The Conversation

Bill Mollison in 2008. Nicolás Boullosa/Flickr, CC BY

It is with great sadness that I acknowledge the passing of Bill Mollison on Saturday, September 24 (1928-2016). He was one of the true pioneers of the modern environmental movement, not just in Australia but globally.

Best known as co-originator of the “permaculture” concept with David Holmgren, and recipient of the Right Livelihood Award in 1981, Mollison helped develop a holistic body of environmental theory and practice which is widely recognised as one of Australia’s finest and most original contributions to the global sustainability challenge.

A brief history of permaculture

Mollison grew up in Stanley, Tasmania. After leaving school at 15 he moved through a range of occupations before joining the CSIRO in the Wildlife Survey Section in 1954, where he developed his research experience and understanding of ecological systems.

He was later appointed to the University of Tasmania, which is where, in 1974, he met the brilliant and radical young research student, David Holmgren

The collaboration between Mollison and Holmgren resulted in the permaculture concept, culminating in the publication of their seminal work, Permaculture One in 1978, which sparked the global movement.

What is permaculture?

Permaculture defies simple definition and understanding. The term began as a fusion of “permanent” and “agriculture”. Even back in the 1970s, Mollison and Holmgren could see how destructive industrial agriculture was to natural habitats and topsoils, and how dependent it was on finite fossil fuels.

It was clear that these systems were unsustainable, a position ratified by scientific reports today which expose the alarming effects industrial agriculture has on biodiversity and climate stability. The two pioneering ecologists began to wonder what a “permanent agriculture” would look like. Thus permaculture was born.

In the broadest terms, permaculture is a design system that seeks to work with the laws of nature rather than against them. It aims to efficiently meet human needs without degrading the ecosystems we all rely on to flourish.

Put otherwise, permaculture is an attempt to design human systems and practices in ways that mimic the cycles of nature to eliminate waste, increase resilience and allow for the just and harmonious co-existence of human beings with other species.

A wide range of design principles were developed to help put these broad ideas and values into practice. This practical application and experimentation is what really defines permaculture. Before all else, participants in the movement get their hands in the soil and seek to walk the talk.

There is now a vast array of excellent books detailing the practice of permaculture, as well as outstanding websites such as the Permaculture Research Institute for those wanting to learn, share, explore and connect.

Although permaculture was initially focused on sustainable methods of organic food production, the concept soon evolved to embrace the broader design challenges of sustainable living – not just “permanent agriculture”, but “permanent culture”.

Today we face profound environmental and social challenges: ecological overshoot, climate instability, looming resource scarcity, and inequitable concentrations of wealth. In such a world the permaculture ethics of “care of people, care of planet, and fair share” imply radical changes to the way we live with each other and on the planet.

As well as transitioning away from fossil-fuel-dependent agriculture toward local organic production, permaculture implies the embrace of renewable energy systems, “simple living” lifestyles of modest consumption, as well as retrofitting the suburbs for sustainability and energy efficiency.

From a grassroots or community perspective, the transition towns and ecovillage movements acknowledge their profound debts to permaculture.

From a macroeconomic perspective, permaculture implies a degrowth transition to a steady-state economy that operates within the sustainable limits of the planet. Permaculture even has implications for what alternative forms of global development might look like.

So, in answer to the complex question “what is permaculture?”, perhaps the most concise response is to say with others that “permaculture is a revolution disguised as organic gardening”.

Bill Mollison’s legacy: a challenge to us all

Despite developing into a thriving global movement, permaculture still has not received the full attention it deserves. As the world continues to degrade ecosystems through the poor design of social and economic systems, it has never been clearer that permaculture is a way of life whose time has come.

Nevertheless, permaculture is not a panacea that can answer all challenges. Permaculture is not without its critics (see, for example, here and here). But I would argue that the lens of permaculture can certainly illuminate the path to a more sustainable and flourishing way of life, such that we ignore its insights at our own peril.

Thank you, Bill Mollison, for the inspiration and insight – and the challenge you have left us with to design a civilisation that regenerates rather than degrades our one and only planet. May humanity learn the lessons of permaculture sooner rather than later.

Only then, I suspect, will “Uncle Bill” rest in peace.

Samuel Alexander 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.

Eastern quolls – small, fleet-footed and ferocious – are one of Australia’s few surviving marsupial predators. They were once so common in southeast Australia that when Europeans arrived the quolls were reportedly hyperabundant.

But by the 1960s they were extinct on the mainland, driven down by a combination of disease, poisoning, persecution and predation.

Despite their mainland demise, eastern quolls continued to thrive in Tasmania – until recently. Across Tasmania, quoll numbers declined by more than 50% in the 10 years to 2009 and show no sign of recovery.

Recognising this worrying decline, the quolls have recently been listed as endangered internationally and in Australia. This is a stark reminder of how quickly a common species can plunge towards extinction.

But the quolls can still recover, as long as we act now while we still have an opportunity. In research published in Wildlife Research, I looked at what caused the decline, and how we can help.

Change in the weather

Several factors coincided with the decline, but after five years of investigation I found that a period of unfavourable weather was the most likely explanation.

Eastern quolls prefer areas with low rainfall and cold winters. But an 18-month period of warm winters and higher seasonal rainfall during 2002-03 resulted in most of Tasmania becoming unsuitable for eastern quolls. This rapidly drove their numbers down. In fact, the amount of environmentally suitable habitat in this period was lower than at any other time during the previous 60 years.

With the frequency of extreme weather events predicted to increase over coming decades, the future for eastern quolls looks uncertain.

Eastern quoll numbers declined as unfavourable weather conditions reduced the amount of environmentally suitable habitat across Tasmania (grey shading). Fancourt et al (2015) The predator pit

Interestingly, while weather conditions have since improved, eastern quolls have not recovered. With their numbers pushed so low, the remaining small populations can no longer breed faster than other threats kill them off. Historically, when quoll numbers were higher, they could cope with these threats.

Quolls are now trapped in what ecologists call a “predator pit”. Predators, cars, poison and a range of other threats are killing quolls as quickly as they can reproduce.

So population growth is in limbo – not because any threats have increased, but because small populations don’t have the capacity to outpace those same threats anymore.

Contrary to earlier predictions, feral cat numbers in Tasmania have not increased following declines in the Tasmanian devil population. Quoll populations could previously cope with the loss of a few quolls (mainly juveniles) to cats. However, that same number of quolls killed by cats is now potentially enough to wipe out any population growth, preventing the species’ recovery.

While feral cat numbers have not increased in Tasmania, cat predation of juvenile quolls could still be preventing their population from recovering. Bronwyn Fancourt Numbers game

The key factor preventing quoll recovery is their current small population. Quoll numbers need a boost, increasing reproductive capacity so that they can once again outpace the threats they are facing. This could be done by supplementing small, surviving populations in Tasmanian with quolls from captive-breeding colonies, insurance populations or the wild population on Bruny Island (which is doing better than mainland Tasmania).

Reducing feral cat numbers at key sites in early summer could also help reduce predation as juvenile quolls enter the population. That would potentially increase juvenile survival and allow quoll populations to grow and recover.

Increasing survival rates of juvenile quolls in the wild is key to helping the species recover. Bronwyn Fancourt Should quolls be reintroduced to the mainland?

Since word of the eastern quolls’ plight has spread, there has been increasing talk of reintroducing them to Australia’s mainland, where they disappeared more than 50 years ago. Such proposals are often well-intentioned and could potentially help restore some mainland ecosystems.

However, this could actually serve to drive wild populations in Tasmania closer to extinction, making the species’ recovery more difficult.

With only small populations persisting in the wild, removing only one or two individuals from a population could be enough to render that population functionally extinct – and once a population is functionally extinct it is on the path to total extinction.

Similarly, using quolls from captive colonies and insurance populations for mainland reintroductions further removes valuable quolls that could be used to repopulate and recover wild populations in Tasmania.

The eastern quoll’s persistence in Tasmania decades after it disappeared from the mainland suggests Tasmania is a far safer place for eastern quolls and offers them the best chance to recover. Removing them from a relatively safe place and reintroducing them to high-risk mainland sites filled with dingoes, foxes and toxic fox baits could actually hinder, not help, their recovery. For example, while baiting foxes may reduce the threat from foxes, it takes less than half of one fox bait to kill an adult female eastern quoll.

Mainland reintroductions should definitely be a goal in the longer term. But given the dangerously low numbers in Tasmania, we shouldn’t take Tasmanian quolls for high-risk mainland reintroductions until the Tasmanian population is safe. Once numbers in the wild have recovered, wild-sourced Tasmanian quolls could be reintroduced to mainland sites without putting wild populations at risk.

It’s time to act

Australia’s declining species face a slippery slope towards extinction. The key to recovery is understanding why the species declined, then acting while there is still time.

Australia’s history is littered with examples where delays and inaction prevented small populations from recovering, with some species now lost forever. The eastern quolls’ fate is not yet sealed. But we have to act now.

Bronwyn Fancourt 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.

Small power generators like solar panels take pressure of the electricity grid. Solar image from www.shutterstock.com

The governing body for our energy market, the Australian Energy Market Commission, has just missed a major opportunity to modernise our electricity networks. Last week the commission rejected a proposal to pay credits to small, local generators (such as small wind, solar and gas). Our research shows that this could save electricity consumers A$1.2 billion by 2050.

In July 2015, the City of Sydney, Total Environment Centre and NSW Property Council proposed the Local Generation Network Credit rule change. This would have required network businesses to pay a credit for electricity exported into the distribution grid – that is, close to where it is actually consumed.

This is different to the credit (known as a “feed-in tariff”, or FIT) paid by electricity retailers for solar households that export power, which reflects the energy value of the solar rather than any network value. FITs are a fixed payment for the amount of power exported with no variation for the time of day. In most states, retailer FITs have replaced generous mandatory FITs set by state governments, and usually have an upper limit on system size somewhere between 5 and 100 kilowatts.

The network rule change would have been a small but crucial step towards recognising that in the future electricity will flow both to and from consumers, as more and more individuals, communities and businesses install their own generation.

It is just one of the rule changes needed to make an orderly, efficient transition, rather than a cycle where consumers get more and more frustrated as they are forced into workarounds to deal with outdated regulations, and regulators and markets play catch-up.

The cost of connection

About half of our electricity prices are made up of network charges. These cover the cost of building and maintaining the poles and wires that get electricity from generators to our homes and businesses. Traditionally, that was a long way, as electricity all came from large centralised generators.

This is all changing, as homes and businesses increasingly install their own solar, wind or gas generators. These trends are being driven by the increase in electricity prices, cost reductions in renewable energy, and a range of other motives such as climate targets, aspirations for self-sufficiency, and wishing to take control of energy spending.

Network costs have been the main contributor to a big jump in Australian electricity prices over the last 15 years. There was a huge investment to cope with the projected rise in electricity demand, which has so far failed to happen.

Described as “gold plating”, it would have been smarter and cheaper to do a whole mix of other things – energy efficiency, local generation and so on – instead of the big investment focused on network infrastructure.

Because the electricity from local generators is used physically close to where it is generated, it reduces congestion on the network and so can reduce the need to upgrade. The proposed rule change is aimed at rewarding local generators for export at peak times, when the network is under most strain, and so avoiding the long-term need for network investment.

The rule change would also enable many local generation projects, and keep them using the network to share energy. Without this incentive most generators will use their energy onsite rather than exporting to the grid.

This gets the biggest return, as it means each unit you generate avoids the entire volume charge of a unit imported from the grid.

Consumers lose out

But what if you have several buildings and want to generate at one and use it at the other? Tough luck.

Unless you can connect those buildings with a private wire – instead of connecting them via the grid – it’s unlikely to be economic. Consumers pay the same network charges whether the energy is transported across the road or halfway across the state.

This rule change would have meant that you got a network credit for the generation, and therefore helped reduce what you pay to use the network. It would be a win-win for everyone, as putting in a private wire is just duplication of the network that already exists and makes everyone – the network business, the organisation and, by implication, other consumers – worse off.

Of course, a private wire isn’t possible in all situations, but the principle remains: the local network credit offers an alternative to behind-the-meter generation.

The Institute for Sustainable Futures recently led a year-long project looking at local generation network credits and local electricity trading. The results showed pretty clearly that, if designed well, this rule change would be good for local energy projects and good for electricity consumers.

As a result of the economic modelling, we recommended that existing systems and all small (less than 10 kilowatt) systems do not receive the network credit, in order to maximise benefits for everyone. The payments are unlikely to make a difference to whether those small systems go in, and paying them the credit would means an overall cost, rather than a long-term benefit of A$1.2 billion for everyone.

This was a change from the original proposal and was presented to the AEMC in great detail. The rule change proponents were also quite happy with these limits being imposed.

So what did the AEMC decide?

The AEMC considers rule change proposals – and accepts, rejects, or makes what is called a “preferred rule”. It is a very arcane process, with little scope for collaborative outcomes.

On this issue, the AEMC delivered a “preferred rule” – which does nothing to solve the problem. The commission ignored the opportunity to work with stakeholders to deliver an alternative rule that would benefit both local projects and all consumers.

Instead, it proposes that network businesses be required to provide information on upcoming constraints, including a dollar value for alternatives to network investment. That’s all well and good, except that the information is already available in the form of Network Opportunity Maps.

Unfortunately it’s just more evidence that the AEMC has lost touch with what is actually happening in the market, and with what consumers want.

So where to now? There is a six-week consultation period on the draft rule – and we can only hope that the AEMC reconsiders its decision.

Jay Rutovitz will be online for an Author Q&A between 4 and 5pm on Wednesday, September 28, 2016. Post any questions you have in the comments below.

The research by Institute for Sustainable Futures was supported by funding from ARENA, UTS, Ergon Energy, Moira Shire Council, Swan Hill Rural City Council, Wannon Water, City of Sydney, Byron Shire Council, and Willoughby City Council, with in-kind support from AGL, NSW Government Department of Industry, Powercor the Total Environment Centre, and other project participants.

The Scottish Fold is a lovely cat, but unfortunately suffers from health problems related to its breeding. Cat image from www.shutterstock.com

Cats are one of the world’s favourite pets, but in our efforts to breed more attractive felines, we are metaphorically loving them to death.

Like British Bulldogs and extreme styles of pigeons, some cats bred to please a human sense of beauty suffer from serious health problems. This is the case for a particularly lovely cat, the Scottish Fold.

It has long been known that breeding Scottish Folds risks health problems, but research is mounting that it is impossible to mitigate this risk. It is time to ban the breeding of this type of cat, as other nations have done.

Why so cute?

The Scottish Fold is a rare feline breed. It originated when a naturally occuring mutant cat was born in Scotland during the last century, at a farm near Coupar Angus in Perthshire. The cat had forward-folding ears because her ear cartilage wasn’t rigid enough to support her ears.

Her name was Susie and she looked cute. Cute enough that, in a great UK tradition, they wanted to preserve the mutation by breeding her with British short-haired cats and local farm cats. And so the Scottish Fold was born.

Why do people like cats with floppy ears? Many authorities think this is because of the Lorenzian theory of beauty, named in honour of Konrad Lorenz who was awarded the Nobel Prize for his work on ethology, the study of animal behaviour.

Most people, especially children, find a round face resembling that of a human comforting, whereas the longer snout and erect ears (of, say, a wolf) is potentially frightening. For this reason, many people find the appearance of owls pleasing to the eye, which is why they have owl cafes in Tokyo, and why so many people collect owl figurines.

So a Scottish Fold looks owl-like, and for many people this is a highly desirable trait.

Tracing the mutation

It didn’t take long for veterinarians and scientists to figure out that if the cartilage in the ear was defective, then cartilage in the joints might also be dodgy. The British geneticist Oliphant Jackson demonstrated this unequivocally in a most elegant series of classic genetic and radiological experiments in a hospital basement in the 1970s.

Cats, like people, have two copies of most genes. Jackson showed that cats like Susie (and her daughter Snooks), which both had a single copy of the postulated defective gene, were reasonably normal.

In contrast, cats with two copies of the dud gene developed crippling arthritis from an early age. Sensibly, Jackson suggested the breeding of such cats be banned, and that’s what happened in the UK and France.

But some Scottish Folds were exported to the US. Unfortunately, in that jurisdiction breeding was allowed, with the proviso that a Scottish Fold only be mated to a Scottish Shorthair (a normal cat with a similar genetic background, but with normal ears and hence normal cartilage). This type of mating resulted in half of each litter of kittens (on average) having folded ears, the other half being Scottish Shorthairs. And so the breed went on.

In the early 1990s a group of Australian veterinarians demonstrated convincingly that all Scottish Fold cats have abnormal bone development of their distal limbs. This is generally associated with early onset and accelerated progression of osteoarthritis (degenerative joint disease) in joints of the distal limbs and tail. The ankle and wrist were the joints most obviously affected, especially the ankles.

In time all Folds develop adverse changes. This work was confirmed and extended subsequently by Japanese and Korean investigators. Yet Scottish Folds are still bred in the US, Asia and even Australia.

Two years ago a collaboration between Australian, European and American researchers uncovered the science behind the problem. Their research was recently published in the journal Osteoarthritis and Cartilage.

The problem lies in a gene that affects cells involved with pressure and pain sensing within cartilage. Children with a very similar genetic defect have comparable bone deformities to affected Scottish Fold cats.

What does this mean for the cats?

Scottish Shorthairs have normal ears and are completely healthy. They are lovely, sweet-natured cats.

Scottish Folds have shortened limbs, an abnormal gait, a peculiar and sometimes stiff or painful tail, and the propensity to develop osteoarthritis at an earlier age. This causes variable lameness (often severe) and secondary deformity.

The truth is, we have known since Jackson’s work in the 1970s that breeding Scottish Fold cats is ethically indefensible.

Yet the practice has continued in most jurisdictions, with cat breeders and veterinarians turning a blind eye to the frequently obvious problems.

While there are still questions to be answered, we already possess sufficient information to know that breeding these cats is cruel. Vets and cat breeders who condone this practice have no scientific basis with which to defend this practice. They are not breeding cats – they are perpetuating a disease state.

What to do

The breeding of Scottish Folds has been effectively banned in Victoria. It should be the same in every state of Australia and every country overseas.

In my opinion, the RPSCA should seek out people who advertise these cats for sale and prosecute them.

We cannot condone breeding cats because it’s in our nature to think they are cute, when pain and suffering will afflict a substantial proportion of these cats for much of their life, with ongoing requirements for medication and sometimes even radiation therapy or surgery.

Scottish Shorthairs have the same sweet personality and behavioural features of Scottish Folds, but they don’t get the joint issues. These could be bred and shown in the place of the Folds. They are lovely cats.

The solution is that simple. It’s time to stop pussyfooting around.

Richard Malik 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.

Native bees are just some of the wildlife found in your backyard. MirandaKate/Flickr, CC BY-NC

As the weather warms and days lengthen, your attention may be turning to that forgotten patch of your backyard. This week we’ve asked our experts to share the science behind gardening. So grab a trowel and your green thumbs, and dig in.

Whether you live in an urban apartment or a rural homestead, your outdoor area is more than just a private space. Ecologically, a garden is another jigsaw piece in the landscape.

Whatever their size, gardens can contribute to natural functions and processes in the local area, such as regulating water drainage, buffering the damaging effects of strong winds, or providing food and shelter for native wildlife.

Many wildlife species survive in urban areas, but their presence and persistence depend on how specific their food and shelter needs are, how they respond to disturbances, and the quality and quantity of other green spaces in the landscape.

For larger animals, such as birds and mammals, a home garden could become a stepping stone across an otherwise hostile urban landscape. For smaller animals, such as insects, it could be the centre of their home range.

In urban areas, where space is often limited, gardening with pollinators in mind is a simple way to encourage biodiversity in the backyard. And, depending on the surrounding landscape, habitat for pollinators will also be habitat for other animals.

Butterflies are important pollinators in backyards. John Tann/Flickr, CC BY Flowers are just the first step

Flowers produce sugar (nectar) and protein (pollen), the main diet for many adult insects and birds. Unlike other insect groups, native bee larvae develop almost exclusively on pollen collected by their parents, so flowers are essential to grow native bee populations.

There is no single best combination of flowers for wild bees. Many “plants for pollinators” lists available online are based on local experiences and rarely apply to all geographic regions. A general rule of thumb for a pollinator garden is one that produces flowers for most of the year and is built on diversity – monocultures of any single flower type or colour will suit only a very small number of generalist species.

Native plants are an ideal option for attracting native pollinator insects and birds, but many garden exotics, especially herbs, fruit and vegetable plants, are just as popular. Modern hybrid varieties should be chosen carefully, as some are bred for commercial fruit or flower traits (like size or colour), but the flowers lack the nectar or scent cues that attract pollinators looking for food.

Native plants can attract birds, such as this New Holland honeyeater. Cazz/Flickr Build it and they will come

The structure and design of a garden can determine what wildlife species will visit or make a home. Vertical structure, built from multiple layers of different plant heights, provides more spaces for wildlife to co-exist. Small plants and shrubs provide good shelter for insects and very small birds, while larger trees will attract visits from more mobile birds and mammals.

Large trees with rough or shedding bark that creates lots of cracks and crevices are excellent shelter for insects and small lizards. Trees that produce resins and sap flows, such as conifers, acacias and eucalypts, are also useful for some native bee and wasp species that use resin to seal their nest cells.

Insect hotels can provide homes for insects that usually nest in dead wood. But only a small proportion of the world’s bee species are wood-nesters. About 75% of bee species dig their nests into the ground, usually in sandy, uncompacted soil, preferably on a slope that won’t get waterlogged.

Insect hotels attract wood-nesting insects. Insect hotel image from www.shutterstock.com

It can be difficult to build all of this into small gardens, but many pollinator insects will have home ranges of a few hundred metres, while birds and mammals can travel much further. So landscape composition can also influence the wildlife potential of an individual garden. A high proportion of paved areas can reduce the number of wild bees or native birds in the neighbourhood. Highly manicured green spaces can also have a negative effect on wild bee species.

Disrupting the food chain

Like any ecosystem, gardens involve an intricate web of life, from the soil microbes underground to the birds in the trees. It’s easy to grab the spray bottle to kill off the dandelions and blow down the flies, but what are the knock-on effects?

Many of the animals and plants we think of as a backyard nuisance often provide services we don’t see. For example, many native wasp and fly species (even blowflies!) are pollinators as adults. And as larvae, they control many of the insect pests we see on our plants, or decompose organic wastes. Small reptiles, like geckoes and skinks, mostly feed on small insects that annoy us, like mosquitoes and midges.

Plants we think of as lawn weeds, particularly dandelions and clover, are a favourite food source for native bees and hoverflies. Aphids and scale insects also produce a sugary substance called honeydew as they suck on plants, which is an important sugar source for some beneficial insects like wasps, bees, ants and hoverflies.

Aphids produce sugars which are an important food source for other insects. ron_n_beths pics/Flickr, CC BY-NC

Limiting synthetic chemical use is one of the easiest and cheapest ways to enhance wildlife in gardens. Insecticides can kill beneficial insects, or affect them indirectly by disrupting their metabolism or reproductive cycles. Overuse of herbicides removes important food resources, like dandelions, that pollinators rely on if other flowers are scarce.

There is also the potential for chemicals to work in combination and have a greater impact.

Managing gardens as ecosystems

Many wildlife don’t like regular disturbances, which is why urban areas can be intimidating environments for animals. It can be hard to balance human needs with the habitat needs of wildlife. Many actions that minimise risks for humans can have the opposite effect for wildlife.

For example, pollinators generally prefer open grassy areas to dark forested areas. In urban environments, grassed areas are often mown regularly for human recreational and safety needs. This affects the availability of flowers for pollinators and also affects the persistence of these plant species. Mowing less often and outside peak flowering times can make a big difference for plants and pollinators.

Leaving a few weeds in the lawn can be a good thing for pollinators. tuchodi/Flickr, CC BY-SA

Similarly, large old trees are homes to myriad animals. Unless they pose a very real risk of danger to human lives, pruning overhanging branches can be better for the local ecosystem than removing the whole tree.

Wildlife are rarely deterred by fences, so it is likely that most of the animals you see in your yard are also using your neighbours’ yards. Managing gardens as a collective landscape, rather than individual gardens, can keep wildlife happy while also enhancing neighbourhood communication.

Manu Saunders is affiliated with the Institute for Land Water & Society and is co-founder of the Wild Pollinator Count.

Melting ice sheets – such as this one in Greenland – are one way the Earth amplifies global warming. Ice sheet image from www.shutterstock.com

Current greenhouse gas concentrations could warm the world 3-7℃ (and on average 5℃) over coming millennia. That’s the finding of a paper published in Nature today.

The research, by Carolyn Snyder, reconstructed temperatures over the past 2 million years. By investigating the link between carbon dioxide and temperature in the past, Snyder made new projections for the future.

The Paris climate agreement seeks to limit warming to a “safe” level of well below 2℃ and aim for 1.5℃ by 2100. The new research shows that even if we stop emissions now, we’ll likely surpass this threshold in the long term, with major consequences for the planet.

What is climate sensitivity?

How much the planet will warm depends on how temperature responds to greenhouse gas concentrations. This is known as “climate sensitivity”, which is defined as the warming that would eventually result (over centuries to thousands of years) from a doubling of CO₂ concentrations in the atmosphere.

The measure of climate sensitivity used by the Intergovernmental Panel on Climate Change (IPCC) estimates that a doubling of CO₂ will lead to 1.5-4.5℃ warming. A doubling of CO₂ levels from before the Industrial Revolution (280 parts per million) to 560ppm would likely surpass the stability threshold for the Antarctic ice sheet.

As the world warms, it triggers changes in other systems, which in turn cause the world to warm further. These are known as “amplifying feedbacks”. Some are fast, such as changes in water vapour, clouds, aerosols and sea ice.

Others are slower. Melting of the large ice sheets, changes in the distribution of forests, plants and ecosystems, and methane release from soils, tundra or ocean sediments may begin to come into play on time scales of centuries or less.

Other research has shown that during the mid-Pliocene epoch (about 4.5 million years ago) atmospheric CO₂ levels of about 365-415ppm were associated with temperatures about 3–4 °C warmer than before the Industrial Revolution. This suggests that the climate is more sensitive than we thought.

This is concerning because since the 18th century CO₂ levels have risen from around 280ppm to 402ppm in April this year. The levels are currently rising at around 3ppm each year, a rate unprecedented in 55 million years. This could lead to extreme warming over the coming millennia.

More sensitive than we thought

The new paper recalculates this sensitivity again – and unfortunately the results aren’t in our favour. The study suggests that stabilisation of today’s CO₂ levels would still result in 3-7℃ warming, whereas doubling of CO₂ will lead to 7-13℃ warming over millennia.

The research uses proxy measurements for temperature (such as oxygen isotopes and magnesium-calcium ratios from plankton) and for CO₂ levels, calculated for every 1,000 years back to 2 million years ago.

Some other major findings include:

The Earth cooled gradually to about 1.2 million years ago, followed by an increase in the size of ice sheets around 0.9 million years ago, and then followed by around 100,000-year-long glacial cycles.

Over the last 800,000 years, and particularly during glacial cycles, atmospheric greenhouse gas concentrations and global temperature were closely linked.

The study shows that for every 1℃ of global average warming, Antarctica warms by 1.6℃.

So what does all this mean for the future?

Global warming past and future, triggered initially by either changes in solar radiation or by greenhouse gas emissions, is driven mainly by amplifying feedbacks such as warming oceans, melting ice, drying vegetation in parts of the continents, fires and methane release.

Current CO₂ levels of around 400ppm, combined with methane (rising toward 1,900 parts per billion) and nitric oxide (around 310ppb), are already driving such feedbacks.

According to the new paper, such greenhouse gas levels are committing the Earth to extreme rises of temperature over thousands of years, with consequences consistent with the large mass extinctions.

The IPCC suggests warming will increase steadily as greenhouse gases increase. But the past shows there will likely be abrupt shifts, local reversals and tipping points.

Abrupt freezing events, known as “stadials”, follow peak temperatures in the historical record. These are thought to be related to the Mid-Atlantic Ocean Current. We’re already seeing marked cooling of ocean regions south of Greenland, which may herald collapse of the North Atlantic Current.

As yet we don’t know the details of how different parts of the Earth will respond to increasing greenhouse gases through both long-term warming and short-term regional or local reversals (stadials).

Unless humanity develops methods for drawing down atmospheric CO₂ on a scale required to cool the Earth to below 1.5°C above pre-industrial temperature, at the current rate of CO₂ increase of 3ppm per year we are entering dangerous uncharted climate territory.

Andrew Glikson 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.

Aviation emissions are growing about 5% each year. Flying image from www.shutterstock.com

Tomorrow, delegates from more than 190 nations will begin an 11-day meeting in Montreal to determine the final form of a scheme to reduce greenhouse emissions from the aviation industry.

The meeting – the latest in a series of three-yearly summits held by the International Civil Aviation Organisation (ICAO), the United Nations agency tasked with reducing aviation emissions – is poised to decide on a scheme that would ultimately make it mandatory for most airlines from member countries to buy carbon offsets for their flights.

The resolution would fill a key gap in global climate policy. The Paris climate agreement, brokered last December, makes no mention of aviation emissions, despite having featured these in earlier drafts.

Earlier this month, the ICAO Council issued the final draft of a resolution text to be considered – and, presumably, after some debate, approved – at the Montreal meeting.

In its current form, questions will be raised over the scheme’s effectiveness, not least because it won’t become mandatory until 2027 – and even then not for all carriers. But these loopholes make it more likely that the plan will be adopted.

Mandatory offsetting (in the future)

The planned carbon offsetting scheme set out in the draft resolution would begin with a pilot phase running from 2021 to 2023, involving states that have volunteered to participate. These states will have some flexibility in determining the basis of their aircraft operators' offsets.

The purpose of this pilot phase is not really clear, and some aviation industry organisations, such as the Air Transport Action Group, regard it as unnecessary.

A first “formal” phase from 2024 to 2026 would apply to states that voluntarily participate in the pilot phase, and again would offset with reference to options in the resolution text. The main difference between the pilot and first phases is that, for the pilot phase, states can determine the applicable baseline emissions year.

A second, mandatory phase would only operate from 2027 to 2035 and would exempt the least developed countries and those with the smallest proportion of international air travel.

There are also exemptions based on the routes themselves. While the rules would apply to all flights between countries covered by the offsetting requirements, they will not apply to flights that take off or land in a non-member state.

Offsetting the issue

Then there are the well-publicised problems with the whole concept of carbon offsetting. Most countries and groups of countries (and ICAO is a group of countries) have ignored offsets in favour of mechanisms such as emissions trading schemes or carbon taxation – and with good reason.

Offsets, which by definition simply move emissions from one source to another, have little net effect on emissions. As such, offsets could be viewed as a diversion from regulations that genuinely encourage emissions reduction, such as carbon pricing. The Paris Agreement does not directly rely on offsets because all governments recognise that it’s collective, substantive action that counts.

What is really needed is a policy that motivates major industrial sectors – aviation included – to cut emissions and use resources more efficiently. Market-based mechanisms offer the best way to apply the price pressure needed to drive such a change.

The question in designing any market-based mechanism is whether to base it on quantity or price. A quantity-based instrument is an ETS, the most common example of which is a cap-and-trade system; a price-based instrument is a carbon tax.

ICAO has chosen neither of these options. Instead, it has chosen a system of voluntary and then mandatory carbon offsets, with all their attendant problems.

Other issues

An analysis by Carbon Brief has found that even if the aviation industry meets all of its emissions targets, by 2050 it will still have consumed 12% of the global carbon budget for keeping warming to 1.5℃. This could increase to as much as 27% if the industry misses its targets.

Meanwhile, airlines estimate that air travel will grow by an average of almost 5% each year until 2034, in an industry where low-carbon alternatives are difficult to find.

It is perhaps good news, then, that three weeks ago 49 states indicated they were willing to opt into the ICAO’s offsetting scheme in its earliest phase. The following week, in a joint statement, the European Union, Mexico and the Marshall Islands said they would join the scheme. And at G20 talks earlier this month, China and the US offered support.

Brazil, one of the fastest-growing aviation markets, said, however, that it will not join until the mandatory scheme begins in 2027.

Notwithstanding substantive draft texts prepared before the assembly, there is still plenty of negotiating to do before we know its final shape. And despite the pitfalls of carbon offsetting and some difficulty with integrating the scheme with the Paris process, a resolution at the meeting would be a step forward (to be followed by further steps and leaps) for an industry with emissions roughly equal to those of the entire nation of South Korea.

The authors will be attending the 39th ICAO Assembly in Montreal.

The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond the academic appointment above.

It is September 27, 1956. At a dusty site called One Tree, in the northern reaches of the 3,200-square-kilometre Maralinga atomic weapons test range in outback South Australia, the winds have finally died down and the countdown begins.

The site has been on alert for more than two weeks, but the weather has constantly interfered with the plans. Finally, Professor Sir William Penney, head of the UK Atomic Weapons Research Establishment, can wait no longer. He gives the final, definitive go-ahead.

The military personnel, scientists, technicians and media – as well as the “indoctrinee force” of officers positioned close to the blast zone and required to report back on the effects of an atomic bomb up close – tense in readiness.

And so, at 5pm, Operation Buffalo begins. The 15-kilotonne atomic device, the same explosive strength as the weapon dropped on Hiroshima 11 years earlier (although totally different in design), is bolted to a 30-metre steel tower. The device is a plutonium warhead that will test Britain’s “Red Beard” tactical nuclear weapon.

The count reaches its finale – three… two… one… FLASH! – and all present turn their backs. When given the order to turn back again, they see an awesome, rising fireball. Then Maralinga’s first mushroom cloud begins to bloom over the plain – by October the following year, there will have been six more.

RAF and RAAF aircraft prepare to fly through the billowing cloud to gather samples. The cloud rises much higher than predicted and, despite the delay, the winds are still unsuitable for atmospheric nuclear testing. The radioactive cloud heads due east, towards populated areas on Australia’s east coast.

Power struggle

So began the most damaging chapter in the history of British nuclear weapons testing in Australia. The UK had carried out atomic tests in 1952 and 1956 at the Monte Bello Islands off Western Australia, and in 1953 at Emu Field north of Maralinga.

British nuclear bomb test sites in Australia. Jakew/Wikipedia, CC BY-SA

The British had requested and were granted a huge chunk of South Australia to create a “permanent” atomic weapons test site, after finding the conditions at Monte Bello and Emu Field too remote and unworkable. Australia’s then prime minister, Robert Menzies, was all too happy to oblige. Back in September 1950 in a phone call with his British counterpart, Clement Attlee, he had said yes to nuclear testing without even referring the issue to his cabinet.

Menzies was not entirely blinded by his well-known anglophilia; he also saw advantages for Australia in granting Britain’s request. He was seeking assurances of security in a post-Hiroshima, nuclear-armed world and he believed that working with the UK would provide guarantees of at least British protection, and probably US protection as well.

He was also exploring ways to power civilian Australia with atomic energy and – whisper it – even to buy an atomic bomb with an Australian flag on it (for more background, see here). While Australia had not been involved in developing either atomic weaponry or nuclear energy, she wanted in now. Menzies’ ambitions were such that he authorised offering more to the British than they requested.

While Australia was preparing to sign the Maralinga agreement, the supply minister, Howard Beale, wrote in a top-secret 1954 cabinet document:

Although [the] UK had intimated that she was prepared to meet the full costs, Australia proposed that the principles of apportioning the expenses of the trial should be agreed whereby the cost of Australian personnel engaged on the preparation of the site, and of materials and equipment which could be recovered after the tests, should fall to Australia’s account.

Beale said that he did not want Australia to be a mere “hewer of wood and drawer of water” for the British, but a respected partner of high (though maybe not equal) standing with access to the knowledge generated from the atomic tests.

That hope was forlorn and unrealised. Australia duly hewed the wood and drew the water at Maralinga, and stood by while Britain’s nuclear and military elite trashed a swathe of Australia’s landscape and then, in the mid-1960s, promptly left. Britain carried out a total of 12 major weapons tests in Australia: three at Monte Bello, two at Emu Field and seven at Maralinga. The British also conducted hundreds of so-called “minor trials”, including the highly damaging Vixen B radiological experiments, which scattered long-lived plutonium over a large area at Maralinga.

The British carried out two clean-up operations – Operation Hercules in 1964 and Operation Brumby in 1967 – both of which made the contamination problems worse.

Legacy of damage

The damage done to Indigenous people in the vicinity of all three test sites is immeasurable and included displacement, injury and death. Service personnel from several countries, but particularly Britain and Australia, also suffered – not least because of their continuing fight for the slightest recognition of the dangers they faced. Many of the injuries and deaths allegedly caused by the British tests have not been formally linked to the operation, a source of ongoing distress for those involved.

The cost of the clean-up exceeded A$100 million in the late 1990s. Britain paid less than half, and only after protracted pressure and negotiations.

Decades later, we still don’t know the full extent of the effects suffered by service personnel and local communities. Despite years of legal wrangling, those communities' suffering has never been properly recognised or compensated.

The Maralinga landscape today. Wayne England/Wikimedia Commons, CC BY

Why did Australia allow it to happen? The answer is that Britain asserted its nuclear colonialism just as an anglophile prime minister took power in Australia, and after the United States made nuclear weapons research collaboration with other nations illegal, barring further joint weapons development with the UK.

Menzies’ political agenda emphasised national security and tapped into Cold War fears. While acting in what he thought were Australia’s interests (as well as allegiance to the mother country), he displayed a reckless disregard for the risks of letting loose huge quantities of radioactive material without adequate safeguards.

Six decades later, those atomic weapons tests still cast their shadow across Australia’s landscape. They stand as testament to the dangers of government decisions made without close scrutiny, and as a reminder – at a time when leaders are once again preoccupied with international security – not to let it happen again.

Liz Tynan will launch her book, Atomic Thunder: The Maralinga Story, on September 27. A travelling art exhibition, Black Mist Burnt Country, featuring art from the Maralinga lands, will open on the same day.

Liz Tynan 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.

Time spent weeding, potting and pruning can be as good for the gardener as it is for the garden. Image from www.shutterstock.com

As the weather warms and days lengthen, your attention may be turning to that forgotten patch of your backyard. This week we’ve asked our experts to share the science behind gardening. So grab a trowel and your green thumbs, and dig in.

“That’s all very well put,” says Candide, in the final line of Voltaire’s novel of the same name, “but we must go and work our garden.”

I studied this text at high school before I became a gardener and professional horticulturist. We were taught that Candide’s gardening imperative was metaphorical not literal; a command for finding an authentic vocation, not a call to take up trowels and secateurs.

In fact, Voltaire himself really believed that active gardening was a great way to stay sane, healthy and free from stress. That was 300 years ago.

As it turns out, the science suggests he was right.

The science of therapeutic horticulture

Gardens and landscapes have long been designed as sanctuaries and retreats from the stresses of life – from great urban green spaces such as Central Park in New York to the humblest suburban backyard. But beyond the passive enjoyment of a garden or of being in nature more generally, researchers have also studied the role of actively caring for plants as a therapeutic and educational tool.

“Therapeutic horticulture” and “horticultural therapy” have become recognised treatments for stress and depression, which have served as a healing aid in settings ranging from prisons and mental health treatment facilities to schools and hospitals.

Gardening and school

Studies of school gardening programs – which usually centre on growing food – show that students who have worked on designing, creating and maintaining gardens develop more positive attitudes about health, nutrition and the consumption of vegetables.

They also score better on science achievement, have better attitudes about school, and improve their interpersonal skills and classroom behaviour.

Research on students confirms that gardening leads to higher levels of self-esteem and responsibility. Research suggests that incorporating gardening into a school setting can boost group cohesiveness.

Gardening and mental health

Tailored gardening programs have been shown to increase quality of life for people with chronic mental illnesses, including anxiety and depression.

Another study on the use of therapeutic horticulture for patients with clinical depression sought to understand why gardening programs were effective in lessening patient experience of depression. They found that structured gardening activities gave patients existential purpose. Put simply, it gave their lives meaning.

In jails and corrective programs, horticultural therapy programs have been used to give inmates positive, purposeful activities that lessen aggression and hostility during and after incarceration.

In one detailed study from a San Francisco program, involvement in therapeutic horticulture was particularly effective in improving psychosocial functioning across prison populations (although the benefits were not necessarily sustained after release.)

Gardening has been shown to help improve the lives of military veterans and homeless people. Various therapeutic horticulture programs have been used to help people with learning difficulties, asylum seekers, refugees and victims of torture.

Gardening and older people

As populations in the West age, hands-on gardening programs have been used for older people in nursing homes and related facilities.

A systematic review of 22 studies of gardening programs for older adults found that gardening was a powerful health-promoting activity across diverse populations.

One study sought to understand if patients recovering from heart attack might benefit from a horticultural therapy program. It concluded:

[Our] findings indicate that horticultural therapy improves mood state, suggesting that it may be a useful tool in reducing stress. Therefore, to the extent that stress contributes to coronary heart disease, these findings support the role of horticultural therapy as an effective component of cardiac rehabilitation.

Horticulturist and nurse Steven Wells talks about his work at Austin Health.

While the literature on the positive effects of gardening, reflecting both qualitative and quantitative studies, is large, most of these studies are from overseas.

Investment in horticultural therapy programs in Australia is piecemeal. That said, there are some standout success stories such as the Stephanie Alexander Kitchen Garden Foundation and the work of nurse Steven Wells at the Royal Talbot Rehabilitation Centre and beyond.

Finally, without professionally trained horticulturists none of these programs – in Australia or internationally – can take place.

Chris Williams 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.

South Australia is leading the way on wind energy - but that's posing problems for the electricity sector. Wind image from www.shutterstock.com

Australia’s energy markets got a big shock in July this year, when wholesale electricity prices spiked in South Australia, alarming the state government and major industrial customers. Commentators rushed to find the immediate culprits. But the real issues lie elsewhere.

As shown by the Grattan Institute’s latest report the market worked. Having soared, prices fell back to more manageable levels. The lights stayed on.

Yet South Australia’s power shock exposed a looming problem in Australia’s electricity system – not high prices or the threat of blackouts, but an emerging conflict between Australia’s climate change policies and the demands of our energy market.

A perfect storm

On the evening of July 7, the wind wasn’t blowing, the sun wasn’t shining, and the electricity connector that supplies power from Victoria was down for maintenance. This meant gas set the wholesale price, and gas is expensive these days, especially during a cold winter. At 7.30pm wholesale spot prices soared close to A$9,000 per megawatt hour. For the whole month they averaged A$230 a megawatt hour. They were closer to A$65 in the rest of the country.

Australia has committed to a target to reduce greenhouse gas emissions by 26-28% below 2005 levels by 2030. Despite this well known and significant target, the national debate on climate change has been so toxic and so destructive that almost no policy remains to reduce emissions from the power sector in line with that target.

By 2014 the much maligned renewable energy target (RET), a Howard government industry policy to support renewable energy, remained as the only policy with any real impact on the sector’s emissions.

Wind power has been the winning technology from the RET, and South Australia has been the winning state. Wind now supplies 40% of electricity in South Australia due to highly favourable local conditions. Because wind has no fuel costs it suppressed wholesale prices in the state and forced the shutdown of all coal plants and the mothballing of some gas plants. But wind is intermittent – it generates power only when it is blowing, and the night of July 7 it barely was.

A report by the Australian Energy Market Operator noted that the market did deliver on reliability and security of supply in July. It reviewed the behaviour of market participants and concluded there were “no departures from normal market rules and procedures”.

The events of July do not expose an immediate crisis, but they have exposed the potential consequences of a disconnection between climate change policy and energy markets. If it is not addressed, the goals of reliable, affordable and sustainable energy may not be achieved.

The bigger problem

Climate change policy should work with and not outside the electricity market. With a fixed generation target of 33,000 gigawatt hours of renewable electricity by 2020 and a market for renewable energy credits outside the wholesale spot market under the RET, the conditions for problems were established some time ago.

The specific issues that arose from the design of the RET would have been far less problematic if one of the attempts over the last ten years to implement a national climate policy had been successful. A rising carbon price would have steadily changed the relative competitiveness of high and low emissions electricity sources and the RET would have quietly faded.

The first lesson for governments is that we need to establish a credible, scalable and predictable national climate change policy to have a chance of achieving emissions reduction targets without compromising power reliability or security of supply. A national emissions trading scheme would be best, but pragmatism and urgency mean we need to consider second best.

While such an outcome is the first priority, it will not provide all the answers. The rapid introduction of a very large proportion of new intermittent electricity supply creates problems that were not foreseen when traditional generation from coal and gas supplied the bulk of Australia’s power needs.

All of the wind farms in one state could be offline at the same time – a far less likely event with traditional generation. The problem can be solved by investment in storage and in flexible responses such as gas and other fast-start generators. Commercial deals with consumers paid to reduce demand could also contribute.

Lower average prices combined with infrequent big price spikes are not an obvious way to encourage long-term investors. The market may find solutions with new forms of contracts for flexibility or the market operator could introduce new structures or regulations to complement the existing wholesale spot market.

Much uncertainty exists, no easy fixes are in sight and the consequences of failure are high. Getting it right will provide clear signals for new investment or for withdrawal of coal plants as flagged by speculation over the future of the Hazelwood power station in Victoria.

Josh Frydenberg, as the new minister for the environment and energy, and his fellow ministers on the COAG Energy Council would be unwise to waste a near crisis.

Tony Wood owns shares in energy and resources companies via his superannuation fund

The Hazelwood power station has been named Australia's 'dirtiest' for its carbon emissions. Takver/Flickr, CC BY-SA

Over the weekend Fairfax media reported that the Hazelwood power station in the Latrobe valley could close as early as next April. Senior management at Engie, the French company which is the majority owner of the brown coal-fired power plant, has emphasised that no decision has been made yet.

As was the case with the Northern Power station in South Australia, the imperative to close Hazelwood has evidently come from the company’s board.

Earlier this year, Engie, the majority owner of Hazelwood, flagged it was considering closing or selling the plant. But at this point, no timeline for closure was suggested. Now it seems that Engie is planning to make a decision on the future of the plant at its board meeting in October.

There are many factors that would be contributing to their deliberation. These include, but are not limited to, the plant’s age, changes in the electricity market, and an erosion of the social license to operate, courtesy of long running campaigns from environment groups such as Environment Victoria.

Commissioned in the late 1960s, the power plant is almost 50 years old and one of the oldest coal-fired power plants still operating in the National Electricity Market (NEM). Smaller coal plants of similar age have closed in recent years, including Playford B in South Australia and Anglesea and the Morwell Energy Bricks Complex in Victoria.

Increasing amounts of renewable energy, and expected future increases would also be weighing on decisions to close. As has been well documented, there has been be an oversupply of electricity capacity in recent years. This has the effect of lowering wholesale prices and is exacerbated by increasing renewable energy generation.

What is interesting about both the potential closure of Hazelwood and the closure of Northern and Playford in South Australia, is that these have occurred in the absence of schemes like the (failed) “contracts for closure” and ANU professor Frank Jotzo’s proposal for brown coal exit.

On the one hand, this is good news for taxpayers and consumers. To date, the companies that own these assets are not being paid to close. On the other hand, the decision is made at the company level, without consideration for local workers and communities.

What would replace Hazelwood’s output?

Hazelwood has historically generated about 11-12 terrawatt-hours of energy each year. This is approximately 20% of all energy generated in Victoria, and 5% of energy generated in the National Electricity Market.

Like other brown coal power stations, Hazelwood produces cheap electricity (if we ignore carbon emissions). As a result, these power stations are used a lot (on average at more than 80% of their total capacity) and Victoria is a significant net exporter of energy.

Victoria exported 8.5 terrawatt-hours of electricity in 2014-2015 and 7 terrawatt-hours in 2015-2016, representing about 70% of Hazelwood’s output. A large share of this (approximately 5 terrawatt-hours) flowed to New South Wales.

If Hazelwood closes, the flows might substantially change. Generation in New South Wales could be expected to increase.

New South Wales is dominated by black coal generation, which is slightly more expensive that brown coal, and currently is used relatively infrequently. Over the past five years, NSW’s black coal power stations have operated at approximately 50% of their total capacity on average.

The idle black coal capacity in NSW alone could more that replace the energy output of Hazelwood.

But coal and other fossil fuel generation is only part of the story. By 2020, a large amount of renewable generation will have to be built to fulfil the obligations of the national Renewable Energy Target.

And the Victorian government’s Renewable Auction Scheme will see 5,400 megawatts of new renewable energy built in Victoria alone by 2025. This 5,400 megawatts will produce approximately 30% more energy than is currently delivered by Hazelwood.

What about emissions?

Hazelwood is also the most emissions-intensive coal generator still in operation in Australia. In fact it was previously identified by WWF as the most emissions-intensive generator in the major industrialised nations.

Based on current emission intensity estimates, Hazelwood produces around 15 million tonnes of CO₂ emissions per year, approximately 2.8% of Australia’s emissions.

However, this does not represent the overall emissions impact in the short term. In a high emissions scenario, the output of Hazelwood might be entirely replaced by NSW black coal (assuming the remaining brown coal power stations cannot dramatically increase their output). In this case, the total emissions from the electricity sector might reduce by only 5.5 million each year.

So, while we don’t know whether Hazelwood will close yet, we do know that Australia could easily replace the energy, and it could make a substantial difference to our carbon emissions.

The Melbourne Energy Institute, the Grattan Institute, the EU Centre on Shared Complex Challenges, GEE-21, the Australian-German Climate and Energy College, and ATSE are holding a symposium on Australia’s Electricity System: Transition to 2030 this week.

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

Australia’s offshore petroleum industry regulator is set to rule next week whether to grant oil giant BP’s application to drill in the Great Australian Bight.

But BP’s environmental plan, released last week, suggests that the company’s proposed plan for dealing with a blowout displays less urgency than would be expected in some other parts of the world.

If a blowout does occur, BP proposes to cap it with a piece of equipment known as a capping stack. These devices did not exist at the time of BP’s Gulf of Mexico blowout in 2010, when a capping strategy had to be developed on the run, which is why it took 87 days to cap that well.

Since then, capping stacks have been designed, constructed and located strategically around the world. For its proposed operations in the Bight, BP would have access to a capping stack in Singapore. It would take up to 35 days to bring this stack to the Bight and cap the well.

The company has rejected the suggestion that a capping stack be located locally. It claims that the time needed to transport the device from Singapore to the Bight is not a critical issue. In its earlier environmental plan, released last October, BP said that capping a blowout would require significant preparatory work, by which time the Singapore capping stack would have arrived.

Yet the idea of spending more than a month to plug a flowing well hardly seems compatible with avoiding major environmental damage. According to BP’s own estimate, oil from a spill in the Bight could reach the shore in as little as nine days.

A recent exercise in the Gulf of Mexico shows that a blowout could be capped in 15 days, using a locally available capping stack. In this respect, BP’s estimate of the time it would take to cap a blowout is a long way short of industry best practice.

Whether or not travel time from Singapore is the critical issue, it is worth noting that there are five different capping stacks available for use in the Gulf of Mexico and three for use in UK waters. The expectation is that these stacks could be on site within 24-48 hours.

Note also that new rules imposed by the US regulator for drilling in the Arctic require that a capping stack be located within 24 hours' travel time of the drill site. If the Arctic justifies this level of protection, why not the Bight?

Drilling a relief well

Should the capping strategy fail for any reason, BP has a backup plan for stopping the flow. This is to drill a relief well to intersect the blowout well below the sea floor and “kill” it by pumping it full of heavy fluid or cement.

The question this raises is: where would BP find a spare drilling rig to carry out this operation? After the Montara blowout off Western Australia in 2009, a suitable drilling rig was located near Singapore. But this rig would have been no use in the deep water of the Bight.

Oil companies operating in Australian waters have a memorandum of understanding among themselves to provide a suitable drilling rig in an emergency. Yet it remains unclear how easy it would be for another company to release a rig quickly for this purpose. As such, BP has assumed that it will take up to 149 days to acquire an appropriate rig, drill a relief well and plug the blowout.

The new Arctic regulations require that a relief rig be available nearby, to guarantee that a relief well can be drilled before winter sea ice moves in. The situation in the Bight is not as constrained by the seasons, but even so, 149 days seems an unacceptably long time to plug a well.

The Gulf of Mexico blowout was stopped in 87 days, during which time it inflicted damage worth at least A$40 billion. Who knows what the toll would have been if it had lasted almost twice as long?

Protecting the shore

Finally, BP has various strategies for reducing the amount of oil reaching the shoreline in the event of a spill. These include using dispersant chemicals, both subsea, at the point of release, and on the sea surface. The company puts particular emphasis on subsea dispersal, but recognises that this strategy would also be subject to delay.

It estimates that subsea dispersal would begin within 10 days “where that is possible”. This can never be a fully effective way to prevent coastal pollution, because BP’s modelling suggests oil would begin arriving on the coast in less time than this.

BP has also noted that traditional methods of containment and recovery of oil using booms and skimmers “are not expected to provide significant benefit” in the open ocean.

What seems more likely in the event of a spill is that the company will find itself fighting a last-ditch battle against the oil as it approaches sensitive parts of the shoreline, and where this fails it will implement shoreline and oiled wildlife clean-up.

It is difficult to forecast any other scenario, given the time frames described in BP’s own documents. Its published response plan gives no guarantee that an oil spill in the Bight would not reach the shoreline and damage the environment.

Experience elsewhere in the world suggests that these timelines can be tightened. The question for the regulator is whether BP has reduced the risk to a level that is “as low as reasonably practicable”.

It is by no means obvious that the answer is yes.

Andrew Hopkins is the author of Disastrous Decisions: The Human and Organisational Causes of the Gulf of Mexico Blowout.

Andrew Hopkins 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.

Many businesses are committing to sourcing all of their energy from renewable sources. Wind farm image from www.shutterstock.com

The Paris climate agreement is getting closer to coming into force. This week 31 countries ratified the deal, including Brazil (the world’s 12th-largest greenhouse gas emitter), the United Arab Emirates and Bangladesh.

To become official, the deal requires 55 nations representing at least 55% of global emissions to ratify it. The current tally sits at 60 nations and 47.76% of emissions. Others are expected to ratify in coming months.

But outside of national action, businesses are shaping up to be leaders on climate. Alongside the UN General Assembly this week, representatives from national governments and businesses met in New York for the first post-Paris Climate Week.

Among an elite line-up of corporate heavyweights, including Bank of America, Philips, Apple and Siemens, all have made carbon-neutral commitments by 2020 or 2030. This means they will offset emissions that they can’t reduce.

There has been a convergence of political, technological and environmental understanding: a low-carbon economy is no longer a trade-off or threat. It’s an opportunity. And it is happening now.

New commitments

Identifying the urgent need for energy transition, 81 multinational companies have signed on to RE100, committing to 100% renewable electricity across their global operations.

Launched at Climate Week 2014 by The Climate Group and CDP, this initiative includes companies representing a wide range of sectors. Among them are Amalgamated Bank, Ikea, General Motors, Swiss Re, Goldman Sachs, BMW Group, Google, Aviva, P&G, Walmart, Nestle, Microsoft, SAP, Adobe, Bloomberg, H&M, Hewlett Packard, Novo Nordisk, ING, Unilever and Apple.

In addition to achieving 97% renewable electricity across its global operations, Apple is also working actively with its suppliers to increase renewable uptake. Apple is bringing necessary expertise and capability to help a number of its suppliers reach 100% renewable electricity for its products by 2018.

A new and complementary initiative, EP100, attracts companies that commit to a 100% increase in their energy productivity. This mirrors a global campaign calling for governments to double energy productivity. Led by The Climate Group and the Global Alliance for Energy Productivity, EP100 includes signatories such as Mahindra & Mahindra, Danfoss and Johnson Controls.

In its hospitality operations, Mahindra has already achieved a 46% improvement in its energy productivity. Its vice president of sustainability, Anirban Ghosh, is confident the firm will achieve 100% energy productivity improvements.

Danfoss is a global engineering company in heating, cooling and electric controls. According to John Galyen, president of its North American business, improving energy efficiency and energy productivity makes good business sense, both in cost savings and revenue growth.

These corporate voices are global, and their actions will flow through their global activities and supply chains. Australian corporations can be expected to follow these global trends.

Investors are also becoming leaders, increasing efforts to improve disclosure of climate-related risks. Leading disclosure groups met in New York with pension funds and asset managers to contribute to a climate disclosure task force of the Financial Stability Board.

This board, run by governors of national reserve banks and finance ministers, is working to develop a way for companies to disclose their exposure to risks associated with climate change.

The role of government

Public and private sectors have equally important leadership roles. The relationship must be symbiotic. In the same way that business leadership gives governments confidence to introduce ambitious policies, governments can also provide businesses with confidence through demonstrating leadership.

There is a resounding call for governments to provide greater certainty. Clear carbon and financial signals are needed to support major investments in the energy sector.

There have been some heartening moves in this respect. The United States, Canada and Mexico agreed recently to source half of their electricity from low-carbon sources by 2025, and to cut methane emissions from the oil and gas sector by almost half over the same period.

At the sub-national level, local, state and provincial governments are making decisive moves towards the end goal of net zero emissions. Alberta in Canada is home to 11% of the world’s oil reserves, but plans to peak emissions in the next five years while the economy continues to grow.

In Australia, Victoria, the ACT and South Australia have all committed to net zero emissions by 2050, with the latter supporting Adelaide to become the world’s first carbon-neutral city.

The next display of international leadership will be measured in November at the next UN climate summit in Marrakech, Morrocco. While previous meetings leading up to Paris were platforms for negotiation, the next will play a key role in implementing the deal. As we all know, actions speak louder than words.

Wei Sue 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.

Getting around on a bike, a (mostly) fun way to travel green Bike riding image from www.shutterstock.com

When you’re on holiday, relaxing on a beach or soaking up a vibrant city’s culture, the last thing you want to think about is your responsibility to the planet. But carefree holidays are a luxury that is costing more than our bank balances. The food and services sectors are major contributors to greenhouse gases. Tourism, often an expression of our modern hedonic desires, is particularly high in resource use.

But it can be hard to change people’s behaviours. For instance, would you choose a holiday marketed for its low energy and material needs? What about if you could have a 5-star holiday without costing the Earth?

Our research on tourist behaviour shows that people are happy to curb their material consumption on holiday, as long their holiday is rich in other experiences.

This is the challenge that the services sector faces in the drive to decouple happiness, consumption and resource depletion or pollution.

The consumption issue in the services sector

While many of us advocate for the tourism sector to reduce its carbon footprint, efficiency in energy use is not going to be enough to make tourism sustainable.

The call to switch to sustainable consumption is growing, often through combining a degrowth economic model with the decoupling of material consumption from well-being and happiness.

But these ethical and moral considerations around sustainable consumption appear to have relatively little substantial effect in the long term. For the services sector, particularly, the predicament to become more sustainable directly involves the customer.

Asking customers to consume more critically might be a confronting prospect for an industry worried about maintaining customer satisfaction in a consumerist society. But not always.

Showing strength of character

Our solution lies in applying positive psychology. People get fulfilment from using their own character strengths. It builds on the evidence that focusing on character strength-building and human happiness works better than any other approach when it comes to sustainable change.

So, can this be applied to tourism, a sector driven by its promise of carefree behaviour? What would a luxury tourism experience, designed around less material consumption and the application of character strengths look like? And what impact would it have on guests’ experience and sustainable tourism practices?

Our research suggests there are many ways that guests can become involved in making tourism green, using their innate character strengths. We applied these principles to six real-world examples from Christopher’s ecotourism venture.

Guests save their food scraps and feed them to the chickens. They get to meet their feathered friends and collect eggs (often for the first time). Result: together with recycling bins has halved landfill waste and sustains egg production.

Guests apply strength of self-regulation as they have to regulate behaviour by separating food waste the chickens can eat from other waste, placing it into a container and then visiting and feeding the chickens. There are no financial incentives; the motivation is to reduce harmful landfill waste.

Plant a native tree. The host provides interpretation and materials; guests pay $5 for materials, plant trees and take photographs. Guests receive a certificate and sign a register. Result: bird species increased from 20 to 50 on site and guests physically connect to the soil.

Guests apply strength of hope as they feel a healthy environment is something that can be achieved by their contribution. Hope increases when planting their tree after seeing trees maturing about them, the result of previous guests’ plantings.

Choosing a siesta and staying up later. Host provides ceiling fans, cool drinks in fridge (made from the property’s own limes) and attractive al fresco barbecue setting. This encourages guests to rest in the hottest part of the day, then enjoy cooler extended evenings outside connecting with nature. Result: contributes to 30% electricity saving.

Guests apply strength of citizenship as they acknowledge their social responsibility to consume less, change their behaviour to do their bit to minimise resource use, and share the experience as a group.

Sleeping is good for you, and the environment. Hammock image from www.shutterstock.com

Selecting natural ventilation at night instead of air conditioning. Host explains how to use the natural ventilation in the accommodation, as cooler night air in summer means cottages are 4℃ cooler in the morning. Result: contributes to 30% electricity saving and guests hear charming frogs at night.

Guests apply strength of social intelligence as often they are fearful for their security at night and prefer to have windows locked. They acknowledge this conflicts with the need to consume less and not rely on the air conditioning. Accepting their concerns, they adapt and use natural ventilation in an uncommon location.

Host explains rainwater harvesting resource limitations and benefits of homemade aromatherapy bath treats. Guests choose to share baths or rotate bath use. Result: contributes to 25% gas and water saving while the aromatherapy recipes use natural essential oils and offer guests long-lasting scents.

Guest applies strength of leadership as they try to apply pro-environmental action and encourage other members of their party to change their bathing routines.

Choosing greener travel. Guests can choose not to drive but use the complimentary bicycles and buy a picnic of locally sourced treats. Guests relax and reconnect. Result: memorable experiences (including proposals of marriage!) and less carbon dioxide car pollution.

Guests draw on strength of zest to choose to ride a bicycle (which they may not have done for some time) and joyfully discover the peaceful lanes and the invigorating ride.

In sum, targeting character strengths such as self-regulation, citizenship, hope, perspective and social intelligence may be an effective way to drive change towards more sustainability-oriented behaviours.

Happy, frugal tourism

Today people want personalised travel experiences. Here lies the opportunity for business people seeking to build their brand in the most sustainable way possible.

Involving people in creating a sustainable tourism experience can lead them to behaviour in new, fun ways. Examples like Coral Cay Conservation, Echidna Walkabout and Chepue Ecolodge all directly involve the customers to help conserve resources.

This year commemorates 20 years of the Responsible Tourism movement. Tourism is slowly evolving and with it opportunities for individuals to apply new knowledge and skills which can become transformational experiences. These small actions (known as the “Copenhagen effect”) can make a significant difference.

By introducing positive psychology into the design of tourism experiences, guests willingly and happily trade in their material consumption for forms of non-material consumption that benefit them, their health and the environment, allowing the services sector to ask customers to tread more gently and happily.

Christopher Warren is a partner in Crystal Creek Meadows, and consults in sustainable & responsible tourism accommodation. He is affiliated with International Centre for Responsible Tourism and a member of the Griffith Institute For Tourism Advisory Board.

Alexandra Coghlan 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.

Images of this year’s coral bleaching on the Great Barrier Reef shocked the world. Some tour operators expressed concern that the extensive and sometimes simplistic media coverage would hurt their businesses.

The reef was a hot-button issue during the federal election, with both major parties pledging funding for programs to enhance water quality. Some politicians and tour operators expressed optimism about the reef’s ability to recover.

It was the culmination of the longest, most extensive and most severe mass coral bleaching event ever recorded – an event that began in the North Pacific in mid-2014. The Great Barrier Reef was not spared, this year experiencing its hottest sea surface temperatures since records began – 29.1℃ in February (1.1℃ above the 1961-90 average), 29.1℃ (1.3℃ above average) in March and 27.8℃ (1.0℃ above average) in April.

Evidence of bleaching was found on 93% of the more than 900 individual reefs surveyed that month, with the most severe impacts on the most pristine and isolated reefs of the far north. A preliminary estimate is that 22% of coral has now died, with 85% of these deaths occurring between Cape York and just north of Lizard Island.

Map of the extent of coral bleaching observed on the Great Barrier Reef. GBRMPA/AIMS/Commonwealth Government/Queensland Government

At the height of the bleaching, the Climate Council’s chief executive, Amanda McKenzie, and councillor Tim Flannery visited a reef off Port Douglas that local tour operators have long regarded as one of the best – the quintessential underwater wonderland.

Amanda and Tim reported their shock and anger at what they saw – extensive areas of corals bleached brilliant white (see the Climate Council’s May 2016 report for a summary of the bleaching).

Several months later, the public’s shock and outrage has largely dissipated, but the question remains: are there signs that the reef’s hoped-for recovery is actually happening?

Reef revisited

This week, I joined Tim and Amanda in revisiting the site that had so dismayed them back in April. We were guided by the passionate conservationist John Rumney, who has been diving here for more than 40 years. John’s son-in-law Dean Miller was our videographer, above and below the water.

It was a beautiful day on the reef – calm and sunny. We noted that it was three years to the day since the incoming Abbott government sacked the Climate Commission – which in turn led to the establishment of the ongoing Climate Council.

Wet-suited, we slipped into the water and paddled towards the coral, our progress monitored by a drone buzzing overhead like some giant, demented mosquito.

So what did we find? Structurally, the reef appears intact, but the whole landscape is, well, subdued. While pockets of brilliant blue staghorn remain, much of the coral that bleached earlier this year is dead, the white skeletons filmed over by greenish-brown filamentous algae.

The fish community has also changed. Algae-eating species such as surgeon fish are doing well, but coral-feeders are hardly to be seen – I spotted only a single parrot fish in an hour of snorkelling. Meanwhile, the corals themselves seem to be showing symptoms of white spot and white band diseases, conditions associated with their diminished immune systems after the stress of bleaching.

The mood on the boat after the snorkelling was also subdued. The locals had not visited this particular reef since the height of the bleaching. Having now seen the extent of the coral death that has resulted, they fear this will eventually weaken the structural integrity of the reef, making it susceptible to future damage from storms.

This November’s spawning will hopefully reseed the reef, but our companions on the trip acknowledged that any repeated bleaching within the next few years will greatly reduce the chances of recovery.

As our boat pulled away from the reef, another took its place, full of tourists donning their snorkelling gear. I found myself hoping that most of them were first-timers – unencumbered by memories of the reef’s former glory.

Back in the real world, Australia’s greenhouse emissions continue to rise (by 1.1% in 2014-15) and the government’s current target of reducing emissions 26-28% below 2005 levels by 2030 is manifestly inadequate, even if achieved.

The continued burning of coal, oil and gas is estimated to have made the bleaching on the Great Barrier Reef this year at least 175 times more likely. At present rates of climate change, this level of bleaching could occur every two years by the 2030s. That would make recovery between events virtually impossible.

The forlorn, diminished state of Australia’s greatest natural treasure must continue to serve as a visible warning of what we stand to lose. The new normal is a very sad place to be.

Lesley Hughes is affiliated with WWF-Australia (Board member and member of Eminent Scientist Advisory Group), Wentworth Group of Concerned Scientists, Climate Council of Australia

Carbon dioxide standards for cars are the cheapest way to cut emissions. Car exhaust www.shutterstock.com

The Australian government has started looking into carbon dioxide emissions standards for light vehicles, as part of new measures to meet the nation’s 2030 climate targets.

However, some are already questioning the use of standards, with media reports pointing to higher costs for new car buyers and the possibility of the government bungling the introduction of standards.

Ministers Josh Frydenberg (energy and environment) and Paul Fletcher (urban infrastructure) have acknowledged these concerns, stating that “the reform agenda raises issues which need to be carefully considered including for their impact on motorists, the automotive sector and others”.

In 2015, new Australian vehicles produced an average of 184 grams of CO₂ for each kilometre. Introducing a standard is the cheapest way to cut carbon emissions in Australia’s economy.

At ClimateWorks Australia, we’ve long been calling for best-practice standards for new light vehicles. This has been supported by Global Fuel Economy Initiative, Future Climate Australia, and other environmental groups. Indeed, the latest report from the Climate Change Authority also recommended a mandatory CO₂ emission standard.

Our research shows that the introduction of emission standards for light vehicles has considerable benefits for motorists and Australia more broadly.

So let’s look at five key concerns and why light vehicle CO₂ emission standards should be introduced in Australia.

Emission standards will cuts costs for drivers

Based on a conservative estimate, we estimate that more efficient vehicles would add A$2,500 to the upfront costs for motorists (the Climate Change Authority estimates A$1,500). However, our research shows that the average driver could recoup these within three years through fuel savings, or even sooner for fleet drivers travelling greater distances. These payback periods are well within the average ownership periods for new cars.

With best-practice vehicle emission standards in place, by 2025 the average vehicle owner driving 14,000km a year would achieve annual fuel savings of up to A$850, while a fleet driver averaging 20,000km each year would save up to A$1,200.

Emission standards are the cheapest way to cut carbon

ClimateWorks’ Low Carbon Growth Plan for Australia and a range of other studies shows that reducing emissions from cars and light commercial vehicles through better fuel use is the cheapest way to reduce emissions across our economy.

Our analysis shows best-practice standards for new light vehicles, equivalent to 130g of CO₂ per km in 2020 and 95g CO₂ per km in 2025, would reduce CO₂ emissions by about 100 million tonnes from 2020 to 2030. This is bigger than the 76 million tonnes of CO₂ previously identified by the federal government.

Currently Australia is one of the few remaining developed countries without light vehicle CO₂ emission standards in place, with standards covering over 80% of the global automotive market. Any delay in implementing CO₂ emission standards will lock-in less efficient vehicles, resulting in higher costs to consumers, and higher emissions.

We don’t have to wait for better testing

The Volkswagen emissions scandal has increased scepticism about introducing standards here. The scandal highlighted the issue that laboratory testing of emissions does not reflect on-road driving conditions resulting in an overestimate of actual emissions reductions.

In fact, a recent report found completely legal inconsistencies between testing and on-road use in car models across Europe.

Some argue that Australia should do nothing until a better testing system has been developed to address these issues. However, even taking into account the fact that on-road emissions may possibly be higher than what current standards testing show, Australia would still improve the efficiency of its vehicle fleet by 50% with standards in place.

Fuel quality standards won’t get in the way

Some groups argue that Australia’s lack of low-sulfur fuel could be a roadblock in meeting future new vehicle CO₂ standards and that we need to have more stringent fuel quality standards in place before we look to introduce CO₂ standards.

Vehicles do run more efficiently with low-sulfur fuel, meaning they produce less CO₂. However, the sulfur content of our current fuel quality standards does not present an obstacle for vehicle efficiency technologies for compliance with CO₂ standards. The International Council on Clean Transportation has stated that Australia’s fuel quality now doesn’t present any impediment to reduce vehicle emissions at rates comparable to the other regions of the world.

As improving fuel efficiency now is shown to be cost-effective and technically feasible, we shouldn’t delay the implementation of CO₂ emission standards. Our research shows that any delay in improving vehicle emissions standards will lead to a level of emissions lock-in – where a larger proportion of vehicles on our roads will be less efficient than they would be with standards in place – reducing the potential by which vehicle emission standards can contribute to Australia’s emission reduction targets.

Australians will have more choice

The introduction of best-practice emission standards does not mean that drivers will have less choice. Under emissions standards, manufacturers are required to meet an average emissions standard across the entire fleet. This allows manufacturers to provide a range of models so long as the average emissions of the fleet as a whole does not exceed the agreed standard.

Rather than limit consumer choice, standards should increase the availability of more efficient vehicles into the Australian market and continue current trends of increasing the number of green vehicles.

The federal government has the opportunity to introduce best practice emission standards for light vehicles. If designed well, in collaboration with industry and consumers, it presents a significant opportunity to reduce emissions from the transport sector while providing benefits for vehicle owners and the broader economy.

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.

Crocodiles are protected in Australia, but it wasn't always so. from www.shutterstock.com

Crocodiles are protected in Australia. These impressive, if dangerous, animals are icons of the north. But it wasn’t always so. Crocodiles used to be hunted freely in northern Australia, an activity that led to their decline and eventual protection.

There have been calls to cull crocodiles to improve safety, but experts argue that this will make little difference to the risk. Besides, crocodiles are already sustainably farmed for leather products.

However, there are also calls – for instance, from federal MP Bob Katter – to allow crocodiles to be shot for safari. Selling hunting licences worth thousands of dollars to rich shooters, the argument goes, could provide vital income.

But this ignores Australia’s history of crocodile hunting.

Crocodile hunters in the Northern Territory. Australian News and Information Bureau, July 1968/National Archives of Australia, CC BY Postwar crocodile hunting

Immediately after the second world war, .303 rifles were widely available and were capable of reliably killing crocodiles. Crocodile skins suddenly increased in value — the Australian crocodile-hunting boom was the result.

The boom attracted hunters from southern Australia, including new immigrants. Some made significant amounts of money as the price of crocodile skins rose, but the prospect of adventure was often a far more significant lure. For many, coming north to hunt crocodiles was a working holiday combined with a boy’s own adventure. It was also an opportunity for men restless from the war to put off settling back into domesticity.

Australian News and Information Bureau, July 1968/National Archives of Australia, CC BY

That mood of adventure was captured in a 1956 home movie, aptly titled Northern Safari. Shown as a feature film, it packed cinemas in Australia and overseas. Northern Safari documented a family trip north and showed the accessibility of hunting in northern Australia to anyone with the time and practical skills to get there.

In addition to this accessible but rugged style of hunting, some postwar entrepreneurs began to offer organised hunting. Aimed at people with more money, less time and a greater desire for comfort, the commercial Australian safari was born.

The Australian Crocodile Shooters’ Club actively promoted safari cruises to hunters who wished to shoot in luxury. In 1952 it established one of Australia’s first safari camps in the Gulf of Carpentaria.

However, the Australian safari at this time was less exclusive than the original African version. While expensive, hunters might subsidise their holidays through the sale of crocodile skins – and the services and amenities provided could not be described as truly luxurious.

Safari hunting in the present

Nevertheless, the Australian safari has evolved since the ban on crocodile hunting and has taken its place among international safari organisations. Safari operations cater to visiting sportsmen by providing access to introduced species and game fish. The Australian experience is one of many such distinct experiences promoted at the annual Safari Club International convention.

An NT croc hunter in 1949. National Archives of Australia, CC BY

New Zealand provides an example of how such tourist trophy hunting operates. Based on privately owned red deer estates, some hunting providers sell clients the right to hunt an animal selected for its probable value under the Safari Club International scoring system.

Estate deer are bred for their trophy value and their antlers command scores unmatched by red deer found on public land. Access to them is limited and the cost of hunting one of the highest-scoring stags is more than NZ$20,000. Estate deer hunting is largely invisible to ordinary New Zealand hunters.

Despite the enthusiasm of proponents, there is widespread unease about the killing of big game. As with the red deer industry in New Zealand, the safari industry in Australia at present depends on introduced species of game, and so avoids controversy.

Overseas the death of Cecil the lion brought public unease about big game hunting into the open, as did the participation of touring New Zealand rugby players in a legal hunt in South Africa. Privileged access to native game and the killing of large native animals for sport has been made more visible by the sharing of images via the internet, and that visibility has demonstrated widespread public unease with the safari.

So who gets to hunt?

Scientific commentators agree that crocodile culling is unlikely to decrease the number or severity of crocodile attacks on humans in Australia. Neither is hunting crocodiles in Australia about managing an introduced pest.

A croc hunter stuffing crocodiles for sale in 1949. National Archives of Australia, CC BY

Instead, it is desirable because of the adventure involved, because for some hunting provides a meaningful connection with nature and because for others killing large animals brings prestige. These motivations aren’t being discussed.

If the crocodile safari were to be re-established in Australia it wouldn’t be the freely available experience it once was. Modern safari hunting is expensive and the preserve of only a few. Australians need to consider if they really wish to entice elite international hunters to Australia using a native species (even one as unlovable as the saltwater crocodile) as prey.

Claire Brennan 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.

Invasive species are a threat to wildlife across the globe – and invasive, predatory mammals are particularly damaging.

Our research, recently published in Proceedings of the National Academy of Sciences, shows that these predators – cats, rats and foxes, but also house mice, possums and many others – have contributed to around 60% of bird, mammal and reptile extinctions. The worst offenders are feral cats, contributing to over 60 extinctions.

So how can we stop these mammals eating away at our threatened wildlife?

Counting the cost

Our study revealed that invasive predators are implicated in 87 bird, 45 mammal and 10 reptile extinctions — 58% of these groups’ contemporary extinctions worldwide.

Invasive predators also threaten 596 species classed as vulnerable, endangered or critically endangered on the International Union for the Conservation of Nature Red List. Combined, the affected species include 400 birds, 189 mammals and 149 reptiles.

Twenty-three of the critically endangered species are classed as “possibly extinct”, so the number of extinctions above is likely to be an underestimate.

Until now, these shocking statistics have been unknown, and the heavy toll of invasive predators on native biodiversity grossly underappreciated. Species extinctions attributed to invasive predators include the Hawaiian rail (Zapornia sandwichensis) and Australia’s lesser bilby (Macrotis leucura).

Australia’s lesser bilby, now extinct. Who are the worst offenders?

We found that three canids (including the red fox and feral dogs), seven members of the weasel family or mustelids (such as stoats), five rodents, two primates, two mongooses, two marsupials and nine species from other families negatively impact threatened species. Some of these species, such as hedgehogs and brushtail possums, don’t immediately spring to mind as predators, yet they are known to prey on many threatened species.

Feral cats threaten the most species overall (430), including 63 that have become extinct. This equates to one-quarter of all bird, mammal and reptile extinctions – making the feral cat arguably the most damaging invasive species for animal biodiversity worldwide.

Five species of introduced rodent collectively threaten 420 species, including 75 extinctions. While we didn’t separate out the impacts of individual rodent species, previous work shows that black rats (Rattus rattus) threaten the greatest number of species, followed by brown rats (R. norvegicus) and Pacific rats (R. exulans).

The humble house mouse (Mus musculus) is another interesting case. Despite their small size, house mice have been recorded eating live chicks of albatrosses, petrels and shearwaters.

Other predators that threaten large numbers of species are the domestic dog (Canis familiaris), pig (Sus scrofa), small Indian mongoose (Herpestes auropunctatus), red fox (Vulpes vulpes) and stoat (Mustela erminea).

Invasive mammalian predators (clockwise from top left): feral dog, house mouse, stoat, feral pig, feral cat, brushtail possum, black rat, small Indian mongoose and red fox (centre). Clockwise from top-left: Andrey flickr CC BY 2.0 https://flic.kr/p/4M2E7y; Richard Adams flickr CC BY 2.0 https://flic.kr/p/7U19v9; Mark Kilner flickr CC BY-NC-SA 2.0 https://flic.kr/p/4D6LPe; CSIRO CC BY 3.0 http://www.scienceimage.csiro.au/image/1515; T. Doherty; Toby Hudson CC BY-SA 3.0 https://commons.wikimedia.org/wiki/File:BrushtailPossum.jpg; CSIRO CC BY 3.0 http://www.scienceimage.csiro.au/image/10564; J.M.Garg CC BY-SA 3.0 https://commons.wikimedia.org/wiki/File:Herpestes_edwardsii_at_Hyderaba.jpg; Harley Kingston CC BY 2.0 https://flic.kr/p/ceWFr7 (centre). Island species most at risk

Species found only on islands (insular endemics) account for 81% of the threatened species at risk from predators.

The isolation of many islands and a lack of natural predators mean that insular species are often naive about new predators and lack appropriate defensive responses. This makes them highly vulnerable to being eaten and in turn suffering rapid population decline or, worse, extinction. The high extinction rates of ground-dwelling birds in Hawaii and New Zealand — both of which lack native mammalian predators — are well-known examples.

Accordingly, the regions where the predators threatened the greatest number of species were all dominated by islands – Central America and the Caribbean, islands of the Pacific, the Madagascar region, New Zealand and Hawaii.

Conversely, the continental regions of North and South America, Europe, Africa and Asia contain comparatively few species threatened by invasive predators. While Australia is a continent, it is also an island, where large numbers of native birds and mammals are threatened by cats and foxes.

Along with feral cats, red foxes have devastated native mammals in Australia. Tom Rayner Managing menacing mammals

Understanding and mitigating the impact of invasive mammal predators is essential for reducing the rate of global biodiversity loss.

Because most of the threatened species studied here live on islands, managing invasive predators on islands should be a global conservation priority. Invasive predators occur on hundreds of islands and predator control and eradication are costly exercises. Thus, it is important to prioritise island eradications based on feasibility, cost, likelihood of success and potential benefits.

On continents or large islands where eradications are difficult, other approaches are needed. This includes predator-proof fencing, top-predator restoration and conservation, lethal control, and maintenance of habitat structure.

Despite the shocking statistics we have revealed, there remain many unknowns. For example, only around 40% of reptile species have been assessed for the Red List, compared to 99% for birds and mammals. Very little is known about the impact of invasive predators on invertebrate species.

We expect that the number of species affected by invasive predators will climb as more knowledge becomes available.

This article was co-authored by Al Glen from Landcare Research, New Zealand.

Tim Doherty has received funding from Earthwatch Institute Australia, Gunduwa Regional Conservation Association, Holsworth Wildlife Research Endowment, Edith Cowan University and Deakin University. Tim is affiliated with the Society for Conservation Biology (Oceania).

Chris Dickman receives funding from the Australian Research Council, the Long Term Ecological Research Network and the Threatened Species Recovery Hub of the National Environmental Science Programme.

Dale Nimmo receives funding from the Hermon Slade Foundation, the Department of Land, Water and Planning, the Department of Parks and Wildlife, Parks Victoria, and The Australian Academy of Science. He is affiliated with the Ecological Society of Australia.

Euan Ritchie receives funding from Pozible, the Australia and Pacific Science and Hermon Slade Foundations, and the Australian Research Council. Euan Ritchie is affiliated with the Ecological Society of Australia and the Australian Mammal Society.

The second-noisiest animal in the ocean, the snapping shrimp. Dr Tullio Rossi, CC BY-SA

Despite appearances, the oceans are far from silent places. If you dunk your head underwater you’ll hear a cacophony of sounds from wildlife great and small, crashing waves, and even rain. And it’s louder still for creatures attuned to these sounds.

However, humans are changing these ocean soundscapes. Our recent research showed that changes caused by people, from ocean acidification to pollution, are silencing the seas' natural noises. (We’re also filling the oceans with human noise).

This is bad news for the species that depend on these noises to find their way.

Ocean soundscapes

All over the world you can hear a lively crackling sound made by thousands of snapping shrimp that live along coastlines.

These common shrimp, often referred to as pistol shrimp, have a large claw that they can close with such force that a cavitation bubble is formed. As this bubble implodes on itself a loud snap is created – like a pistol shot – which can be heard over long distances.

In fact, snapping shrimp are the loudest marine invertebrates, and second only to the noisest marine animals, which are sperm whales! Snapping shrimp are found all over the world, including in coral reefs, kelp forests, seagrass beds and mangroves.

Other types of animals create ocean noise too. Urchins and parrotfish make clearly audible chomping sounds as they scrape algae off rocks. Many fish are frequent and loud talkers and make an array of sounds such as chirps, burps, whistles, knocks and so on. They use these to mark out their territory, during fights and to locate mates.

These biological sounds, together with those from rain, crashing waves and seismic activities, form the so-called underwater soundscape.

Learn more about marine soundscapes watching this video.

Sounds that are emitted from temperate and tropical reefs are loud and quite constant. As such these sounds form a reliable source of information for animals, particularly for navigation.

Most animals in the sea let go of their fertilised eggs without providing any parental care. As these eggs hatch, small babies (larvae) are dispersed by ocean currents. Growing up away from coastal areas provides a safer place with fewer predators.

However, after growing for a few weeks or months in the open ocean, it is time for these young animals to return to the coast to find a home. How do they find their way in the vast and uniform open ocean? Sounds and odours from coastal habitats are key cues that allow marine animals to find their new homes and replenish adult populations.

Going quiet

Humans are increasingly dominating the physical and chemical environment. We are altering the carbon cycle through the burning of fossil fuels and the nitrogen cycle by extracting vast amounts of nitrogen for food production and releasing it as waste. Large amounts of this carbon and nitrogen liberation end up in the ocean.

About one-third of the carbon dioxide that humans emit into the atmosphere dissolves in the ocean, leading to increased seawater acidity (or ocean acidification). This is an obvious problem for animals that produce a calcium carbonate shell or skeleton (such as corals, some plankton, and snails). Remarkably, ocean acidification also alters the behaviour of many animals by messing up their brain functioning.

Earlier studies (see also here) have shown that ocean acidification can change the response of fish larvae to settlement habitat sounds by deterring them rather than attracting them.

Learn more about the effects of ocean acidification on fish behaviour watching this animation video.

Two of our recent studies (see also here) showed that ocean acidification not only affects sound reception, but also the sounds that ocean ecosystems produce. If we don’t reduce greenhouse gas emissions, rocky reefs could be much quieter in 2100 than now. And snapping shrimps are the reason.

Coastal discharge of nutrients from sewage plants and catchment runoff also degrades kelp forests and seagrass beds. These coasts are more silent than their healthy counterparts.

In many parts of the world, kelp forests, seagrass beds and coral reefs have been replaced by carpets of turf-forming or mat-forming algae. These weedy types of algae have much lower diversity of species and provide less shelter and feeding opportunities for shrimps and other noisy animals.

Degraded habitat means fewer animals, which means less noise. For larvae that use sound as a navigational cue, this means that fewer larvae will be able to successfully locate their home. And fewer returning larvae means less replenishment of fish stocks.

The effects of ocean acidification on fish orientation and soundscapes. Dr Tullio Rossi Options for restoration

Climate change and ocean acidification act at global scales and are difficult to stop in the short term. In contrast, nutrient pollution is a local stressor, which makes it more manageable.

Various options exist for local communities to reduce nutrient pollution of coastal areas. These include improved sewage treatment, restoration of coastal vegetation (such as mangroves) and swamps that extract sediment and nutrients from stormwater runoff, and decreasing the use of rivers as outlets for polluted waters.

Reducing the impacts of nutrient pollution on coastal ecosystems makes these systems more robust and provides them with increased resilience to cope with the impacts of ocean warming and acidification.

Ivan Nagelkerken receives funding from The Australian Research Council.

Sean Connell receives funding from The Australian Research Council.

Tullio Rossi owns the YouTube channel where the linked videos are hosted.

The fate of the Australian Antarctic Division’s research base on Macquarie Island hangs in the balance, after last week’s surprise announcement that it would close in March 2017 was followed on Friday by a suggestion that the government could yet reprieve it.

Why all the fuss over a scattering of buildings on a windswept island (admittedly a UNESCO World Heritage-listed one) perched on a tectonic ridge halfway between Australia and Antarctica?

Macquarie Island is the perfect natural laboratory for scientific research. Unique climate, geological, biological and astronomical measurements are collected year-round. The data is fed into many large-scale, international science programs and reports, including those published by the Intergovernmental Panel on Climate Change.

It is something of an anomaly in Australia’s national Antarctic program. Unlike Heard Island, Macquarie Island lies outside the areas covered by the Antarctic Treaty and the Convention on the Conservation of Antarctic Marine Living Resources. The Tasmanian government manages the island.

The buildings at the island’s north end are home to research infrastructure and accommodation for various organisations. These include the Tasmanian Parks and Wildlife Service, the Bureau of Meteorology, and the Australian Radiation Protection and Nuclear Safety Agency, which monitors the Southern Ocean for evidence of nuclear events. These buildings are increasingly exposed to ocean inundation.

Death by a thousand cuts

Collaborations of this nature are common in Antarctic science. Budgetary decisions made in one section of the community have a direct impact on the programs of others.

This sudden closure announcement followed the harrowing CSIRO job cuts announcement earlier this year. Tasmanian Premier Will Hodgman, the Tasmanian and Antarctic science community and the Australian Greens understandably responded with dismay to last Tuesday’s announcement.

While funding to Australia’s Antarctic science program seemed assured with the long-awaited Australian Antarctic Strategy and 20-Year Action Plan this year, there is a reasonable correlation between previous successive cuts to the Antarctic program and the disrepair of Australian Antarctic infrastructure. Labor Senator Lisa Singh called this a “death of a thousand cuts”.

Competing interests

Given the huge scale of Australia’s interests in Antarctica and the Southern Ocean, there will always be competing budget priorities.

Environmental contamination from long-term human habitation, for example, is an issue common to Australia’s research infrastructure throughout the Antarctic region.

Any research in the Antarctic and sub-Antarctic must be done in a way that minimises the direct impact on the surrounding environment. Australian Antarctic Division director Nick Gales has cited the footprint of this research as one reason for withdrawal from Macquarie Island.

Environmentally sensitive replacements suited to such harsh and remote conditions are expensive. The ongoing remediation work on many old Antarctic and sub-Antarctic bases continues to cause further budgetary and logistical headaches.

Macquarie Island, Heard Island and Australia’s Antarctic Territory are notoriously difficult to access, particularly for long-term, logistically demanding tasks such as major remediation and refurbishment works. Access involves battling the increasingly unpredictable sea ice and ice airstrip conditions that already disrupt delicate resupply, search and rescue, and medical evacuation operations.

Given its position deep in the Southern Ocean, there remains a strong case for a small but permanent presence on Macquarie Island. For example, resident climate scientists have collected weekly ozone measurements for 20 years. There is a place for other Commonwealth departments, the Tasmanian government, private industry and research institutions to shoulder responsibility for maintaining this presence.

A silver lining for Tasmania?

Given successive budget cuts, precariously short-term funding of Antarctic research programs, the potential domino effect of budget cuts between collaborators and the doubt created within the community by the CSIRO climate job cuts saga, Tasmania needs to continue to build its capacity to ride out the vagaries of the federal political issues that have left it reeling over the past year.

Regardless of the current station’s fate, this could be seen as an opportunity for Tasmania’s Antarctic, climate and oceans science community to collaborate and innovate with various industries to ensure that crucial climate research and observations can continue.

By leveraging from existing programs such as the Antarctic Gateway Partnership, and with world-class scientific expertise, Tasmania is perfectly poised to innovate and invest in the areas of remote and autonomous scientific instruments, technology and data handling.

Private enterprise, including smaller non-icebreaking vessels that already operate as research and tourism platforms in the sub-Antarctic, also has a chance to fill the logistical gap.

The closure of the Macquarie Island station after almost 70 years would be sad and shocking for the generations of scientists who fondly visited “Macca”.

The continuation of a presence on the island, however, is largely a Tasmanian government responsibility. With innovation and collaboration, Tasmania can lead the way in a new, stable and less environmentally damaging era of science on Macquarie Island.

Indi Hodgson-Johnston is an Expert in Antarctic Law and Policy at the London-based Polar Research and Policy Initiative. She also works for the Integrated Marine Observing System at the University of Tasmania.