climate system by accelerating greenhouse gas emissions is absurd.

Cyclone Debbie – a category-four cyclone – actually impacted on the areas of the mine itself, and delivered more peak rainfall than Cyclone Yasi, which was a category-five cyclone only six years ago. Since 2006, insurers have paid more than $6.8 billion in cyclone- and flood-related claims in Queensland alone. Debbie is expected to add another $1 billion.

5) That the Northern Australia Infrastructure Fund could be used to subsidise the mine is in contempt of any claim to responsible climate – and financial – policy. That such a fund could be so directly controlled by so few people and have such enormous impact on greenhouse concentrations is a travesty.

6) The argument that the royalties from the mine would benefit Australia are not supported by the recent revelations that Adani has set up an elaborate network of subsidiaries and trusts which are ultimately owned and controlled from the tax haven of the Cayman Islands.

7) That the Queensland Labor government could buy into a jobs campaign around the mine when renewable technologies can carry the promise of even more jobs, and without risk to the Great Barrier Reef that is threatened by the dredging associated with the mine, and therefore is a danger to the tourism industry, is outrageous.

Adani’s own consultants have suggested the mine would produce fewer than 1,500 full-time jobs. This amounts to a public subsidy of $683,000 per job.

8) Adani’s argument that somehow the mine will be lifting Indians out of poverty is a PR disguise for a company that has been accused of blatant human rights abuses.

This argument, invented by the now-failed Peabody Energy and most famously popularised by Bjorn Lomborg, has also been a favourite of Coalition MPs. This argument is thoroughly patronising – not simply because India itself has declared renewables to be more important than coal, but because it is the oppressive legacy of colonialism that under-developed third-world countries in the first place.

9) The desperate plea by Resources Minister Matt Canavan, mounted in the face of a greater lunacy, that the coal Adani would export is “clean coal” that would actually cut emissions, has been dismissed by analysts at the International Energy Agency.

10) To commit to a mine that it supposed to run for 60 years as the price of coal continues to be devalued in the face of investment moving to renewables is business suicide.

It does not even take account of what the world’s climate will be like in 35 years. With the equator in a permanent heatwave and so much more storm-feeding energy in the system, coal won’t just be the new tobacco. It will become the grim reaper we see in our rear-view mirror.

With thanks to Tahnee Burgess for research assistance on this article.

Corals on the Great Barrier Reef have bleached again in 2017 as a result of extreme summer temperatures. It’s the fourth such event and the second in as many years, following earlier mass bleachings in 1998, 2002 and 2016.

The consecutive bleaching in 2016 and 2017 is concerning for two reasons. First, the 12-month gap between the two events is far too short for any meaningful recovery on reefs that were affected in 2016.

Second, last year’s bleaching was most severe in the northern section of the reef, from the Torres Strait to Port Douglas, whereas this year the most intense bleaching has occurred further south, between Cooktown and Townsville. The combined footprint of this unprecedented back-to-back bleaching now stretches along two-thirds of the length of the Great Barrier Reef.

Last year, after the peak temperatures in March, 67% of the corals died along a 700km northern section of the reef – the single greatest loss of corals ever recorded on the reef.

Further offshore and to the south, most of the bleached corals regained their colour after the 2016 bleaching, and survived. The patchiness of the bleaching means that there are still sections of the Great Barrier Reef that remain in good condition.

It is still too early to tell how many corals will survive or die over the next few months in the central section as a result of this year’s bleaching.

Four major events

Each of the four bleaching events has a distinctive geographic pattern that can be explained by where the water was hottest for sustained periods during each summer.

For example, the southern Great Barrier Reef escaped bleaching in both 2016 and 2017 because the summer sea temperatures there remained close to normal. Similarly, the earlier mass bleaching events in 1998 and 2002 were relatively moderate, because the elevated water temperatures experienced then were lower than those in 2017 and especially 2016.

The marine heatwaves in 1998 and 2016 coincided with El Niño periods, but this was not the case in 2002 or this year, when water temperatures were also abnormally high. Increasingly around the tropics, we are seeing more and more bleaching events, regardless of the timing relative to the El Niño-La Niña cycle. This reflects the growing impact of global warming on these events.

The local weather also plays an important role in determining where and when bleaching occurs. For example, in 2016, ex-Tropical Cyclone Winston came from Fiji to Australia at the end of February as a rain depression, and cooled the southern region of the Great Barrier Reef, saving it from bleaching.

This year, the category 4 Tropical Cyclone Debbie tracked across the reef in late March, close to the southern boundary of the latest bleaching.

But TC Debbie was too far south to prevent the bleaching that was already under way in the reef’s central and northern sections. Instead of helping to ameliorate the bleaching, this powerful cyclone has added to the pressures on some southern reefs by smashing corals and exacerbating coastal runoff.

Prospects for the future

The fallout from this and last year’s events will continue to unfold in the coming months and years. It takes several months for severely bleached corals to regain their colour, or to die. On some reefs in the Great Barrier Reef’s central region, underwater surveys in 2017 are already documenting substantial loss of corals.

The recovery times for northern and now central reefs that have lost many corals will be at least 10-15 years, assuming that conditions remain favourable for corals during that period.

We have a narrowing window of opportunity to tackle global warming, and no time to lose in moving to zero net carbon emissions. We have already seen four major bleaching events on the Great Barrier Reef with just 1℃ of global average warming.

The goals enshrined in the Paris climate agreement, which aims to hold global warming well below 2℃ and as close as possible to 1.5℃, will not be sufficient to restore the Great Barrier Reef to its former glory. But they should at least ensure that we continue to have a functioning coral reef system.

In contrast, if the world continues its business-as-usual greenhouse emissions for several more decades, it will almost certainly spell the end of the Great Barrier Reef as we now know it.

Terry Hughes receives competitive research funding from the Australian Research Council, and provides regular advice to both the Commonwealth and Queensland governments.

James Kerry does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.

It is easy to feel overwhelmed when confronted with reports of the second mass bleaching event on the Great Barrier Reef in as many years. But there is a way to help scientists monitor the reef’s condition.

CoralWatch is a citizen science program started at The University of Queensland 15 years ago, with two main aims: to monitor the environment on a vast scale, and to help people get informed about marine science.

These goals come together with coral health monitoring. Divers, snorkelers or people walking around reef areas during low tides can send us crucial information about coral bleaching, helping us to build detailed pictures of the health of different reefs.

Participants can use a colour chart, backed up through the CoralWatch app or website, to measure accurately the colour and type of coral they see. The chart covers 75% of known corals, and can be used with no prior training.

We also ask people to enter the type of coral (branching, boulder, plate or soft), the location, and the weather. This allows scientists to identify the location and extent of any problems quickly (and is an excellent way to learn more about our reefs).

In fact, you don’t even have to go to a reef to participate and discover through CoralWatch; we have classroom and virtual reef systems, and just talking the problem through can help.

CoralWatch chart. Volunteers match the colour and four basic coral types: branching, boulder, plate and soft. CoralWatch

The graphs shown below are samples of CoralWatch data from the northern and southern reef during 2016’s catastrophic mass bleaching event, while the pair of graphs further down the page show data from just a few days ago at Lady Elliot Island and the very remote North Mariana Islands in the West pacific.

The Heron Island graph shows a healthy reef, as the southern areas of the reef escaped the worst of the bleaching last year. In contrast, Monsoon Reef (which lies off Port Douglas) and many others in the north bleached badly, or in some cases simply died.

Scores averaging between four and six are normal and represent good levels of symbiotic algae, which generate nutrients for the coral. Scores below three signify that coral is in distress.

The impact of this year’s mass bleaching is still being quantified. However, reefs in the middle section and far south of the reef – such as Lady Elliot Island – are now showing varying degrees of bleaching, from light to severe. Many of the remaining corals in the north are also showing signs of bleaching again.

What seems certain is that we will lose many more corals, along with the fish and invertebrate life they support, again this year.

The results for the North Mariana Islands, from a CoralWatch survey conducted last week, shows mid-level coral bleaching and demonstrates that even very remote reefs are not climate-proof.

Australians increasingly believe the government needs to act on climate change, and some of this change in opinion is likely fuelled by continued reports of coral bleaching.

CoralWatch doesn’t only help build a detailed picture of reef health. Like other citizen science projects, such as Reef Check, it can help speed up our fatally slow response to climate change. There are three key benefits.

First, we need to improve mutual understanding between scientists and the public. The CoralWatch mantra is: tell me and I’ll forget; teach me and I may remember; involve me and I’ll learn. Citizen science is a natural fit for everyone, no matter your level of education or knowledge.

Children are the citizens of the future, and helping them to understand their changing world is a moral and social imperative. CoralWatch works closely with schools and groups like the Marine Teachers Association of Queensland, and is used in more than 75 countries worldwide.

Second, we need to encourage lifestyle change. Many people, as they become more engaged in citizen science, will naturally adopt more environmentally friendly habits. Getting involved in protecting the Great Barrier Reef – and other citizen science projects – can be a great dose of perspective on our place in the natural world.

However, as personally rewarding as they can be, individual lifestyle choices alone won’t deliver the rapid and widespread change we need to save our reefs. That’s why we need to bridge the disconnect between what most of Australia wants and the politicians who ultimately have the power to fast-track change. Citizen scientists are also informed voters and consumers, who can demand better policies from companies and governments.

The future of the Great Barrier Reef is in the hands of Australians, and it will take all of us to preserve it for our children.

Justin Marshall is affiliated with Coral Watch which has recently received Queensland State Government funding for this project and previously from the Sustainable Tourism Cooperative Research Centre, the Australia Indonesia Institute and the Information Society Innovation Fund Asia.

Chris Roelfsema is affiliated with CoralWatch as a volunteer trainer and science adviser.

Diana Kleine is a project manager for CoralWatch, which has recently received Queensland State Government funding for this project and previously from the Sustainable Tourism Cooperative Research Centre, the Australia Indonesia Institute and the Information Society Innovation Fund Asia.

A man stretches his leg on the bank of the Han River as a ship passes by amid thick haze. Tens of thousands of premature deaths in east Asia every year are caused by shipping pollution. REUTERS/Stringer

Do you wear runners, drink coffee or own a mobile phone? The chances are that these products cruised to you on a ship. In 2015, the global merchant fleet carried a record 10 billion tonnes of cargo, a 2.1% increase from the previous year.

However, while it’s an essential part of international trade, shipping also poses serious risks to the environment. Apart from damage caused by dredging shipping channels and the spread of marine pests around the world, there is also growing concern about pollution. According to a report from the European Union, international shipping contributes 2.5% of global greenhouse gas emissions annually. This is predicted to rise by between 50% and 250% by 2050.

As well as contributing to global warming, ship pollution includes toxic compounds and particles that cause a host of other health hazards. A 2016 Chinese-led study found the shipping boom in east Asia has caused tens of thousands of premature deaths a year, largely from heart and lung disease and cancer.

Commercial ships are designed to be used for a long time. As a result, their engines are typically older and less efficient than those used in many other industries, and replacing them is prohibitively expensive. But there are some immediate solutions to this problem that use existing technology: increasing fuel quality, treating engine emissions, and adopting other energy-conservation measures so that ships burn less fuel.

Improve fuel quality

When diesel ship engines burn poor-quality fuel, their smoke stacks release oxides of nitrogen and sulfur as well as carbon. These pollutants, as well as contributing to greenhouse warming, are highly toxic. Sulfur dioxide readily dissolves in water, creating acid rain that causes harm to both people and the environment.

Refinement of crude oil removes sulfur, which reduces the amount of sulfur dioxide produced when the fuel is burned. Higher-grade diesel also reduces the volume of heat-trapping nitrous oxide, but is more expensive to produce because it requires more purification at the refinery.

The International Maritime Organization, the UN body that regulates the safety and security of shipping, is planning to reduce the amount of sulfur allowed in fuel. However, it is currently considering whether the change will take place in 2020 or will be deferred to 2025.

Install exhaust scrubbers

Clean fuel is an important part of reducing emissions, but the higher cost of low-sulfur fuel will deter many companies. Another way for ships to meet clean-air requirements is by capturing engine exhaust and passing it through scrubbers. These scrubbers convert nitrous oxide gases into harmless nitrogen and water.

This process requires retrofitting older ships, and updating the design of new ship exhaust systems. One advantage of this approach is that it allows ships to meet the different pollution regulations around the world without having to swap fuels.

Another way to reduce production of nitrous oxide is by reducing the temperature at which diesel fuel burns, but this leads to decreased fuel efficiency and increased fuel consumption. Scrubbers are potentially a cheaper and more accessible option.

Reduce energy use overall

Ships don’t just burn diesel fuel to propel themselves through the water. Fuel also generates electricity so that people on board can do things like use computers and read at night.

To increase fuel efficiency, other energy conservation measures can be adopted so that ships burn less fuel and decrease their emissions. The US Navy’s Green Fleet has, for example, replaced their old light fixtures with energy-saving LEDs.

They have also undertaken a temperature control initiative, where thermostats have been checked to ensure they are in proper working order and faulty parts in their water cooling systems replaced. Some ships have gone further, and installed stern flaps that modify the flow of water under the ship’s hull to reduce drag, thus increasing fuel efficiency.

All of this means the shipping industry can lower its fuel bill through conserving energy, and at the same time reduce its negative impacts on the health of humans and the planet. With more than 20,000 ships in the global fleet, these immediate solutions to reducing greenhouse gas emissions and other types of pollution will make a real difference.

Martina Doblin has received funding from the Australian government to advise them on the risks of invasive species being introduced to Australian waters via shipping.

President Donald Trump is keeping some of his promises. Late last month he signed an executive order that tore up Barack Obama’s Clean Power Plan. Some commentators see this as putting the world on “the road to climate catastrophe”, while others have described it as an effort at “killing the international order”.

Will America lose out? Will China, which has chided Trump for selfishness, be the prime beneficiary as its solar panel industry continues to expand?

Here in Australia, in response to Trump’s order, Liberal backbencher Craig Kelly, chair of the government’s Environment Committee, took predictable aim at Australia’s international climate commitments, labelling the 2015 Paris Agreement “cactus”.

Kelly is on the record as disputing climate science and poured scorn on the Paris deal when it was struck. He is certainly not alone among the government’s ranks in this view.

The day after Trump’s election win last November, Australia ratified the Paris deal and Prime Minister Malcolm Turnbull said that it would take four years for Trump to pull out.

So is the Paris deal really “cactus”? What would we have lost if so? And does it matter?

What was agreed in Paris?

The Paris Agreement came after the United Nations Framework Convention on Climate Change (agreed at the Rio Earth Summit in 1992) had suffered a body blow at the 2009 UN climate talks in Copenhagen .

Opinion was divided on the reasons for the failure of the Copenhagen summit, but the then prime minister Kevin Rudd didn’t mince words in blaming the Chinese, infamously accusing them during the negotiations of trying to “rat-fuck us”. (For what it is worth, the British climate writer Mark Lynas agreed, albeit in less incendiary tones.)

A series of fence-mending meetings and careful smoothing of frayed nerves and wounded egos followed over the next five years. The French took charge and, with the price of renewable energy generation plummeting (and so making emissions reductions at least theoretically “affordable”), a deal was struck at the Paris summit in December 2015.

The agreement, notably silent on fossil fuels, calls on nations to take actions to reduce their emissions so that temperatures can be held to less than 2℃ above the pre-industrial average. This limit, which is not actually “safe”, will require a herculean effort and luck. If you add up all the national commitments, they will most likely take us to roughly 3℃ or beyond.

Australia’s commitment of a 26-28% reduction in greenhouse emissions by 2030, relative to 2005 levels, was seen as being at the low end of acceptable, and not enough to help meet the 2℃ limit.

Eminent climate scientist James Hansen labelled Paris a fraud, while Clive Spash (the economist monstered by Labor in 2009 for pointing out that Rudd’s Carbon Pollution Reduction Scheme was not much cop) thought it was worthless.

British climatologist Kevin Anderson is similarly dubious, arguing that the agreement assumes we will invent technologies that can suck carbon dioxide out of the atmosphere in, well, industrial quantities in the second half of this century.

So why the relative optimism among the climate commentariat? They’re desperate for a win after so many defeats, which stretch back all the way to the Kyoto climate conference of 1997.

Second time as farce?

After Australia’s initial promises to be a “good international citizen”, reality quickly set in during the early years of serious climate diplomacy.

Although Australia was an early ratifier of the treaty that emerged from the Rio summit, it nevertheless went to the first annual UN climate talks (chaired by a young Angela Merkel) determined to get a good deal for itself, as a country reliant on coal for electricity generation and eyeing big bucks from coal exports.

That meeting resulted in the “Berlin Mandate”, which called on developed nations to cut emissions first. Australia, gritting its teeth, agreed. Later that year the Keating Government released economic modelling (paid for in part by fossil fuel interests) which predicted economic Armageddon for Australia if a uniform emissions-reduction target was applied. This work was picked up by the new Howard government.

After much special pleading and swift footwork, Australia got two very sweet deals at Kyoto in 1997. First, its “reduction” target was 108% of 1990 levels within the 2008-12 period (the then environment minister Robert Hill reportedly refused to push for Howard’s preferred 118%).

Second, Australia successfully lobbied for a clause in the Kyoto treaty allowing reductions in land clearing to count as emissions reductions. This meant that Australia could bank benefits for things that were happening for entirely different reasons.

Australia signed the Kyoto Protocol in April 1998, but in September of the same year the cabinet decided not to ratify the deal unless the United States did. In March 2001 President George W. Bush pulled out, and Howard followed suit on World Environment Day in 2002.

Kyoto ratification then became a symbol of green virtue out of all proportion with its actual impact. Rudd got enormous kudos for ratifying it as his first official act as Prime Minister. And then reality set in again when he tried to actually implement an emissions-reduction policy.

Why does it matter?

Reality keeps on impinging. In a beautifully written piece in the New York Times, Ariel Dorfman lists disasters befalling Chile (readers in Queensland will feel like they know what he is on about). He concludes:

As we get ready to return to the United States, our friends and relatives ask, over and over, can it be true? Can President Trump be beset with such suicidal stupidity as to deny climate change and install an enemy of the earth as his environmental czar? Can he be so beholden to the blind greed of the mineral extraction industry, so ignorant of science, so monumentally arrogant, not to realize that he is inviting apocalypse? Can it be, they ask. The answer, alas, is yes.

Will the opinions of politicians like Donald Trump and Craig Kelly matter at all as long as the price of renewables keeps dropping? Well, possibly. “Shots across the bow” of renewables policy have in the past made investors nervous.

As Alan Pears on this website, and Giles Parkinson at Reneweconomy have explained, investors in electricity generation got spooked by the policy uncertainty caused by former prime minister Tony Abbott’s hostility to the Renewable Energy Target. That’s the real (and presumably intended) effect of statements like Kelly’s.

Will it work? Optimists will point to last week’s announcement that a $1bn solar farm will be built in South Australia, regardless of the concatenating Canberra catastrophe. Perennial pessimists will point to the Keeling Curve, which shows a remorseless and escalating rise in the level of atmospheric carbon dioxide. Time and prevailing politics are certainly not on our side.

Prime Minister Malcolm Turnbull’s response to the looming east coast gas shortage has been to secure a promise from gas producers to increase domestic supply.

In a televised press conference last month, he said:

We must continue the pressure on state and territory governments to revisit the restrictions on gas development and exploration.

But if an onshore gas boom is indeed in the offing, my research suggests that gas companies should tread carefully and take more seriously the social context of their operations.

Shell chief executive Erik van Beurden, one of the big players in the Australian gas industry, recently admitted that “social acceptance [for our industry] is just disappearing”, while Shell Australia’s chairman Andrew Smith last year urged the industry to be less hubristic and more willing to collaborate.

Industrial developments have social consequences, particularly in the case of unconventional gas extraction. But my analysis of the social research done by gas firms in the Darling Downs – Queensland’s coal seam gas heartland – indicates a lack of rigorous research to identify community attitudes.

I looked specifically at the “social impact assessments” carried out for Arrow Energy’s Surat Gas Project. I evaluated this assessment against the academic literature on best-practice methods and the results of my own anthropological fieldwork on coal seam gas developments in the Darling Downs, including interviews and participant-observations among a broad variety of residents. This included farmers with and without gas wells on their land, town residents, Indigenous people, activists, and those who viewed the industry favourably.

In my experience, the industry’s social impact assessments do not generally meet the benchmark of good social anthropological research. They are largely completed using computer surveys, with limited amounts of direct local fieldwork and relatively little real attention paid to the particular issues raised by vulnerable groups or what actually matters to local communities.

Social impact assessments should be participatory and take into account the unequal distribution of the impacts among local populations. Some people will feel the impacts more than others – this means that in-depth research in the region is required.

A desktop analysis of census data, complemented with information obtained during a few “consultation” meetings, is unlikely to reveal the variety of impacts caused by industrial projects. The conclusion is that such studies, combined with a regulatory agenda that prioritises economics, have created problematic “silences in the boom”.

Conflicting priorities

In Australia, policies governing extractive industries such as onshore gas are mostly viewed in terms of economic cost and benefit – or to use the current mantra, jobs and growth. The projects themselves, meanwhile, are seen chiefly as a series of technical challenges to be overcome by scientists and engineers.

Public concerns about the effect on quality of life or uncertainties about underground impacts are commonly dismissed as irrational, emotional or uninformed. But the main problem faced by onshore gas producers is not an engineering one.

Social research has shown that the fundamental problems include lack of trust between gas producers and local communities, as well as differing views on livelihoods, culture and the environment.

In the coal seam gas fields of the Darling Downs – a rural and agricultural area – the effects on the ground, including concerns about extraction techniques such as fracking really matter. While individual gas wells typically have a relatively small footprint of about one hectare, the cumulative regional footprint of numerous connected gas fields and associated infrastructure is considerable.

The management of the impacts is negotiated in individual agreements with landholders as well as indigenous groups with traditional connections to country. Dealing with this social world is relatively new to many oil and gas companies that have previously focused mainly on offshore projects.

Unconventional gas and fracking developments have led to demonstrations, blockades, and the rise of vocal anti-fracking groups both in Australia and around the world. Gas producers in Colorado, for example, seem to have been shocked and surprised at the level of protest against fracking, a technique they have used for decades.

Instead of dismissing public concerns as irrational or ill-informed, politicians and gas producers could look carefully at why their proposals provoke these reactions. Just calling for more gas, more science, and less red tape is unlikely to diminish anti-fracking sentiment.

Invisible gas

Gas can be scary. It is everywhere and nowhere. You can’t feel it, see it, hear it or smell it unless you add something to it or measure it with an expensive device. Gas doesn’t have the same cultural symbolism as coal, the black gold of our settler history, or the Snowy Mountains, scene of the great “nation-building” hydroelectric project that Turnbull has pledged to make even bigger.

Anti-fracking activists, meanwhile, have sought to imbue gas with a cultural symbolism that draws on the underground world of demons and danger. Footage of burning tapwater is a potent example of “matter out of place”. No matter that methane is sometimes found naturally in water. Cultural anxieties are rarely be eased by natural science.

So while the federal government and industry figures call on states and territories to ease restrictions on gas exploration, they should bear in mind that unconventional gas can provoke strong anxiety and opposition. The architects of Queensland’s coal seam gas boom were slow to recognise this.

Energy is fundamental to our ways of life, and social support is crucial for the companies that provide this energy. Such support is not earned with desktop studies or by dismissing non-economic concerns. It is earned with genuine engagement and social policies that take seriously the experiences and diverse views of people now on fractured and uncertain ground.

Kim de Rijke works for The University Queensland and intermittently undertakes contract native title research for Indigenous groups around Australia. He received funding for his postdoctoral research on coal seam gas and fracking disputes in Queensland and the Northern Rivers region of New South Wales from The University of Queensland.

The devastating flood damage wreaked by Tropical Cyclone Debbie has left many residents in northern New South Wales facing an enormous cleanup that could take months.

Any Lismore local will tell you that flooding is a fact of life in the Northern Rivers. In the floods of 1954 and 1974, the Wilsons River rose to a record 12.17 metres. This time around, the river peaked at 11.59m, breaching the flood levee built in 2005 for the first time.

So what are the conditions that caused those historic floods? And are they any different to the conditions of 2017?

Like the current flood, cyclonic rains also caused the 1954 and 1974 events. But unlike those past events, both of which were preceded by prolonged wet weather, almost all of the extreme rainfall from ex-Tropical Cyclone Debbie fell within 24 hours.

More interesting still is the fact that we are not currently experiencing La Niña conditions, which have historically formed the backdrop to severe flooding in eastern Australia.

The 1954 flood was preceded by an east coast low from February 9-11, followed by a decaying tropical cyclone from February 19-22. Thirty people were killed as flood records were set in Lismore, Kyogle, Casino, Nimbin and Murwillumbah. Some places received more than 1,000mm of rain in 14 days.

In 1974, former Tropical Cyclone Zoe unleashed torrential rain over Lismore, Wyrallah and Coraki. From March 10-13, some stations received almost 1,000mm in just four days. One analysis described the flood as a once-in-70-year event.

This time around, the remains of Tropical Cyclone Debbie delivered extreme rainfall to northern NSW towns including Murwillumbah, Chinderah and Lismore, despite having crossed the coast several days earlier and more than 1,200km to the north. Floods as far apart as Rockhampton in central Queensland and northern New Zealand show the storm’s colossal area of influence.

During the event, 20 rainfall stations in Queensland and 11 sites in NSW recorded their wettest March day on record. Mullumbimby, in the Brunswick River catchment, received a staggering 925mm during March – over half the annual average in a single month – causing major flooding in the region.

The heaviest rainfall in the Wilsons River catchment was at Terania Creek, which received 627mm over March 30-31, 99% of it in the 24 hours from 3am on March 30. Lismore recorded 324.8mm of rain in the 18 hours to 3am on March 31, its wettest March day in more than 100 years. A little further out of town, floodwaters submerged the gauge at Lismore Airport, so unfortunately we do not have reliable figures for that site.

March 2017 rainfall across Australia. Tropical Cyclone Debbie’s track down the east coast is visible in the trail of above-average falls. Bureau of Meteorology

The main difference between the current flooding and the 1954 and 1974 floods is that the previous events both occurred against a background of sustained La Niña conditions. These tend to deliver above-average tropical cyclone activity and high rainfall totals, which increase flood risk.

During the early 1970s, Australia experienced the longest period of La Niña conditions in the instrumental record. This unleashed phenomenal deluges across virtually the entire country. By the end of 1973, many catchments were already saturated as the wet season started early, culminating in the wettest January in Australia’s rainfall records.

In 1974 the Indian Ocean was also unusually warm (what meteorologists call a “negative Indian Ocean Dipole (IOD) phase”), further enhancing rainfall in the region. When negative IOD events coincide with La Niña conditions in the tropical Pacific, the warm sea temperatures reinforce one another, resulting in more evaporation and increased rainfall. This double whammy resulted in the exceptionally wet conditions experienced across the country during 1974.

In January 1974, the Northern Territory, Queensland and Australia as a whole recorded their wettest month on record, while South Australia and New South Wales recorded their second-wettest January on record. Torrential monsoon rains in the gulf country of Queensland transformed the normally dry interior into vast inland seas, flooding all the way to Lake Eyre in the arid zone of South Australia.

Vast swathes of Australia were much wetter than average during the mid-1970s. Bureau of Meteorology

In contrast, Tropical Cyclone Debbie formed under neutral conditions, rather than during a La Niña. In fact, the Bureau of Meteorology is currently on El Niño watch, meaning that there is double the normal risk of an El Niño event bringing low rainfall and high temperatures to Australia by mid-2017.

So, unlike the 1950s and 1970s, the current flooding happened despite the absence of conditions that have driven major flooding in the past. It seems extraordinary that such a damaging cyclone could develop under these circumstances, and deliver such high rainfall over such a short time. This suggests that other factors may be at play.

A rapidly warming climate means that storms are now occurring in a “super-charged” atmosphere. As temperatures increase, so does the water-holding capacity of the lower atmosphere. The oceans are also warming, especially at the surface, driving up evaporation rates. Global average surface temperature has already risen by about 1℃ above pre-industrial levels, leading to an increase of 7% in the amount of water vapour in the atmosphere.

Ocean evaporation, before and after ocean warming. Climate Council

Of course, it is hard to determine the exact impact of climate change on individual storms. However, climate scientists are confident about the overall trends.

Australia’s land and oceans have warmed by 1℃ since 1910, with much of this warming occurring since 1970. This influences the background conditions under which both extremes of the rainfall cycle will operate as the planet continues to warm. We have high confidence that the warming trend will increase the intensity of extreme rainfall experienced in eastern Australia, including southeast Queensland and northern NSW.

While it will take more time to determine the exact factors that led to the extreme flooding witnessed in March 2017, we cannot rule out the role of climate change as a possible contributing factor.

CSIRO’s latest climate change projections predict that in a hotter climate we will experience intense dry spells interspersed with periods of increasingly extreme rainfall over much of Australia. Tropical cyclones are projected to be less frequent but more intense on average.

That potentially means longer and more severe droughts, followed by deluges capable of washing away houses, roads and crops. Tropical Cyclone Debbie’s formation after the exceptionally hot summer of 2016-2017 may well be a perfect case in point, and an ominous sign of things to come.

Joelle Gergis receives funding from the Australian Research Council.

The Great Barrier Reef is currently experiencing a second wave of bleaching. AAP Image/WWF AUSTRALIA, BIOPIXEL

The Great Barrier Reef is under serious threat, as the coral-bleaching crisis continues to unfold. These problems are caused by global climate change, but our ability to react to them – or prevent more harm – is clouded by a tangled web of bureaucracy.

Published this week, my latest research shows the increasingly complex systems for governing the Reef are becoming less effective.

Earlier this month, the Great Barrier Reef Marine Park Authority and the National Coral Reef Taskforce confirmed that a second wave of mass bleaching is now unfolding on the Reef. The same week, the Australian government quietly announced an unexpected review of the governance of the Great Barrier Reef Marine Park Authority.

This most recent coral bleaching crisis brings the governance of the reef into stark relief.

How did we get here?

Yet this problem didn’t always exist. In 2011, a state-of-the-art system governed the complete range of marine, terrestrial, and global threats to the reef. The management of the Great Barrier Reef Marine Park was (and still is) the responsibility of the Australian government, primarily through the statutory Great Barrier Reef Marine Park Authority.

A highly collaborative working relationship, dating back to 1979, existed with the State of Queensland. Complementary marine, land, water, and coastal arrangements were established over four decades. The United Nations Educational, Scientific and Cultural Organization (UNESCO) provided important international oversight as a consequence of the 1981 World Heritage listing.

By 2011, the management of the reef had received international acclaim, with the 2004 rezoning process (which divides the reef into eight zones for different activities) receiving 19 international, national, and local awards.

Yet despite the attention of federal lawmakers and considerable acclaim, in 2014 UNESCO was considering the Great Barrier Reef for an “In Danger” listing. Appearing on this list is a strong signal to the international community that a World Heritage area is threatened and corrective action needs to be taken.

Lizard Island in 2016, after the worst climate change-induced coral bleaching event ever recorded. AAP Image/XL Catlin Seaview Survey What went wrong?

So what went wrong? My study examined the structure and context of the systems for protecting the reef, which offers insight into how well they’re working.

It’s worth noting that complex systems aren’t inherently bad. A polycentric approach – which literally means “multiple centres”, instead of a single governing body – can be both stable and effective. But I found that in the case of the Great Barrier Reef, it masks serious problems.

A number of stresses, like climate change, economic crises, resource industry pressure and local political backlashes against conservation, have all combined to impact effective management of the reef.

Furthermore, successive governments keep making new announcements (new laws, programs, funds, and plans) while at the same time chipping away at the pre-existing laws, departments and funding.

Low visibility examples include the 2012 introduction of a policy that requires developers who want to build on or near the reef to make an offset payment into the Reef Trust, which funds activity to improve water quality. However, this has also made getting consent for development easier.

It’s also concerning that, while there is no evidence of actual corruption, there is no mechanism to minimise the potential for undue industry influence under this policy. The Department of Environment grants approval for developments, and also oversees the offset fund into which the developers pay. Most people would regard this as a conflict of interest.

More visible examples include the dismantling of complementary policies and institutions, including the repeals of Queensland coasts and catchments legislation in 2013, and Australian climate law and policy in 2014.

A 2015 study of OECD countries singled out the Australian Department of Environment for unusually frequent changes of both name and composition. The same study also showed that Australia has one of the sharpest declines in staff at national environment authorities since the 1990s, relative to other OECD countries.

The Great Barrier Reef Marine Park Authority itself has seen its resources plateau, and an increasing politicisation of decisions. Its independence has also been reduced through a series of small, incremental actions. Since 2005, there has been at least ten “regime changes”, ranging from small tweaks to large restructurings.

Schematic of major changes to regime structure, context, and effectiveness over time. Different types of change influence the structure and effectiveness of the regime in different ways. PNAS

Core funding across all relevant agencies has failed to keep pace with costs, at the same time as demands on them rose in response to the Queensland resources and population boom, not to mention global climate change.

On top of that, reef stakeholders must increasingly focus their attention on how all of this fits together as a streamlined system or as a network, rather than how to actually make it effective.

If we are to save the Great Barrier Reef from climate change, then we need to fix its governance.

What needs to come next

In 2015, after the government released their Reef 2050 Plan, UNESCO decided not to list the Reef as in danger, pending a 2016 assessment of progress. UNESCO is yet to make a recommendation, although the fact that the plan has very little mention of human-induced climate change may prove to be an issue.

Despite scientific outcry, the Australian government successfully lobbied UNESCO to remove the Great Barrier Reef and other Australian sites from its draft report on World Heritage and Tourism in a Changing Climate in 2016.

In response to public concern, the National Climate Change Adaptation Research Facility and the ARC Centre of Excellence for Coral Reef Studies held a policy consultation workshop with stakeholders and experts from all levels of government, industry representatives, environmental NGOs and peak scientific bodies like the Australian Institute of Marine Science. Participants made various recommendations for reform, including:

• meeting the national climate mitigation challenge that Australia supported at COP21 in Paris (first and foremost)

• strengthening independent oversight of environmental decision-making (for example, reinstating the formal joint ministerial council)

• reinstating the independence and diversity of the Great Barrier Reef Management Authority, by improving the role and composition of the board and executive management

• properly costing and funding the protection of the Great Barrier Reef.

Yes, the Great Barrier Reef is in crisis, but the coral-bleaching problem is also a governance disaster. Regressive change, both large and small, has been masked by the complexity of the governance regime. Clear analysis of the minor and major transformations required to update the regime will be critical. If there’s no real reform, a UNESCO “in danger” listing seems inevitable.

Tiffany Morrison does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.

Hundreds of thousands of crown-of-thorns starfish have invaded North Queensland, devastating reefs. iStock

Crown-of-thorns starfish are one of the most aggressive reef-destroyers in the world. A single female can produce up to 120 million offspring in one spawning season, and these spiny invaders eat coral, weakening entire reef systems. They’re a serious problem in northern Queensland, and are likely to move south.

But after three years of work, my colleagues and I have made a discovery, published in Nature today, that could offer a whole new way to fight them: we have decoded the gene sequence for the crown-of-thorns’ pheromones, which prompt them to gather for mating.

The project was built on the premise that if we could tap into the communications systems of starfish, we could modify their behaviours, and then eventually set up a program to capture them.

The ultimate goal was to find a way to get the starfish to converge, so it’s possible to set traps and remove them from the reef. Currently, crown-of-thorns starfish are removed by divers, who either collect them by hand or inject them with toxic solutions. This is labour-intensive and deeply inefficient.

So how do we get them into one place? Well, we exploited their natural mating behaviour. Starfish, like a lot of other marine animals – including corals – release their eggs and sperm into the water, and fertilisation occurs externally. For starfish to do this successfully they need to form a tight cluster, so there’s a strong imperative gather in one spot, given the right stimulus.

Crown-of-thorn starfish grazing on healthy coral leaving behind dead white skeletons. Outbreaks of this starfish is one of the leading causes of coral reef destruction throughout the Indo-Pacific. Oceanwide Images How do starfish communicate?

We thought if we could figure out how starfish know how to get together, we might be able to replicate it. To find out what was going on, we put a group of crown-of-thorns starfish in a large aquarium, and waited for them to aggregate. We then set up what’s called a choice experiment.

We used a Y-shaped maze, and put new starfish at the base of the Y. The two arms of the Y contained either fresh seawater, or water that had just passed over the aggregating starfish in the other aquarium.

As expected, fresh seawater had no effect. These starfish aren’t very active animals – they just sat there. But as soon as the water from the aquarium hit them, they became highly active and moved towards the source.

That told us immediately that the aggregating starfish had changed the chemistry of the seawater in a significant way.

The next step was to actually sequence the pheromone proteins in that seawater. We then mapped these sequences back to the genome, and identified the genes that encode the pheromones that are making the starfish do this.

The beauty of this whole process is that there’s a direct one-to-one relationship between the sequence of proteins that make up the pheromones, and the gene sequence. Because genes are a lot easier to analyse than proteins, we can then look at them in great detail, and use that information in future projects.

A crown-of-thorns starfish eating a brain coral. Australian Institute of Marine Science Eco-friendly pest control

What’s particularly good about this result is that these pheromones are unique to the crown-of-thorns starfish. The genes that encode the proteins have evolved rapidly and recently, and aren’t shared by other species of starfish that we’ve looked at. It looks like each starfish has its own unique repertoire of pheromones.

This means that any attractants or bait we develop from this project will only be recognised by crown-of-thorns starfish, and won’t impact other species.

We look at this paper as phase one: the discovery of the communication pheromones. We’re now in phase two: trying to mimic those pheromones so we can develop baits for traps to remove the starfish from the reef before they reproduce.

Ultimately we’d like for fishers up and down the Queensland coast to be able to go out and fish them and make some money out of it. That could be through a bounty, or through developing some useful (or edible) product out of the starfish to sell.

We need a quicker way to remove crown-of-thorns starfish, and real incentive to get plenty of people involved. No-one knows how many there are around Australia, but there are some reefs in Queensland that have had hundreds of thousands, or even millions, removed by conservation projects. If we see those amounts on individual reefs, the true numbers across the Indo-Pacific ocean must be astronomical.

The final, most exciting aspect of this project is the possibility of wider applications. This approach hasn’t been used before in a marine environment, but it could potentially work for a wide range of invasive species. Pest organisms are a multibillion-dollar global problem – and this could mean we move beyond mitigating invasive species and actually start controlling them.

Bernard Degnan received funding from the Australian Research Council to fund this project.

Last year in Paris, for the very first time, English sparkling wine beat champagne in a blind tasting event. Well established French Champagne houses have started buying fields in Britain to grow grapes, and even the royal family is investing in this new venture.

At the same time, coffee-growing regions are shrinking and shifting. Farmers are being forced to move to higher altitudes, as the band in which to grow tasty coffee moves up the mountain.

The evidence that climate change is affecting some of our most prized beverages is simply too great to be ignored. So while British sparkling wine and the beginning of the “coffeepocalypse” were inconceivable just a few decades ago, they are now a reality. It’s unlikely that you’ll find many climate deniers among winemakers and coffee connoisseurs. But there are far greater impacts in store for human society than disruptions to our favourite drinks.

Dramatic examples of climate-mediated change to species distributions are not exceptions; they are fast becoming the rule. As our study published last week in the journal Science shows, climate change is driving a universal major redistribution of life on Earth.

Documented and predicted changes in species distribution are occurring all over the globe. Pecl et al. 2017

These changes are already having serious consequences for economic development, livelihoods, food security, human health, and culture. They are even influencing the pace of climate change itself, producing feedbacks to the climate system.

Species on the move

Species have, of course, been on the move since the dawn of life on Earth. The geographical ranges of species are naturally dynamic and fluctuate over time. But the critical issue here is the magnitude and rate of climatic changes for the 21st century, which are comparable to the largest global changes in the past 65 million years. Species have often adapted to changes in their physical environment, but never before have they been expected to do it so fast, and to accommodate so many human needs along the way.

For most species – marine, freshwater, and terrestrial species alike – the first response to rapid changes in climate is a shift in location, to stay within their preferred environmental conditions. On average, species are moving towards the poles at 17km per decade on land and 78km per decade in the ocean. On land, species are also moving to cooler, higher elevations, while in the ocean some fish are venturing deeper in search of cooler water.

Why does it matter?

Different species respond at different rates and to different degrees, with the result that new ecological communities are starting to emerge. Species that had never before interacted are now intermingled, and species that previously depended on one another for food or shelter are forced apart.

Why do changes in species distribution matter?

This global reshuffling of species can lead to pervasive and often unexpected consequences for both biological and human communities. For example, the range expansion of plant-eating tropical fish can have catastrophic impacts by overgrazing kelp forests, affecting biodiversity and important fisheries.

In wealthier countries these changes will create substantial challenges. For developing countries, the impacts may be devastating.

Knock-on effects

Many changes in species distribution have implications that are immediately obvious, like the spread of disease vectors such as mosquitoes or agricultural pests. However, other changes that may initially appear more subtle can also have great effects via impacting global climate feedbacks.

Mangroves, which store more carbon per unit area than most tropical forests, are moving towards the poles. Spring blooms of microscopic sea algae are projected to weaken and shift into the Arctic Ocean, as the global temperature rises and the seasonal Arctic sea ice retreats. This will change the patterns of “biological carbon sequestration” over Earth’s surface, and may lead to less carbon dioxide being removed from the atmosphere.

Redistribution of the vegetation on land is also expected to influence climate change. With more vegetation, less solar radiation is reflected back into the atmosphere, resulting in further warming. “Greening of the Arctic”, where larger shrubs are taking over from mosses and lichens, is expected to substantially change the reflectivity of the surface.

These changes in the distribution of vegetation are also affecting the culture of Indigenous Arctic communities. The northward growth of shrubs is leading to declines in the low-lying mosses and lichens eaten by caribou and reindeer. The opportunities for Indigenous reindeer herding and hunting are greatly reduced, with economic and cultural implications.

Reindeer in the Arctic are very important components of Indigenous and traditional ways of life. Snowchange 2016 /Tero Mustonen Winners and losers

Not all changes in distribution will be harmful. There will be winners and losers for species, and for the human communities and economic activities that rely on them. For example, coastal fishing communities in northern India are benefiting from the northward shift in the oil sardine’s range. In contrast, skipjack tuna is projected to become less abundant in western areas of the Pacific, where many countries depend on this fishery for economic development and food security.

Local communities can help forge solutions to these challenges. Citizen science initiatives like Redmap are boosting traditional scientific research and can be used as an early indication of how species distributions are changing. Having local communities engaged in such participatory monitoring can also increase the chances of timely and site-specific management interventions.

Even with improved monitoring and communication, we face an enormous challenge in addressing these changes in species distribution, to reduce their adverse impacts and maximise any opportunities. Responses will be needed at all levels of governance.

Internationally, the impacts of species on the move will affect our capacity to achieve virtually all of the United Nations Sustainable Development Goals, including good health, poverty reduction, economic growth, and gender equity.

Currently, these goals do not yet adequately consider effects of climate-driven changes in species distributions. This needs to change if we are to have any chance of achieving them in the future.

National development plans, economic strategies, conservation priorities, and supporting policies and governance arrangements will all need to be recalibrated to reflect the realities of climate change impacts on our natural systems. At the regional and local levels, a range of responses may be needed to enable affected places and communities to survive or thrive under new conditions.

For communities, this might include changed farming, forestry or fishing practices, new health interventions, and, in some cases, alternative livelihoods. Management responses such as relocating coffee production will itself have spillover effects on other communities or natural areas, so adaptation responses may need to anticipate indirect effects and negotiate these trade-offs.

To promote global biodiversity, protected areas will need to be managed to explicitly recognise novel ecological communities, and to promote connectivity across the landscape. For some species, managed relocations or direct interventions may be needed. Our commitment to conservation will need to be reflected in funding levels and priorities.

The success of human societies has always depended on the living components of natural and managed systems. For all our development and modernisation, this hasn’t changed. But human society has yet to appreciate the full implications for life on Earth, including human lives, of our current unprecedented climate-driven species redistribution. Enhanced awareness, supported by appropriate governance, will provide the best chance of minimising negative consequences while maximising opportunities arising from species movements.

Gretta Pecl receives funding from several sources including the Australian Research Council, Fisheries Research development Corporation, National Environment Research Council, Inspiring Australia and Holsworth.

Adriana Vergés receives funding from the Australian Research Council.

Ekaterina Popova receives funding from Natural Environment Research Council, UK.

Jan McDonald has received funding from the National Climate Change Adaptation Research Facility and the Western Australian Marine Science Institute. She on a board member of the National Environmental Law Association.

Cyclone Debbie, which lashed the Queensland coast a week ago, has hit farmers hard in the area around Bowen – a crucial supplier of vegetables to Sydney, Melbourne and much of eastern Australia.

With the Queensland Farmers’ Federation estimating the damage at more than A$100 million and winter crop losses at 20%, the event looks set to affect the cost and availability of fresh food for millions of Australians. Growers are reportedly forecasting a price spike in May, when the damaged crops were scheduled to have arrived on shelves.

The incident also raises broader questions about the resilience of Australia’s fresh vegetable supply, much of which comes from a relatively small number of areas that are under pressure from climate and land use change.

In 2011 the Bowen area produced 33% of Australia’s fresh beans, 46% of capsicum and 23% of fresh tomatoes, making it the country’s largest producer of beans and capsicums, and number two in fresh tomatoes.

The region also produces a significant amount of chillies, corn, cucumbers, eggplant, pumpkin, zucchini and squash, and is a key production area for mangoes and melons.

Coastal Queensland’s vegetable regions are among the highest-producing in the country, especially for perishable vegetables. The Whitsunday region around Bowen, and the area around Bundaberg further south are each responsible for around 13% of the national perishable vegetable supply.

As the chart below shows, vegetable production is highly concentrated in particular regions, typically on the fringes of large cities. These “peri-urban” regions, when added to the two major growing areas in coastal Queensland, account for about 75% of Australia’s perishable vegetables.

Proportion of State Perishable Vegetable Production by weight. ABS 7121.0 Agricultural Commodities Australia, 2010-11

Australia’s climate variability means that most fresh produce can be grown domestically. The seasonable variability allows production to move from the south to the north in the winter, when the Bundaberg and Bowen areas produce most of the winter vegetables consumed in Brisbane, Sydney and Melbourne. The Bowen Gumlu Growers Association estimates that during the spring growing season in September—October, the region produces 90% of Australia’s fresh tomatoes and 95% of capsicums.

Besides damaging crops, Cyclone Debbie has also destroyed many growers’ packing and cool storage sheds. The cost of rebuilding this infrastructure may be too much for many farmers, and the waterlogged soils are also set to make planting the next crop more difficult.

The recovery of production in these areas is crucial for the supply. Growers who have lost their May crop will first have to wait until the paddocks dry out, then source new seedlings and plant them. It could be weeks until crops can be replanted, and storage and processing facilities replaced.

The Queensland government has announced natural disaster relief funding, including concessional loans of up to A$250,000 and essential working capital loans of up to A$100,000, to help farmers replant and rebuild.

Meanwhile, consumers of fresh vegetables in Sydney and Melbourne and many other places are likely to find themselves paying more until the shortfall can be replaced.

Fresh food for growing cities

Australia’s cities are growing rapidly, along with those of many other countries. The United Nations has predicted that by 2050 about 87% of the world’s population will live in cities. This urban expansion is putting ever more pressure on peri-urban food bowls.

Food production is also under pressure from climate change, raising the risk of future food shocks and price spikes in the wake of disasters such as cyclones. Meanwhile, the desire for semi-rural lifestyles is also conflicting with the use of land for farming (see Sydney’s Food Futures and Foodprint Melbourne for more).

These pressures mean that Australia’s cities need to make their food systems more resilient, so that they can withstand food shocks more easily, and recover more quickly.

Key features of a resilient food system are likely to include:

• geographic diversity in production, which spreads the risk of crop damage from extreme weather events across a number of different production areas;

• more local food production, to reduce transportation and storage costs and avoid over-reliance on particular regions;

• a diverse, healthy and innovative farming community;

• greater consumer awareness of the importance of seasonal and locally produced food;

• recycling of urban waste and water for use on farms, to reduce the use of fresh water and fertilisers;

• the capacity to import food from overseas to meet shortfalls in domestic supply;

• increased use of protected cropping systems such as greenhouses, which are better able to withstand adverse weather.

Two recent studies of food production around Sydney and Melbourne provide examples of a range of mechanisms and policies for increasing the resilience of the food systems of Australian cities.

Our food system has served us well until now, but land use pressures and climate change will make it harder in future. When a cyclone can knock out a major production region overnight, with knock-on effects for Australian consumers, this points to a lack of resilience in Australia’s fresh vegetable supply.

Ian Sinclair is a PhD Candidate and Rural Planning Consultant and has consulted to and received funding from Whitsunday Regional Council as well as Sydney peri-urban Councils and the Department of Planning and Environment.

Brent Jacobs receives funding from NSW Office of Environment and Heritage and the NSW Environmental Trust. He has conducted research on peri-urban food production for the Sydney's Food Future project. Partners in this project included Wollondilly Shire Council.

Laura Wynne managed a research project on peri-urban food production for the Sydney's Food Futures project, which received funding from the Office and Environment and Heritage and the NSW Environmental Trust. The project involved Wollondilly Shire Council, the Sydney Peri-Urban Network of Councils and other partners.

Rachel Carey led the Foodprint Melbourne project, which was funded by the Lord Mayor's Charitable Foundation. Project partners included the City of Melbourne and the peak bodies representing the local government areas in Melbourne's city fringe foodbowl. She is also a Research Fellow on the project 'Regulating Food Labels: The case of free range food products in Australia', which is funded by the Australian Research Council.

Henry Lawson in 1915. State Library of New South Wales, CC BY

Henry Lawson is one of Australia’s best-known poets. His married life, documented in Kerrie Davies’ newly published A Wife’s Heart: the untold story of Bertha and Henry Lawson, was tumultuous. Bertha and Henry were married in 1896 and had two children, Bartha and Jim. In an April 1903 affidavit, discussed in the following edited extract, Bertha alleged that Henry was habitually drunk and cruel. They received judicial separation on June 4 of the same year.

Written from Bertha’s lodging, 397½ Dowling Street, Moore Park, dated Monday, 15 June 1903:

Harry,

Your letter has just come.

Your papers are not here. I looked for them before. There are also a good many of my private letters and papers missing, and I thought they may be amongst your things. Re the children. I will not consent to let them go. Not through any paltry feelings of revenge, but as a matter of duty. You see, you left me, with these two little children. I was turned into the world, with 1/6 and not a shelter or food for them. I had to pawn my wedding ring to pay for a room. And then had to leave the little children shut up in the room, while I sought for work. And when I got work to do I had to leave them all day, rush home to give them their meals. And back to work again. And mind you, I was suffering torture all the time with toothache, and had to tramp the cold wet streets all day, knowing unless I earnt some money that day the children would go hungry to bed. (I was a fortnight working before Robertson gave Miss [Rose] Scott that money.) I had no money to pay a dentist. (I wrote to you at P.A. Hospital telling you, you were forcing me to place the children in the Benevolent Asylum and you took no notice of the letter.) I went to the Dental Hospital and had a tooth extracted. They have broken part of the jaw bone. And I go into hospital on Wednesday and go under an operation to have the dead bone removed. The children will be well looked after. While I am away I have to pay a pound where they are going. So I trust you will endeavour to send Mr Henderson some more again this week. You know my condition and I am certainly not fit at the present moment to struggle for a living.

As far as the case goes, the sooner it is over the better. You alone have forced this step. God alone knows how often I have forgiven you and how hard I struggled for you. And how have you treated me. Harry there is no power on the earth will ever reunite us. You are dead to me as far as affection goes. The suffering I have been through lately has killed any thought of feeling I may have had for you.

When you have proved yourself a better man and not a low drunkard you shall see your children as often as you like. Until then, I will not let you see them. They have nearly forgotten the home scenes when you were drinking – and I will not let them see you drinking again. I train them to have the same love for you as they have for me. And if baby’s prayers are heard in heaven, you should surely be different, to what you have been. They will have to decide the right and wrong between us, when they are old enough to understand. I think you are very cruel to make the statements you do about me. You know Harry as well I do they are absolutely false. Why don’t you be a man. And if you want to talk to people of your troubles, tell them drink is the sole cause. Do not shield yourself behind a woman. Mr Henderson cannot influence me one way or another, nor any one else. You had your chance to sign a mutual separation and you would not do it. I dread the court case and publicity more than you do. Still I will not draw back again. And I only wish it was settled and over today. I am so weary of struggling against pain and sorrow that I do not give a tinker’s curse for anything – or anybody.

Bertha.

UQP

*

Facts drift like the pollen on Dowling Street the day I visit. The terraces are rusted and dusted by the constant traffic driving past. One of them is undergoing renovation; through an open door you can see new floorboards, a glossy fireplace and rickety steps to the second floor.

Outside number 397, two plane trees have grown as tall as the terrace, and the balcony has been walled in with glass. Next door, the crucial fraction – 397½ – is written on the window above the door.

The terrace Bertha brought the children to is now painted an undercoat pink, with a green corrugated-iron balcony, windowed-in like its neighbour. Plants entwine the security bars, and large council garbage bins blight the entrance. Upstairs the tree branches are reflected in the windowpanes. It was from inside here, beyond today’s sky-blue front door, that Bertha wrote an angry letter to Henry about having to pawn her wedding ring and leave the children shut up in her room while she looked for work. She warned of more proceedings, perhaps to continue to full dissolution of marriage.

Their daughter, Barta, later wrote that her mother was sometimes overly dramatic. Bertha’s own mother lived in Sydney – surely that was an alternative to leaving them alone, or threatening to place them in the asylum? And what about her sister, Hilda?

But then conjecturing comes up against solid fact: You know my condition. Perhaps Bertha wasn’t thinking at all about anything except survival.

I will not draw back again.

*

Still the facts keep drifting. In April 1903, the same month she filed her affidavit alleging cruelty and drunkenness, Bertha had written to Henry on the 23rd, saying that unless he sent money she would be forced to place the children “in the Benevolent Asylum … I don’t care about myself, but I cannot see my children starve … I think it is most dreadfully cruel for any Mother, to have to part with her children let alone be placed in the position that I am in.” Initially it reads solely as financial but, having had two children, she must surely have suspected the significance of the missed periods, the swollen breasts, the heightened sense of smell that transforms the slightest scent into a stench. Or, perhaps, she tried to ignore them. There is no clear mention of a new baby in the letters until June.

The Benevolent Asylum’s admissions and discharge ledger is an album of life stories, like this one on Wednesday, April 5 1903: “Father Frederick sent to Gaol for four months for neglecting to support. Mother dead. Children committed by Newtown Police Court.” It’s fearful to look, then a relief to find that young Barta and Jim Lawson weren’t there then.

Statue of Lawson by George Lambert in the Royal Botanic Garden Sydney, dedicated in 1931.

In July, Bertha was clearer still: “I am forced to write to you. I do not think you realize my position. I will be laid up either the end of October or first week in November … There is the nurse to engage, and all my sewing to do, you know I have not any baby clothes.”

Counting nine months back to summer from her due date – it was February, and they were still living in Manly when the Critic article gossiped that Mrs Lawson and Henry were sighted holding hands as they strolled around the beach cliffs. She must have conceived during this brief reunion. Now she warned Henry: “I have to solely depend on you for an existance [sic]…I cannot walk far or stand long … You promised I should have every comfort. I am not asking you for that but for bare necessary’s”.

Bertha might have blanched at food, but put her upset tummy down to stress. Realising that she was with child could have finally driven her to the lawyers, to pin down an agreement for continual support. But there was no mention of pregnancy enhancing her vulnerability in the April affidavit.

The baby is coming. The father is not. What do you do? Do you to try to reconcile again for the baby’s sake? Or is it too late?

Too late.

*

Each word Bertha wrote feels like a clue: “I think considering what Dr Brennand told you and after all your promises, it is most cruel that I should suffer all that agony again. If it were not for the sake of Jim and Bertha, I should not go through with it.”

Did she mean that she would not go through with having the baby? Abortion was an open but illegal secret, especially in the bohemian world that Henry and Bertha inhabited. In a leather-bound report, Royal Commission on the Decline of the Birth-Rate and the Mortality of Infants in New South Wales, published in 1904, a witness told the commission he had treated 150 women suffering from “the effects of abortion” at his hospital. Hannah Thornburn had died only the previous year, three days after she had collapsed from a feverish infection.

Despite his prominent Macquarie Street practice, Bertha’s doctor, Henry Wolverine Brennand, was not one of the doctors, midwives, pharmacists, undertakers or religious witnesses who gave evidence to the royal commission that investigated the prevalence of abortion and contraceptive practices among women in New South Wales. These women and their midwives were, predictably, being blamed for the declining birth rate despite many being in Bertha’s position, where they were reluctantly increasing it.

Bertha wrote to Henry of her pregnancy: “it is not a very cheerful prospect to look forward to, knowing as you know well, I will very likely die.” She sounds like she is being dramatic again, but pregnancy complications were dramatic in 1903.

Bertha may have given birth with a midwife at home, or at Crown Street Women’s Hospital. Or she may have been helped by the Benevolent Society of New South Wales, which took in not only children but also destitute and single mothers at their “lying in” wards. On today’s flickering microfilm, those emotional lives are again compressed into crisp factlets, such as: “Single. Pregnant. Alleged father. Emergency. Married. Deserted.’”

The only thing certain is that Bertha and Henry’s last baby was stillborn sometime in late 1903. A nurse would have certified the stillbirth, and no other notification was required. This lack of birth or death registration was raised at the Royal Commission on the Decline of the Birth-Rate and the Mortality of Infants in New South Wales, because of its potential to conceal infanticide and midwifery negligence.

Bertha confirmed: “the little one that we lost was born and the sad time came of our parting. For sorrow had come to us, and difficulties.”

The sorrow.

A Wife’s Heart: The Untold Story of Bertha and Henry Lawson by Kerrie Davies is published by UQP. It will be launched in Sydney by Jane Caro at Berkelouw Books, Paddington, on Wednesday, April 5. Kerrie will also be appearing at the National Folk Festival on Friday, April 14.

Kerrie Davies does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.

Emergency services in Australia are struggling to hold onto their volunteer staff. In New South Wales, for example, only half of the 1,700 volunteers who join the State Emergency Service are still active members a year later. In Western Australia, the overall yearly turnover is 12-18% and rising.

This represents a serious drain on the sector. Precise volunteer numbers are not always collated, but we estimate that more than 240,000 emergency service volunteers across Australia help to protect regional, rural and remote communities where the sprawling areas make it impractical to rely solely on career emergency workers.

The large turnover is an economic liability, as training and uniforms (including personal protective equipment) are expensive. Meanwhile, the constant drain of volunteers can affect not just operational capacity, but morale too.

Volunteer brigades and units are managed by the volunteers themselves. This can lead to tensions between these quasi-independent groups and the paid staff who work in the regional, district of head office. But such tensions can also arise within the volunteer groups themselves, and effective leadership is therefore a crucial element in retaining new recruits.

Keeping volunteers on board

Our research group has therefore partnered with Australian emergency service agencies to try to give leaders the interpersonal skills required to support members and hold onto volunteer staff more effectively.

To do this, we trialled a training program based on self-determination theory (SDT). Our results suggest this could be a very useful tool.

Self-determination theory recognises three basic psychological needs required for motivated, happy staff:

• autonomy: the need for volition, to make decisions and express one’s personal initiatives and ideas

• competence: the need to feel effective and capable

• relatedness: the need to feel accepted and part of the group

Self-determination theory’s basic psychological needs have been researched and applied across diverse social environments such as homes, workplaces, schools, sports teams, and health care. Research suggests that when workers’ needs for autonomy, competence and relatedness are met they are more motivated, engaged, satisfied, and less likely to be considering quitting.

To try to apply this approach to volunteer emergency services, we developed a nine-week program called Inspire Retain Engage (IRE), to teach leaders to interact with their members using SDT principles.

The program consisted of a one-day face-to-face training to learn about self-determination theory and leadership, where leaders worked together to identify key strategies to support each of the three basic psychological needs. For example, leaders could build relatedness by getting to know volunteers and their interests.

Participants then developed their own nine-week action plan that they implemented in their units and brigades with the support of an online mentor. This was followed by a final day of reflection, sharing successes and identifying best practice.

We piloted the IRE program in 2014 with volunteer leaders from the New South Wales State Emergency Service and the NSW Rural Fire Service. It was then further refined and tested in 2016 with volunteer leaders and staff of the Victoria State Emergency Service and the Queensland Fire and Emergency Services.

In total, we have trialled this approach with 72 members from four different volunteer-based emergency service agencies.

We evaluated the program’s impact by surveying IRE participants, volunteer members supervised by participants and other volunteer leaders not a part of the program, both before and after IRE.

The findings revealed that the self-determination theory principles – encouraging autonomy, competence and relatedness in their role – were linked with higher job satisfaction among volunteers, and a more widespread intention to continue volunteering with their current agency. Basic psychological needs accounted for 56% of the variance in volunteers’ job satisfaction and 49% of turnover intention.

Getting results

When emergency service leaders were surveyed about current volunteer leadership courses available respondents told us that such training is often hard to access, limited in scope, and does not focus on interpersonal skills.

The results of the evaluation showed the IRE program improved leaders’ managerial orientation. When compared to other leaders in the organisation, program participants adopted more motivational and less controlling managerial approaches nine weeks later. In addition, 46% of members reported a difference in their team leader’s interactions with them during the program.

Overall, the feedback was overwhelmingly positive. 100% of leaders agreed that self-determination theory was a valuable model for emergency service leadership, and 84% said they would recommend the program to other leaders in their organisation.

As of 2017, the IRE program is available to all emergency service agencies in Australia and we are satisfied with its benefit to volunteer leaders, staff and their agencies.

But of course, only time will tell whether this kind of thinking will improve retention of our valued volunteer emergency workers in the long term.

Michael Jones's research is supported the Commonwealth of Australia through the Bushfire and Natural Hazards Cooperative Research Centre.

Vivien Forner and Yoke Berry do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.