Australia to ratify the Paris climate deal, under a large Trump-shaped shadow

Marc Hudson, University of Manchester

Australia’s government has announced that it is to ratify the Paris climate agreement, which was struck 11 months ago and entered into force last Friday.

The move comes despite the election of Donald Trump, who has called climate change a Chinese-inspired hoax. Trump has pledged to turn his back on the Paris treaty after he takes office in January, although this would take at least a year and technically leave the Agreement still in force, albeit weakened.

The question for Australia is how Canberra will react to such a seismic shift in US climate policy. The last time a US president pulled the plug on international climate negotiations was in March 2001, when George W. Bush withdrew from the Kyoto treaty. Australia’s prime minister John Howard followed suit on Earth Day 2002.

The temptation for Australia’s current government would be to follow in Trump’s slipstream in much the same way. Despite its 2030 climate target being widely seen as unambitious, Australia still lacks a credible plan to deliver the necessary emissions cuts, and has no renewable energy target beyond 2020.

While Prime Minister Malcolm Turnbull may be a vocal supporter of climate action, not everyone on on his side of politics is as keen – such as MPs Craig Kelly and George Christensen. (It was not always thus under the Liberals.)

The temptation to defect might be strong, but the countervailing pressure will be much stronger that it was in 2002, and the clean energy transition is already underway. Just this week, a high-powered group of business leaders, energy providers, academics and financiers called on Turnbull to expand the renewable energy target and create a market mechanism to phase out coal.

Yet the US election has also reinvigorated Australian opponents of climate action, such as One Nation senators Pauline Hanson and Malcolm Roberts, who were cracking champagne at the prospect of Trump in the White House, and media commentator Andrew Bolt, who jubilantly described Trump’s victory as a “revolt against the left’s arrogance”.

Which bit of history will repeat?

On balance, then, it is still hard to predict Australia’s next move – and past form is little guide for future performance.

Over the past 26 years, Australia has made two largely symbolic commitments to international climate action, and one very concrete refusal.

In 1990, ahead of the 2nd World Climate Conference which fired the starting gun for the United Nations’ climate negotiations, the Hawke government announced a target of a 20% reduction by 2005.

The pledge, however, was laced with crucial caveats, like this one:

…the Government will not proceed with measures which have net adverse economic impacts nationally or on Australia’s trade competitiveness in the absence of similar action by major greenhouse-gas-producing countries.

This target was sidelined in the final United Nations Framework Convention on Climate Change, which Australia signed and ratified in 1992.

In 1997, Australia got a very sweet deal at the Kyoto climate talks, successfully negotiating an 8% increase in greenhouse gases as its emissions “reduction” target, as well as a special loophole that allowed it take account of its large reduction in land clearing since 1990. Australia signed the deal in April 1998, but never ratified it.

Kyoto’s rules hid a multitude of sins, anyway, as Oxford University’s Nicholas Howarth and Andrew Foxall have pointed out:

…its accounting rules obscure the real level of carbon emissions and structural trends at the nation-state level… it has shifted focus away from Australia as the world’s largest coal exporter towards China, its primary customer.

Although Kevin Rudd famously ratified Kyoto and received a standing ovation at the Bali Climate summit in 2007, a stronger Australian emissions reduction target was not forthcoming.

The next big moment came at the Paris negotiations of 2015. Australia’s official pledge was a 26-28% reduction on 2005 levels by 2030 – a target unveiled by the former prime minister Tony Abbott, and which met with a lukewarm response from analysts.

Since then, pressure has been building for Australia to explain how it can meet even that target, given the hostility to renewable energy among the federal government, the lack of a post-2020 renewables target, and the inadequacy of the current Direct Action policy.

And now we are looking at the prospect of a Trump presidency, already described as “a turning point in the history of climate action” and “the end of any serious hope of limiting climate change to 2 degrees”.

In a chaotic world that has confounded pollsters, it seems foolish to bet on anything. But two predictions seem sure: atmospheric concentrations of carbon dioxide will rise, and the future will be … interesting.

Marc Hudson, PhD Candidate, Sustainable Consumption Institute, University of Manchester

This article was originally published on The Conversation. Read the original article.

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The third global bleaching event took its toll on Western Australia’s super-corals

Verena Schoepf, University of Western Australia

Australia’s iconic Great Barrier Reef has suffered through the worst bleaching event in its history, part of the world’s third mass bleaching event.

However, coral reefs from the other side of the continent have also experienced unprecedented bleaching and coral death. This is bad news because the unique coral reefs of Western Australia’s northwest are home to some of the toughest coral in the world.

Western Australia’s unique coral reefs

Although much less well-known, coral reefs in Western Australia are highly diverse. They include, for example, Australia’s largest fringing reef, the World Heritage-listed Ningaloo Reef, as well as Australia’s largest inshore reef, Montgomery Reef which covers 380 square kilometres.

WA’s remote Kimberley region also features “super-corals” – corals that have adapted to a naturally extreme environment where tidal swings can be up 10m. These corals can therefore tolerate exposure to the air during low tide as well as extreme daily temperature swings.

My past research has shown that these naturally extreme conditions increase the heat tolerance of Kimberley corals but that they are nevertheless not immune to bleaching when water temperatures are unusually hot for too long.

Previously I had put these super-corals in tanks and subjected them to a three-week heatwave to see how they would respond, but I always wondered how they would cope in the wild where such events typically unfold over longer timescales. Unfortunately, I did not have to wait long to find out.

Kimberley reef exposed at low tide before…
Verena Schoepf, Author provided

….and during the bleaching.
Morane Le Nohaic, Author provided

The hottest years on record

2015 was the hottest year on record and 2016 will likely be hotter still. This has caused an unprecedented global coral reef crisis. Although global coral bleaching events already occurred in 1998 and 2010, this third global bleaching event is the longest on record and still ongoing.

Sadly, in WA the Kimberley region was hit the hardest. As part of Australia’s National Coral Bleaching Taskforce, colleagues and I conducted extensive monitoring before, during and after the predicted bleaching event along the entire WA coastline. In the southern Kimberley, we also carried out aerial surveys to assess the situation on a regional level.

Aerial view of a bleached inshore Kimberley reef in April 2016.
Claire Ross and Steeve Comeau, Author provided

The severity and scale of bleaching that we observed in April was devastating. Almost all inshore Kimberley reefs that we surveyed had about 50% bleaching, including Montgomery Reef. Researchers from the Australian Institute of Marine Science found that offshore Kimberley reefs such as Scott Reef fared even worse, with 60-90% bleaching in shallow lagoon waters.

Many corals had already died from the severe bleaching in April, but the final death toll has only been revealed during visits to the Kimberley last month. Vast areas of coral reef are now dead and overgrown with algae, both at the inshore and offshore Kimberley reefs.

According to local Indigenous Rangers and Traditional Owners who assisted in the research, this appears to be unprecedented. Such events had never previously been described in their rich local history of the coastal environment.

Bleached staghorn coral on inshore Kimberley reefs in April 2016.
Verena Schoepf

Dead staghorn coral on the same reefs in October 2016.
Verena Schoepf

Some good news

There was nevertheless some good news. Corals living in intertidal areas, where they regularly experience exposure to air, stagnant water, and extreme temperature fluctuations, bleached less than corals from below the low-tide mark, where conditions are far more moderate. And importantly, the majority of intertidal corals were able to fully recover within a few months.

Similarly, researchers from the Western Australian Museum and Curtin University confirmed last month that intertidal coral reefs in the central Kimberley (Bonaparte Archipelago) were in great condition.

Overall, these observations confirm the findings from my past research which showed that highly-variable, extreme temperature environments can boost the bleaching resistance of corals.

It is also important to note that the 2016 severe bleaching event in WA was restricted to the Kimberley region. Ningaloo Reef as well as coral reefs in the Pilbara and the Abrolhos Islands all escaped the bleaching. This is great news because some of these locations are still recovering from major bleaching in 2010-11 and 2013.

Healthy coral at Ningaloo Reef in 2016.
Morane Le Nohaic

The future of WA’s coral reefs

Although it is now clear that WA’s coral reefs are at risk of bleaching during both El Niño (as in 2016) and La Niña years (as in 2010-11), they have some advantages over other reefs that may hopefully allow them to recover from bleaching more quickly and stay healthy in the long term.

For example, most of WA’s coral reefs are located far away from major population centres and are thus less affected by environmental threats such as poor water quality (though other threats such as oil and gas exploration do exist). We also know that their isolation, particularly in the case of offshore reefs, helped them recover from previous mass bleaching events.

Finally, it is critical that we identify coral populations worldwide that are already naturally adapted to higher temperatures and have a greater bleaching resistance, such as the Kimberley corals.

These super-corals, while not immune to climate change, should be a priority for research into the limits of coral tolerance, as well as conservation efforts.

Verena Schoepf, Research Associate, University of Western Australia

This article was originally published on The Conversation. Read the original article.

Woodpeckers and Concussion

We’ve learned a lot about heatwaves, but we’re still just warming up

Sarah Perkins-Kirkpatrick, UNSW Australia and Christopher J. White, University of Tasmania

The journal Climatic Change has published a special edition of review papers discussing major natural hazards in Australia. This article part of a series looking at those threats in detail.

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Australia is no stranger to heatwaves. Each summer, large areas of the continent fry under intense heat for days on end, causing power outages, public transport delays, and severe impacts to human health. The estimated impact on our workforce alone is US$6.2 billon per year. Heatwaves are also Australia’s deadliest natural hazard, accounting for well over half of all natural disaster-related deaths.

Along with our colleagues, we have taken a close look at what we know and don’t know about heatwaves in Australia, as part of a series of reviews produced by the Australian Energy and Waster Exchange initiative.

Let’s start with the stuff we know. First, we are very clear on the weather systems that drive heatwaves in Australia’s densely populated coastal areas. Typically, a persistent high-pressure system sits next to the region experiencing the heatwave, pushing hot air from the centre of Australia towards that region. The location of the high depends on the region experiencing the heatwave, but there is always one there.

These high-pressure systems are created and sustained by other weather influences farther afield, for instance. We know for instance that heatwaves in Melbourne are coupled with tropical cyclones to the northwest of Australia.

Other, longer-term variables can affect not just individual heatwaves but their patterns, timing and severity too. So heatwaves are likely to be much longer and more frequent during El Niño than La Niña phases over much of northern and eastern Australia. However, this does not influence heatwaves over Australia’s far southeast – here, the most important driver is changes to wind patterns over the Southern Ocean.

We also know that heatwave trends have increased in the observational record, and, unfortunately, that they will continue to do so. By far the strongest trend is in the number of heatwave days experienced each season. Over much of eastern Australia, this trend is as large as two extra days per season, per decade.

Trends in seasonal heatwave days, per decade.
Perkins-Kirkpatrick et al., Climatic Change, Author provided

Looking into the future, heatwaves are projected to become more frequent, with increases of between 20 and 40 extra days per season in the north and 5-10 extra days in the south likely by the end of this century, under a “business as usual” scenario. The intensity of heatwaves over southern Australia is also increasing faster than the average temperature. This is not good news for our ageing population, our fragile ecosystems and our outdated infrastructure.

The Australian research community has been successful in leading the development of a comprehensive way to measure marine heatwaves. Just like the atmosphere, areas of the ocean can experience prolonged periods of abnormally warm temperatures. These marine heatwaves can be every bit as damaging as atmospheric ones, decimating marine habitats and killing coral.

What we don’t yet know

Perhaps surprisingly, given the amount of research and public attention that heatwaves attract, they still do not have an official definition. The Bureau of Meteorology uses a concept called excess heat factor, which looks at maximum temperatures and ensuing minimum temperatures over a three-day period, incorporating the key characteristic of heatwaves of heat tending to persist overnight. However, we still do not have a universal definition that fits all situations.

We are also unclear on how the physical mechanisms that drive heatwaves will change under ongoing greenhouse warming. Recent research suggests that background warming will predominantly drive future increases in heatwaves, with some heatwave-inducing systems moving further south. But we don’t really know how future changes to patterns such as El Niño will continue to influence our heatwaves.

We also don’t really understand the extent to which the land surface drives Australian heatwaves. European studies have shown that dry conditions leading up to heatwave season, resulting in more parched soils, are a recipe for more intense and longer events, particularly when coupled with a persistent high-pressure system.

For Australia, we know that dry soil contributed to the deadly heatwave that preceded the Black Saturday bushfires in 2009. But more extensive studies are needed to understand this complex relationship over Australian soil (pun intended).

We also need a more comprehensive understanding of marine heatwaves. So far there has been only a handful of studies describing individual events. We still don’t know how much marine heatwaves have increased over recent decades, or how their causes and severity will change in the future. Given how vulnerable we are to marine heatwaves here in Australia, this topic should be a national research priority.

Finally, we need to develop more practical predictions of how heatwaves are likely to affect people in the future. We know how bad the impacts of heatwaves can be, and we know in general terms how heatwaves will change in the future. Yet the vast majority of our projections come from global climate models. Forecasting the exact impacts calls for finer spatial detail, using regional climate models. But these models are far more computationally expensive to run, and more investment into this area is necessary.

There is no doubt that heatwaves have been, and will continue to be, an integral feature of Australia’s climate, and recent research has taught us a lot about them. But there is more work to be done if we want to safeguard Australians properly from their deadly impacts in the future.

Sarah Perkins-Kirkpatrick, Research Fellow, UNSW Australia and Christopher J. White, Lecturer in Environmental Engineering, University of Tasmania

This article was originally published on The Conversation. Read the original article.

Keeping warming below 1.5℃ is possible – but we can’t rely on removing carbon from the atmosphere

Kate Dooley, University of Melbourne

This week international leaders are meeting in Marrakech to thrash out how to achieve the Paris climate agreement, which came into force on Friday. The Marrakech meeting is the 22nd Congress of Parties (or COP22) to the United Nation’s climate convention. One of the key goals of the agreement is to limit global warming to well below 2℃, and aim to limit warming to 1.5℃.

With global greenhouse gas emissions still rising, this is a daunting task. Numerous models, including recent research, suggest we will not be able to achieve this without removing large amounts of greenhouse gases from the atmosphere later this century (known as “negative emissions”).

But scientists are becoming increasingly sceptical of the concept, as it may create more problems than it solves, or fail to deliver. Instead, we need to ramp up action before 2020, before even the earliest targets of the Paris Agreement.

Going negative

Some models suggest that up to 1 trillion tonnes of carbon dioxide needs to be removed from the atmosphere to meet the 1.5℃ goal.

This idea is increasingly being called out as a risky and “highly speculative” strategy to limit warming to 1.5℃, as it puts food security and biodiversity at risk, and may not even be possible to deliver. The Convention on Biodiversity has also now weighed in on the issue, declaring that carbon removal techniques are highly uncertain.

A recent report from the Stockholm Environment Institute (SEI), summarised here, argues that the scale of negative emissions assumed by many climate models is improbably high.

The key components of negative emissions are reducing deforestation, planting trees, and an untested technology called “bioenergy with carbon capture and storage” or BECCS. The involves burning plant matter to produce energy, capturing the waste CO₂, and then storing it underground. The result is less CO₂ in the atmosphere.

But there are several problems with these strategies. For one, the scale of land required for the expected level of negative emissions suggests serious social and ecological risks, since land plays a crucial role in food security, livelihoods and biodiversity conversation.

Indeed, the scale of bioenergy supply in many cases is equivalent to the current global harvest of all biomass – for food, feed, and fibre – assuming a doubling of human harvest of biomass by 2050.

The SEI paper argues that the risks and uncertainties associated with negative emissions could lock us into much higher levels of warming than intended, substantially undermining society’s overall mitigation efforts.

Better ways to remove carbon

So does all of this mean the 1.5℃ goal is out of reach? Some may think so.

However, the SEI analysis finds that if emissions were cut sufficiently quickly and ambitiously, we wouldn’t need to rely so much on negative emissions. We could also choose negative emissions methods with lower impacts on biodiversity, resource demands, and livelihoods.

The SEI analysis optimistically suggests that a maximum of 370 billion to 480 billion tonnes of CO₂ could be removed without exceeding biophysical, technological and social constraints. This would be done through protecting forests and allowing degraded forests to regenerate, along with some reforestation.

Even that would be extremely challenging to achieve, but done right, for example through community forestry and agro-ecological farming,, climate mitigation and sustainable development could go together.

In fact, securing land rights of indigenous peoples and local communities who protect and preserve the carbon stocks in forests is one of the most cost-effective forms of climate mitigation we have, with obvious social co-benefits.

Scaling up

The real threat of negative emissions is the potential to delay emissions reduction into the future. Many modelled pathways for 1.5℃ that include substantial negative emissions suggest that emissions do not begin to decline until the late 2020s.

But limiting negative emissions to lower levels would require immediate global mitigation on a scale greatly exceeding that which has so far been pledged by nations under the Paris Agreement.

We cannot wait until 2020 to speed up global action on climate change – less action now will mean more work later.

Key for strengthening pre-2020 action in Marrakech will be a facilitative dialogue on enhancing ambition and support and a high level ministerial meeting on increased ambition of 2020 commitments under the Kyoto Protocol.

Many countries, including Australia, still have completely inadequate targets for 2020, making arguments about whether they are on track to meet them or not moot.

The Moroccan government has dubbed Marrakech the “action COP”. Action here must focus on the urgent need for global emissions to begin declining before 2020, and on the finance needed to deliver it. This includes scaling up the rollout of renewable energy, halting and reversing the loss of the world’s forests, and tackling rich world consumption patterns to ensure equitable mitigation pathways.

Limiting global warming to 1.5℃ is not only possible, it is the only chance of survival for the most vulnerable communities around the world, who are increasingly exposed to rising sea levels, drought and food shortages.

As Erik Solheim, head of the UN Environment Program (UNEP), and Jacqueline McGlade, UNEP’s chief scientist, wrote in a recent report, those most vulnerable “take little comfort from agreements to adopt mitigation measures and finance adaptation in the future. They need action today”.

Kate Dooley, PhD candidate, Australian German Climate and Energy College, University of Melbourne

This article was originally published on The Conversation. Read the original article.

Should genetically modified organisms be part of our conservation efforts?

Fern Wickson, GenØk – Centre for Biosafety

Biotechnology is rapidly evolving through developments in genome editing and synthetic biology, giving birth to new forms of life.

This technology has already given us genetically modified (GM) plants that produce bacterial pesticides, GM mosquitos that are sterile and GM mice that develop human cancers.

Now, new biotechnological techniques are promising to deliver a whole host of new lifeforms designed to serve our purposes – pigs with human organs, chickens that lay eggs containing cholesterol controlling drugs, and monkeys that develop autism. The possibilities seem endless.

But do these genetically modified organisms (GMOs) have conservation value?

The biodiversity of life on earth is globally recognised as valuable and in need of protection. This includes not just wild biodiversity but also the biodiversity of agricultural crop plants that humans have developed over thousands of years.

But what about the synthetic forms of biodiversity we are now developing through biotechnologies? Does anyone care about this synbiodiversity?

It’s a question I was compelled to ask while conducting research into the Svalbard Global Seed Vault (SGSV).

A frozen ‘Noah’s Ark’ for seeds

The SGSV is the global apex of agricultural biodiversity conservation, an approach to conservation where collections of diverse seed samples are kept in frozen storage in genebanks for future use by plant breeders.

The SGSV is a frozen cavern in a mountain on the arctic island of Svalbard, halfway between mainland Norway and the North Pole. It has been called a Noah’s Ark for crop plants (also the “doomsday vault”) because it is the place where genebanks from all around the world send backup copies of their seed collections for safe-keeping.

Here the seeds are sealed inside bags sealed inside boxes locked in a freezer locked in a mountain. They are sent there to be kept safe from the threats genebanks can face, such as energy shortages, natural disasters and war.

The Svalbard Global Seed Vault.
Flickr/Landbruks og matdepartementet, CC BY-NC-ND

Seeds in the SGSV can only be accessed by the genebank that deposited them and only one withdrawal has been made so far, by researchers from the International Center for Agricultural Research in the Dry Areas (ICARDA ) seeking to restore their collections after the destruction of Aleppo in war-torn Syria.

The SGSV is managed through a collaborative agreement between the Norwegian government, the Crop Trust and the Nordic Genetic Resource Center (NordGen).

It opened in 2008 and currently houses 870,971 different samples of 5,340 species from 233 countries, deposited by 69 institutes.

Inside the frozen Svalbard Global Seed Vault.
Flickr/Landbruks og matdepartementet, CC BY-NC-ND

Are there any GMOs frozen in the vault?

During my research into the SGSV I asked if it held any GM seeds.

Despite initially receiving conflicting responses, the formal answer was ultimately “no”. But different reasons were given for this and all are open to change.

The vault is not a certified facility for GMO storage

Facilities working with GMOs require certification to do so.

While the SGSV is not currently certified, it could be since requirements typically relate to ensuring strict containment and the SGSV is already oriented towards this goal.

Also, since no analysis of seeds is performed at the SGSV or required for deposits, the collections may actually be unintentionally (and unwittingly) contaminated. This is because a mixing with GM crops could have happened via seed or pollen flow before the material was sent to the vault.

There is no political will to include GM crops

Currently, no one in the SGSV management wants to become (any further) entangled in the controversy surrounding GM crops.

They already face what they see as false conjectures about the role of the biotechnology industry (fuelled no doubt by the fact that organisations involved in the biotechnology industry have donated funds to the Crop Trust).

Several of the depositing genebanks also actively support biotechnology research. Therefore, if they wanted to store GMOs in the future, the will to seek certification may certainly change.

Norway has a strict GMO policy that requires not just evidence of safety but also of social utility and contribution to sustainable development. This means no GM crop has yet been approved for either cultivation or import.

But this is currently being challenged by a government committed to speeding up assessments and advocating for weakened interpretations of the law. This further indicates the potential for political will to change.

GM crops do not meet the requirements for multilateral access

The International Plant Treaty is a crucial foundation for the SGSV. As such, depositing genebanks are required to agree to multilateral access to their collections if they wish to deposit backup copies in the SGSV.

But GM crops are not freely accessible to all as part of the common heritage of humanity. They are patented inventions owned by those claiming to have created them. The SGSV requirement that deposits be available for multilateral access can be waived though.

But if GM crops are not in the SGSV, should they be?

Do GMOs have conservation value?

Very little work has examined the moral status and conservation value of GM crops.

As the fields of genome editing and synthetic biology are now undergoing rapid development though, we have an important opportunity to consider how we relate to biotechnological forms of biodiversity. We can also think about whether it might be possible to navigate through syn- to symbiodiversity.

That is, instead of focusing on these life forms as synthetic human inventions, we could begin to think about them as co-creations of human-nature interactions. In doing so, we may then shift the focus away from how to make synthetic organisms to satisfy our needs and place more emphasis on how to interact with other life forms to establish symbiotic relations of mutual benefit.

The French sociologist of science and anthropologist Bruno Latour has urged us to love our monsters, to take responsibility for our technologies and care for them as our children.

Certainly it seems fair to argue that if we don’t care for our biotechnological co-creations with a sense of (parental) responsibility, perhaps we shouldn’t be bringing them to life.

How do we care for GM crops?

The model of freezing seeds in genebanks and backing up those collections at the SGSV is one way to conserve biodiversity. Another, however, is the approach of continuing to cultivate them in our agricultural landscapes.

While this model of conservation has generated and maintained the biodiversity of traditional crop varieties for thousands of years, there is now a significant shift taking place. More than 90% of traditional crop varieties have now disappeared from our fields and been replaced by genetically uniform modern varieties cultivated in large-scale monocultures. Meaning, there may be no GM crops frozen in the SGSV, but there are plenty in the ground.

So this leaves me questioning what it is we really cherish? Are we using our precious agricultural resources to expand the diversity of humanity’s common heritage?

Or are we rather placing our common heritage on ice while we expand the ecological space occupied by privately owned inventions? And who cares about synbiodiversity anyway?

Fern Wickson, Senior Scientist & Program Coordinator, GenØk – Centre for Biosafety

This article was originally published on The Conversation. Read the original article.

Canary Islands: La Palma

Radical overhaul needed to halt Earth’s sixth great extinction event

Bill Laurance, James Cook University and Paul Ehrlich, Stanford University

Life has existed on Earth for roughly 3.7 billion years. During that time we know of five mass extinction events — dramatic episodes when many, if not most, life forms vanished in a geological heartbeat. The most recent of these was the global calamity that claimed the dinosaurs and myriad other species around 66 million years ago.

Growing numbers of scientists have asserted that our planet might soon see a sixth massive extinction — one driven by the escalating impacts of humanity. Others, such as the Danish economist Bjørn Lomborg, have characterised such claims as ill-informed fearmongering.

We argue emphatically that the jury is in and the debate is over: Earth’s sixth great extinction has arrived.

Collapse of biodiversity

Mass extinctions involve a catastrophic loss of biodiversity, but what many people fail to appreciate is just what “biodiversity” means. A shorthand way of talking about biodiversity is simply to count species. For instance, if a species goes extinct without being replaced, then we are losing biodiversity.

But there’s much more to biodiversity than just species. Within each species there usually are substantial amounts of genetic, demographic, behavioural and geographic variation. Much of this variation involves adaptations to local environmental conditions, increasing the biological fitness of the individual organism and its population.

Natural variation within two species of sea snails. Upper row: Littorina sitkana. Lower row: Littorina obtusata.
Copyright David Reid/Ray Society.

And there’s also an enormous amount of biodiversity that involves interactions among different species and their physical environment.

Many plants rely on animals for pollination and seed dispersal. Competing species adapt to one another, as do predators and their prey. Pathogens and their hosts also interact and evolve together, sometimes with remarkable speed, whereas our internal digestive systems host trillions of helpful, benign or malicious microbes.

Hence, ecosystems themselves are a mélange of different species that are continually competing, combating, cooperating, hiding, fooling, cheating, robbing and consuming one another in a mind-boggling variety of ways.

All of this, then, is biodiversity – from genes to ecosystems and everything in between.

The modern extinction spasm

Cumulative vertebrate species extinctions since 1500 compared to the ‘background’ rate of species losses.
G. Ceballos et al. (2015) Scientific Advances.

No matter how you measure it, a mass extinction has arrived. A 2015 study that one of us (Ehrlich) coauthored used conservative assumptions to estimate the natural, or background rate of species extinctions for various groups of vertebrates. The study then compared these background rates to the pace of species losses since the beginning of the 20th century.

Even assuming conservatively high background rates, species have been disappearing far faster than before. Since 1900, reptiles are vanishing 24 times faster, birds 34 times faster, mammals and fishes about 55 times faster, and amphibians 100 times faster than they have in the past.

For all vertebrate groups together, the average rate of species loss is 53 times higher than the background rate.

Extinction filters

To make matters worse, these modern extinctions ignore the many human-caused species losses before 1900. It has been estimated, for instance, that Polynesians wiped out around 1,800 species of endemic island birds as they colonised the Pacific over the past two millennia.

And long before then, early human hunter-gatherers drove a blitzkrieg of species extinctions — especially of megafauna such as mastodons, moas, elephant birds and giant ground sloths — as they migrated from Africa to the other continents.

In Australia, for instance, the arrival of humans at least 50,000 years ago was soon followed by the disappearance of massive goannas and pythons, predatory kangaroos, the marsupial “lion”, and the hippo-sized Diprotodon among others.

Changes in climate could have contributed, but humans with their hunting and fires were almost certainly the death knell for many of these species.

As a result of these pre-1900 extinctions, most ecosystems worldwide went through an “extinction filter”: the most vulnerable species vanished, leaving relatively more resilient or less conspicuous species behind.

Giant ground sloths such as this elephant-sized Megatherium vanished soon after humans arrived in the New World.
Copyright Catmando.

And it’s the loss of these survivors that we are seeing now. The tally of all species driven to extinction by humans from prehistory to today would be far greater than many people realise.

Vanishing populations

The sixth great extinction is playing out in other ways too, especially in the widespread annihilation of millions (perhaps billions) of animal and plant populations. Just as species can go extinct, so can their individual populations, reducing both the genetic diversity and long-term survival prospects of the species.

For example, the Asian two-horned rhinoceros once ranged widely across Southeast Asia and Indochina. Today it survives only in tiny pockets comprising perhaps 3% of its original geographic range.

Three-quarters of the world’s largest carnivores, including big cats, bears, otters and wolves, are declining in number. Half of these species have lost at least 50% of their former range.

Likewise, except in certain wilderness areas, populations of large, long-lived trees are falling dramatically in abundance.

WWF’s 2016 Living Planet Report summarises long-term trends in over 14,000 populations of more than 3,700 vertebrate species. Its conclusion: in just the last four decades, the population sizes of monitored mammals, birds, fish, amphibians and reptiles have shrunk by an average of 58% worldwide.

And as populations of many species collapse, their crucial ecological functions decline with them, potentially creating ripple effects that can alter entire ecosystems.

Hence, disappearing species can cease to play an ecological role long before they actually go extinct.

Once a widespread and dominating predator, the tiger today is vanishingly rare across most of its former range.
Copyright Matt Gibson

Paying the extinction debt

Everything we know about conservation biology tells us that species whose populations are in freefall are increasingly vulnerable to extinction.

Extinctions rarely happen instantly, but the conspiracy of declining numbers, population fragmentation, inbreeding and reduced genetic variation can lead to a fatal “extinction vortex”. In this sense, our planet is currently accumulating a large extinction debt that must eventually be paid.

And we’re not just talking about losing cute animals; human civilisation relies on biodiversity for its very existence. The plants, animals and microorganisms with which we share the Earth supply us with vital ecosystem services. These include regulating the climate, supplying clean water, limiting floods, running nutrient cycles essential to agriculture and forestry, controlling serious crop pests and carriers of diseases, and providing beauty, spiritual and recreational benefits.

Are we preaching doom? Far from it. What we’re saying, however, is that life on Earth is ultimately a zero-sum game. Humans cannot keep growing in number and consuming ever more land, water and natural resources and expect all to be well.

Limiting harmful climate change has become a catchphrase for battling such maladies. But solutions to the modern extinction crisis must go well beyond this.

We also have to move urgently to slow human population growth, reduce overconsumption and overhunting, save remaining wilderness areas, expand and better protect our nature reserves, invest in conserving critically endangered species, and vote for leaders who make these issues a priority.

Without decisive action, we are likely to hack off vital limbs of the tree of life that could take millions of years to recover.

The Slow Loris, a primitive primate, is a denizen of intact rainforests in southern Asia.
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Paul Ehrlich will present a lecture on the current mass extinction, at James Cook University’s Cairns campus on November 10.

Bill Laurance, Distinguished Research Professor and Australian Laureate, James Cook University and Paul Ehrlich, President, Center for Conservation Biology, Bing Professor of Population Studies, Stanford University

This article was originally published on The Conversation. Read the original article.

2015’s record-breaking temperatures will be normal by 2030 – it’s time to adapt

Sophie Lewis, Australian National University

Generation Y has grown up in a rapidly warming world. According to the US National Climate Data Centre, every month since February 1985 has seen above average global temperatures, compared with the twentieth century. I have no memories of a “normal” month.

2016 is on track to be the hottest year on record, surpassing the previous records set in 2015 and in 2014. These are just a few of the flurry of recent record temperatures, which includes Australia’s hottest day, week, month, season and year.

The question now is what the future will look like. At some point in the decades to come, these record-breaking temperatures will not be rare; they will become normal. But when exactly?

In a new study just released in the Bulletin of the American Meteorological Society, I (together with co-authors Andrew King and Sarah Perkins-Kirkpatrick) find that on the current greenhouse gas emissions trajectory, global temperatures like 2015 will by normal by 2030, and Australia’s record-breaking 2013 summer will likely be an average summer by 2035.

While we still have time to delay some of these changes, others are already locked in – cutting emissions will make no difference – so we must also adapt to a warmer world. This should be a sobering thought as world leaders gather in Marrakech to begin work on achieving the Paris Agreement which came into force last week.

Today’s extremes, tomorrow’s normal

The recent record-breaking temperatures have often been described as the “new normal”. For example, after the new global temperature record was set in 2016, these high temperatures were described as a new normal.

What is a new normal for our climate? The term has been used broadly in the media and in scientific literature to make sense of climate change. Put simply, we should get used to extremes temperatures, because our future will be extreme.

But without a precise definition, a new normal is limited and difficult to understand. If 2015 was a new normal for global temperatures, what does it mean if 2017, 2018, or 2019 are cooler?

In our study we defined the new normal as the point in time when at least half the following 20 years are warmer than 2015’s record breaking global temperatures.

We examined extreme temperatures in a number of state-of-the-art climate models from an international scientific initiative. We also explored how different future greenhouse gas emissions impact temperatures.

We used four different greenhouse gas scenarios, known as Representative Concentration Pathways, or RCPs. These range from a business-as-usual situation (RCP8.5) to a major cut to emissions (RCP2.6).

It is worth emphasising that real-world emissions are tracking above those covered by these hypothetical storylines.

2015’s record temperatures will likely become normal between 2020 and 2030.

Future extremes

Our findings were straightforward. 2015’s record-breaking temperatures will be the new normal between 2020 and 2030 according to most of the climate models we analysed. We expect within a decade or so that 2015’s record temperatures will likely be average or cooler than average.

By 2040, 2015’s temperatures were average or cooler than average in 90% of the models. This result was unaffected by reducing greenhouse gas emissions or not – we are already locked in to a significant amount of further warming.

We also looked at the timing of a new normal for different regions. Australia is a canary in the coal mine. While other regions don’t see extreme temperatures become the new normal until later in the century, Australia’s record-breaking 2013 summer temperatures will be normal by 2035 – according to the majority of the models we looked at.

At smaller spatial scales, such as for state-based based temperature extremes, we can likely delay record-breaking temperatures becoming the new normal by committing to significant greenhouse gas cuts. This would clearly reduce the vulnerability of locations to extreme temperatures.

Cutting emissions (top) and business as usual (bottom) makes little difference to the new normal globally.
Author provided

Living in a warmer world

If you like heading to the beach on hot days, warmer Australian summers seem appealing, not alarming.

But Australia’s position as a hot spot of future extremes will have serious consequences. The 2013 summer, dubbed the “angry summer”, was characterised by extreme heatwaves, widespread bushfires and a strain on infrastructure.

Our results suggest that such a summer will be relatively mild within two decades, and the hottest summers will be much more extreme.

My co-authors, Andrew and Sarah, and I all grew up in a world of above-average temperatures, but our future is in a world were our recent record-breaking temperatures will be mild. Our new research shows this is not a world of more pleasantly hot summer days, but instead of increasingly severe temperature extremes.

These significantly hotter summers present a challenge that we must adapt to. How will we protect ourselves from increases in excess heat deaths and increased fire danger, and our ecosystems from enhanced warming?

While we have already locked ourselves into a future where 2015 will rapidly become a new normal for the globe, we can still act now to reduce our vulnerability to future extreme events occurring in our region, both through cutting emissions and preparing for increased heat.

Sophie Lewis, Research fellow, Australian National University

This article was originally published on The Conversation. Read the original article.

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