The Conversation

We are only just starting to appreciate the full sexual diversity of animals. What we are learning is helping us understand evolution and how animals will cope with a changing world.

In humans and other mammals, sex chromosomes (the Xs and Ys) determine physical sex. But in reptiles, sometimes sex chromosomes do not match physical sex. We call this “sex reversal”.

Environmental factors such as temperature can trigger sex reversal in reptiles. In our recent study, we investigated how common sex reversal is in reptiles. We concluded that it is widespread and a powerful evolutionary force.

This raises important questions about how reptiles will survive in a warming world.

Xs and Ys, Ws and Zs

In humans, sex chromosomes determine if an embryo’s physical sex is either male (XY) or female (XX).

Reptile sex determination is more complicated. Some species, including snakes, use sex chromosomes like humans do. But in other species, such as crocodiles and marine turtles, sex is determined by the temperature the eggs are raised in.

We’ve recently come to realise that many species use a combination of both. When the temperature sends opposite signals to the embryo’s sex chromosomes, sex reversal is the result. For these lizards, the sex chromosomes don’t match their physical appearance and reproductive function.

The central bearded dragon (Pogona vitticeps) is probably the best-known example of reptile sex reversal. Its sex chromosomes are named Z and W.

Male dragons have two Z chromosomes and females have a Z and W. Female dragons normally produce roughly equal numbers of male (ZZ) and female (ZW) offspring. But when the eggs are incubated in a hot environment (greater than 32℃), more females than males hatch. Some of these females from hot nests are sex-reversed.

Sex-reversed females are fully functional. In fact they produce twice as many eggs as females with female sex chromosomes. This suggests that sex reversal might actually be an advantage in this species.

Another fairly well-understood example from Australia is the eastern three-lined skink (Bassiana duperreyi).

In this species males are XY and females are XX. Although these chromosomes share the same name, they aren’t the same as those found in humans. They have arisen independently and use different genes to trigger male and female development.

In this skink, females (XX) can reverse to males, but at cool incubation temperatures, a phenomenon we’ve observed both in the lab and in a wild alpine population.

In both species, the sex with matching sex chromosomes (ZZ males in the dragon and XX females in the skink) is the one that reverses. In dragons it happens at high temperatures, and in the skink at low temperatures.

Why reverse sex?

Sex reversal can have major effects on the behaviour of an individual. Male-to-female central bearded dragons are bolder than males and females with matching sex chromosomes. This may help them find food and mates, but at the same time exposes them to predators.

Not all lizards lay eggs. Sex reversal caused by temperature is also thought to occur in species that give birth to live young, such as Tasmania’s snow skink (Niveoscincus ocellatus). In live bearers, sex reversal is caused by the environmental temperatures that a mother experiences during pregnancy.

We believe that sex reversal is widespread in reptiles. Emerging evidence suggests that environmentally induced sex reversal may also be common in fish and amphibians, playing a role in evolution of new species and having serious implications in rapidly changing environments.

We suspect the reason no one has yet fully appreciated the role of sex reversal in reptiles is because much research has focused on mammals and birds, where sex reversal is usually caused by mutations that affect gene expression during embryonic development. This has created the false impression that sex reversal is harmful to an individual.

Another reason is that many reptile species have sex chromosomes that are very difficult to tell apart. That makes instances of sex reversal very difficult to spot.

An obvious question of deep concern is whether climate change could cause extinction by reversing the sex of entire populations. For temperature-sensitive species like the bearded dragon, crocodiles and marine turtles, is the future a warmer world without males?

The answer will be different for each species. Reptile survival under climate change depends on the answer to several questions.

Can the species control when and where they nest? How quickly are environmental conditions changing? Can the temperature at which sex reversal occurs change?

Each species will face a unique path as we experience an uncertain and changing environment. Some paths will undoubtedly lead to extinction, but others may utilise flexibility in sex-determination strategies to survive.

This research was conducted at the Australian National Wildlife Collection CSIRO, in partnership with the Institute for Applied Ecology at the University of Canberra and the University of the Sunshine Coast.

Clare Holleley receives funding from the Australian Research Council and the Commonwealth Scientific and Industrial Research Organisation (CSIRO).

An emissions intensity trading scheme increases the cost of coal power compared to other electricity sources. Indigo Skies Photography/Flickr, CC BY-NC-ND

The preliminary report from the Finkel Review of electricity market security will be presented to COAG today. Leaked versions indicate that the report notes the urgent need for long-term policy certainty on climate change and that some policies (such as carbon pricing) reduce emissions at lower cost than others (renewable energy targets or regulation).

These are hardly inflammatory observations. Yet they link directly with this week’s furious debate within the Coalition government over the inclusion of a particular form of carbon pricing, an emissions intensity scheme, and whether it, and all of its relatives, should be excluded from next year’s climate policy review.

How does it work?

An emissions intensity scheme sets an intensity baseline – effectively a limit on how much carbon dioxide the generators can emit for each unit of electricity they produce.

Power stations can produce electricity above the baseline, but they would have to buy permits for the extra CO₂. Power stations that have lower emissions intensity create permits, which they can then sell.

For example, the intensity baseline might be set at one tonne of CO₂ for every megawatt hour (MWh) of electricity. A brown coal generator produces electricity at 1.3 tonnes CO₂ per MWh.

For every MWh the generator produces, it therefore has to purchase 0.3 permits. Alternatively, a wind farm that emits no CO₂ will create 1 permit for every MWh of electricity generated.

An emissions intensity scheme increases the cost of producing electricity from high-emitting generation, while reducing the relative cost of low-emitting generation. It thus drives emissions down in the electricity sector, because the cost difference favours a switch from high- to low-emitting generators.

Why this type of scheme?

Other forms of carbon pricing, such as a cap-and-trade emissions trading scheme, also increase the costs of high-emitting generation relative to low-emitting generation. But there are differences between the two schemes.

The main one is the short-term impact on prices. A cap-and-trade scheme places a price on each tonne of CO₂ emitted, which is paid to the government. Under an emissions intensity scheme, a price is imposed only on the carbon emitted above the intensity baseline.

Under a cap-and-trade scheme, our brown coal generator would have to purchase 1.3 permits for each MWh it produced, as opposed to the 0.3 it purchases under the intensity scheme.

As a result, electricity prices do not increase as much under an emissions intensity scheme as under a cap-and-trade scheme, at least in the short term. But there are drawbacks.

An emissions intensity scheme does not raise any revenue, as permits are purchased from other generators rather than the government. No revenue means no compensation to those impacted by decarbonisation.

Smaller price increases also mean that consumers are less likely to cut back on their own electricity use. This means that overall emissions will not be reduced as much as under a cap-and-trade scheme.

On the plus side, the lower price increase also means that there is less effect on overall economic activity. This can be mitigated under a cap-and-trade scheme, however, if the government uses the revenue wisely.

Bipartisan support at last?

Consulting firm Frontier Economics assisted the New South Wales government with the design of its greenhouse gas abatement scheme, an emissions intensity scheme that ran in that state from 2003 until 2012, with some success.

In 2009, Senator Nick Xenophon championed the emissions intensity approach as a better alternative to then prime minister Kevin Rudd’s proposed Carbon Pollution Reduction Scheme (CPRS). Malcolm Turnbull joined with Xenophon to attempt to persuade Rudd to adopt the scheme as an alternative to the CPRS; that attempt failed.

In the past couple of years, an emissions intensity scheme has again been advocated as a potential circuit-breaker to the climate policy impasse that has been the norm in Australia for the past decade. The electricity market rule-maker, the Australian Energy Market Commission, the Climate Change Authority and we at the Grattan Institute have all advocated for an emissions intensity scheme in the electricity sector.

This position was also reflected in the Labor Party manifesto at the last general election. While ambivalent about what form it takes, the major generation companies and business groups have all been arguing for a form of carbon pricing.

The Coalition government could get to an emissions intensity scheme in the electricity sector from its existing policies. An absolute limit on total emissions for the sector has already been set under the safeguards mechanism. Arithmetic and legislation are required to change the absolute limit to an emissions-intensity limit.

The advantages and disadvantages of an emissions intensity scheme against other forms of carbon pricing have been debated by academics, economists and policy wonks ever since Australia first committed to tackling climate change. But two things are clear.

First, an emissions intensity scheme would provide the stable carbon policy that the electricity sector needs to have investment confidence and contribute to electricity security.

Second, an emissions intensity scheme would, for some time, limit the impact on electricity prices. Apparently, these are matters of importance to both sides of politics.

Tony Wood owns shares in Origin energy and other energy and resources companies through his superannuation fund.

David Blowers 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.

Solar subsidies encouraged a massive take-up of solar panels in Australia. Solar image from www.shutterstock.com

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

This year many Australian households will find themselves cut off from generous incentives paid for electricity they export into the grid from rooftop solar systems.

Between September and December, state feed-in tariff (FiT) schemes in New South Wales, Victoria and South Australia will finish. The FiTs applying to over 275,000 customers will drop from between 16 and 60 cents per kilowatt hour to between 5 and 7.2 cents per kWh. In NSW, the replacement FiT won’t be mandatory, with retailers allowed to decide what they pay. Of course, many of those customers have already recouped their investment.

Now that our rooftop solar industry has matured, we need to reconsider the purpose of FiTs and align them with our goals for the electricity system in the future.

Why pay solar households?

FiTs have been hugely important in getting the global solar industry to where it is now. Solar electricity costs have fallen to levels that were unimaginable just 10 years ago.

Governments have traditionally used FiTs to achieve a policy aim, such as increasing renewable energy production by bridging the gap between current costs of electricity and the cost of new sources.

Australian states began to introduce mandated FiTs in 2008. There has never been a national FiT in Australia, and Queensland, NSW and the ACT no longer have mandated FiTs. However, many electricity retailers offer FiTs, even when not mandated by government.

Current state of feed-in tariffs in Australia for new customers. Authors

The costs of FiTs are recovered in different ways, depending on whether they are government-mandated or not, but ultimately they fall on all electricity consumers. As governments wind back mandated FiTs, it’s assumed that FiTs will be roughly cost-neutral.

Have they worked?

Residential solar installations soared after the introduction of FiTs in 2008. Installations quadrupled each year in Australia until 2012, leading to 11,600 jobs and the highest penetration of households with rooftop solar in the world.

Cumulative and annual installed solar PV capacity in Australia. Chapman et al 2015

This boom stimulated a competitive solar market in which residential installation costs have plummeted (as you can see below). Australia now enjoys some of the lowest installation costs for rooftop solar in the world.

Module and system installation price with number of installations. Chapman et al 2015

The trick that state policymakers missed, however, was making FiT policies sustainable.

Early FiTs were excessively high, especially in NSW and Queensland, causing policy fallout and sudden withdrawal. This was partly because the rapid reduction in solar prices exceeded expectations.

For example, the NSW government was forced into a hasty reassessment of its 2010 policy in order to prevent a cost blowout after massively underestimating the level of uptake. By October 2010, just 10 months after it began, the NSW gross FiT was slashed from 60 to 20 cents per kWh. The scheme was closed to new participants in April 2011.

Across Australia most states cut or entirely removed FiTs within four years. Most current FiTs are now well below retail prices. This means that customers are being encouraged to use as much as possible of their solar energy to power their own homes rather than exporting it to the grid. This is one of the reasons why the system size for solar installations in Australia tends to be smaller than elsewhere.

The fallout from these unsustainable FiT policies has unfortunately polarised the national conversation about solar. Hundreds of thousands of solar power system owners are facing bill shock as FiTs are withdrawn, while those who do not have solar have been told they are footing the bill for their neighbours’ systems.

Politicians have sought to capitalise on this discontent, by blaming solar tariffs for high electricity prices. In many states, the actual value of rooftop solar has been pushed out of the conversation.

The real value of solar

A recent Victorian report found that the value of solar energy depends on when electricity is fed into the grid. Solar energy is more valuable when exported to the grid at times of peak demand.

The report argued that the value of solar should account for the reduction in transmission losses (the losses associated with transporting electricity from large power plants over great distances) and environmental effects, primarily the reduction in greenhouse gases from displacing fossil fuel generation.

Solar installations can potentially add value in other ways too. For example, installing battery storage along with solar systems may allow domestic solar systems to offer other network services such as frequency and voltage control.

Encouragingly, since the report the Victorian government has bucked the national trend and announced a multi-rate FiT scheme.

The scheme offers different rates for exporting during peak, shoulder and off-peak times. It will also reward solar owners for the greenhouse gas offsets related to their system’s output. The scheme is expected to raise FiTs from around 5c per kWh to an average of between 6.5c and 7c per kWh.

What next?

Nationally, we need to refocus the conversation about the purpose and value of FiTs. Having already established a world-leading solar industry, we need to ask what FiTs can do for us now and into the future.

If we want our electricity system to take advantage of technological advances, such as battery storage, we need to repurpose our FiTs to reflect the benefits of these technologies. The Victorian example is a great step forward, providing a mechanism where consumers can leverage Australia’s low installation costs to become players in a more competitive energy market.

But there are even more benefits to distributed energy systems that could be realised with intelligently applied FiTs. This means we need more consideration of what solar systems can do for us, and less simplistic conversations about electricity costs.

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

Shelly Beach near Ballina, one of the new shark net locations, was the scene of a fatal shark attack in February 2015. Dave Hunt/AAP, CC BY-SA

The recent spate of shark attacks in New South Wales has led to the announcement by NSW Premier Mike Baird and Primary Industries Minister Niall Blair of an expansion of the Shark Meshing Bather Protection Program. New shark nets are being installed at five locations in the Ballina and Evans Head area of the state’s north coast.

However, shark nets are controversial because they are designed to kill potentially dangerous sharks. In the process, nets may also injure or kill non-target animals, including endangered and protected species.

Whether or not shark nets actually reduce the risk of an attack is also a tricky question, although there has only been one fatal attack at a netted beach since the NSW meshing program began in 1937.

While some people welcome more nets, there is increasing support for the use of non-lethal shark attack mitigation measures. This is largely driven by concerns about the potential ecological impacts of shark nets. However, there are also substantial economic and logistical constraints on deploying nets at all locations where people might enter the water.

Beyond shark nets

So what other strategies can we use? As well as large-scale initiatives to reduce the chance of shark attacks at popular beaches, such as the installation of shark-proof barriers and enhancing public awareness of attack risk, concern about shark attacks has also led to a proliferation of personal shark deterrent technologies – so much so that there are now too many to list and describe in detail.

Broadly, the devices include those that produce strong electrical or magnetic fields, those that produce a repulsive light, sound or odour, and those that reduce the visibility of the wearer to sharks.

Shark net trial locations, NSW north coast. NSW Department of Primary Industries. Can new devices prevent attacks?

Because of the upsurge in technologies being developed to reduce shark attacks, shark researchers are often asked which are the most effective deterrent devices and which do not work.

However, many of these technologies are still in development. Fewer still have undergone independent testing of their effectiveness in deterring sharks under different conditions. This means that the general public have limited information when deciding if a particular shark deterrent might be suitable and whether it is worth purchasing, especially given that most commercially available devices cost several hundred dollars.

Our current research focuses on the new generation of magnetic and electrical deterrents, especially those designed to be used or worn by surfers and swimmers. We will test these devices in the field with white sharks to assess their efficacy. In the case of the electrical devices, we will map the electrical fields they emit to assess the strength and shape of these fields.

Importantly, by combining these approaches, we can correlate electric field strength with actual deterrent efficiency. This will help to streamline the development and testing of such devices by weeding out prototypes that do not work because their electrical fields are too weak to repel a motivated shark.

Fundamental shark research is essential

Our research will also focus on the physiological response of the shark’s electroreceptive system to the devices’ electrical and magnetic fields. This information will provide an improved biological understanding of the effect of these different stimuli on the sharks’ senses.

History shows that developing shark deterrents based on what we know about shark sensory biology is far more efficient than a trial-and-error approach. This research will also assist in adapting some of the personal deterrent technologies or concepts for use at a larger scale, such as the electric shark barrier being trialled in South Africa.

Any shark attack can be traumatising to the people directly or indirectly involved, and it is critical to reduce risks as much as possible. However, it is also important that scientists and governmental agencies do not overstate their ability to reduce risks of a shark attack.

The general public should be aware that there is no magic bullet when it comes to preventing attacks. No deterrent will prevent every shark attack in every situation.

The only way to remove all risk of an attack is to swim within a well-maintained enclosure that excludes sharks by means of an impervious barrier, or to stay out of the water altogether.

For those determined to venture further into the ocean, we encourage responsible SharkSmart behaviour. This includes staying close to shore, swimming in groups and avoiding large schools of bait fish.

Nathan Hart has received research funding from the Australian Research Council Linkage Program, The State Government of Western Australia Applied Research Program, The NSW DPI Small Grant Program and the Sea World Research and Rescue Foundation to study shark sensory systems and shark deterrents. He has provided design criteria (under contract) to companies that market shark deterrent wetsuits (Shark Mitigation Systems) and advice (based on our independent testing) to companies that produce electronic shark deterrent devices (Shark Shield).

Charlie Huveneers receives funding from NSW DPI Small Grant Program.

Sea ice covering the Arctic Ocean during the winter peak in February 2015. NASA's Scientific Visualization Studio

There is no doubt that 2016 has been a record-breaking year for Earth’s climate.

We will have to wait another couple of months for the final tally, but 2016 will be the hottest year in recorded history globally. Average temperatures are well above 1℃ warmer than a century ago.

Global average temperatures, and “global warming”, often give the impression of a gradual change in Earth’s climate occurring uniformly across the planet. This is far from the truth – particularly at the ends of the Earth. The Arctic and Antarctic are behaving very differently from the global picture.

One particular polar change that has caught the attention of scientists and the media this year has been the state of sea ice. The seasonal growth and decay of sea ice over the Arctic and Southern oceans is one of the most visible changes on Earth.

But in the past few months its seasonal progression has stalled, plunging Earth’s sea ice cover off the charts to the lowest levels on record for November. Explaining what has caused this unexpectedly dramatic downturn in sea ice is a tale of two poles.

Global sea ice area (including Antarctica and the Arctic) by year, 1977-2016. National Snow and Ice Data Centre. Wipneus/NSIDC Arctic amplifiers

The northern polar region is an epicentre for change in our warming world.

On average, the Arctic is warming at around twice the global average rate. This is due to several environmental processes in the Arctic that amplify the warming caused by rising atmospheric greenhouse gas levels.

One of these amplifiers is the sea ice itself.

As the climate warms, it’s no surprise that ice melts. What is less obvious is that when bright, white ice melts it is replaced with a dark surface (the ocean or land). Just as a black car parked in the sun will warm up faster than a white one, so the dark surface absorbs more heat from the sun than ice. This extra heat promotes more ice loss, and so the cycle goes.

This can explain the marked long-term decline of Arctic sea ice. But it can’t explain why the past month has seen such a sudden and dramatic change. For this we need to look to the weather.

Arctic climate is characterised by very large natural swings – so much so that in the past few weeks some regions of the Arctic have been a whopping 20℃ warmer than expected for this time of year.

The polar regions are separated from milder equatorial climates by a belt of westerly winds. In the northern hemisphere these winds are commonly referred to as the jet stream.

The strength of the jet stream is related to the north-to-south (cold-to-warm) gradient in northern hemisphere climate. The amplification of warming in the Arctic has reduced this gradient, and some scientists believe that this is allowing the northern jet stream to develop a more meandering path as it travels around the globe.

Jet stream winds in the northern hemisphere, November 11 2016. Screenshot from Global Forecast System/National Centres for Environmental Information/US National Weather Service.

A weaving jet stream allows warm air to penetrate further northwards over the Arctic (the flip side is that extremely cold polar air can also be pulled south over the northern hemisphere continents, causing extreme cold snaps). This appears to be responsible for the current extremely warm temperatures over the Arctic Ocean, which have caused the normal advance of winter sea ice to stall.

In effect, what we are seeing in the Arctic is the combined effect of long-term climate change and an extreme short-term weather event (which itself is probably becoming more common because of climate change).

The southern story

It’s a different story when we look at the ocean-dominated southern hemisphere.

Antarctic climate records point to a delay in some of the effects of “global warming”. The reasons are still debated, partly because of the much shorter climate records that scientists have to work with in the Antarctic.

But it is likely that the expansive Southern Ocean is an important climate change dampener that is able to “hide” some of the extra heat being absorbed by our planet beneath the ocean surface where we don’t feel it – yet.

Unlike the dramatic declines in Arctic sea ice over recent decades, the sea ice that surrounds Antarctica has been increasing slightly over the past three-and-a-half decades and 2014 set records for the most extensive Antarctic sea ice on record. So the decline in Antarctic sea ice since August this year to record low levels has come as somewhat of a surprise.

Again, the weather may hold part of the answer.

The westerly winds that circle the Southern Ocean (analogous to the northern hemisphere’s jet stream) have strengthened and moved closer to Antarctica over the past few decades. One of the effects of this has been to push sea ice away from the Antarctic continent, making for a more expansive coverage across the surrounding ocean.

But the westerly winds are fickle. They are able to change their path across the Southern Ocean very quickly. And so while the southward march in their average position over many years is clear, predicting their behaviour from month to month remains difficult. This spring the westerly winds have tended to sit closer to Australia and out of reach of Antarctica’s sea ice.

What Antarctica’s sea ice will do in the future is still an open question. Climate models indicate that Antarctica won’t remain protected from global warming forever, but just if and when this might cause Antarctica’s sea ice to replicate the Arctic sea ice loss is still anyone’s guess.

Lessons in the madness

Extreme years, such as 2016, are important as they provide glimpses of what the new normal of our climate system may look like in the not-too-distant future.

But these pointers to where we are going also need to be assessed in terms of where we have come from. For sea ice, logbooks from the age of heroic exploration suggest that the Antarctic system is mostly still operating within its normal bounds.

The same cannot be said for the Arctic. The decline of sea ice there has been likened to a ball bouncing down a bumpy hill – some years it will bounce higher than others, but eventually the ball will reach the bottom.

When it does, the Arctic Ocean will be ice-free in summer. That’s a boon for shipping, but don’t expect to see any polar bears on those Arctic cruises.

Nerilie Abram receives funding from the Australian Research Council.

Different foods have different amounts of greenhouse gases embedded in their production. Food image from www.shutterstock.com

The food we eat is responsible for almost a third of our global carbon footprint. In research recently published in the Journal of Cleaner Production we ranked fresh foods based on how much greenhouse gas is produced from farm to fork.

Perhaps unsurprisingly, we found that red meat is the most emissions-intensive food we consume. But we also found that field-grown vegetables produce the least greenhouse gas. For instance, it takes about 50 onions to produce a kilogram of greenhouse gas, but only 44 grams of beef to produce the same amount.

We hope that chefs, caterers and everyday foodies will use this information to cook meals without cooking the planet.

From farm to fork

To produce our ranking, we compiled 369 published life-cycle assessment studies of 168 varieties of fresh produce, including fresh vegetables, fresh fruits, grains and nuts, dairy and livestock.

To find out how much greenhouse gas is produced in food production, we need to look at all the activities that produce emissions on the way from paddock to the regional distribution centre.

This includes: farm inputs from chemicals and fertilisers; fuel and energy inputs from irrigation and machinery for cultivation, harvesting and processing; and transport and refrigeration to the regional distribution centre.

It also includes emissions released from fertilised soils, plants and animals in fields, but doesn’t include activities such as retail, cooking in the home and human consumption.

CC BY-ND

In the case of non-ruminant (chicken and pork) and ruminant (lamb and beef) livestock, processes covered include breeding, feed production, fertiliser use, farm/broiler energy use including heating, as well as transport, processing at the slaughterhouse and refrigeration to the regional distribution centre.

For lamb and beef the main source of emissions is methane. This is due to the fermentation process in which bacteria convert feed into energy in the animals’ stomachs. Methane can contribute anything above 50% of the total for ruminant livestock.

In the case of fish, species caught offshore by longline fishing fleets and trawlers have higher values because of the significantly higher fuel consumption than coastal fishing fleets.

It is difficult to compare different life-cycle analyses as these are unique to a particular growing region, farming practice, or methodological calculation. We agree there is danger in comparing one analysis with another to make direct comparisons and concrete conclusions.

However, after comparing 1,800 life-cycle analysis results, we feel far more comfortable in generalising the findings.

There is a large variation (median values) in results between food categories and also within categories, as illustrated below:

CC BY-ND Cooking with less gas

Due to different culinary and dietary requirements, it is hard to argue that you can replace beef with onions. However, it is possible to substitute red meat with other meats, or plant-based protein sources, such as lentils and nuts, that have a lower impact.

Our study can help everyday citizens gain a better appreciation of the life-cycle impacts associated with the growing, harvesting and processing of food. With this knowledge, they can better plan, shop, prepare and cook food while reducing their carbon footprint.

CC BY-ND

As the world grapples with the estimated US$940 billion per year in economic losses globally as a result of food loss and waste, these data illustrate the embedded carbon impacts when food is wasted in the supply chain.

Our results could be used to plan menus for individuals and catering companies who want to reduce their carbon footprint, by selecting foods from different categories.

Limited studies are available, however, for many popular foods. This includes tree nuts such as almonds and cashews, and quinoa, duck, rabbit, turkey and kangaroo.

We need to know more about the emissions intensity of these foods as they are often presented as alternative protein sources with low emissions. The lack of published data makes emissions intensity of these foods harder to validate, and such information is critical if attempts are made to inform dietary choice for environmental purposes.

Karli Verghese undertakes research projects on a variety of food related, packaging, waste and life cycle assessment studies that have been and are funded by the commercial sector, government grants and competitive grants.

Stephen Clune previously worked for the Centre for Design at RMIT on a variety of food related research projects. Which were funded by the commercial sector, and competitive grants.

Prime Minister Turnbull and Environment and Energy Minister Josh Frydenberg hold a press conference after ratifying the Paris Agreement in November 2016. AAP Image/Lukas Coch, CC BY-SA

Ten years ago on Saturday (December 10) Prime Minister John Howard announced the Coalition government would investigate an emissions trading scheme to reduce greenhouse gas emissions.

It was a remarkable backflip after a decade of rejecting such a policy. But fast-forward ten years and we have seen a dizzying array of U-turns on climate, most of them bad news for the atmosphere.

In the latest turn of events, the Coalition government has ruled out an emissions intensity scheme (a form of carbon trading) ahead of a national review of climate policy.

So as Australia gears up to review both its electricity market, with an initial report to be released on Friday, and climate policies, what might the future hold?

Howard’s slow warming

Emissions trading and carbon taxes were considered as far back as the very early 1990s.

In August 2000 an emissions trading proposal from the Australian Greenhouse Office fell in Cabinet, a result ascribed by journalists to then-Senator Nick Minchin. A second proposal, in July 2003 from at least five ministers, was personally vetoed by John Howard.

However, the pressure became overwhelming as the Millennium Drought wore on and states proposed to knit together a national scheme from below. Federal bureaucrats forced Howard’s hand. In Triumph and Demise, journalist Paul Kelly describes the moment Howard realised he would need to consider emissions trading:

[Department of Prime Minister and Cabinet secretary Peter] Shergold reached the bullet point advocating an ETS [Emissions Trading Scheme], Howard asked: “What’s that doing there?” It was the decisive moment; the next exchange was a classic in the advisory art.

[Treasury secretary Ken] Henry said: “Prime Minister, I’m taking as my starting point that during your prime ministership you will want to commit us to a cap on national emissions. If my view on that is wrong, there is really nothing more I can say.” It was a threshold moment.

“Yes, that’s right,” Howard said cautiously. Henry continued: “If you want a cap on emissions then it stands to reason that you want the most cost-effective way of doing that. That brings us to emissions trading, unless you want a tax on carbon.”

Howard did not want a tax on carbon.

Howard after a speech outlining his ETS policy on the third day of the Liberal Party’s Federal Council in June 2007. AAP Image/Paul Miller, CC BY

Kelly goes on to describe the shift in the business community as a “tipping point”.

So, on December 10 2006, John Howard put out a press release declaring that Peter Shergold and a panel would investigate an ETS. Shergold delivered his report in May 2007, and both the Coalition and Labor went to the 2007 election with an ETS policy.

Rudd’s great backflip

Kevin Rudd began auspiciously, receiving a standing ovation for ratifying the Kyoto Protocol, and famously declaring that:

climate change represents one of the greatest moral, economic and environmental challenges of our age.

But then Rudd and his inner circle began the tortuous process of formulating their own Carbon Pricing Reduction Scheme.

Rudd formally hands over the official document ratifying the Kyoto Protocol to UN Secretary-General Ban Ki-moon. AAP Image/Ardiles Rante, CC BY

It quickly became bogged down in concessions to the mining and electricity sectors. The first attempt at legislation, in May 2009, had a higher emissions reduction target of up to 25% if international action materialised, but failed.

The second effort created an even more generous cushion for the miners (doubled to A$1.5 billion) , but also failed after the Liberals replaced Turnbull with Tony Abbott on December 1, and the Greens in the Senate refused to vote for the plan.

Fresh from the horror of the Copenhagen climate conference, Rudd could have triggered a double-dissolution election over the scheme, but didn’t. A Greens proposal for an interim carbon tax was ignored. Rudd toyed with a behaviour change package, but was overruled.

On April 27 2010, Lenore Taylor broke the story that Rudd was kicking an ETS into the long grass for at least three years. Rudd’s approval ratings plummeted.

The toxic tax

After Julia Gillard replaced Rudd in 2010, she negotiated a three-year fixed carbon price as part of an emissions trading scheme. It was quickly politicised as a “great big tax on everything”, and lasted two years after coming into effect.

Abbott proposed a different way of reaching the same emissions reduction target – a Direct Action scheme, which critics said simply subsidised polluters. Turnbull famously called it “bullshit” in 2009.

A pro-carbon tax protest for climate action in Sydney in June 2011. AAP Image/Dean Lewins, CC BY

Turnbull didn’t change Abbott’s policy when he became prime minister in September 2015. It has been recently reported that the Direct Action scheme’s Emissions Reductions Fund is “running out of steam”.

What next?

Only the brave or ignorant would make any specific predictions about the absurd(ist) rollercoaster that is Australian climate change policy.

In the last few months we’ve seen the Climate Change Authority issue a majority and minority report.

On Tuesday, transmission companies called for a trading scheme at least for the electricity sector, but the right wing of Turnbull’s own party seems implacably opposed, as do commentators such as Andrew Bolt. Now the Turnbull government appears to have capitulated.

Business, industry and green groups have been crying out for policy consistency and an orderly transition away from coal.

Now we wait for the results of the two reviews into Australia’s electricity and climate policy.

There’s the Finkel Review into the reliability and stability of the National Electricity Market, which was commissioned in response to the South Australian blackout of September 28. That will presumably create new terrain in the debate on renewable energy for which there is currently no additional target beyond 2020.

Then there’s the review of Direct Action itself, and its safeguard mechanism. In 2015, under pressure from Nick Xenophon, the government promised it would begin the review on “30 June 2017, and complete it within five months”.

Meanwhile, the Labor Party will have to come up with its own specifics for how it would hit the Paris targets. It’s hard to see the Liberal and National parties changing their minds on this issue, having somewhat painted themselves into a corner (it was not always so).

Ten years ago, after successfully fending off action, John Howard finally had to do a U-turn, but it was too little too late. The pressures are now building again. It will be interesting to see if Labor is capable of capitalising on them, and if social movements are more able than they were to keep Labor to its rhetoric this time around.

Ten years from now, will we be charting another ten tempestuous and wasted years?

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

It’s a rare week when natural resource management policy penetrates the national news cycle not once, but twice.

Nonetheless, last Thursday the federal government struck a deal with the Greens to increase funding to Landcare programs by A$100 million in exchange for their support on other matters. No one quite seems to know yet how this money will be spent – presumably in ways that support the thousands of volunteer community Landcare groups dotted around Australia.

Then on Sunday, the Australian Financial Review reported that the government will abolish the Green Army program as part of its mid-year budget update later this month.

Introduced in 2014 as a signature policy under the then prime minister, Tony Abbott, the Green Army aimed to mobilise 15,000 young and unemployed people to work on conservation projects and receive complementary training. Axing the program would deliver budget savings of around A$350 million.

Abbott took to Facebook on Monday to criticise the move. His main concern seems to be the implication that the Greens’ policy priorities are more important than the Coalition’s. That’s a bad look, he argues, for a “centre-right government”.

Yet the move would arguably be very much in keeping with centre-right values. By reinvigorating Landcare’s model of personal responsibility and self-regulation, the government could reduce pressure to regulate land use or to pay landholders financial incentives to improve their environmental management.

But consistency with any particular political philosophy is not the issue here. The hyper-polarised political landscape of recent years, particularly on environmental policies, encourages parties to differentiate on any grounds they can. Thus, the cross-party support long enjoyed by Landcare can perversely work against it. Incoming governments believe they need new programs to claim as their own, diverting attention and resources from those already in place.

The A$484 million cut to Landcare in the 2014 budget needs to be remembered in this context. Both Coalition and Labor governments have made changes over the years that either reduced the financial support available to community Landcare groups, or imposed more top-down modes of decision-making.

The 2015 Senate inquiry into the National Landcare Program revealed considerable community concern about the impacts of budget cuts on Landcare’s activities and on private commitment to natural resource management. Every dollar of public money invested in Landcare is believed to leverage between A$2.60 and A$12.00 of community and landholder investment.

When the Green Army was launched, many people questioned whether it would deliver this kind of value for money. With a three-year review of the Green Army due for release early next year (subject to ministerial approval), we might have expected to see some answers.

So why is the Green Army is being cut before the review? Perhaps the government is sparing itself the embarrassment of defending a program that is failing to meet its objectives. Perhaps, despite the critics, the findings would have been positive and the government is avoiding having to explain why the Green Army is being killed off anyway. Perhaps it’s just looking for easy budget savings.

Strategic plan?

Whatever the motivation, the biggest concern is the absence of a strategic and coherent approach to natural resource management policy in Australia. Major program changes are being made with limited consultation and transparency, and precious little evidence of planning.

At the same time, some policies and programs appear to be working at cross purposes. For example, tree clearing is increasing in much of Australia at the same time that some landholders are being paid through the Emissions Reduction Fund to conserve native vegetation.

Questions need to be asked about the genuine impacts of existing policy, about the way in which regulations intersect with voluntary programs, and about coordination between Commonwealth and state governments, among other issues.

The recent Senate inquiry into Landcare called for long-term investment and stability in natural resource management programs. Achieving this will require a return to genuine cross-party support coupled with broader community and industry support. The key to achieving this, I suspect, is less wheeling and dealing among political parties and more consultation and planning with all interested stakeholders.

It might be time to consider a white paper process to inform the next phase of natural resource management policy. At least that would give us some confidence policy is not being decided on the run.

Stewart Lockie receives funding from the Australian Research Council, the Department of Foreign Affairs and Trade and Mission Australia.

The unassuming dusky hopping mouse. Ben Moore

You should stop skylarking about with those bloody desert mice and try and stop those woody weeds. I could see clear through that paddock in the ‘60s. Now look at it. That scrub costs us tens of thousands of dollars in lost fodder and it’s almost impossible to muster the livestock.

That blunt assessment of our research, first offered by a local farmer in Australia’s arid rangelands almost seven years ago, raised an irresistible question for us as field ecologists. Why are Australia’s (and many others around the world) grasslands becoming woodier?

It certainly was a question worth asking. Shrub encroachment – an increase in the cover of woody shrubs in areas once dominated by grasses – is not just an issue in Australia.

In two recent papers published in the journals Ecography and the Journal of Animal Ecology, we looked at one key reason why trees are invading grasslands, and how we could stop them. And it all comes down to tiny desert mice.

Shrub invasion

“Invasive native vegetation”, as bureaucrats call it, is a major problem for livestock producers in drylands throughout the world. This is because the shrubs compete for space and light with the grasses needed to feed their cattle and sheep.

Shrub encroachment ‘inside’ the Dingo Fence. Dr Ben Moore

It is a hard problem to tackle. Clearing and fire are the most common methods of controlling woody shrubs. But these methods are laborious and often hard to implement on large scales.

Removing shrubs is also contentious because these are typically native species that provide important habitat for wildlife. The New South Wales parliament’s controversial relaxation in November of regulations governing vegetation clearing were designed partly to allow farmers to remove invasive native vegetation.

What’s going on?

The causes for the spread are complex and poorly understood. Shrub encroachment is often attributed to overgrazing by livestock, which favours the growth of shrubs over grasses. It has also been linked to a reduction in bushfires that wipe out the shrubs and an increase in atmospheric carbon dioxide, which can promote their growth.

However, we suspected another important factor could be at play. And it was those little desert mice that provided us with a big clue – and a possible solution.

Since European settlement, livestock grazing and the introduction of foxes, feral cats and rabbits have decimated Australia’s native mammals, especially in arid and semi-arid areas.

The bilbies, bettongs, native rodents and other small mammals that became rare or extinct across much of the continent in the early 20th century once played essential roles in Australian ecosystems, by shifting vast amounts of soil and consuming vegetation and seeds.

Historical accounts suggest that shrub encroachment quickly followed European settlement and mammal extinctions in many areas. This coincidence led us to ask: could the loss of native mammals be making Australia’s drylands woodier?

Hopping to it

To answer this question, we went to the northwest corner of NSW. Here the Dingo Fence marks the border with Queensland and South Australia.

The Dingo Fence. Ben Moore

We wanted to know whether the local extinction of a native mammal, the dusky hopping mouse, which eats shrub seeds and seedlings, would allow more shrubs to grow. The Dingo Fence was the perfect study site because dusky hopping mice are common on the northwest side, “outside” the fence, where dingoes are present.

Dingoes keep fox numbers down, which are the mouse’s major predator. However, dusky hopping mice are rare on the “inside” of the fence (the NSW side), where dingoes are less common and foxes roam.

We first used historical aerial photographs to show that shrub cover was consistently higher inside the dingo fence (rodents rare) than outside (rodents common). We then did field surveys, which showed that the numbers of shrubs, their seedlings and their seeds were greater where rodents were rare.

We also showed that dusky hopping mice were major consumers of shrub seeds and capable of keeping the numbers of shrub seeds in the soil down.

Fieldwork in the Strzelecki Desert. Dr Ben Moore Going wild again

These results are exciting because they suggest that the loss of native mammals such as the dusky hopping mouse may be an important and overlooked driver of shrub encroachment, not only in arid Australia but also globally.

Perhaps more exciting, however, is how we can apply our work. Our research suggests that “rewilding” drylands by re-establishing rodents and other native mammal species that eat shrub seeds and seedlings, such as bettongs and bilbies, could curb the shrub invasion.

Although an abstract and even controversial idea, rewilding of native mammals would provide a long-term solution to a problem that has affected pastoralists for more than a century.

Further, it would represent a natural and cost-effective strategy with enormous benefits for the conservation of imperilled native mammals.

Before we can do so, we have to control foxes and feral cats across vast areas, which is no small feat. However, the economic and conservation potential make it an approach that is well worth taking seriously.

Mike Letnic has received funding from the Hermon Slade Foundation and Australian Research Council.

Christopher Edward Gordon 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.

Sulphur-crested cockatoos form long-term pair bonds, perhaps explaining their emotional intelligence. Ian Sanderson/Flickr, CC BY-NC

July on the Northern Tableland, near Armidale in New South Wales, is usually the beginning of the breeding season and field observations start early.

I sat and watched in freezing temperatures. The sun was just rising above the horizon of this 1000m-high plateau when through binoculars I saw a young lone magpie, walking gingerly, literally tip-toeing, occasionally interrupted by little bouts of running and, unusually, heading straight for its territorial boundary.

In the last stretch to the border, the bird edged along a row of pine trees, staying low, and kept looking over its shoulder, especially when crossing the neighbour’s border. Shortly afterwards, a female was seen in his company.

Later, the male backtracked and, when far enough into his own territory, started foraging rather aimlessly as if nothing had happened.

The magpie who snuck over the border. Gisela Kaplan

What had I witnessed? Did this young male magpie understand that he was breaking several important magpie social rules and could face punishment for this transgression if caught? Did he have a sense of morality?

Science has traditionally shunned the idea of emotions in animals, not just for fear of anthropomorphism or over-interpretation, but also because there is a very long cultural history that played out a divide between mind and body and reason and emotions.

Reason, thinking and making judgements were stubbornly thought to be outside the capacity of animals. For a long time it was not believed that animals were even capable of feeling pain, let alone complex emotions. We now know that is far from the truth.

Birds with feelings

Pet owners have always known that their pets can be affectionate, sulky, jealous, sad, excited and deliberately naughty, as well as doing extraordinary things for their owners. The animals we know best in this regard are obviously dogs and cats.

Charles Darwin was the first to discuss emotions in animals in the mid-19th century. A century later, Niko Tinbergen addressed the vexing question of emotions.

Following on from Darwin, he identified “four Fs” as part of survival: fight, flee, fornicate and feed. These translate into basic feelings of fear, hunger and sexual drive – now called motivational states.

Tawny frogmouths are monogamous. cskk/Flickr, CC BY-NC-ND

But there is a lot more to bird emotions. Dangerous and horrible experiences are usually remembered. Memory helps survival. Modern urban birds have been shown to remember faces of people considered dangerous and threatening.

We now know that the bird brain is lateralised (each side of the brain controls a different set of functions) as in humans and other vertebrates. The right hemisphere expresses intense emotions (such as fear and attack). The left hemisphere has routine, considered responses and may inhibit some of the strong responses of the right hemisphere.

So birds are more similar to humans than had ever been thought, but with an important difference: birds are generally not aggressive without cause. Technically, aggression is an emotion that is dysfunctional, has no purpose and often even harms the individual displaying it.

Birds can certainly get very angry – and the owner of a galah or corella would be well advised not to get near this bird when the head feathers are raised — but birds can be joyful and playful, can get depressed and, as studies have shown, a neglectful or bare environment can even make them pessimistic.

Birds may feel for others (have empathy) and even console them, may have a sense of justice, may show deep affection for their partner and grieve for their loss. I witnessed the mate of a fatally injured tawny frogmouth not moving from the spot next to its dead partner for three days, and then dying on the fourth.

Social smarts

Australian native birds have an unusually high percentage of pair-bonding (over 90% of species) and the highest concentrations of cooperative species (relatives or siblings helping at the nest) anywhere in the world. Cockatoos bonding for life often have intense close partnerships, which are nurtured by constant grooming and attention to each other’s needs.

Such intense cohabitation of individuals, often for many years (how about 60 years of “marriage” in sulphur-crested cockatoos?), may also create frictions and dissatisfactions that require solutions to keep the pair or group together.

For instance, the lazy helper at the nest who only pretends to help in feeding, as happens among white-winged choughs, may get scolded by an adult. A group of apostlebirds building a mud nest together, transporting mud to the nest in relays, may spot an individual that is not pulling its weight.

I have witnessed on several occasions near Copeton Dam (in Inverell, NSW) apostlebirds become so outraged that they approach the individual with heightened calling and may even peck it until the intimidated individual falls back into line and does its share.

Empathy, altruism and consoling the injured or vanquished have all been observed in birds, thought to be the ultimate in consideration for another individual’s state of mind.

For instance, there are observations of dusky wood-swallows (belonging to the same family of birds as butcherbirds and magpies) in Western Australia’s Wheatbelt hassling a restless flycatcher with a larva in his beak, perched on a branch. One wood-swallow flew above the flycatcher, while the other simultaneously flew directly at it, snatched the larva from its beak while it was distracted by the other bird hovering overhead, and took it away. So who got the prize?

If all behaviour in animals is selfish, then the one who caught it should have gulped it down, but it did not. It gave it to the bird that had distracted the flycatcher. Perhaps the two birds reversed roles in the next, similar, situation. But it still meant overcoming the temptation to eat.

A noisy miner, one of the cooperative honeyeaters, I had hand-raised grew up over several weeks in the company of very young ridgeback pups near the edge of a nature reserve in a NSW coastal area.

One pup was sleeping on the porch in the sun and I was some distance away. I was alerted by the alarm calls of the noisy miner and turned around to see it swooping right down to a lace monitor’s head – doing so over and over again. I ran as quickly as I could, by now also shouting once the risk to the pup was more than apparent.

When the monitor spotted me, it turned and fled. The noisy minor had risked its life to save the pup. At no other occasion did the bird attempt to swoop a lace monitor. Its response was very specific to this situation.

And, as I have been asked often, could birds have a sense of humour? Perhaps.

Our galah, Philip, deeply affectionate (and jealous!) had learned the names of all our dogs and was such a good mimic of our voices that he could easily and effectively call the dogs to attention.

Imagine the picture: a bird less than a foot tall, standing on the floor and calling four massive Rhodesian ridgebacks to attention. Then, when he got them all in line in front of him, he walked away, swaying his head and even making little chuckling sounds.

The degree to which emotions and complex feelings for others were developed may well depend on social organisation. It may be that birds with long-term social bonds show more complex behaviour and brains than those whose associations are only fleeting.

What they get out of it is perhaps not debatable — more joy, more grief, but also a greater degree of safety and usually a longer life. There are clear benefits of sticking together in a difficult and fickle continent.

Gisela is speaking at the Mornington Peninsula Regional Gallery on Tuesday, December 6, and Wednesday, December 7.

Professor Gisela Kaplan received funding from the ARC and bequests from private benefactors She is at the School of Science and Technology at the University of New England, Armidale, NSW and there are no conflicts of interests or personal benefits derived from writing this article.

Shark nets are being trialled at five locations in northern New South Wales in response to a recent spate of shark attacks in this area.

The goal of these nets is to reduce the number of encounters of sharks with humans. The nets may do this by catching large sharks, and possibly by changing the way sharks visit these beaches.

There has been some doubt as to the effectiveness of shark nets in reducing attacks, so it’s important we continue to evaluate their role in bather protection.

But unfortunately it’s not as straightforward as it sounds, and it could take years to find out whether the nets will truly work.

Rare events

Shark attacks are very rare. According to the Australian Shark Attack File, 51 unprovoked attacks by white sharks have been recorded in NSW since 2006, 19 of them along the north coast (between Byron Bay and Evans Head).

There have undoubtedly been spikes in attacks over the last decade, especially in northern NSW, but the number of attacks has varied a lot between years and locations.

The problem is that when events (like shark encounters) are both rare and variable, it is very difficult to spot when there has been a genuine increase. And, crucially for the shark net trial, it is also difficult to tell whether policies are reducing them.

In the area of NSW where the shark nets will be trialled, between Broken Head and Evans Head, white shark attacks have ranged from zero to six per year in recent years. One way of getting an idea about how many attacks might occur in the future is to fit a statistical distribution to these data, and use this to predict the frequency at which attacks will occur (assuming the attack rate doesn’t change much).

In a hypothetical scenario in which the trialled shark nets are a success and reduce the attack rate by white sharks in the area by (say) 75%, our statistical distribution tells us that almost all years will have zero or one attack (see the red line below).

However, if the nets do nothing and the attack rate stays the same, we would still expect most years to have zero or one attack (the pink line below). This shows that it will be very difficult to know in the short term if the shark nets truly are reducing the risk of attack. This graph shows how difficult it can be to identify a reduction in risk, even by a large amount.

Even if there are zero attacks at a netted beach next year, that doesn’t necessarily tell us the net has worked, because statistically we would expect zero attacks in most years anyway. By the same token, if someone is bitten by a shark at one of the netted beaches, it doesn’t mean the nets aren’t effective. They may be greatly reducing the risk, just not eliminating it completely.

Because these encounters are so rare and variable, it will probably take years (rather than the six months planned for the trial) before there is enough evidence to show whether the nets have reduced attacks.

How and why

We also know very little about which factors influence encounters with large sharks. Without this information it is even harder to recognise whether the nets bring a decline in shark encounters.

In the above example, I used the recent history of attacks as the only guide to the future, but this is the most basic approach to exploring trends and assumes that recent history is a reliable indicator of the near future. A great way to improve this approach is to look for factors that can help explain why attacks vary between years – in essence basing our analysis on ecology rather than purely statistics.

The environment will almost certainly change the chance of a shark encounter. Factors like ocean temperature may have a big influence in determining when large sharks swim close to shore. The more of this “biological” information we have, the better we can account for variation in the number of shark attacks, and thus the better we will get at assessing whether policies like shark nets are working.

As described above, a six-month trial is not really long enough to learn anything meaningful about whether nets reduce shark attacks. It will provide other useful information, though, such as the likely impact on marine life. So we might find out whether the nets harm sharks, turtles, dolphins etc, but not whether they are making people any safer.

I am not suggesting that the trial won’t be useful – evaluating the impact on marine life is essential for assessing the costs of the nets. But what I am saying is that we need to avoid jumping to conclusions about whether they are “reducing the rate of unprovoked interactions with potentially dangerous sharks”. It will be years before we can attempt to answer that question.

In the meantime, there is much to be gained by increasing our understanding of how the environment influences shark distributions, by linking locations of tagged or caught sharks with the kinds of environments they inhabit. This will remove some of the guesswork in the “where and when” of shark attacks, and hopefully contribute to a more scientific approach to bather protection.

James Smith receives funding from the Australian Research Council to research coastal environments, including fish habitats and artificial reefs.

Traditional hunting poses no threat to dugongs. Flickr, CC BY-SA

Recent calls for a ban on legal traditional hunting of dugongs and marine turtles imply that hunting is the main threat to these iconic species in Australia. The science indicates otherwise.

While more is being done to address traditional hunting than any of the other impacts, the main threats to their survival often pass unnoticed.

The real threat to sea turtles

The draft Recovery Plan for Marine Turtles in Australia evaluated 20 threats to the 22 populations of Australia’s six species of marine turtle. Climate change and marine debris, particularly “ghost nets” lost or abandoned by fishers, are the greatest risks for most stocks.

Indigenous use is considered to be a high risk for three populations: Gulf of Carpentaria green turtles, Arafura Sea flatback turtles and north-eastern Arnhemland hawksbill turtles.

However, in each of these cases it is the egg harvest, not hunting, that causes concern. International commercial fishing is also a high risk for the hawksbill turtle, whose future remains uncertain. Traditional hunting of marine turtles in Australia is limited to green turtles.

Is hunting a threat?

The Torres Strait supports the largest dugong population in the world and a globally significant population of green turtles. Archaeological research shows that Torres Strait Islanders have been harvesting these species for more than 4,000 years and the dugong harvest has been substantial for several centuries.

Our research shows that the Torres Strait dugong population has been stable since we started monitoring 30 years ago and that the harvest of both species is sustainable.

The situation for dugongs is very different in the waters of the Great Barrier Reef south of Cooktown. The Great Barrier Reef Outlook Report classifies the condition of the dugong population in this region as poor.

Modelling indicates that the southern Great Barrier Reef stock of the green turtle, which live and breed south of Cooktown, is increasing.

Nonetheless, both green turtles and dugongs died in record numbers in the year after the extreme floods and cyclones of the summer of 2010-11. Dugongs stopped breeding in the Great Barrier Reef region south of Cooktown.

Thankfully, our current aerial survey indicates that dugong calving has resumed as inshore seagrass habitats recover. There is no evidence that the 2011 losses significantly affected green turtle numbers.

Working together

Traditional owners are the first managers of our coastal waters, with cultural practices extending back thousands of years. They have the most to lose from any loss of turtles and dugongs. It is therefore in their best interests, and the government’s best interest, to work in partnership to protect and sustainably manage these species.

Longstanding tensions between traditional owners and tourist operators are behind much of the opposition to traditional hunting in the Cairns area. Some of these tensions have been relieved by the Gunggandji Traditional Use of Marine Resources Agreement signed in June 2016.

Under this agreement, the traditional owners decided to cease hunting turtles and dugongs in the waters surrounding Green Island, Michaelmas Cay and Fitzroy Island.

The Gunggandji agreement is the seventh to be signed between the Great Barrier Reef Marine Park Authority and traditional owners. In addition, there are two Indigenous land use agreements that address hunting issues in the Great Barrier Reef.

In the Torres Strait, dugong and turtle hunting is managed through 14 (soon to be 15) management plans. There are similar agreements with traditional owners and management agencies in other regions in northern Australia.

Indigenous rangers are crucial to implementing all these agreements in collaboration with management agencies and research institutions. Rangers deliver the practical, on-the-ground arrangements to conserve these species in their Sea Country.

The Great Barrier Reef Marine Park Authority has implemented an Indigenous Compliance Program that authorises trained Indigenous rangers to respond to suspicious and illegal activities that they encounter as part of their work.

Indigenous rangers and community members from Badu Island in Torres Strait help JCU scientists fit a dugong with a satellite tracking device. Takahiro Shimada/James Cook University

Indigenous rangers also remove marine debris from remote beaches. The community-based organisation GhostNets Australia has worked with 31 coastal Indigenous communities to protect over 3,000km of northern Australia’s saltwater country from ghost nets. These community projects have been instrumental in rescuing turtles, clearing ghost nets off beaches and identifying key areas to aid management agencies to better understand the impact.

Traditional owners from the Torres Strait and the northern Great Barrier Reef also play a valuable role in intervention works at Raine Island, one of the world’s most significant green turtle rookeries. This includes rescuing stranded turtles, using fences to stop turtles from falling over cliffs, and altering beach profiles.

What about welfare?

Traditional hunting raises animal welfare issues. The turtle and dugong management plans developed by the Torres Strait communities explicitly address animal welfare. The Torres Strait Regional Authority has been working with a marine mammal veterinarian and traditional owners to develop additional methods of killing turtles humanely.

Indigenous hunters who breach state and territory animal welfare laws can be prosecuted. But more widespread animal welfare problems, not associated with hunting, are largely hidden and ignored. The Queensland Strand Net Program reported that 879 turtles died of their wounds from vessel strike between 2000 and 2011.

An immature female loggerhead turtle severely injured by a boat strike near Gladstone. This turtle was determined to be unrecoverable and was euthanased by a local veterinarian in May 2016. Takahiro Shimada/James Cook University

Other serious animal welfare issues are associated with animals drowning in nets and being caught in and ingesting marine debris. In addition, the potential impact of emerging threats like underwater noise pollution and water quality remain as substantial knowledge gaps. These matters tend not to make the headlines.

Australian waters are home to some of the world’s largest populations of marine turtles and dugongs. A comprehensive and balanced approach to their conservation and management is required to enable our grandchildren and their children to enjoy these amazing animals.

Helene Marsh FAA, FTSE, Distinguished Professor of Environmental Science at James Cook University, is a conservation biologist who has been studying dugongs for 40 years. She has co-authored two books and some 200 professional articles. Helene currently receives funding from the federal government via the Australian Research Council, the Department of Environment and Energy, the National Environmental Science Program and the Great Barrier Reef Marine Park Authority. She provides professional advice to the Torres Strait Regional Authority, the Great Barrier Reef Marine Park Authority. Helene chairs the Threatened Species Scientific Committee, is a member of the Reef 2050 Plan Independent Expert Panel and Co–chair of the IUCN Sirenia Specialist Group. https://research.jcu.edu.au/portfolio/helene.marsh/

Mark Haman is an Associate Professor in the College of Science and Engineering at James Cook University. He currently receives funding from the federal government via the Australian Research Council and the National Environmental Science Program and from the Gladstone Port Authority. Mark provides professional advice to the Torres Strait Regional Authority, the Great Barrier Reef Marine Park Authority, the Department of Environment and Energy and the Queensland Government. Mark is a Co-vice Chair of the IUCN Marine Turtle Specialist Group and a member of the Science Advisory Committee for the IOSEA MoU for Marine Turtles and their Habitats.

OPEC’s recent decision to cut oil production for the first time in eight years marked the return of the oil cartel’s favourite tactic: squeeze supply in a bid to jack up the price.

Of course, this is nothing new. In 1851, during the Pennsylvania oil rush, the Oil Creek Association helped to push the price of oil up from 10 US cents a barrel to US$4.

OPEC can only dream of having the power to move prices by 4,000%. The reality is that its power to move prices at all is waning rapidly, as factors move beyond the bloc’s control.

It’s worth noting what happened to the oil drillers of Pennsylvania after they installed a floor under their high oil prices. Investors shifted their focus elsewhere, looking to Russia, Texas and eventually the Middle East. Precisely the same thing is happening to OPEC, particularly through the advent of the US shale oil industry. And this time it’s happening not in the golden age of oil but in an era when market conditions for polluting fuels are much tougher.

In 2008, when oil prices were high, Goldman Sachs predicted that oil would hit US$200 a barrel. But they are financial wizards, not historians. It has been 75% less for most of the period since.

Over the decades we have also grown used to hearing predictions that there are “only 30 years of oil left at current production rates”. (The horizon never seems to move any closer or further away.)

But bear in mind that oil reserves are a function of technology and price. When prices rise and technologies improve, more oil becomes economically viable to extract, effectively increasing the world’s oil reserves. As prices fall, these reserves effectively cease to exist until prices rebound or technology gets cheaper.

So, in one sense, the oil game hasn’t changed. OPEC needs high prices to justify extracting the oil. But bigger factors are now at play, which makes it harder for OPEC to squeeze supply as effectively as it once did.

What has changed?

OPEC was at its most powerful when the United States, the world’s largest oil consumer, relied on OPEC member states to meet its oil needs. Since the US shale boom increased US energy independence, OPEC can no longer threaten supply as it did during the 1970s. Now it simply risks squeezing itself out of the market.

It’s not just the US domestic market that has grown. If OPEC restricts supply, Canada can increase oil production from tar sands, and Brazil can bring on more deep-water oil production.

All of this challenges the perception that there is a shortage of oil, although more sophisticated peak-oil followers have shown that cheap oil from conventional sources did indeed peak in 2007, prompting the most recent big surge in oil prices.

In a bid to maintain its influence on supply and therefore prices, OPEC has turned to Russia, the world’s largest state-controlled oil producer, which has agreed to cut production in tandem with OPEC nations.

But even this will not be enough to keep pace with the changes wrought by new markets, new technologies and energy efficiency. Two years ago we wrote that OPEC had lost its power and, despite the latest move, we don’t see much to indicate that it has returned.

The knock-on effects

The fundamentals of the oil industry haven’t changed with this latest deal. In Australia the effect will be a roughly 5% increase in the oil price, and a larger increase in the price of petrol (perhaps up to 10%), as distributors and retailers take advantage.

Aside from the small effect on Australian consumers, this announcement will probably be helpful to Australian oil companies, giving them some good news to tell shareholders and employees.

But before boardrooms get too excited, it is worth noting that oil is also suffering a demand problem. All developed nations have now begun to decouple economic growth from fossil fuels. For oil, the chief threat is one of being replaced by electric public transport and electric or hybrid cars.

Oil’s murky future

Oil’s future suffers from another problem: it’s not good for your health. An announcement that will have a more powerful effect on the oil price, but which received much less media attention, came in 2012 when the International Agency for Research on Cancer (IARC) updated its classification of diesel engine exhaust from “probably carcinogenic to humans” (Group 2A) to “carcinogenic to humans” (Group 1). Petrol exhaust is listed as probably carcinogenic.

Health impacts are a large driver for moving away from fossil fuels – even for those who don’t accept the predicted climate impacts. With the fundamental shift towards fuel efficiency and electric vehicles, the Volkswagen emissions scandal and the awareness that petrol and diesel cause cancer, respiratory disease and lower birth weights in babies with mothers living near major roads, the trend for oil consumption is downward.

So the drivers for change are as they have always been – demand and technology are behind the wheel, not OPEC making “important” announcements. Look for a small, short-lived increase in your local fuel price, but remember that if your tank of fuel goes up by 10c a litre, most of that isn’t down to OPEC. It’s mainly retailers looking for a bigger Christmas bonus.

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

The Great Barrier Reef's major threat is climate change. Great Barrier Reef image from www.shutterstock.com

At first glance, the progress reports on the Great Barrier Reef released last week by the Australian and Queensland governments might seem impressive.

The update on the Reef 2050 Plan suggests that 135 of the plan’s 151 actions are either complete or on track.

The Australian government’s apparent intention in releasing five recent reports is to reassure UNESCO that the Great Barrier Reef should not be listed as “World Heritage in Danger” (as the World Heritage Committee has previously threatened).

Sadly, behind the verbosity and colour of these reports, there is disappointingly little evidence of progress in the key areas needed to make a significant difference to a World Heritage Area that is in crisis.

Poor baseline

The government framework for protecting and managing the Reef from 2015 to 2050, the Reef 2050 Plan, has been widely criticised as failing to provide a sound basis for the necessary long-term protection of the Reef.

As well as providing a shaky basis to build effective actions, the Reef 2050 Plan has few measurable or realistic targets. It is therefore not easy to report on the actual progress.

Several of the actions that will have the greatest impacts on the overall health of the Reef are shown in the progress reports as “not yet due”. In some cases, such as climate change, the Reef 2050 Plan is silent, instead simply referencing Australia’s national efforts on climate change.

Instead, the plan is to “[improve] the Reef’s resilience to climate change by reducing local pressures”. Besides addressing water quality, there are many things that should also be considered but they involve making some really hard decisions, such as choosing between coal and coral.

Progress versus reality

The overview of progress claims that 135 of the 151 actions in the Reef 2050 Plan are either completed (dark green) or are on track for their expected milestones (light green), as shown below.

Reef 2050 Plan: Update on Progress, 2016, CC BY

The reality, however, is that many of the 103 of the actions described as “on track/underway” have not progressed as initially proposed when the Reef 2050 Plan was submitted to UNESCO, and that the definition of “underway” is far too loose to be meaningful.

Our rapid assessment of the status of actions indicates that the level of progress reported for at least 32 of these 151 actions (around 21%) has been overstated. The following are just some examples:

The unfortunate truth is that neither UNESCO nor the IUCN has the time or resources to conduct their own comprehensive assessment of the Great Barrier Reef. They rely heavily on these reports when deliberating on what to recommend to the World Heritage Committee, including whether the Reef should be placed on the World Heritage in Danger list.

Our rapid assessment indicates there are real concerns with relying on the government to self-report accurately. It would appear the only way that UNESCO will receive an accurate update is if that assessment is done independently of government. Fortunately, UNESCO and IUCN do consider other evidence.

It is also concerning that the members of the government’s Independent Expert Panel and the Reef 2050 Advisory Committee were not involved in making the final assessments for the 2016 update report.

Despite pronouncements that the Great Barrier Reef remains healthy, the evidence of the 2015 Water Quality Report Card, along with numerous expert opinions (for example, Jon Brodie on water quality; Terry Hughes on coral health; the Queensland government on scallops; and the Marine Park Authority on inshore dolphins) shows that the real situation is not as rosy as UNESCO and the Australian public are being told.

Some real progress, but not enough

It is important to recognise some progress is being made – but sadly too little and not enough to reverse the declining trend for many of the values for which the Reef was listed as World Heritage.

We should also question some of the priorities in the Reef 2050 Plan given the widely acknowledged critical issues (see page 252 in the government’s 2014 Outlook Report). Adopting best practice for water quality from point sources such as sewage discharge (action WQA11 under the plan) and protecting habitat for coastal dolphins (BA12) should be immediately addressed.

Whether we have the money to do what’s necessary is another question. The government’s pledge to spend A$2 billion over 10 years is the current collective yearly spending (A$200 million) of four federal agencies, six state agencies and several major research programs, extrapolated over the coming decade.

While the level of funding is significant compared with many other World Heritage areas, the amount and priorities must be questioned, given that many of the Reef’s values are continuing to decline.

So far most funding has been spent on addressing water quality, and while this has achieved some positive results, it has not managed to stop the deteriorating trends.

As Jon Brodie recently wrote on The Conversation:

The best estimate is that meeting water quality targets by 2025 will cost A$8.2 billion … If we assume that … A$4 billion is needed over the next five years, the amounts mentioned in the progress report (perhaps A$500-600 million at most) are … totally inadequate.

More action needed

The Reef is unquestionably of global significance. Given its sheer size and location, no other World Heritage Area on the planet includes such biodiversity.

The worst-known bleaching event in the Great Barrier Reef demonstrates the limitations of the Reef 2050 Plan, which is silent on the impact of greenhouse emissions from Queensland’s coal mines and the effects of climate change more generally.

Governments have an obligation to protect all the Reef’s values for future generations. To do this they must recognise growing global moves to address climate change, and the widespread national and international expectations that more needs to be done to protect the Reef.

Australia is a relatively rich country and has the technical capability to address the issues. This provides an opportunity to show some global leadership for managing such a significant part of the world’s heritage.

Listing the reef as World Heritage in Danger won’t in itself fix the problems – but it will certainly focus the spotlight on the issues.

As the World Heritage Committee prepares for its next meeting in July 2017, and considers once again whether to officially list the reef as in danger, it will need to study all the evidence, not just the government’s reports.

Certainly the true picture is more complicated and dire than the most recent government reports imply.

Alana Grech receives funding from the Australian Research Council.

Jon Brodie is a partner in the environmental consulting partnership C2O.

Jon C. Day 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.

Rooftop solar proves a challenge to keeping prices low on the grid. Solar image from www.shutterstock.com

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

Australia’s low-cost electricity, thanks to cheap coal, was once a source of substantial competitive advantage. While Australia’s electricity prices are still below the OECD average, the urgent need to reduce greenhouse gas emissions is a major challenge to cheap electricity.

In a report released today by CSIRO and Energy Networks Australia, we show that Australia is so far making rocky progress on reducing emissions, maintaining energy security and keeping prices low. But we also show how Australia can regain world leadership, delivering cheap electricity with zero emissions by 2050.

A Balanced Scorecard for Australia’s electricity sector in 2016. ELECTRICITY NETWORK TRANSFORMATION ROADMAP The challenge facing Australia

Australia is the world leader in adopting rooftop solar. Rising retail electricity prices and subsidies have encouraged households to embrace solar with enthusiasm. As a result 17% of Australian households now have solar panels.

This can be seen as Australians exercising greater choice about how their electricity is supplied. However, it also highlights some of the problems our electricity network is facing.

Retailers sell electricity in Australia by volume (the kilowatt hours and megawatt hours on your electricity bill). This made sense when most households contained a similar set of fairly low-energy appliances.

But the rapid increase in high-energy air conditioners and the adoption of rooftop solar mean fees are less suited to each customer’s demand on the system or any services they provide.

More panels and electric cars

The are two major opportunities to reduce electricity prices for Australia.

First, we need to harness the power of more households producing their own electricity through solar or other distributed sources. In coming decades, households are expected to invest a further A$200 billion in distributed energy sources.

We need to avoid duplicating network expenditure (poles and wires) and support balancing supply and demand as the share of renewable electricity increases. But this can be an opportunity if we introduce the right prices and incentives.

This means using household devices such as batteries to support the electricity network, and paying customers for this service instead of building more poles and wires. This would require many actions (detailed in the report), including pricing reform, some regulation change, improved information sharing and minimum technology standards.

Second, we need to use the existing network more efficiently. Demand has fallen in recent years, chiefly through improvements in energy efficiency and increasing rooftop solar.

Because of the reliance on volume-based retail pricing, when consumption falls, networks are forced to increase prices to recover the fixed cost of delivering their services. Conversely, if it were possible to increase demand for grid-supplied electricity without increasing the fixed costs of the system, then network price could be stabilised or reduced.

Our research found that electric vehicles offered the greatest opportunity to increase demand for grid-supplied electricity. These have the added benefit of supporting greenhouse gas emission reduction goals.

The report recommends that light vehicle emission standards should be pursued as a relatively cheap way of supporting electric vehicles. Appropriate pricing and incentives will also be needed to encourage car owners to charge their vehicles at off-peak times, reducing the need to add more capacity to the network.

Keeping bills low

Residential electricity bills will need to increase gradually over time in all countries due to the cost of decarbonising electricity supply. Australia’s goal should be to be the most efficient at achieving that.

Relative to taking no action on these issues, CSIRO estimates that the measures described above will together reduce the average residential electricity bill by A$414 per year by 2050.

Projected savings in average residential bills (in real terms) Electricity Network Transformation Roadmap

Those savings are funded through reduced network spending and customers needing to spend less on their own distributed energy devices (to avoid higher bills or go off grid). These savings add up to A$101 billion by 2050.

Cumulative electricity system total expenditure to 2050 (in real terms) compared with the counterfactual (business as usual). Electricity Network Transformation Roadmap

At the same time, customers have more choice to participate in providing services to the grid, are receiving fairer payments for doing so, and the electricity system is using distributed energy resources to balance the system. All of these will help reduce greenhouse gas emissions from the electricity sector to zero by 2050.

The Electricity Network Transformation Roadmap Key Concepts Report will be livestreamed here today at 10am AEDT.

Paul Graham leads the Energy Networks Transformation Roadmap which is funded in equal parts by CSIRO and Energy Networks Australia. CSIRO is responsible for overall program delivery and is a key research provider along with other institutions from Australia, United States and United Kingdom. The roadmap is based on work captured in almost 20 supporting reports available or soon to be published on the Energy Networks Australia webpage.

These red and yellow blobs are yellow lac scale insects that feed crazy ants. A tiny wasp could reduce both populations. Parks Australia

A couple of days ago I published an article with Peter Green about the imminent release of a tiny wasp that will be used for biological control of a bug that feeds the crazy ants that kill red crabs on Christmas Island.

It is understandable that people are nervous about the introduction of exotic species to manage wildlife in a natural setting. It turns out that ecologists are even more nervous than the public about this, so if they have decided to do it anyway, then there is a remarkably good reason.

Parasitoid wasps use scale insects

The release of the wasp has concerned some readers because they imagine swarms of biting insects setting up their nests in the back garden. The truth is that the wasps that will be released are tiny and unlikely to be noticed at all.

First of all, Tachardiaephagus somervillei are only 2 mm long and cannot sting humans or other animals. They do not form colonies, they do not swarm, and they do not build nests. In fact, they won’t be at all interested in hanging around human habitations unless there is a tree nearby containing a colony of the yellow lac scale insect (Tachardina aurantiaca).

This is because these wasps are parasitoids – a type of parasitic organism that kills its host species. They don’t need a nest or a colony because the scale insects they target are both their food source and their home.

The specificity of the wasp for this particular type of scale insect can be seen in the first part of their Latin names: Tachardiaephagus literally means “eater of Tachardina”.

Scale insects use ants

Scale insects are a type of true bug (in the Order Hemiptera) that line up along tree branches like barnacles, sucking sap from the tree and in their mature form, releasing a sweet liquid known as honeydew from their backsides for the benefit of ants. They don’t do this for nothing. Their strategy is to use the ants as body guards.

In a situation where scale insects are relatively rare this increases the number of the ants who will in turn protect the scale insects. On Christmas Island, where the introduced yellow lac scale insects have become common because they do not have any natural predators, the invasive crazy ants have access to large quantities of honeydew. In this case, the crazy ants are using the yellow lac scale insects as a super abundant food source.

The super colonies that have formed as a result have instigated an environmental disaster. The crazy ants kill red crabs and other species mostly due to their extremely high densities driven by the abundance of honeydew.

Any detractors concerned about the dangers of yet another invasive species have not fully grasped the consequences of doing nothing. Chemical baiting of the ants is ongoing but has consequences for other animals and is not environmentally desirable or sustainable.

People using wasps

If the scale insects can use the ants as bodyguards and the ants can use the scale insects as a free food source, why can’t we use a tiny wasp as a biological control?

Unlike birds, lizards or other predators that may be deterred by ants crawling all over the scale insects, the tiny parasitoid wasps can slip through and lay their eggs in a scale insect without being noticed by the ants. Their eggs hatch and develop inside the scale insect, emerging as adult wasps that are ready to lay their eggs in another scale insect nearby.

In essence, the wasp uses the scale insect as a one-stop nursery, food source and conveniently located launching pad for the next generation. Inside a scale insect colony, they are likely to find another scale insect less than a centimetre from where they were born.

Consider how this will allow the wasp population to quickly grow and, perhaps, reduce the scale insect colony density so that the wasps will eventually have to fly further and further to find another scale insect. At some point the effort to find more scale insects will balance the benefit of finding an insect, and the two populations (wasp and scale insect) will reach a new equilibrium at a lower density.

How will the crazy ants respond?

The wasp will not run out of food, nor will the scale insects become extinct, but the ants will find themselves deprived of excess honeydew and will have to adjust their populations accordingly.

How do you empirically test the response of the ants to the removal of excess honeydew from their environment? Well, you can’t remove the scale insects but you can prevent the ants from getting into the trees where the scale insects live, even though it wasn’t easy. Apparently, doing this involves Glad wrap, Mr Sheen furniture polish, and daily vigilance by a research student.

The result was a 95% decrease in crazy ant activity in a few weeks, an outcome that suggests this approach has every chance of reducing the impacts of crazy ants on Christmas Island.

What happens next?

I understand that the team is gathering in Malaysia today to pack up some wasps and fly them to Christmas Island. The release will not happen right away, as the wasps will be acclimatised and grown up in large numbers in a dedicated facility. Monitoring programs are planned to observe the impacts, both short and long term, on the scale insects, the ants, the crabs and the forest structure.

The research to understand the ecology of Christmas Island sufficiently to identify a biological control agent started decades ago, and many scientists were involved along the way. It is not possible to provide links to all the research articles produced thus far, but here is a link to the final risk report.

I am not involved with the research but am familiar with it and in my view there are two things that could happen next. Either the wasp will fail to reduce the scale insect populations and nothing changes, or they will reduce the scale insect populations which could kick start a cascade of beneficial environmental outcomes for Christmas Island.

We are all really hoping that it is the latter.

Disclosure

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

Dry period in semi-arid central Australia James Cleverly

Back in 2010-11 Australia “greened”, as record-breaking rains triggered a boom in plant growth that removed huge amounts of carbon dioxide from the atmosphere and stored it as carbon in the landscape.

But what happened after that? Our latest research, published in Scientific Reports, shows that this greening was short-lived and was rapidly dissipated through drought and fire.

Our study also shows that as extreme wet years are getting wetter and more common, Australia’s terrestrial ecosystems will play a larger role in the global carbon cycle.

Carbon, water and climate change

Each year, land plants absorb the equivalent of more than a quarter of the carbon emissions generated by burning fossil fuels and deforestation. This helps to partly offset global increases in atmospheric CO₂ concentration. In 2011, this “land carbon sink” was unusually large, thanks largely to the greening of Australia’s vegetation, which accounted for 60% of the global carbon uptake anomaly that year.

Flux towers for measuring carbon and water fluxes between ecosystem and the atmosphere: (left) Calperum near Adelaide; (right) Alice Springs Mulga woodland in central Australia. Both sites are part of Australia’s Terrestrial Ecosystem Research Network, or TERN. from www.ozflux.org.au

Satellite imaging and ground observations from CO₂ “flux” towers showed that much of the 2011 greening happened in savannas and grasslands, largely in central Australia. New data shows that the return of drought conditions in many of these areas has quickly un-greened them.

Mulga dry tropical forest in central Australia was extraordinarily green and took large amounts of carbon dioxide from the atmosphere. James Cleverly Be resilient, be prepared

To an extent this is no surprise. Australia’s dryland plant species live in the most variable climates in the world. As such these ecosystems can swing rapidly between being highly productive in wet years and becoming nearly dormant to withstand drought during dry ones.

Given that the 2010-11 extreme greening followed on rapidly from the protracted Millennium Drought, it should hardly be surprising that we find the ecosystem has now swung back the other way so promptly.

Australia’s climate is the most variable in the world. (a) shows the variability of rainfall (coefficient of variance or CV) compared with other continents; (b) shows the same in Australia for four periods. Ma et al. (2016) Australia’s unique native hummock grassland (Spinifex) in dry season (left) and wet season (right). James Cleverly Drought and fire count

On a biological level, the reason that plants take up less carbon dioxide during dry periods is because this process costs water. Plants exchange gases with the atmosphere via tiny pores on their leaves called stomata, through which CO₂ diffuses in during the day but through which water also escapes.

When water is scarce it is more important to conserve it. This is why during drought conditions plants tend to reduce their carbon dioxide uptake by closing stomata or even shedding leaves entirely.

Sometimes the combination of heat and drought can be so stressful that plants die, ultimately decomposing or burning and releasing all of their stored carbon back to the atmosphere.

Australia’s ungreening

Our research shows that these processes began to take hold across Australia during the second half of 2012 and into 2013. As the chart below shows, this diminishes Australia’s large net carbon uptake as boosted by the 2010-11 wet year.

Drought rapidly eliminates Australia’s large land carbon uptake. (left) SPEI drought index; (right) satellite measures of ecosystem productivity and water storage across Australia. Ma et al. (2016)

We also found that carbon dioxide emissions from fires increased during this period. This makes sense too, given that the productive wet period spurred more plant growth, which then became fuel for fire during the subsequent drought.

As a result, Australia’s semi-arid landscapes are mostly dry once again, although the speed with which they greened and then ungreened suggests that they will be quickly refreshed when the next big deluge arrives.

Not alone

Australia’s giant green carbon sink was remarkable, but was it unique? There are two ways we can answer this question: we can wait and see if there’s another one, or we can go back and look at the historical record.

Fortunately, with long-term satellite observations, we have measurements of the entire continent back to 2000, and even earlier for some data sets. Our new research shows that the 2010–11 event was not unique. Rather, it was something that tends to happen whenever Australia has a strong wet phase, such as the one in 2000-01.

This means we can expect more large greening events to happen again in the future. One important question is whether these will be as strong as in 2010-11 – or perhaps even stronger?

Wilder, not milder

Interestingly, by looking at continent-wide rainfall records for each significant wet period dating back to 1900, we found that Australia’s wet episodes have become significantly wetter over the past century. Given this trend, we expect that in the near future Australia’s terrestrial ecosystems will come to play a larger role in the global carbon cycle. The intensification of these wet pulses is mostly seen in central and northwestern Australia.

A wilder future with more rain during wet years will have important implications, not only for carbon uptake by plants, but also for many other important issues such as flood risk management, water rights and increased bushfire danger once the landscape dries out again. We had better keep an eye on that.

Intensification of Australia’s wet extremes since 1900s. Most of the intensification is seen in central and northwestern Australia. Ma et al. (2016)

Australian ecosystems are important locally and globally: they absorb carbon, produce food and contain huge species diversity. But these “ecosystem services” are vulnerable to climate change and the increasing frequency of extreme wet and dry events.

Knowing in detail how the landscape is likely to respond to these ever more erratic swings between wet and dry will be a crucial help in learning how we can best respond to drought and deluge in future.

So long, farewell, (for now) Australia’s “great green boom”.

Xuanlong Ma receives an Early Career Research Grant (PRO16-1358) from the University of Technology Sydney.

Alfredo Huete receives funding from The Australian Research Council, NSW-RAAP, NHMRC, TERN, and UTS.

Ben Poulter receives funding from the United States National Science Foundation, the United State Geological Society, and the National Aeronautics and Space Administration.

Derek Eamus receives funding from The Australian Research Council, Google, Hunter Water Corporation, Mid-Coast Water and UTS.

James Cleverly 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.

Germany gets 12% of its electricity from wind power. Renewable energy Germany photo from www.shutterstock.com

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

The Finkel review of the National Electricity Market is an opportunity to consider how Australia can transition its electricity system to be less carbon-intensive.

Germany’s energy transition is often held up as an incredible success story. Starting from a sector relying predominantly on fossil fuels and nuclear energy in the 1990s, renewable energy now provides about 30% of Germany’s electricity.

Germany is on track to achieve its 80% renewable target by 2050. This transformation has been the result of a range of policy measures.

The depth and breadth of these legal and regulatory reforms can provide valuable lessons for Australia.

Strong policy

Energy policy and climate policy have been expressly integrated in Germany since 2007. The government’s Energy Concept sets out Germany’s energy policy until 2050 with a strong focus on transforming the energy system.

It contains short, medium, and long-term targets for reducing greenhouse gases, increasing renewable energy, and improving energy efficiency in consumption, the building and transport sectors. While target-setting in a policy document may seem no more than a political gesture, it shows ambition and leads to political pressure for action. The policy targets for renewable energy are also binding as objectives in the German Renewable Energy Sources Act.

Notably, German legislation for the electricity industry, the Electricity Industry Act 2005, picks up on the ambition of transforming the energy system. It provides that electricity supply should not only be “cost-effective, consumer friendly and efficient”, but also “environmentally compatible” and “increasingly generated from renewable sources”. While the reference to environmental compatibility was already contained in the 1998 law, the express reference to renewables was added in 2011.

Australia, in contrast, continues to keep climate and energy policy separate. The National Electricity Objective remains narrowly-confined to achieving the reliable supply in an efficient way. Overall, Australia lacks long-term target setting, which stymies the necessary planning.

Supporting generators

Germany’s generous feed-in-tariffs (FITs) for renewable energy have been a major driver of transformation since they were first introduced in 1990. The FITs were set separately for each generation source. As a result they have funded a diverse range of renewable sources.

They also enabled the emergence of small and medium-sized renewable generators, which greatly reduced the political power of the big “gentailers” (generators and electricity retailers owned by the same companies).

Twenty-year payback periods and guaranteed dispatch for renewable energy made the FIT a major driver in Germany’s electricity transformation. They have also been a very costly way of supporting renewables.

With renewable energy now maturing, Germany is moving to increased market exposure for renewable energy through reverse auctions similar to mechanisms employed in the Australian Capital Territory.

The Australian Renewable Energy Target (RET) and state-based FITs have predominantly supported wind and rooftop solar. However, both are hampered by the lack of ambitious and long-term targets and considerable policy insecurity. Reverse auction schemes may provide a way forward to efficient support for a diverse range of renewables.

Transforming networks

A crucial part of Germany’s energy reforms is the focus on making networks more renewable-energy friendly. Germany’s renewable energy act requires network businesses (the owners of the poles and wires) to prioritise connecting renewable energy, and upgrade infrastructure where needed. This investment is overseen by the regulator.

No such mechanism for network investment to enable renewable energy exists in Australian network regulation.

German regulation now considers the whole system to strategically update electricity networks. This includes a nationwide and binding planning regime and investment into north-south interconnection. This is to help absorb the massive investment in wind generation in the north.

Network constraints are a major barrier to a 100% renewables future in Australia. Different modelling exercises for large amounts of renewable energy have been done by Beyond Zero Emissions or the Australian Energy Market Operator. Achieving these scenarios would require strategic and binding network planning across the whole of the NEM.

The Australian Energy Market Operator provides information to support efficient network planning, but actual investment decisions are in the hand of the network businesses. The network businesses continue to operate within each of the states. They invest in networks if necessary to guarantee reliable electricity supply.

There are no incentives for “greening” the network and strategically planning beyond state borders in the current regulatory framework.

Lessons for Australia

The German example is by no means a blueprint for Australia. Australia has different natural resources, existing network and generation infrastructure and the lack of neighbouring countries to connect to.

We can see though that a single instrument, be it a RET, Direct Action or a carbon price, will not be enough to enable a transformation.

Energy transitions need reform across the sector. This starts with a high level setting of ambitious, binding and long-term targets for emissions reductions and renewable energy.

It requires not only mechanisms to support generators financially, but also targeted regulation to adapt electricity networks to enable more renewables.

Reform in Germany is ongoing. There is now an impressive amount of legislation and amending legislation that deals with different aspects of the transition.

Crucially, the German government has shown willingness to go back and adapt policy instruments to changing circumstances or to address unintended consequences. Yet the overall commitment to the energy transition remains steady.

The terms of reference for the Finkel review recognise the need to integrate energy and climate policy in Australia. Hopefully it can take a more holistic view of the reforms necessary for decarbonisation of the industry.

A more detailed comparison of German and Australian reforms can be found here A Barrier for Australia’s Climate Commitments? Law, the Electricity Market and Transitioning the Stationary Electricity Sector.

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

Our food system depends on nitrogen fertilisers. Nitrogen image from www.shutterstock.com

While carbon pollution gets all the headlines for its role in climate change, nitrogen pollution is arguably a more challenging problem. Somehow we need to grow more food to feed an expanding population while minimising the problems associated with nitrogen fertiliser use.

In Europe alone, the environmental and human health costs of nitrogen pollution are estimated to be €70-320 billion per year.

Nitrogen emissions such as ammonia, nitrogen oxide and nitrous oxides contribute to particulate matter and acid rain. These cause respiratory problems and cancers for people and damage to forests and buildings.

Nitrogenous gases also play an important role in global climate change. Nitrous oxide is a particularly potent greenhouse gas as it is over 300 times more effective at trapping heat in the atmosphere than carbon dioxide.

Nitrogen from fertiliser, effluent from livestock and human sewage boost the growth of algae and cause water pollution. The estimated A$8.2 billion damage bill to the Great Barrier Reef is a reminder that our choices on land have big impacts on land, water and the air downstream.

Lost nitrogen harms farmers too, as it represents reduced potential crop growth or wasted fertiliser. This impact is most acute for smallholder farmers in developing countries, for whom nitrogen fertiliser is often the biggest cost of farming. The reduced production from the lost nitrogen can represent as much as 25% of the household income.

The solution to the nitrogen challenge will need to come from a combination of technological innovation, policy and consumer action.

The essential ingredient

Nitrogen is an essential building block for amino acids, proteins and DNA. Plant growth depends on it; animals and people get it from eating plants or other animals.

Nitrogen gas (N₂) makes up 78% of the air, but it cannot be used by plants. Fertilisers are usually made from ammonia, a form of nitrogen that the plants prefer.

A century after the development of the Haber-Bosch process gave us a way to manufacture nitrogen fertiliser, our demand for it has yet to level off.

The use of nitrogen fertiliser has risen from 11 million tonnes in 1961 to 108 million tonnes in 2014. As carbon dioxide levels continue to rise in the atmosphere, some plants such as grains will also likely demand more nitrogen.

Wheat with and without nitrogen fertiliser. Deli Chen/ The University of Melbourne

In fact, nitrogen from fertiliser now accounts for more than half the protein in the human diet. Yet some 50% of applied nitrogen is lost to the environment in water run-off from fields, animal waste and gas emissions from soil microbe metabolism.

These losses have been increasing over the decades as nitrogen fertiliser use increases. Reactive nitrogen causes wide-ranging damage, and will cause more damage if nitrogen losses are not reined in.

Faced with a growing population and changing climate, we need more than ever to optimise the use of nitrogen and minimise the losses.

From farm to fork

One way to understand our nitrogen use is to look at our nitrogen footprint – the amount of nitrogen pollution released to the environment from food, housing, transportation and goods and services.

Research by University of Melbourne PhD candidate Emma Liang shows Australia has a large nitrogen footprint. At 47kg of nitrogen per person each year, Australia is far ahead of the US, which came in with 28kg of nitrogen per person.

A high-animal-protein diet appears to be driving Australia’s big nitrogen footprint. The consumption of animal products accounts for 82% of the Australian food nitrogen footprint.

Animal products carry high nitrogen costs compared to vegetable products. Both products start with the same cost in nitrogen as a result of growing a crop, but significant further losses occur as the animal consumes food throughout its life cycle.

The N-Footprint project aims to help individuals and institutions calculate their nitrogen footprints. It shows how we can each have an impact on nitrogen pollution through our everyday choices.

We can choose to eat lower nitrogen footprint protein diets, such as vegetables, chicken and seafood instead of beef and lamb. We can choose to reduce food waste by buying smaller quantities (and more frequently if necessary) and composting food waste. The good news is, if we reduce our nitrogen footprint, we also reduce our carbon footprint.

Back to the farm

In the meantime, efforts to use nitrogen more efficiently on farms must continue. We are getting better at understanding nitrogen losses from soil through micrometerological techniques.

From sitting in the sun with plastic bucket chambers, glass vials and syringes, scientists now use tall towers and lasers to detect small changes in gas concentrations over large areas and send the results directly to our computers.

Eddy covariance tower. Mei Bai/ The University of Melbourne

We now know nitrification (when ammonia is converted to nitrate) is an important contributor to nitrogen losses and therefore climate change and damage to ecosystems. It is a process researchers – and farmers – are targeting to reduce nitrogen losses.

Nitrification inhibitors are now used commercially to keep nitrogen in the ammonium form, which plants prefer, and to prevent the accumulation of nitrate, which is more easily lost to the environment.

As this technology advances, we are starting to answer the question of how these inhibitors affect the microbial communities that maintain the health of our soil and form the foundation of ecosystems.

For example, our research shows that 3,4-dimethylpyrazole phosphate (better known as DMPP) inhibits nitrification without affecting soil microbial community diversity.

There have also been exciting observations that the root systems of some tropical grasses inhibit nitrification. This opens up a management option to slow nitrification rates in the environment using genetic approaches.

Solving the challenge of nitrogen use will require research into more efficient ways for primary producers to use nitrogen, but it will also need government leadership and consumer choices to waste less or eat more plant protein. These tools will make the case for change clearer, and the task of feeding the world greener.

On December 4-8, leading international researchers are meeting in Melbourne for the 7th International Nitrogen Initiative Conference to discuss the best new solutions to problems in nitrogen use. For a more in-depth look at these issues, visit the INI2016 website or join a range of food and production experts at the Good Food for 9 Billion: Community Forum.

Ee Ling Ng works for The University of Melbourne. She receives funding from the Commonwealth Government.

Deli Chen receives funding from Australia Research Council, Meat Livestock Australia, Australian Centre for international Agricultural Research

Robert Edis receives funding from The Australian Centre for International Agricultural Research (ACIAR). He is affiliated with and employed by ACIAR.

Emma Liang receives funding from Meat and Livestock Australia​ and the ​Australia-China Joint Research Centre at the University of Melbourne.

Water quality is one of the biggest threats facing the Great Barrier Reef. Tatters ❀/Flickr, CC BY-NC

The Australian and Queensland governments have delivered their progress report to the UN on the Reef 2050 Plan to ensure the long-term survival of the Great Barrier Reef.

The report focuses on water quality, and managing pollution runoff, but only deals in a superficial way with the other preeminent issue for the reef - climate change.

It shows recent progress on water quality has been slow, and ultimately we will not meet water quality targets without major further investments.

Progress?

The progress report claims some success in managing water quality through improved practices in sugarcane cultivation under the SmartCane program, and in rangeland grazing.

But actual reductions in sediment and nutrients loads to the reef over the last two years have been very small, as shown in the Reef Report Card 2015. This contrasts with the first five years of Reef Plan (2008-2013) where there was modest progress, as you can see below.

Great Barrier Reef Report Card 2015

The positive news out of the Report Card was that grain cropping and non-banana horticulture were doing well, but these are the industries we have little robust data on.

And there’s been little progress towards adequate management practices in sugarcane and rangeland grazing as well as gully remediation in the large dry tropics catchments of the Burdekin, Fitzroy and Normanby.

The specific actions and funding promised in this area over the next five years mentioned in the progress report which have some real substance are:

1. Direct a further A$110 million of Reef Trust funding towards projects to improve water

2. Bring forward the review of the Reef Water Quality Protection Plan and set new scientifically based pollutant load targets

3. Invest A$33 million of Queensland government funding into two major integrated projects

4. Better prioritise of water quality as a major theme in Reef 2050 Plan.

What we need to do

However these fall far short of the real requirements to meet water quality targets on the reef, set out in the Reef 2050 Plan and the Reef Water Quality Protection Plan.

The best estimate is that meeting water quality targets by 2025 will cost A$8.2 billion. Other estimates suggest we’ll need at least A$5-10 billion over the next ten years.

If we assume that about A$4 billion is needed over the next five years, the amounts mentioned in the progress report (perhaps A$500-600 million at most) are obviously totally inadequate.

There is thus almost no chance the targets will be reached at the nominated time.

This reality has been clearly acknowledged by Dr David Wachenfeld, the Director of Reef Recovery at the Great Barrier Reef Marine Park Authority. In fact the current progress towards the targets is so poor that we will not even get close.

The actions actually needed to manage water quality for the Great Barrier Reef are well known and have been published in the Queensland Science Taskforce Report and scientific papers.

The most important of these are:

1. Allocate sufficient funding (A$4 billion over the next five years)

2. Use the legislative powers already available to the Australian government under the Great Barrier Reef Marine Park Act (1975) and the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act) to regulate agriculture and other activities in the reef’s water catchment

3. Examine seriously the need for land use change in the reef catchment. For example, we may need to look at shifting away from more intensive forms of land use such as cropping, which produce more pollutants per hectare, to less intensive activities such as beef grazing, forestry or conservation uses

4. Continue to improve land management in sugarcane, beef grazing and horticulture but acknowledge the need to extend these programs. We also need better practices in urban and coastal development

5. Critically examine the economics and environmental consequences of the further expansion of intensive agriculture in the reef’s catchment as promoted under the Australian government’s Northern Australian Development Plan

Progress on water quality management for the Great Barrier Reef, as clearly reported in the 2015 Report Card is poor. There is little chance we will reach the water quality targets in the next ten years, without upping our game.

Jon Brodie is also a partner in the consulting partnership C2O. See: http://www.c2o.net.au/