The Conversation

Red crabs migrate across Christmas Island in their thousands each year. Ian Usher/Wikimedia, CC BY-SA

Have you heard the one about the wasp that kills the bug that feeds the ants that kill the crabs that keep the forests healthy on Christmas Island?

If not, that’s because it hasn’t happened yet, but it is a tale worth telling.

In the coming weeks, Parks Australia will release a 2mm wasp on Christmas Island to control the island’s yellow crazy ant infestation. Crazy ants are a major threat to the island’s wildlife, including its famous red crabs.

Biological control – when we use one species to control another – is infamous for giving Australia its cane toad invasion. So, how do we know this one will work?

Christmas Island and its crabs

Christmas Island is a unique natural habitat with many endemic species. The national park covers two-thirds of the island, which has been referred to as the Galapagos of the Indian Ocean.

Many people are aware of the red crabs whose mass migration to the sea has been described as one of the wonders of the natural world.

Christmas Island has many other species of crabs, including the impressive robber crabs. These may be the largest land-dwelling arthropod (the group that insects and crustaceans belong to) on earth.

Together these abundant land crabs clear the forests of leaf litter and maintain burrows that prevent soil becoming compacted, creating an open and diverse forest.

But this thriving natural system was disrupted when an invasive ant species became abundant on the island.

The ants

In the early 20th century, yellow crazy ants (Anoplolepis gracilipes) found their way to Christmas Island. These ants now form super-colonies, with billions of individuals across hundreds of hectares.

The crazy ants spray formic acid in the eyes and leg joints of the crabs, which immobilises them. The crabs soon die and become food for the ants.

In some cases, crabs that live in areas free of crazy ants are killed during their annual migration and so never return to their original forest. This creates crab-free zones even where the ants do not live.

With fewer crabs, the forest has become less diverse, with a dense understory and compacted soils due to the collapse of crab burrows. Other invasive species such as the giant African land snail have become common where crabs declined.

Parks Australia has been trying lots of different methods from aerial to hand-baiting to reverse the impact of yellow crazy ants on red crabs.

The impact was so severe that a chemical control program targeting the super-colonies began in 2001. This program has slowed the decline of crab populations but is expensive and time-consuming, so researchers began to look into other options, including using other species.

The bug: a scale insect

Super-colonies of yellow crazy ants require a reliable food source and this is provided by yet another invasive species: the yellow lac scale insect (Tachardina aurantiaca).

Scale insects (a type of true bug) suck the sap of trees and produce a sweet secretion from their anal pore called honeydew, which ants then harvest.

It seems that the super-colonies of these crazy ants could not survive without the carbohydrate-rich honeydew provided by abundant scale insects in a patch of forest.

There is evidence that the scale insects increase ant reproduction and make them more likely to attack other species. One large field experiment demonstrated that if we stopped the ants getting access to the scale insects, ant activity on the ground fell by 95% in just four weeks.

The scale insects may need the ants as much as the ants need the scale insects. Some ants protect the scale insects in the same way that humans protect their livestock, by chasing away other predators.

The interaction between these two invasive species has allowed them to build their populations to extremely high densities, something known as invasional meltdown.

The good news is that scale insects, unlike ants, are amenable to biological control. For instance, Australian lady bugs were spectacularly successful in controlling the cottony cushion scale in North America.

The wasp

The search began to find a species that could control the scale insect on Christmas Island. And we found it: a tiny wasp known as Tachardiaephagus somervillei, which attacks the yellow lac scale insect in its native Southeast Asia.

This wasp lays its eggs in mature female scale insects and kills them from the inside, producing more wasps that then lay eggs in more females. This wasp (and other predators) are so effective that the yellow lac scale insect is rare in its native habitat.

Obviously, we had to test that the wasp wouldn’t attack other species. Researchers did this in the field in Malaysia, an unusual approach that yielded excellent results. The scientists exposed eight closely related scale insects to the wasp, and none were harmed.

This proves that no other scale insect population on Christmas Island is at risk if the wasp is introduced, with the possible exception of another introduced scale insect that is a pest in its own right.

Researchers also checked that the wasps would still work when the scale insects are being tended by yellow crazy ants – and they still attacked. After years of research it is exciting to be on the verge of releasing this wasp on Christmas Island.

Postscript: the toads

We all know the biological control stories that went wrong. The introduction of cane toads to control cane beetles in Australia backfired spectacularly. In Hawaii, the introduction of mongooses to control rats failed because mongooses are active during the day and the rats were active at night. In both those cases, those species were introduced without sufficient research.

But these examples changed the rules and laws around introducing species. Today governments are much more aware of the risks of invasive species. Rigorous experiments and risk assessments are required before any introduction can occur.

In this case, researchers from La Trobe University have worked closely with Parks Australia and the Forest Research Institute of Malaysia to collect enough data to satisfy the Australian government.

We believe that this is the most closely scrutinised biological control project in Australia. When the wasps arrive on Christmas Island in a few weeks, we are confident that this will set an example for best-practice conservation.

Fewer ants means more crabs, healthier trees, fewer African snails and better soil. And it will save money being spent on expensive conservation efforts for years to come.

Parks Australia has produced a special animation on the program – check it out here at http://www.parksaustralia.gov.au/christmas/news/biocontrol.html.

Susan Lawler has received funding from the Australian Research Council in the past.

Peter Green receives funding from the Department of Environment and Energy

Batteries may be a good way to store energy in the home. Battery image from www.shutterstoc.com

The Australian government is reviewing our electricity market to make sure it can provide secure and reliable power in a rapidly changing world. Faced with the rise of renewable energy and limits on carbon pollution, The Conversation has asked experts what kind of future awaits the grid.

Storage is the word of the moment in the energy industry. Since Tesla unveiled its Powerwall, politicians, commentators and industry have hyped storage – and particularly batteries – as the solution for getting more renewable energy into electricity grids and reducing our reliance on fossil fuels.

The concept of storage is simple. A storage system takes power off the grid or from a local generation source and puts it back onto the grid or uses it locally later. It seems like a good idea if you have too much energy, or it is cheap at some times of the day and expensive at others.

So could storage be the answer, and how much would it cost?

The costs of storage

Of course storage isn’t free. It comes with both a capital cost (buying it in the first place) and a running cost, which is related to the cost of electricity to charge the battery and the round-trip efficiency – how much power is lost in the charging and discharging cycle.

To be a sensible economic investment, the benefits have to outweigh the costs. In other words, the savings on your energy bill have to be greater than the capital costs plus the running costs.

There are many different kinds of storage technologies, each with different characteristics. Lithium ion batteries are attractive as they operate effectively at small scales, are lightweight and have good round-trip efficiency. But they are currently expensive per unit of storage capacity.

Pumped hydro at the other end of the scale operates at very large scales, has good round-trip efficiency and is very cheap per unit.

Flywheels (or rotors) have low round-trip efficiency and don’t store a lot of power, but are able to dispatch lots of power in a short time and can also contribute to frequency stability.

Other storage technologies include compressed air, cryogenic (liquid air) energy storage, flow batteries and hydrogen. Each has its respective pluses and minuses.

Figure on storage characteristics. University of Birmingham Energy Storage Centre Report

Each of these technologies will have an appropriate place in the grid to be installed. Lithium ion batteries are a logical choice for a small-scale distributed application, while pumped hydro will work best at the large scale for grid management.

Flow batteries, liquid air and compressed air are in-between technologies in terms of scale, and flywheels and capacitors are most useful at the substation level for voltage and frequency control.

Batteries versus hydro

Let’s focus on lithium ion batteries and compare them to pumped hydro storage.

Lithium ion batteries are coming down in cost at a significant rate. Bloomberg has plotted the costs of lithium ion alongside solar PV. This shows the two technologies share a similar cost curve gradient, with lithium ion reducing from US$1,200 per kilowatt hour to US$600 per kWh in five years (not including installation costs).

As more batteries are built, the price gets cheaper. Bloomberg New Energy Finance

So where does lithium ion need to get to be cost-effective? Imagine a home with a 4.5kW rooftop PV system and variable electricity rate (for instance off-peak cost of 20c, shoulder of 26c and peak of 40c, similar to this tariff).

In such a home a 7kWh battery needs to cost less than A$7,000 fully installed to actually save the homeowner money. In other words, the cost per kWh of storage should be roughly A$1,000 to break even. Currently, batteries cost A$1,000-3,000 per kWh, so they are on the cusp of being cost-effective.

However, there is an important catch here. Retail electricity rates tend to exaggerate the true range in costs between peak and off-peak. The difference in the wholesale market (where retailers buy their electricity) is around 5-10c per kWh, much less than the 20c range in current variable rates. If retailers begin to lose market share, they may respond by reducing or removing these variable rates. That would make peak rates cheaper and mean that batteries would need to be correspondingly cheaper to be cost-effective.

For instance, a flat electricity rate of 25c per kWh means that batteries would need to cost around A$300 per kWh to be cost-effective. That’s less than a third of their current costs.

You could argue that using batteries also reduces the cost of the network itself. By reducing loads at peak time, we can reduce or even remove the need for infrastructure upgrades (substations and additional power lines, for instance).

But this is only true if electricity demand is growing. If demand is flat or falling, then distribution networks will tend to be under-used. Therefore reducing peak demand will not result in any savings.

Overall demand in the National Electricity Market has declined significantly since 2009, so the benefits of storage on the grid will be negligible other than in high-growth corridors. Demand has rebounded in 2015-16 and it will be interesting to watch and see if this is a resumption of the steady increase or if the demand stays low.

Demand in Australia’s National Electricity Market has been falling.

Pumped hydro, on the other hand, is a relatively inexpensive storage technology (already at around A$100 per kWh) as it can store large amounts of energy using a very inexpensive material.

All you need is some water and the means to pump it uphill. So while it can’t be used everywhere, there are many places in the National Electricity Market where it is possible. There are already 1,500 megawatts of pumped hydro in the market (Shoalhaven, Wivenhoe and Tumut 3).

This would be a more logical solution – cheaper and easier to control by the market operator. But in the same way that rooftop PV has gained more popularity than large-scale solar (even though the latter should be cheaper), distributed storage in the form of lithium ion batteries may be the eventual winner, not because of economics but because of human behaviour.

Roger Dargaville has received funding from the Australian Renewable Energy Agency

Microplastics can carry other pollutants. Oregon State University/Flickr, CC BY-SA

Up to 236,000 tonnes of microplastics – tiny pieces of broken-down plastic smaller than your little fingernail – enter our oceans each year. This has researchers around the world worried, as wildlife can be harmed by eating the plastic or by toxins attached to it.

Another concern is that these plastics and toxins could accumulate in food chains, eventually making their way into animals that eat ocean creatures – such as ourselves.

In two recent studies (one in Marine Biology and the other in Animal Behaviour) we found that microplastics can indeed be passed up the food chain to fish. But we also found some good news: the microplastics appeared to have no effect on their behaviour.

Sweat the small stuff

Microplastics are defined as particles less than 5mm across. A range of animals throughout the marine environment, including corals and zooplankton, consume these particles.

Once in the ocean, persistent toxic chemicals such as bisphenol A (BPAs) and pesticides stick to and accumulate on plastic particles, adding extra layers of contamination.

It is possible that the contaminants on microplastics are absorbed by animals and enter the food chain. If they don’t kill the animals, these toxic chemicals may affect the animals’ behaviour and hormone levels.

The way an animal behaves in its environment is crucial. Sometimes pollutants don’t cause obvious health issues but may alter the way an animal feeds, moves or socialises. Exposure to some chemicals, for example, causes feminisation in males, resulting in reduced breeding activity and ultimately affecting a population’s stability.

Even minor changes in behaviour can affect how an animal performs and may have longer-term implications for survival and reproduction. These changes in behaviour can be an early warning that something is going on, like the canary in the coal mine.

Hop to it

We wanted to know whether microplastics pass through the food web. Microplastics accumulate on beaches, so we assessed how coastal animals respond when they ingest microplastics.

We contaminated microplastics by immersing them in Sydney Harbour for two months and then fed them directly to beach hoppers, small jumping crustaceans at the bottom of the coastal food web.

We then fed the plastic-contaminated beach hoppers to gobies – small fish that commonly eat crustaceans like beach hoppers.

The beach hoppers readily ate microplastics as part of their diet. We found that after just three days the microplastics had accumulated in the beach hoppers. After five days microplastics had caused weight gain, a reduction in the hoppers’ ability to hop, and in some cases death.

But the fish, which we fed with contaminated beach hoppers for four weeks, showed no difference in behaviour compared to fish who weren’t fed plastic-filled hoppers. This was a surprising result, given that hormones (important drivers of behaviour) are so sensitive to pollutants.

Sink or swim

It is vital we understand how animals that are exposed to microplastics are affected.

Beach hoppers are primary consumers, crucial to decomposing seaweed. They play a key role in cycling nutrients back into the beach. They are also an important food source for birds, insects and fish, which makes the hoppers essential in moving energy up the food chain.

If microplastics harm beach hoppers, then the processes carried out by the hoppers may also be affected. This in turn could mean a change in essential coastal processes.

If beach hoppers can’t hop as far or as high, they may not not able to find shelter as quickly, putting them at risk of being eaten or of drying out in the exposed environments of sandy beaches. Fewer beach hoppers could mean less decomposition and nutrient recycling, as well as less food available for animals higher in the food chain.

Gobies are middle-sized predators that live in shallow waters and are important in the connectivity between coastal environments and the deeper ocean. Gobies are themselves eaten by larger fish and sea birds.

We know that fish behaviour can change following exposure to high levels of carbon dioxide and pharmaceuticals, but our study suggests that munching on beach hoppers full of microplastics has little effect.

These results challenge the paradigm that microplastics help contaminants accumulate in the food chain. A recent study suggests that contaminants obtained from the natural environment and prey far outweigh what is absorbed from ingested microplastics, which explains our result.

While this study suggests that microplastics may not be increasing contamination in an obvious manner, there is little doubt about their impact on animals that directly consume them. Perhaps impacts on behaviour will be more apparent with longer exposure times to contaminated food sources than those in our study.

After all, it can’t be a good thing that microplastics are so abundant in the oceans that they will leave an undeniable signature in the fossil record.

Jane Williamson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article. She has previously received funding from the Australian Research Council for other projects.

Culum Brown and Louise Tosetto do 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.

While the Bureau of Meteorology is predicting an increase in the average temperature this summer, entomologists are forecasting an increase in insect activity.

It might seem that insects choose to annoy us over the summer, however, the real reason for their population boom is a complex interaction of winter rainfall, availability of food sources and increasing temperatures.

Insects are ectothermic, or “cold-blooded”, meaning their body temperature depends on the external environment. So in summer an increase in temperature typically correlates with an increase in insect activity.

Many insect species emerge from a winter resting phase in spring and summer to begin their winged adult life stages. These highly mobile, hungry, sex-obsessed young adults are the ones that interact with us over summer. Imagine schoolies’ week for insects, lasting an entire three months.

Rain leads to aphids

We all know that a decent rain can be great for our gardens. Last winter was the second wettest on record and rainfall was above average for most of Australia. This means not only did our backyard foliage and flowering plants do well, but so did common varieties of weeds. Common garden weeds around much of eastern and southern Australia include dandelions and sowthistle.

An increase in vegetation over the winter increases the breeding environment for aphids, and the population explodes. Aphids are sap-sucking true bugs (insect order Hemiptera) that can stunt tree growth, destroy flower buds and reduce the quality of fruit.

Most species, including the peach-potato aphid (Myzus persicae), lay eggs on plant stems, leaves and under bark during winter. These eggs hatch in spring or summer as temperatures and day lengths increase. Female aphids can produce 50 to 100 offspring in a very short period.

Natural pest management

Luckily our gardens already have a built-in defence system against aphid attack – flower flies. Flower flies, sometimes called hover flies, are a group of harmless wasp-mimicking flies (order Diptera, family Syrphidae) that you’ve probably noticed in your garden hovering above flowers, giving the flies their common name. They are found all over the world and include more than 6,000 species, 165 of which are unique to Australia.

While some flies, such as mosquitoes, bushflies and blowflies, will try and crash your summer party, most species, such as the flower flies, are busy eating pests in your garden for free. The natural food source of many flower fly larvae (also known as maggots) are nymph and adult aphids. Flower fly larvae eat a staggering number of aphids, potentially clearing a plant of these pests within a matter of hours.

Flower fly larvae eat aphids and are part of your gardens natural pest management.

Aphids spend their days sapping a plant of its fluids, including plant sugars. Consequently their excrement, known as honeydew, is quite sweet. Adult flower flies will seek out aphid honeydew to feed on and lay their eggs close by to ensure that their larvae will have a viable food source.

If you have ever noticed a swarm of adult hover flies resting on your car’s windshield or bonnet, you may have parked under a tree raining aphid honeydew. These flies are feeding on the honeydew stuck to your car.

Flies feeding on honeydew from a car parked under an aphid infested tree. CSIRO

Many other insect predators, such as ladybird larvae and adults, and lacewing larvae (known as aphid lions) are also feasting on the abundance of aphids in our gardens, competing with the flower fly larvae.

So there is quite a lot going on in your garden at this time of year. All of these predators are quite susceptible to insecticides and will be knocked out if you resort to spraying your aphids.

Insects gardening Australia

There are many benefits to having more insects in your garden and community. Many native Australian plants rely on insects for pollination, including a medley of hard working ants, bees, flies, wasps, beetles, butterflies, and moths.

Recent studies have shown that blowflies can carry twice as much pollen and have potential to out-pollinate the European honey bee. Soldier flies also do a fantastic job of turning your organic waste into compost.

So celebrate this summer by firing up the barbecue in the garden and embrace the Aussie salute! Live and let live is a good way to ensure that our natural pest control agents remain intact, although, keep some repellent on hand, just in case.

Bryan Lessard receives funding from the CSIRO and the Australian Biological Resources Study.

David Yeates receives funding from the CSIRO, the Australian Biological Resources Study, the US National Science Foundation, and holds the Schlinger endowed research position at the Australian National Insect Collection.

Renewable energy poses a number of challenges for the grid. Wind turbine image from www.shutterstock.com

The Australian government is reviewing our electricity market to make sure it can provide secure and reliable power in a rapidly changing world. Faced with the rise of renewable energy and limits on carbon pollution, The Conversation has asked experts what kind of future awaits the grid.

Unreliable electricity supply can cause many inconveniences, such as the inability to check Facebook, being forced to play board games by candlelight in the evenings, and even, God forbid, missing out on a punt on the Melbourne Cup. But electricity blackouts have a more serious side too.

Findings from research overseas and in Australia show people are more likely to die during power outages. This is because of the increased risk of accidents, extreme cold or heat, food poisoning and communications breakdowns that can delay emergency responders.

So whatever our electricity grid looks like in the future, it will need to be reliable.

Meeting demand (most of the time)

Electricity demand varies during the day, so reliable electricity grids must be able to vary their output. Power supply needs to be constant and regular (this is known as “baseload power”) but also able to respond quickly to unexpected surges in demand (so-called “dispatchable power”). Finally, the grid must be responsive when extreme circumstances (such as storms or bushfires) affect supply.

Our current fossil-fuel-dominated electricity generation system is able to match supply with demand all but 0.002% of the time. It does this by relying largely on coal baseload power (64% of generation) which works together with other dispatchable power technologies – primarily gas (21%), as well as hydro (7%), oil (2%) and biomass (2%).

Generators in eastern Australia are also part of an interlinked transmission grid across New South Wales, South Australia, Victoria, Queensland, the Australian Capital Territory and Tasmania.

Variability in renewable resources (such sun and wind) is one of the main challenges to achieving the same reliability (or better) for a grid with more renewable energy generation.

There are several ways to manage this. First, there can be more generators than are required at any one point in time – power in one area can then be moved to areas that need it across a dispersed but highly interconnected transmission grid.

Second, we can avoid too much reliance on one particular technology (such as more than 30% wind). Having a mix of technologies provides a buffer.

Finally, we can include sufficient dispatchable energy sources or storage technologies. The list can include hydro, biomass, concentrated solar, geothermal, or batteries.

But herein lies the cost. Having more generators than needed at any point in time means that spare generators may sometimes sit idle.

Varying renewable resources also means that electricity may be produced but not purchased at times of low demand (and therefore wasted).

Buffering variable electricity supply would require an expansion of the transmission network across our vast continent to access our rich supply of renewable resources. But as distances increase, so do transmission losses.

So the question remains, at what cost would these strategies work?

The cost of reliability

Our recent research took a highly conservative approach to testing the cost question.

We assumed that there would be no future improvements in technology from what is currently viable and no future decrease in electricity demand. We also used renewable resource supply (sunshine and wind) from 2010 because this was one of the most challenging years for renewables.

Our findings indeed showed that strategies to manage the variability of renewable resources were effective in a 100% renewable energy mix of rooftop solar, wind, large-scale solar, hydro and biofuels.

In one scenario, for instance, current demand could be matched with supply at a cost of producing electricity around 20c per kilowatt hour (the current levelised cost of coal-fired electricity is 7.8-9.1c per kWh), with overall installed capacity of 162 gigawatts (2.5 to 3 times what is installed today), relatively low transmission losses and with less than 20% wasted electricity.

The interconnected eastern Australian transmission grid would need to be 2.5 times the current size, and would need to be linked to the grids in Western Australia and the Northern Territory.

Recent developments look positive for renewables

But recent developments mean that the costs and constraints for reliable renewable energy are not likely to be as conservative as our scenario.

Battery storage has benefited from rapid improvements in technology even in the short period since our research in 2015. Significant battery storage could even mean a restructuring of our largely centralised (big power stations) network to a more decentralised one that includes rooftop solar panels and battery storage.

Decentralisation of power generation opens up the possibility of using waste heat from power generation in buildings to reduce power demand (such as tri-generation).

Our research also indicates that investing in more dispatchable technologies can reduce wasted energy, the cost of energy, the grid expansion required, and overall generation capacity.

With the price of renewables decreasing, the transition to renewables may have benefits for power producers and power consumers.

Future constraints and opportunities for renewable energy are uncertain, but we can’t wait for perfect certainty before we plan and act. In Australia we have some of the world’s leading experts in the field with a range of sophisticated modelling capabilities at hand. These assets could be the foundation of collaboration with policymakers to transition to reliable renewable energy.

Bonnie McBain will be on hand for an Author Q&A from 2-3pm AEDT Thursday December 1. Leave your questions in the comments below.

Bonnie McBain 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.

Think of all the resources needed to transform Shenzhen, a fishing town 35 years ago, into a megacity of more than 10 million people. Wikimedia Commons, CC BY-SA

Cities are the epicentres of human activity. They cover less than 2% of the earth’s land surface but generate about 70% of GDP and house more than half the human population. The importance of cities is only going to increase in coming decades as another 2.5 billion people move to urban centres.

This intense production and consumption requires huge quantities of natural resources. Cities account for more than 60% of global energy use, 70% of greenhouse gas emissions and 70% of global waste. Current practices are depleting the Earth’s finite resources, changing its climate and damaging its natural ecosystems. With our planetary life support system in the red, we need to put cities on a serious resource diet.

Resources efficiency in the New Urban Agenda

The New Urban Agenda adopted at the Habitat III conference outlines a vision for sustainable urban development. These global guidelines, along with the related UN Sustainable Development Goals, recognise the need to use resources more efficiently.

Habitat III included a number of sessions on resource efficiency and associated tools and initiatives. Organisations such as UNEP, UN-Habitat and the European Commission and its research centres typically led these events. The New Urban Agenda includes many references to efficiency and reduced consumption in cities.

We must now act urgently to translate words into actions. This will ease pressure on ecosystems and produce a range of co-benefits, including health, wellbeing and resilience.

How do we create more resource-efficient cities?

Cities use resources directly, such as burning fossil fuels for electricity and transport. However, indirect uses, such as water for growing food crops, are much wider-reaching.

It can be overwhelming to consider the resources used for all goods, processes and infrastructure in cities. Yet it is possible to measure this using a systems approach. Instead of considering components in isolation, the entire city is considered as an open system, connected to others.

This perspective ensures a much broader understanding of complex relationships between scales, resource flows, the built environment, socio-economic factors and ecological outcomes.

There are tools that embrace a systems perspective. For example, the urban metabolism approach considers cities as ecosystems, across which flows of resources (such as energy or water) are measured. Life cycle assessment measures resource use through the entire production, consumption and degradation process of a good or service.

These approaches have been successfully applied at various scales such as cities, neighbourhoods and buildings. This reveals that we are using more resources than shown by traditional assessment techniques (see this example on building energy efficiency regulations).

But measurement without action has no impact on the ground. How can these tools be used to transform our cities?

Recent research enables us to map the quantities of materials in buildings and predict when and where we can reuse or recycle these. Here a map of estimated steel quantities in each building of Melbourne, Australia. Source: authors' own; left: Google and TerraMetrics; right: Stephan, A. and Athanassiadis, A. (In Press) Quantifying and mapping embodied environmental requirements of urban building stocks, Building and Environment

Many initiatives are targeting urban resource efficiency. The circular economy paradigm is a good example, where materials are reused, upcycled and recycled. It demonstrates that waste is a human concept and not an inherent property of cities. Waste does not exist in natural systems.

A range of projects by UNEP, the European Commission and other organisations support local resource efficiency initiatives and encourage local governments to implement related regulations. Blogging, data visualisation and disseminating research all help promote the adoption of resource efficiency concepts. In addition to the pioneering work of groups such as metabolism of cities, the uptake of open data is helping with this.

Learning from those who already live on less

Informal settlements provide interesting lessons in resource efficiency. Construction materials in these settlements are typically not very durable. However, because they are in short supply, they are constantly reused or repurposed, almost never discarded.

Other residents often reuse replaced materials, such as metal sheets, or store them for later use. This practice avoids additional resource use to produce new materials.

Although informal slum areas are often the focus of “upgrading” and improvement, lessons learnt in these settings can enhance material flow management and reduce waste elsewhere in cities.

Informal settlements like Karail next to Banani Lake in Dhaka, Bangladesh, can offer lessons in resource efficiency, waste reduction and material flow management to most cities. Alexei Trundle Co-benefits of resource efficiency

More resource-efficient cities tend to result in better health outcomes. For instance, encouraging walking, cycling and public transport instead of car use can reduce fossil fuel consumption and greenhouse gas emissions, and improve population health through increased physical activity.

Food systems that promote consumption of fresh, local produce can benefit both the environment and nutrition. Energy-efficient housing reduces energy and water use and can improve occupants’ health at the same time.

Resource efficiency can also contribute to urban resilience. Nature-based solutions use relatively few non-renewable materials to increase resilience to environmental change and natural disasters. For example, a park can be designed to be flooded during storms or a tsunami, reduce the urban heat island effect, support urban ecosystems and provide areas for community activities, recreation and urban agriculture.

Efficiency can also ensure that redundancy – a core principle of resilience – is built into urban systems. This means resources can be repurposed in the event of an unanticipated shock or stress. For example, during the recent blackout in South Australia, a household with solar battery storage was able to maintain power for 12 hours “off grid”.

Working together for better solutions

Although these steps move cities in the right direction, more action from governments, the private sector and civil society is needed to transform our growing urban footprints.

Focusing solely on resource efficiency may neglect opportunities to generate co-benefits across sectors and will not provide robust solutions. We need to look at the entire city as a system and work together, across all disciplines, with effective and strong governance structures that support integrated policy definition and long-term implementation. If we don’t, we might simply shift a problem from one area to another, increase resource demand elsewhere, or create social divisions and tensions.

Strong leadership, political stability, effective institutions and awareness-raising among citizens are vital factors for success. Urban resource efficiency is critical, but it should be considered along all other pressing issues highlighted in the New Urban Agenda.

André Stephan receives funding from the Australian Research Council.

Alexei Trundle receives research funding from the United Nations Human Settlements Programme (UN-Habitat), and an Australian Postgraduate Award from the Australian Government.

Dave Kendal receives funding from the Clean Air and Urban Landscape hub of the National Environmental Science Program

Hayley Henderson receives an APA scholarship from the Australian Government.

Hesam Kamalipour receives IPRS and APA scholarships from the Australian Government. He is also a Doctoral Academy member at the Melbourne Social Equity Institute (MSEI).

Melanie Lowe receives funding from the National Health and Medical Research Council and the National Environmental Science Programme.

On average, one person is displaced each second by a disaster-related hazard. In global terms, that’s about 26 million people a year.

Most move within their own countries, but some are forced across international borders. As climate change continues, more frequent and extreme weather events are expected to put more people in harm’s way.

In the Pacific region alone, this year’s Cyclone Winston was the strongest ever to hit Fiji, destroying whole villages. Last year, Cyclone Pam displaced thousands of people in Vanuatu and Tuvalu – more than 70% of Vanuatu’s population were left seeking shelter in the storm’s immediate aftermath.

However, future human catastrophes are not inevitable. The action – or inaction – of governments today will determine whether we see even greater suffering, or whether people movements can be effectively managed.

Human impact

International law does not generally regard people displaced by disasters as refugees, and national responses are ad hoc and unpredictable, resulting in protection gaps.

However, on July 1, a landmark new intergovernmental initiative kicked off: the Platform on Disaster Displacement. Led by the governments of Germany and Bangladesh, and with Australia as a founding member, it addresses how to protect and help people displaced by the impacts of disasters and climate change, one of the biggest humanitarian challenges of the 21st century.

The Platform does not merely envisage responses after disasters strike, but also policy options that governments can implement now to prevent future displacements.

For instance, if effective building codes are put in place and enforced, then people will be safer. If disaster warning systems are installed, then people will have time to get themselves out of harm’s way.

The provision of prompt and adequate assistance after a disaster can also reduce longer-term, secondary migration. In a study of displacement following severe floods in Bangladesh, it was found that people who felt adequately assisted and compensated were less likely to move on.

The Platform on Disaster Displacement succeeds the Nansen Initiative on Disaster-Induced Cross-Border Displacement, led by Switzerland and Norway from 2012–15. Through its groundbreaking work, there have been huge leaps and bounds in global understandings about how people move in anticipation of, or in response to, disasters, and what kinds of proactive interventions can help to avoid displacement – or at least avert some of its negative consequences.

The Nansen Initiative’s chief outcome was the Protection Agenda, which provided a toolkit of concrete policy options and effective practices that governments can implement now, both to avert displacement where possible, and to protect and assist those who are displaced.

Strategies such as disaster risk reduction and climate change adaptation can help to mitigate against displacement if disaster strikes. Temporary, planned evacuation can provide a pathway to safety and emergency support.

In 2015, Northern Australia was battered by two potent tropical cyclones within six hours on the same day, Cyclone Lam and Cyclone Marcia. NASA

Implementing long-term, sustainable development projects can enhance community resilience over time, creating new labour opportunities and technologies, and building capacity for self-help.

Governments also need to develop more predictable humanitarian and temporary stay arrangements to assist those displaced across a border after a disaster. They also need to ensure that those displaced internally have their needs addressed and rights respected.

Facilitating migration away from at-risk areas can open up opportunities for new livelihoods, skills, knowledge and remittances, at the same time as relieving demographic and resource pressures.

Planned response

Indeed, in this context, the Australian government has acknowledged that the promotion of safe and well-managed migration schemes is a key part of building resilience.

The Kiribati–Australia Nursing Initiative is a good example. Kiribati is a Pacific Island nation that is very vulnerable to the impacts of climate change, and which lacks extensive educational and employment opportunities.

The Initiative enabled around 90 young people from Kiribati to train in Australia as nurses, providing them with an opportunity to secure a job in the healthcare sector either in Australia, overseas or back home.

On a larger scale, planned relocations can also help people to move out of harm’s way before disaster strikes, or to relocate to safer locations in the aftermath of a disaster if it’s not safe for them to go home. This requires careful consultation with those affected, ensuring that their rights and interests are safeguarded.

The Platform on Disaster Displacement will implement the Nansen Initiative’s Protection Agenda by building strong partnerships between policymakers, practitioners and experts.

While it does not intend to create new legal standards at the global level, it will encourage governments to build more predictable legal responses at the national and regional levels, including through bilateral/regional agreements relating to the admission, stay and non-return of displaced people.

The Platform is a significant opportunity. Governments that act now can make a major contribution to reducing future displacement and its high economic and human costs.

The UN Secretary-General recently highlighted the displacement risk posed by disasters and climate change, and emphasised the need for strengthened international cooperation and protection.

It is essential that the new Platform on Disaster Displacement continues this forward-looking agenda, placing the needs, rights and entitlements of individuals and communities at the forefront of its activities.

Scientia Professor Jane McAdam is Director of the Kaldor Centre for International Refugee Law and head of the Grand Challenge on Refugees & Migrants at UNSW. She is speaking tonight about climate change and refugees at UNSOMNIA: What keeps you up at night?, the launch event for the University of New South Wales Grand Challenges Program.

Jane McAdam receives funding from the Australian Research Council. She is a member of the Advisory Committee of the Platform on Disaster Displacement, and was a member of its predecessor, the Consultative Committee of the Nansen Initiative on Disaster-Induced Cross-Border Displacement.

After ratifying the Paris agreement on climate change, the government is looking ahead to its 2017 review of climate change policy. Energy and Environment Minister Josh Frydenberg tells Michelle Grattan the government will have more to say about the review before Christmas.

“The key is to ensure we’re on track to meet our 2030 targets, which is a 26-28% reduction in our emissions by 2030 on 2005 levels. We did beat our first Kyoto target by 128 million and we’re on track to beat our 2020 target by 78 million tonnes. But clearly the 2030 target is a larger one and a more challenging one,” Frydenberg says.

“We’ve got some good mechanisms in place but we’ll be looking at the overall settings to ensure we meet our Paris commitments.”

With some in the Coalition rattled by the growing popularity of One Nation, Frydenberg says: “The way to deal with it is to listen and to understand people’s concerns as to why they have left some of the major parties and to take action to ensure that they understand the good things that the government is doing.”

Music credit: “Where the river run”, by Ketsa on the Free Music Archive

Michelle Grattan 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.

The Murray-Darling is a complex freshwater ecosystem. Murray River wetlands image from www.shutterstock.com

Tempers have flared once again over the long-term plan to return water to the Murray-Darling River and improve its health.

The Murray-Darling Basin Authority has released its report into the northern basin (in Queensland and New South Wales). The report finds that the plan, agreed in 2012, has already affected communities. It recommends that less water be returned to the river.

The plan aims to recover 2,750 gigalitres of water from human uses for the environment, but also allows for an extra 450GL to be recovered.

Federal Agriculture Minister Barnaby Joyce has signalled that returning the extra 450GL would be extremely difficult – which has outraged South Australian politicians at state and federal level. In response, Prime Minister Malcolm Turnbull has promised extra monitoring.

While it may seem like a political bunfight, the current argument sheds light on serious flaws in the management of the river.

Liquid gold Murray-Darling Basin Authority, CC BY

The Murray-Darling Basin Plan originates in national water legislation developed as a response to the Millennium Drought. Since the plan was passed in 2012, rains have given breathing space for those seeking to massage the detail around rebalancing Australia’s most famous river system.

The premise of the plan and the related Water Act is shifting water away from irrigation to the river to improve long-term sustainability. Leading up to and during the Millennium Drought, ecosystem health declined.

Too much water was being taken from the river, and it seemed the states were too weak to deal with the politics of sharing water allowances.

However, Joyce’s recent comments show that federal governments are equally susceptible to backsliding on commitments to securing water for the environment.

Flaws in the plan

The plan has two main flaws.

First, the states and federal government are relying on a single planning instrument to miraculously optimise water-sharing for social, economic and environmental outcomes.

Second, the only mechanism for achieving these outcomes is by adjusting the volume of water allocated to the environment.

Various interests have exploited both of these weaknesses since the plan came into force.

First, the requirement to blend multiple policy objectives into a single plan has provided an opportunity for disaffected parties to claim all manner of fallout. This has led to governments opting for high-cost reallocation mechanisms, such as providing infrastructure to farms in return for water for the environment.

Simply buying entitlements from willing sellers would have been much more cost-effective and likely better in the long run. This remains the case. But buying back is now off the table, at least while the next round of expensive infrastructure-for-water swaps occurs.

Second, focusing solely on the volume of water returned to the river is now being exploited by those who know that the environmental needs of riverine systems are more complex than simply “add more water”. Complexity means opportunity for some, and there are two groups at play here.

One is the irrigation enthusiasts reluctant to transfer their water rights. In part, this is because they know if they hold out they can secure more benefits through subsidised on-farm infrastructure that can be capitalised into private assets. These forces are obviously more pronounced in the upstream states where irrigation is most developed – NSW and Victoria.

The second group are environmental groups with particular agendas for which they have struggled to gain support.

Turning wine into water

Collectively, these groups have been active in persuading upstream states and some at the federal level that there are alternatives to simply taking water from irrigators and returning it to the environment. These alternatives have become known as “works and measures”.

In simple terms, some infrastructure can be used to mimic environmental processes but with less water. For instance, a series of water regulators could be constructed on a riverside wetland to mimic natural flood events.

The proponents of works and measures are primarily upstream and have sought to count these interventions as equivalent to water returned to the river – meaning they count towards state targets. Similarly, there are efforts to convert programs that reduce invasive species, such as carp, into an equivalent volume of water.

In practice, the challenge of converting these programs into water is scientifically problematic.

While the Water Act and the basin plan were always flawed because of their heavy focus on water volumes, the prospect of adding alternatives has simply created opportunities for more blurry metrics.

There is also a real prospect that these measures are simply not equivalent. As an ecologist explained to me privately: “It’s like saying the environment is thirsty and offering a hamburger.”

The hamburger may be welcome for some, but ultimately it won’t do the same as a drink of water. We need both water and non-water measures and it would be foolish to think the politically expedient hamburger is a perfect substitute for the politically sensitive water, as others have noted.

The South Australian government has been keen to prevent backsliding by upstream states through these types of deals. Ideally, this would be out of concern for the status of the river system, but history shows that states, including South Australia, are equally keen to use the rivers for their own consumptive ambitions.

Nonetheless, the South Australian government does have a point, even if it has been expressed recently with zeal.

The lesson, of course, is that federal governments using the plan have found shifting water away from irrigation at least as difficult and costly as it is for the states.

Lin Crase receives funding from ARC; ACIAR.

Australia's National Electricity Market brings power to millions of people. Power image from www.shutterstock.com

The Australian government is reviewing our electricity market to make sure it can provide secure and reliable power in a rapidly changing world. Faced with the rise of renewable energy and limits on carbon pollution, The Conversation has asked experts what kind of future awaits the grid.

Australia’s National Electricity Market (NEM) is under review following the state-wide blackout that hit South Australia in September.

The review, led by Chief Scientist Alan Finkel, will “develop a national reform blueprint to maintain energy security and reliability”.

Importantly, the Council of Australian Governments (COAG) specifically agreed that the review would consider Australia’s commitment under the Paris climate agreement, and how climate and energy policy can be integrated.

Before we consider how the NEM might need to change, it is important to understand how it came about.

State responsibility

Electricity supply began as a state responsibility. Originally, state-based utilities owned and operated the entire supply chain, from generation to transmission, distribution and retail. With the exception of the Snowy Hydro Scheme, there were no interstate transmission lines.

Accessibility and affordability were (and still are) key concerns for the states. As such, electricity prices were equal for all citizens, irrespective of their location or the actual cost of bringing electricity to them. This is still partly reflected in network tariffs today.

In the late 1980s, concerns about rising costs to government, but also a worldwide ideological move towards privatisation of public services, drove a shift away from publicly owned utilities. This began with a New South Wales inquiry, which found that NSW could avoid billions of dollars in new investment by connecting its network with Victoria.

This set the scene for the development of a more interconnected grid and more general reform. In particular, this was followed by a report from the former Industry Commission in 1991 and the Hilmer Review on National Competition Policy in 1993. These reports were dominated by market logic. They argued that competition would make the system more efficient.

Governments specifically agreed to reforms that would lead to a fully competitive national electricity market. This involved breaking up and selling the three layers of the electricity sector: generation, networks and retail.

The network businesses were seen as natural monopolies, and were to be regulated as such. Generators and retailers were to compete within their own layer, increasing efficiency and keeping prices down.

The national system

Following these preparatory measures, the state and federal governments agreed to pass the National Electricity Law (NEL) under a cooperative national arrangement. This provided the legal basis to create the National Electricity Market (NEM). The NEM is the national electricity market governed by the NEL and includes the wholesale markets as well as network regulation.

In 2001, the state and federal governments established the Ministerial Council on Energy with the broad aim of overseeing and coordinating national energy policy. In 2002, the council commissioned an independent review of energy markets, which highlighted many deficiencies, including governance and regulation.

The review found that the state-based regulators’ responsibilities overlapped with those of the national regulators and led to costly inconsistencies. It also found that greenhouse policy responses were “ad hoc and poorly targeted”.

The ministerial council subsequently proposed a package of reforms. This led to the formation of the Australian Energy Market Commission for developing market rules, and the Australian Energy Regulator for enforcing them, which governments endorsed through the Australian Energy Market Agreement.

This agreement contains a commitment to reducing greenhouse gas emissions. However, this remained outside the National Electricity Objective, which was introduced in 2005 and is the highest point of reference for policy setting. The National Electricity Objective is to:

…promote efficient investment in, and efficient operation and use of, electricity services for the long-term interests of consumers of electricity with respect to price, quality, safety, reliability and security of supply of electricity; and the reliability, safety and security of the national electricity system.

Parallel to these regulatory developments, the states participating in the market became increasingly intertwined. Five new interconnectors were added between 1990 and 2006.

The competitive layers of the industry also began a period of consolidation, leading to the emergence of the so-called “gentailers”. The wholesale market is now dominated by three gentailers (Origin, AGL and Energy Australia), which collectively supply 71% of all retail customers.

The new review

Shortly after the blackout in South Australia, Federal Energy and Environment Minister Josh Frydenberg called for harmonisation of state renewable energy policies, and announced the latest review.

The Finkel Review is a review into the “security and reliability” of the NEM. However, its scope is wide enough to allow for a fundamental rethink of the role of the electricity sector in addressing climate change.

The blackout provides a great example of the kind of challenge the NEM will face in the future. On one hand, climate policies, especially the RET and state-based renewable energy goals, put pressure on the networks and influence the wholesale electricity market.

On the other hand, climate change is expected lead to more frequent and increasingly severe storm events, such as the one that destroyed transmission towers in South Australia. Networks, markets and their governance framework under the NEM aren’t necessarily prepared for these changing conditions.

As shown by the 2002 review, the overlap of state energy policies and ad hoc climate policies is not a particularly new phenomenon. But market governance frameworks have so far kept climate policies separate from the narrow efficiency concerns of the electricity market and network regulation.

Clearly, in the age of climate change, the NEM and its regulatory and institutional frameworks will need to take account of these new and increasing climate mitigation and adaptation pressures.

Recently, South Australian Energy Minister Tom Koutsantonis called for the federal government to “get serious about bringing climate policy and energy policy together”.

With the energy and environment portfolios combined in some governments (including now the federal one), perhaps the Finkel Review can support a convergence of climate and energy policy on a national level.

For more details on the history of reforms in the electricity market see Environmental norms and electricity supply: an analysis of normative change and household solar PV in Australia and A Barrier for Australia’s Climate Commitments? Law, the Electricity Market and Transitioning the Stationary Electricity Sector.

Dylan McConnell has received funding from the AEMC's Consumer Advocacy Panel and Energy Consumers Australia.

Anne Kallies 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.

Ship strikes can be deadly, as shown by this blue whale off the US northwest. Craig Hayslip/Oregon State Univ./Flickr/Wikimedia Commons , CC BY

Living largely on the fringes of a giant island continent, Australians rely on sea transport for the exports and imports that sustain our economy and lifestyle. Australians also have a strong affinity with the ocean, as reflected in the growth in recreational boating and cruise shipping. But these numbers risk putting people on a collision course – literally – with whales, turtles and other marine life.

In the decade to 2011–12, maritime activity in Australia grew by more than two-thirds, while vessels also grew larger and faster. By 2030, bulk freight is projected to increase by half and container throughput will double.

Australia has good shipping regulations, and the general public strongly values marine life. Even so, these drastic increases in both commercial and recreational vessels are likely to lead to more injuries and deaths of marine mammals, large fish and turtles that are hit by vessels – particularly among whale populations that are rebounding in number since the end of whaling.

In response to increasing concern about collision risk, the Department of the Environment and Energy has released a draft national strategy for reducing the risk of vessel strikes. It is open for public comment until January 31, 2017.

The strategy suggests that before we can develop ways to avoid collisions, we need to know exactly where animals are most in danger, by mapping the risk of vessel strike on a national scale. We are working on a project to do just that.

Looking to the past

The first step is to collate and interpret the existing data. Focusing specifically on whales, the current International Whaling Commission (IWC) database shows 51 reported strikes in Australian waters. Only two happened before 1990.

It would be tempting to think that vessel strikes are therefore a modern issue. But the more likely explanation for this pattern is that there has never been a systematic collection of historic Australian data.

We addressed this challenge by searching online media database archives, in particular TROVE. We found reports of vessel strikes dating back to 1872, and an extra 90 records not captured in the IWC’s database. We have thus created the most comprehensive record of whale vessel collisions off Australia.

Our searches brought the number of reported vessel collisions off Australia up to 141. Meanwhile, we also found an extra 145 suspected unrecorded incidents worldwide.

It is hard to compare strike rates around the world because of different record-keeping methods, but our best estimate is that Australian strikes account for 17% of the total worldwide incidents since records began. This challenges the view that these incidents were historically rarer in Australia than elsewhere.

In the records of Australian collisions where the species could be identified, the majority involved humpback whales (52%), followed by southern right whales (12%) and sperm whales (7%). Based on 95 reports in which the fate of the whale could be reliably determined, 52% of strikes were deemed to be fatal or probably fatal; 23% were reported as injuries or probable injuries; and in 25% of cases the whale was unharmed.

Most modern-era strikes are reported in Queensland, which plays host to the east coast humpback breeding and migration route, as well as lots of recreational vessels which are more likely to report incidents as they get damaged. But again, it is very hard to tell how many strikes go unreported, both in Queensland and elsewhere. It may simply be that Queensland has a better system than other states for reporting incidents.

After reading news reports of whale strikes spanning more than 140 years, we were also struck by the changing public and media perception of these events. Early reports from the 1800s refer to ships coming under attack from frightful monsters of the deep. During much of the 20th century collisions were seen as exciting or interesting events during voyages, whereas modern reports are far more concerned with animal welfare and environmental impacts.

You might ask why it matters what happened decades or centuries ago. But of course the past helps us interpret the present.

For example, modern data do not show many large vessels striking animals in Australian waters, whereas these kinds of collisions seem to have been more common in previous eras. This is possibly because, historically, most large vessels had large crews and/or many passengers, potentially making collisions more likely to be spotted than they would be aboard today’s large automated vessels with small crews. This raises the question of whether significant numbers of collisions are happening without being noticed.

Recording vessel sizes will also help to devise the most effective strategies for avoiding collisions. For example, if small recreational vessels pose the most significant strike threat in a given region, then changing the region’s commercial shipping lanes will be of little use.

What can be done?

The jump in the number of reported vessel strikes in the late 1990s suggests that reporting rates have probably improved, but also highlights the need for a much more rigorous system. With this aim, the Australian Marine Mammal Centre has developed an online tool for reporting collisions.

The next task for our project is to compare information on shipping density and average speeds with data about the habitats and migration routes of at-risk species. This will help us draw up relative risk maps to identify specific areas and times where the risk is greatest, and where efforts to reduce them should be focused.

Some measures, including route changes, speed restrictions and exclusion zones, have already been successfully used in waters off the United States and New Zealand.

With Australia’s increasing appetite for international trade and recreational boating, it is time to develop some effective methods of our own to avoid running over our marine wildlife.

This article was co-authored by Dr Simon Childerhouse, a marine mammal biologist with Blue Planet Marine based in Nelson, New Zealand.

David Peel receives funding from the Marine Biodiversity Hub of the Australian Government's National Environmental Science Programme and previously from the Australian Marine Mammal Centre.

Joshua Smith receives funding from the Department of the Environment and Energy and previously from the Australian Marine Mammal Centre.

Two-thirds of the corals in the northern part of the Great Barrier Reef have died on in the reef’s worst-ever bleaching event, according to our latest underwater surveys.

On some reefs in the north, nearly all the corals have died. However the impact of bleaching eases as we move south, and reefs in the central and southern regions (around Cairns and Townsville and southwards) were much less affected, and are now recovering.

In 2015 and 2016, the hottest years on record, we have witnessed at first hand the threat posed by human-caused climate change to the world’s coral reefs.

Heat stress from record high summer temperatures damages the microscopic algae (zooxanthellae) that live in the tissues of corals, turning them white.

After they bleach, these stressed corals either slowly regain their zooxanthellae and colour as temperatures cool off, or else they die.

The Great Barrier Reef bleached severely for the first time in 1998, then in 2002, and now again in 2016. This year’s event was more extreme than the two previous mass bleachings.

Surveying the damage

We undertook extensive underwater surveys at the peak of bleaching in March and April, and again at the same sites in October and November. In the northern third of the Great Barrier Reef, we recorded an average (median) loss of 67% of coral cover on a large sample of 60 reefs.

The dieback of corals due to bleaching in just 8-9 months is the largest loss ever recorded for the Great Barrier Reef.

To put these losses in context, over the 27 years from 1985 to 2012, scientists from the Australian Institute of Marine Science measured the gradual loss of 51% of corals on the central and southern regions of the Great Barrier Reef.

They reported no change over this extended period in the amount of corals in the remote, northern region. Unfortunately, most of the losses in 2016 have occurred in this northern, most pristine part of the Great Barrier Reef.

ARC Centre of Excellence for Coral Reef Studies Bright spots

The bleaching, and subsequent loss of corals, is very patchy. Our map shows clearly that coral death varies enormously from north to south along the 2,300km length of the Reef.

The southern third of the Reef did not experience severe heat stress in February and March. Consequently, only minor bleaching occurred, and we found no significant mortality in the south since then.

In the central section of the Reef, we measured widespread but moderate bleaching, which was comparably severe to the 1998 and 2002 events. On average, only 6% of coral cover was lost in the central region in 2016.

The remaining corals have now regained their vibrant colour. Many central reefs are in good condition, and they continue to recover from Severe Tropical Cyclones Hamish (in 2009) and Yasi (2011).

In the eastern Torres Strait and outermost ribbon reefs in the northernmost part of the Great Barrier Reef Marine Park, we found a large swathe of reefs that escaped the most severe bleaching and mortality, compared to elsewhere in the north. Nonetheless, 26% of the shallow-water corals died.

We suspect that these reefs were partially protected from heat stress by strong currents and upwelling of cooler water across the edge of the continental shelf that slopes steeply into the Coral Sea.

For visitors, these surveys show there are still many reefs throughout the Marine Park that have abundant living coral, particularly in popular tourism locations in the central and southern regions, such as the Whitsundays and Cairns.

Darkspots

The northern third of the Great Barrier Reef, extending 700km from Port Douglas to Papua New Guinea, experienced the most severe bleaching and subsequent loss of corals.

On 25% of the worst affected reefs (the top quartile), losses of corals ranged from 83-99%. When mortality is this high, it affects even tougher species that normally survive bleaching.

However, even in this region, there are some silver linings. Bleaching and mortality decline with depth, and some sites and reefs had much better than average survival. A few corals are still bleached or mottled, particularly in the north, but the vast majority of survivors have regained their colour.

What will happen next?

The reef science and management community will continue to gather data on the bleaching event as it slowly unfolds. The initial stage focused on mapping the footprint of the event, and now we are analysing how many bleached corals died or recovered over the past 8-9 months.

Over the coming months and for the next year or two we expect to see longer-term impacts on northern corals, including higher levels of disease, slower growth rates and lower rates of reproduction. The process of recovery in the north – the replacement of dead corals by new ones – will be slow, at least 10-15 years, as long as local conditions such as water quality remain conducive to recovery.

As global temperatures continue to climb, time will tell how much recovery in the north is possible before a fourth mass bleaching event occurs.

This article was co-authored by David Wachenfeld, Director for Reef Recovery at the Great Barrier Reef Marine Park Authority.

Terry Hughes receives competitive research funding from the Australian Research Council

Britta Schaffelke works for the Australian Institute of Marine Science, a publicly funded research organization that receives funding from the Australian Government, foundations, State Government Departments and private industry.

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.

Virginia coalminers in the industry's 1970s heyday. Jack Corn/EPA/US Natl Archives & Records Administration/Wikimedia Commons

On the night Donald Trump won the US election, one of the many jubilant supporters featured in the media coverage was 67-year-old Doug Ratliff of Richlands, Virginia. An owner of struggling shopping malls in a region hit hard by coal closures, he said Trump “gives people hope” that these ailing industries can be brought back to health.

But the reality is that Trump won’t be able to do it – any more than he can stop the rising seas flowing over vulnerable coastal areas of Florida, one of the states that helped to elect him president.

King Canute Trump and his aides can deny the veracity of climate change or threaten to shut down NASA’s climate programs all they want, but they are largely powerless to stop the global processes now under way to remove fossil fuels from global and local economies.

As the graph below shows, global economic growth has decoupled from growth in greenhouse gas emissions.

European nations such as Denmark, Spain, Germany, the Netherlands and the UK are now showing “absolute decoupling” – that is, their fossil fuel use is declining while their economies continue to expand. The UK – the birthplace of coal-fired power two centuries ago – will switch off its last coal power station in 2040.

America and Australia have been slower to decouple, but both have shown absolute declines in coal use since 2005 and 2009 respectively, while still growing economically. China is rapidly decoupling (in absolute terms with coal) while India is relatively decoupling.

The reality is that the world has learned to grow economically in the 21st century without needing fossil fuels to do it. Bloomberg New Energy Finance (BNEF) has assessed the trends in prices for different fuels and predicts that coal and gas-based power will go from 57% in 2015 to 31% in 2040, while renewables will go from 11% to 56% of power. This is without subsidies.

Already the world’s financiers have decided that renewables are a better deal than fossil fuels, which are riven with political uncertainties, volatility and declining competitiveness. BNEF’s analysis shows that new investment in renewables passed fossil-fuel-based power in 2005 and is now running at twice the rate.

Is this being driven by politicians, perhaps as a result of the Paris Agreement signed by nearly every government in the world, which took effect earlier this month?

Probably not. Apart from a few long-term goals, you could not say that governments have controlled this market in the past decade. What is actually happening is that they are now recognising the growing market for clean energy and in most cases simply trying to help it along where they can.

Rooftop solar, in particular, has become a dramatic market success story, with Australia leading the world in its recent growth. In Perth, for example, the resources boom led huge numbers of households to invest in solar photovoltaics, which are now available at roughly half the cost compared with the United States. As a result, 25% of houses in Perth have solar panels – a combined total of 550 megawatts, which effectively makes them the biggest power station in Western Australia.

This was not a government plan; it was ordinary householders seeing a good deal provided by smart new Australian businesses. WA Energy Minister Mike Nahan was initially somewhat sceptical, but as a good market economist he now says that the government just needs to get out of the way. Solar panels are well on the way to hitting 70% of households. Along with batteries going through the same dramatic price spiral, no extra fossil fuel power stations are now being envisaged.

It’s a similar story in Australia’s eastern states, where coal plants like Hazelwood are being phased out and the National Electricity Grid is absorbing solar at similarly high growth rates. The same story is being played out across the globe.

Businesses are also becoming their own utilities, as shown by high-tech companies like Apple, which are becoming energy “prosumers” that generate their own solar power and then sell excess back to the grid. The 24 largest current buyers of renewable power – a group that includes Google, Amazon, Microsoft, Ikea, Equinix, Mars, Dow, WalMart and Facebook – have bought 3.6 gigawatts of renewable energy since the beginning of 2015. That’s enough to power about half the state of Connecticut.

How or why would Donald Trump want to stop this?

Turning back the tide

Governments, including Trump’s, can try to stand in the way in a bid to force the economy back to a nostalgic past based on coal. But if they do, the lower levels of government, especially the cities of the world, will drive the agenda forward in tandem with businesses that are already riding high in the green economy.

California has driven much of the climate change agenda in the United States, since its Climate Act of 2006 required all cities to develop a climate action plan. San Francisco is moving to 100% renewable energy by 2030 and has mandated all buildings to install solar panels. The city expects paybacks within five years for everyone making the investment.

For all Trump’s pledges to bend trade to his will, he cannot stand in the way of market forces as strong as this. His place in history will be likened to the last Roman emperor standing on top of the wall in Constantinople as the invading horde bears down on the decaying city.

People in climate science and innovation, solar entrepreneurs and businesses will simply shift to those cities that want to be competitive in the 21st century. Many of them will still be in the United States – maybe even in Richlands, Virginia, assuming they don’t want to be left in the past.

Peter Newman 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.

China's latest energy plan would see coal power increase by 200 gigawatts. Coal image from www.shutterstock.com

China recently announced a 20% increase in coal power capacity by 2020. Does the new target contradict its pledge to peak carbon emissions well before 2030 under the Paris Agreement?

China ratified the Paris Agreement in September 2016 and has put in place policies to achieve its climate target, or Nationally Determined Contribution (NDC). China’s goal is to peak its carbon emissions by 2030 and reduce its carbon intensity (the amount of carbon produced per unit of GDP) by 60-65% below 2005 levels. To do so, it must therefore decouple emissions from economic growth.

These policies include new renewable energy targets and a nationwide emissions trading scheme, coupled with a domestic carbon offsetting scheme.

China’s NDC is expected to scale up clean energy development in China and displace coal-fired power generation.

One goal is to reduce the proportion of coal-fired power to 300 grams of coal equivalent per kilowatt-hour. The 20% increase in coal power seems to be offsetting these efforts, given that more than half of the country’s electricity is generated by burning coal.

But this may not contradict the country’s climate pledge if we look into the details.

A climate U-turn?

The National Energy Administration and the National Development Reform Commission announced China’s coal plan on November 7. It is specified in the country’s 13th Five-Year Plan of Electricity Development, which covers the period 2016-20.

The plan has raised a few eyebrows, in both its timing — the last five-year plan for the electricity sector was released more than 15 years ago — and its content.

The most controversial issue in the plan is the target for coal-fired power generation, which is to limit the total installed capacity to 1,100 gigawatts by 2020. Given that the current installed capacity is about 900GW, this allows for a massive 200GW increase in the next four years.

To put this number in context, Australia’s installed capacity for coal-fired electricity generation was 29GW in 2013-14. The worldwide installed capacity of solar photovoltaics at the end of 2015 was 227GW.

China’s proposed massive increase in coal power has raised questions about the environmental and economic rationales of the plan as well as the consistency between China’s energy and climate policies.

A mini coal boom

To understand the coal target, it is necessary to understand the way energy is governed in China.

Despite being an authoritarian state, China has always had a highly fragmented and complicated system when it comes to governing the country’s electricity systems.

Big power companies are owned by the state but remain relatively autonomous, and they are powerful and profit-driven. Large-scale energy projects such as coal-fired power plants are largely driven by these state-owned enterprises.

The recent decline in coal prices means that the business of owning and operating coal-fired power plants has become highly lucrative. These state-owned enterprises therefore have a strong motivation to build more coal-fired stations.

Moreover, the authority to approve coal plant construction has been delegated to the provincial level since 2014. This has further reduced the ability of national bodies to co-ordinate investment in coal power.

With the exception of a small number of highly developed regions that have enacted coal control policies, most provincial governments remain very receptive towards new investments in coal-fired power plants, because these investments attract jobs and tax incomes. These political and economic factors have resulted in a rapid rise in investment in coal power, a trend that will likely continue into the near future.

Still displacing coal power

The central government of China is trying to control this investment. According to Huang Xuenong, the head of the National Energy Administration’s electricity department, without any policy intervention, China’s coal-fired capacity would be about 1,250GW by the year 2020.

The 1,100GW target in the plan therefore means that the administration intends to restrict the rapid rise of coal power by at least 150GW. While representing a substantial increase from the current level, the main outcome would still be below business-as-usual.

This objective will be achieved primarily through four administrative interventions:

• retire a number of old and inefficient coal units

• halt projects that are under construction but have not received official approval

• suspend projects in provinces that do not have electricity shortages

• suspend the construction of coal stations that have already been approved in provinces that do not have shortage problems.

China remains committed to displacing coal-fired power generation. Perhaps the coal plan is not “green” enough, but behind the scenes are various efforts to shut down coal-fired power plants and suspend new coal projects.

The 20% increase in coal power alone hardly represents a U-turn in climate policy direction. The big picture is largely consistent with China’s policy objective of peaking its carbon emissions by 2030. The question is whether it can finish much earlier or not.

Alex Lo receives funding from the National Science Foundation of China, the Regional Studies Association (UK), and the Academy of the Social Sciences in Australia.

Kevin Lo 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.

Countries have a lot of work to do to achieve the United Nations’ Sustainable Development Goals by 2030. But development projects don’t always go the way you expect.

A resettlement project in Laos recently provided taps and toilets as a way to improve hygiene and health outcomes for communities.

But on revisiting the resettled village, the project team was dismayed to find that the new brick toilet facilities were being used to store rice. The practice of “open defecation” was continuing in nearby farmland.

The community members explained that keeping rice dry and safe from animals was their highest priority. They also thought it was more hygienic for faeces to be washed away, rather than concentrated in one place such as a toilet.

How did this mismatch occur? There had been limited community participation, no awareness-raising and no sense of community ownership generated during the project planning. Getting these things right will be fundamental to achieving any of the development goals.

Toilets aren’t enough

The Sustainable Development Goals (SDGs) recognise the importance of community participation in local development projects.

Involving communities — the people who will use or benefit from the new technology — can enhance both short-term and long-term impacts of a project.

As a signatory to the SDGs, Australia has committed to achieving these goals internationally and at home. This week, Australia and the Asia-Pacific are holding an SDG Week to continue work on the goals.

Our work focuses particularly on Goal 6: improving access to water, sanitation and hygiene. Community participation is an explicit target set out in this goal.

Despite major progress since the earlier UN Millennium Development Goals (which finished in 2015), contaminated drinking water leads to 340,000 child deaths each year from diarrhoea. Worldwide, more than 900 million people still lack access to toilet facilities.

Funding water and toilets alone will not improve these statistics. We need to provide water and toilets in ways that that meet the needs of the people who will use them. That calls for far more careful participation strategies.

Bottom up

In a discussion paper released today by The University of Queensland, we reveal that many organisations managing water, sanitation and hygiene projects only engage communities late in the process when options are constrained.

This “top-down” approach can result in a lack of community ownership, a mismatch between project outcomes and community needs, and a failure to improve water and sanitation outcomes.

Instead, we recommend a “bottom-up”, community-driven approach. This engages communities earlier in the project timeline, as you can see in the figure below.

Stages of water development project planning. GCI/UQ

With this approach, communities can participate in more significant decisions, such as setting policy targets and prioritising technologies, as well as local implementation and maintenance. That, in turn, can contribute to more effectively achieving the UN’s sustainable development agenda towards 2030.

Getting it right

There are excellent examples of getting community participation right in these ways.

For instance, a project in the Solomon Islands understood the importance of gender diversity in development. The training schedule and venue were adjusted to increase participation by local women.

Communities in Vanuatu with DIY wells and latrines in close proximity. Helen Ross, 2008

In Vanuatu, informal settlement residents had built their own water wells and pit toilets close together on floodplains. This caused sewage to contaminate the drinking water.

A community participation process increased local community members’ awareness of the water cycle and water resources management, and empowered them to develop policies requesting adequate water and sanitation infrastructure from their government.

Vanuatu community members participate to build understanding and plan water resources. Terry Chan, 2008

Back in Laos, the resettlement organisation reconsidered their approach to toilet-building. They started working with and through school and women’s groups to build awareness of the links between daily behaviour and health. That same village has now been declared “open defecation free”.

During SDG Week, it is crucial to keep in mind that the SDGs are not just for people, they are by people too. Participation can bridge the gap between the hardware of sanitation infrastructure and the software of a good participation and decision-making process.

Angela Dean receives funding the Cooperative Research Centre for Water Sensitive Cities, Commonwealth of Australia.

Tari Bowling has been employed by a sanitation provider in Laos and continues to evaluate the project as part of her Phd research

Helen Ross and Nina Lansbury Hall 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.

The Carmichael coal mine planned for Queensland’s Galilee Basin has cleared another legal hurdle, with the state’s Supreme Court dismissing a legal challenge to the validity of the Queensland government’s decision to approve the project.

The court found in favour of the Queensland Department of Environment and Heritage Protection, ruling that its approval of Indian firm Adani’s proposal was within the rules.

The decision is another setback for environmentalists’ bid to stop the controversial project. But Adani does not yet have a green light to break ground on the project, and legal questions still remain, both about this project and about climate change litigation more generally.

The Supreme Court ruling

It is important to note that this was a judicial review proceeding – a narrow type of review in which the court is not permitted to consider whether or not the decision to approve the mine was “correct”. The court could only rule on whether correct procedures were followed, while accepting that the decision was at the government’s discretion.

Within this already narrow context, the argument on which the legal challenge hinged was even more constrained. It was brought by an environmental campaign group called Land Services of Coast and Country (LSCC), and was focused on a particular point of Queensland environmental law.

Queensland’s Environmental Protection Act 1994 requires that decisions are made in accordance with the Act’s objective, which is to deliver “ecologically sustainable developent”. LSCC argued that the government failed to do this in approving the coalmine.

The Supreme Court disagreed, finding that the government had considered all matters that it were obliged to consider. So in this respect, the Supreme Court’s decision is an endorsement of the process, but not necessarily the ultimate decision.

Is this the final hurdle overcome for Adani?

In short, no. The decision can be referred to Queensland’s Court of Appeal. There is also ongoing litigation against Adani in the Federal Court of Australia under federal environmental and native title laws. There are also some approvals yet to be obtained by Adani, including a groundwater licence.

Is this ruling a rejection of climate change arguments against the coal mine?

No. This case dealt specifically with the question of whether the Queensland government had complied with a particular aspect of the law. The Supreme Court did not (and was not able to) address the potential climate change impacts of the proposed mine.

These climate issues were addressed more fully by Queensland’s Land Court in the case of Adani Mining Pty Ltd v Land Services of Coast and Country Inc & Ors (2015) QLC 48.

Importantly, the Land Court in this case accepted the scientific basis for climate change, and agreed that “scope 3 emissions” (that is, the emissions produced when the coal is burned overseas) are indeed a relevant consideration in whether or not to approve the mine.

However, Adani successfully used a “market substitution” defence, arguing that if the mine is refused, coal would simply be mined elsewhere and burned regardless.

What does this case say about climate change litigation more generally?

The latest judgement was handed down amid a series of fresh attacks on the rights of environmental groups to use Australia’s environmental laws to hold companies and governments to account. Federal Environment and Energy Minister Josh Frydenberg has raised concerns about “activists … seeking to frustrate” projects with “vexatious litigation”, while Prime Minister Malcolm Turnbull has revived plans to amend federal environmental legislation so as to restrict standing to apply for judicial review – the so-called “lawfare” amendments.

In the wake of the new ruling, the head of the Queensland Resources Council has criticised the delays caused by litigation against mining projects.

This begs the question: is climate change litigation “vexatious”? A close analysis of Queensland court decisions would suggest the opposite. Climate change issues have been considered in a series of three key Queensland Land Court cases: Wandoan Mine in 2012, Alpha Coal Project in 2014, and the Carmichael Mine (Adani) in 2015.

The Alpha Coal matter has proceeded to the Supreme Court, the Court of Appeal, and leave has been sought to appeal to the High Court of Australia. Importantly, none of these cases has been dismissed as vexatious; each resulted in a lengthy judgement analysing the complex legal issues raised by the objector.

Furthermore, although objectors have not yet succeeded in stopping a mining project on the basis of climate concerns, they have nevertheless made modest strides. Most recently, President McMurdo of Queensland’s Court of Appeal found that the Land Court must consider scope 3 emissions in deciding whether a mine should be granted environmental approval. This represents significant progress, given that climate science was questioned by Queensland Courts less than ten years ago.

The only significant barrier remaining to a successful climate change case is the market substitution defence, which will be considered by the High Court if special leave is granted in the Alpha Coal matter.

Climate change litigation has also clarified other environmental and economic impacts. In the Carmichael Mine case, it was discovered that the mine site was a critical habitat for the endangered black-throated finch – evidence that was not previously available. The Land Court ordered strict conditions aimed at protecting this species. The litigation also served to clarify the significantly overstated economic benefits of the mine – particularly Adani’s estimate that it would generate more than 10,000 jobs. It was revealed in court that this figure was more likely to be 1,206 jobs in Queensland, as part of a total of 1,464 jobs in Australia.

Where to for climate change litigation?

Although the latest judgement is another setback for environmental groups, it is part of a bigger body of case law that is making real and discernible progress in ensuring that climate change is considered by decision-makers and courts.

Given that several courts have agreed on the validity of climate litigants’ arguments, it seems perverse for the federal government to try and restrict environmental groups’ right to continue raising these concerns.

Justine Bell-James has previously received funding from the Australian Research Council. She has previously assisted EDO Qld with policy advice.

You can only truly understand the weather by flying above the clouds. NASA

Bob Walker, an adviser to US President-elect Donald Trump, has set alarm bells ringing by recommending that NASA’s climate monitoring programs be axed.

But his dismissal of the “politicised science” at NASA’s Earth Science Division shows an ignorance of the breadth, role and significance of its contributions to society in the United States and worldwide.

It’s unclear what exactly Walker means by his comment that “future programs should definitely be placed with other agencies”. Is the plan merely to shuffle the deckchairs – same science, different badge — or is it code for cutting the research observation and monitoring efforts altogether?

If the former, it is hard to see what it would achieve, beyond risking a loss of expertise as other agencies attempt to develop the same capabilities as NASA. But the latter is a frightening prospect, because it would effectively take us back to what climate scientists refer to as the “pre-satellite era”.

The global climate system is, well, global. There are places where there is no one around to take measurements, such as the vast expanses of our oceans, the central desert of Australia, and the Arctic and Antarctic regions. But what happens in these remote areas affects the climate elsewhere; the atmosphere has no boundary and the oceans are linked.

Before satellites, the patchiness of weather and climate observations for much of the globe made it hard to detect the patterns that govern rainfall, temperatures and winds.

Now we have a continuous global view of Earth, courtesy of NASA’s Earth observation satellite program. Cutting this research and returning to the pre-satellite era would leave us ignorant not only of Earth’s climate processes, but also of whether or not our environmental policies are effective.

The value of satellites

For more than three decades in the early 20th century, the British meteorologist Sir Gilbert T. Walker searched the sparse climate records for patterns that could explain why the Indian monsoon failed in some years. After some laborious number-crunching, he put forward the concept of the “Southern Oscillation”, describing sea-level pressure differences between Darwin and Tahiti in the South Pacific. His Southern Oscillation Index is still used today.

When sea-level pressure is lower in Tahiti than Darwin, it causes wind patterns that bring drought to India and northeast Australia, Walker suggested. But the Southern Oscillation was only part of the story.

Almost half a century later, in the late 1960s, early NASA satellite data provided an unprecedented look at the patterns of clouds above the Pacific Ocean. This helped the meteorologist Jacob Bjerknes to link Walker’s sea-level pressure oscillations with other variables such as wind, rainfall (clouds) and ocean temperature variations right across the tropical Pacific.

Crucially, he identified a low-rainfall zone in the central-eastern equatorial Pacific – of which Walker, with his patchy data, had been completely unaware. The “chain reaction” between the atmosphere and ocean now known as the El Niño-Southern Oscillation emerged in part from NASA satellite imagery.

A visualisation of the strong El Niño that developed in 1997, using NASA sea-surface height data from the TOPEX/Poseidon satellite. NASA

Of course, the holy grail when it comes to El Niño is to forecast events ahead of time, because El Niño is a major factor in bringing droughts and floods to countries bordering the Pacific Oceans. This has huge consequences for millions of livelihoods. Australia’s Bureau of Meteorology uses NASA satellite and model data to forecast an impending El Niño three to six months ahead of time, while real-time observations help to assess the impacts once the event actually arrives.

This level of forecasting and monitoring was a pipe dream in the pre-satellite era. The same could be said about a host of other global phenomena – from severe storms, to massive wildfires, to air pollution.

Verifying policy decisions

If President-elect Trump really needs yet more certainty that human-induced global warming is not a hoax and that the recently enacted Paris Agreement will have a meaningful impact, then one of the best ways to achieve this would be to boost NASA’s Earth Science Division.

NASA satellites recently demonstrated the success of US and European environmental regulations in improving air quality over the past decade. NASA has also been central to monitoring the effectiveness of the Montreal Protocol, the global agreement to safeguard the ozone layer. By keeping a close watch on the size and extent of the ozone hole, NASA has helped to show that it is beginning to recover and that the policy is working.

Our advice to Trump

Gilbert T. Walker wrote in 1940:

I think that the relationships of world weather are so complex that our only chance of explaining them is to accumulate the facts empirically.

His present-day namesake and Trump adviser Bob Walker also says “we need good science to tell us what the reality is”. One of President-elect Trump’s best chances of achieving this aim is to continue funding scientists to observe Earth from space.

So our advice to Trump is to look beyond the cheap talk about politicisation and appreciate the importance of the work done by NASA’s Earth Science Division. This is not, as Bob Walker asserts, “politically correct environmental monitoring” (whatever that is), but essential data that are already being used to ensure society’s health and wellbeing.

As for climate change science, the division’s reports on global temperatures are solely based on robust data. What’s being politicised here is not the science but the story that the science tells: that the planet is warming. Let’s not shoot the messenger.

Helen McGregor receives funding from the Australian Research Council and the University of Wollongong. McGregor is a member of the Australian Meteorological and Oceanographic Society, the American Geophysical Union and the Australasian Quaternary Association.

Jenny Fisher receives funding from the Australian Research Council, the Department of the Environment, NASA, and the University of Wollongong. Fisher is a member of the Australian Meteorological and Oceanographic Society and the American Geophysical Union.

While much of the media focus at this month’s climate meeting in Marrakech (COP22) was on US President-elect Donald Trump, there were signs that several countries have begun the long-term planning needed to avoid dangerous climate change.

During the conference, four countries – Germany, Canada, Mexico and the United States – presented their 2050 climate plans. Under Article 4 of the Paris Climate Change Agreement, all countries are asked to prepare mid-century, long-term strategies to bring greenhouse gas emissions down to low levels.

A common theme from COP22 was the emphasis on long-term strategies to help guide short-term actions. When launching the 2050 Pathways Platform, Laurence Tubiana, the outgoing French high-level climate champion, stated that if you don’t have a plan for the long term, you can’t know what a good decision is today.

Climate change in 2050

The German Climate Action Plan 2050, approved by the German cabinet this month, foreshadows a reduction in greenhouse gases of up to 95% below 1990 levels by 2050. It covers energy, buildings, transport, industry, agriculture and land use, and sets specific milestones and targets for each sector.

As part of its plan, the German government will set up a commission to work with industry and trade unions on the energy transition to 2050. The commission will consider economic development, structural change and social compatibility to accompany climate action. Australia could also consider such an approach to achieve a just transition to a net zero carbon economy.

The United States Mid-Century Strategy sets out several different pathways by which the United States can cut emissions by at least 80% below 2005 levels by 2050 while maintaining a thriving economy. The pathways portray a transformation to a low-carbon energy system using solar, wind, nuclear, hydro and carbon capture.

Under the plan, nearly all fossil fuel plants without carbon capture are to be phased out by 2050. The plan also shows that the land sector in the United States could sequester 23-45% of economy-wide emissions in 2050 by expanding forests and increasing the carbon stored in croplands and grasslands.

Canada’s long-term plan aims to reduce emissions by 80% or more below 2005 levels by 2050. Mexico will reduce its emissions by 50% from 2000 levels. Both plans outline detailed pathways for achieving these emissions reductions.

To support countries, states, cities and businesses to prepare long-term low-emission plans, the 2050 pathways platform initiative was launched at Marrakech. Already 22 countries have started to formulate 2050 plans, including China and India, as have many states, cities and businesses.

New policies and technology

Developing a long-term plan helps identify the policy measures and technological advancements that are needed now. To this end, Marrakech also hosted the first Low-Emission Solutions Conference associated with a climate congress. The conference brought together technical experts, scientists, academics, business and politicians to brainstorm and exchange information about the technological and policy pathways needed to reach net zero carbon emissions.

The Sustainable Development Solutions Network director, Professor Jeff Sachs, told the conference that we need more than political will to make this transition.

We need to mobilise scientists, engineers and experts to identify what the new energy and economic system will look like and to devise pathways to a net zero carbon economy. This will help businesses to identify risks and opportunities and help governments not to waste money on technologies that are not compatible with the long-term goal.

The four pillars of decarbonisation

The conference highlighted the four basic elements of deep decarbonisation. These also underpin the Australian Deep Decarbonisation Pathway Plan developed by ClimateWorks and ANU.

First, there needs to be ambitious energy efficiency across the economy. This includes “smart grid” technologies, green buildings and greater fuel economy in vehicles.

Second, we need zero-carbon electricity supplied by renewables or a mix of renewables, nuclear and carbon capture and storage. The contributions of each of these to the energy mix will depend on country circumstances and on whether carbon capture can be made commercial.

Third, we need a shift to electrification using zero-carbon electricity. This means using electricity to power vehicles and switching from gas to electricity in homes.

Finally, non-energy emissions are reduced by storing more carbon in forests and land as well as reducing methane, nitrous oxide and fluorinated gases from agriculture, waste and industry.

The Australian government has committed to review its climate policies next year and to consider a long-term emissions reduction target. This is an opportunity for Australia to use these four elements of deep decarbonisation and join other countries in preparing a 2050 deep decarbonisation plan.

Already, South Australia, Victoria, NSW and the ACT have pledged a target of zero net emissions by 2050, with South Australia and the ACT signing the UN’s Under 2MOU (a memorandum between states and regions to keep global warming below 2℃). A number of states, including Queensland, have also set ambitious renewable energy targets.

2050 may seem a long way off in the short time frame that dominates so much of modern politics. By 2050 Donald Trump will be 104 and presumably will exert limited influence over global politics.

However, it is worth noting that the children entering our schools next February will still be in their thirties in 2050. They will have a real interest in ensuring that we start planning for their future and taking action now.

John Thwaites is Chair of Monash Sustainable Development Institute and ClimateWorks Australia. These organisations receive funding from governments, business and from philanthropic foundations including the Myer Foundation, the Ian Potter Foundation and the Harold Mitchell Foundation. John Thwaites is a global Co-Chair of the Leadership Council of the Sustainable Development Solutions Network.

ClimateWorks is funded by philanthropy through The Myer Foundation with Monash University. ClimateWorks Australia also periodically conducts research with funding from Federal, State and local governments and from private companies; all our work is focused on supporting strong emissions reductions in Australia. The author has no other relevant affiliations

Cities are bright underwater too. Sydney image from www.shutterstock.com

Light pollution is changing the day-night cycle of some fish, dramatically affecting their feeding behaviour, according to our recently published study.

In one of the first studies of its kind, we found that increased light levels in marine habitats, associated with large coastal cities, can significantly change predator-prey dynamics.

We used a combination of underwater video and sonar to spy on these communities and record how their behaviour changed. Like us, the animals in our study slowed down at night. Predatory fish became sluggish and had little appetite.

But when the lights went on some of these same predators disappeared, while others feasted on the well-lit underwater buffet. Overall, there was much greater predation on seafloor-dwelling communities when the night waters were lit.

Reprinted from Science of The Total Environment, Vol. 576, Bolton et al., Coastal urban lighting has ecological consequences for multiple trophic levels under the sea, pp1-9, Copyright (2017), with permission from Elsevier The dark side of light

The dark blanket of night might once have heralded time to rest, but the great pace of human activity has required that nights get shorter and days become artificially longer.

As the sun sets, streetlights flicker to life, generators go into overdrive and the landscape becomes dotted with artificial light, producing some of the most spectacular images from space. The sky glow from major urban centres can be seen more than 300km away.

While this may have enhanced productivity, we are starting to realise that the ecological effects on animals that have evolved under natural day–night cycles are significant.

Artificial lighting of outdoor areas began in earnest in the late 1700s. We have been manipulating lighting regimes for centuries for purposes that include increased egg production in hens and to encourage birds to sing during winter.

However, we have only recently begun to investigate the damaging ecological consequences. We now know that lighting used on offshore energy installations causes increased deaths of migratory birds and beach lighting can cause turtle hatchlings to become disoriented and reduce the chances of a safe journey from nest to sea.

But these are the more obvious impacts of a disrupted day length. More subtle changes in animal behaviours caused by artificial lighting have yet to be illuminated (pun intended!).

Lights, camera, predation

Using LED spotlights, we manipulated the light patterns underneath a wharf in Sydney Harbour, illuminating sessile (attached to the seafloor and wharf) invertebrate prey communities to fish predators. We recorded fish numbers and behaviour under different lighting scenarios (day, night and artificially lit night), and the prey communities were either protected or exposed to predators.

Despite different changes in different species, overall we found that more animals were getting eaten. The main predators were yellowfin bream (Acanthopagrus australis) and leatherjackets (Monocanthidae). The prey being consumed included barnacles, bryozoans (encrusting and arborescent), ascidians (solitary and colonial), sponges and bivalves.

Large predators are very important in ecosystems and play a major role in the structure of the whole food chain. If these predators are removed from the system, there are cascading effects and sometimes entire ecosystems collapse.

So we should expect that changes to the behaviour of predators will have major consequences for prey communities. When we turned on the lights, we found prey communities changed to more closely resemble communities exposed to predation during the day. This increase in predation pressure highlights the effect prey communities face under a brightening future, possibly leading to shifts in prey structure with flow-on effects to ecosystem functioning.

A bright future

About 70% of the world’s largest cities are situated on the coast, and there has been a corresponding increase in urban lighting that also illuminates the underwater world.

When coupled with the chemical pollution and increasing noise that our urban activities are introducing into waterways, the outlook is harsh for our marine life.

We are beginning to understand the effects of artificial light on the natural world around us, but there is still a long way to go – especially in the underwater realm. World populations continue to grow and increasing pressure is placed on our coastal fringes to support this growth, so we need to find solutions to reduce our impact wherever we can.

One solution for light pollution is to control the wavelength of light used depending on the location of the lights. LEDs are increasingly being used because they are effective and cheap to run, but they emit a broad spectrum with peaks in blue and green wavelengths, which penetrate to great depths underwater. Moving towards other spectra, such as red which doesn’t penetrate as far, could reduce the problem.

Ultimately, while our requirement for artificial light at night is unlikely to diminish, darkness remains a necessary component of many animal’s lives. We must do our best to bring back their night.

Damon Bolton receives funding from UNSW.

Alistair Becker receives funding from the NSW Recreational Fishing Trust

Emma Johnston receives funding from the Australian Research Council.

Graeme Clark receives funding from UNSW, SCAR.

Katherine Dafforn receives funding from the Australian Research Council. She is affiliated with the Sydney Institute of Marine Science.

Mariana Mayer-Pinto receives funding from UNSW.

A large proportion of Australia's perishable vegetables and fruit, such as strawberries, are grown on city fringe farmland around Australia Matthew Carey

Our food systems are under increasing pressure from growing populations, diminishing resources and climate change. But, in a new report, we argue that city foodbowls – the agricultural land surrounding our cities – could supply more secure and sustainable food.

The final report of our Foodprint Melbourne project outlines a vision for “resilient city foodbowls” that can harness city waste to produce food, reduce dependence on distant sources of food and act as a buffer against increasing volatility in global food supplies.

But to do so we need to start planning now. Food is a basic human need – along with water, housing and transport – but it hasn’t been high on the planning agenda for Australia’s cities.

Growing food, and jobs

Australia’s city foodbowls are an important part of the nation’s food supply, particularly for fresh vegetables.

Melbourne’s foodbowl produces almost half of the vegetables grown in Victoria, and has the capacity to meet around 82% of the city’s vegetable needs.

Nationally, around 47% of highly perishable vegetables (such as lettuce, tomatoes and mushrooms) are produced in the foodbowls of the major state capitals, as well as eggs, chicken and perishable fruits such as berries.

New analysis by Deloitte Access Economics has shown that Melbourne’s foodbowl contributes A$2.45 billion each year to the regional economy and around 21,000 fulltime-equivalent jobs. The largest contributors (to the economy and to jobs) in Melbourne’s foodbowl are the fruit and vegetable industries.

Other research estimates that agriculture in Sydney’s foodbowl contributes around A$1 billion to the regional economy. The flow-on effects through the regional economy are estimated to be considerably higher.

City foodbowls at risk

City foodbowls are increasingly at risk. Our project has previously highlighted risks from urban sprawl, climate change, water scarcity and high levels of food waste.

Melbourne’s foodbowl currently supplies 41% of the city’s total food needs. But growing population and less land means this could fall to 18% by 2050.

Australia’s other city foodbowls face similar pressures. For example, between 2000 and 2005, Brisbane’s land available for vegetable crops reduced by 28%, and Sydney may lose 90% of its vegetable-growing land by 2031 if its current growth rate continues.

These losses can be minimised by setting strong limits on urban sprawl, using existing residential areas (infill) and encouraging higher-density living.

However, accommodating a future Melbourne population of 7 million (even at much higher density) will still likely mean we lose some farmland. The Deloitte modelling estimated this will lead to a loss of agricultural output from Melbourne’s foodbowl of between A$32 million and A$111 million each year.

Protecting our food supply

Australia’s city foodbowls could play a vital role in a more sustainable and resilient food supply. If we look after our foodbowls, these areas will strengthen cities against the disruptions in food supplies that are likely to become more common thanks to climate change.

The New Urban Agenda adopted in October 2016 at the United Nations Conference on Housing and Sustainable Urban Development, or Habitat III, emphasises the need for cities to “strengthen food system planning”. It recognises that dependence on distant sources of food and other resources can create sustainability challenges and vulnerabilities to supply disruptions.

Resilient city food systems will need to draw on food from multiple sources – global, national and local – to be able to withstand and recover from supply disruptions due to chronic stresses, such as drought, and acute shocks, such as storms and floods.

Our final report presents a vision of a resilient city foodbowl for Melbourne.

In this future vision, highly perishable foods continue to grow close to the city. City waste streams are harnessed to counter decreasing supplies of water and conventional fertilisers, and increased investment in delivery of recycled water creates “drought-proof” areas of food production close to city water treatment plants.

If Australia’s cities are to retain their foodbowls as they grow, food will need to become a central focus of city planning. This is likely to require new policy approaches focused on “food system planning” that addresses land use and other issues, such as water availability.

We also need to strengthen local and regional food systems by finding innovative ways to link city fringe farmers and urban consumers – such as food hubs. This will create more diverse and resilient supply chains.

Rachel Carey is a Research Fellow at the University of Melbourne on the Foodprint Melbourne project, which is funded by the Lord Mayor's Charitable Foundation. Project partners include 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.

Jennifer Sheridan is a researcher at the University of Melbourne on the Foodprint Melbourne project, which is funded by the Lord Mayor's Charitable Foundation. Project partners include the City of Melbourne and the peak bodies representing the local government areas in Melbourne's city fringe foodbowl.

Kirsten Larsen is a Research Fellow at the University of Melbourne on the Foodprint Melbourne project, which is funded by the Lord Mayor's Charitable Foundation. Project partners include the City of Melbourne and the peak bodies representing the local government areas in Melbourne's city fringe foodbowl. She is also a Director of the Open Food Foundation, which receives money from the Victorian Department of Health.