Climate Council: climate, health and economics are against Carmichael mine



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Many banks are worried that coal investments could be left stranded on their asset books.
Rasta777/Shutterstock.com

Will Steffen, Australian National University and Hilary Bambrick, Queensland University of Technology

Despite the overwhelming evidence that fossil fuels are killing the Great Barrier Reef and making many extreme weather events worse; despite the emphatic thumbs-down from the finance sector; and despite the growing awareness of the serious health impacts of coal, the proposed Carmichael coal mine staggers on, zombie-like, amid reports it has been offered a deferment of A$320 million in royalty payments. The Conversation

A new Climate Council report, Risky Business: Health, Climate and Economic Risks of the Carmichael Coalmine, makes an emphatic case against development of the proposed mine, or of any other coal deposits in Queensland’s Galilee Basin, or indeed elsewhere around the world.

Burning coal is a major contributor to climate change. Australia is already reeling from the escalating impacts of a warming climate. Heatwaves and other extreme weather events are worsening. The Great Barrier Reef has suffered consecutive mass bleaching events in 2016 and 2017. Climate change is likely making drought conditions worse in the agricultural belts of southwest and southeast Australia. Our coastal regions are increasingly exposed to erosion and flooding as sea level rises.

If we are to slow these disturbing trends and stabilise the climate at a level with which we might be able to cope, only a relatively small amount of the world’s remaining coal, oil and gas reserves can actually be used.

The majority must be left unburned in the ground, without developing vast new coal deposits such as those in the Galilee Basin.

On budget

The amount of fossil fuels we can burn for a given temperature target (such as the 1.5℃ and 2℃ targets of the Paris climate agreement) is known as the “carbon budget”.

To give ourselves just a 50% chance of staying within the 2℃ Paris target, we can burn only 38% of the world’s existing fossil fuel reserves. When this budget is apportioned among the various types of fossil fuels, coal is the big loser, because it is more emissions-intensive than other fuels. Nearly 90% of the world’s existing coal reserves must be left in the ground to stay within the 2℃ budget.

When the carbon budget is apportioned by region to maximise the economic benefit of the remaining budget, Australian coal in particular is a big loser. More than 95% of Australia’s existing coal reserves cannot be burned, and the development of new deposits, such as the Galilee Basin, is ruled out.

The health case

Exploiting coal is very harmful to human health, with serious impacts all the way through the process from mining to combustion. Recently the life-threatening “black lung” (coal workers’ pneumoconiosis) has re-emerged in Queensland, with 21 reported cases. Across Australia, the estimated costs of health damages associated with the combustion of coal amount to A$2.6 billion per year.

In India, the country to which coal from the proposed Carmichael mine would likely be exported, coal combustion already takes a heavy toll. An estimated 80,000-115,000 deaths, as well as 20 million cases of asthma, were attributed to pollutants emitted from coal-fired power stations in 2010-11. Up to 10,000 children under the age of five died because of coal pollution in 2012 alone.

Compared with the domestic coal resources in India, Carmichael coal will not reduce these health risks much at all. Galilee Basin coal is of poorer quality than that from other regions of Australia. Its estimated ash content of about 26% is double the Australian benchmark.

This is bad news for children in India or in any other country that ends up burning it.

The economics

The economic case for the Carmichael mine doesn’t stack up either. Converging global trends all point to rapidly reducing demand for coal.

The cost of renewable energy is plummeting, and efficient and increasingly affordable storage technologies are emerging. Coal demand in China is dropping as it ramps up the rollout of renewables. India is moving towards energy independence, and is eyeing its northern neighbour’s push towards renewables.

All of these trends greatly increase the risk that any new coal developments will become stranded assets. It’s little wonder that the financial sector has turned a cold shoulder to the Carmichael mine, and Galilee Basin coal development in general. Some 17 banks worldwide, including the “big four” in Australia, have ruled out any investment in the Carmichael mine.

From any perspective – climate, health, economy – the proposed mine is hard to justify. And yet the project keeps on keeping on.

Will Steffen, Emeritus professor, Fenner School of Environment and Society, Australian National University and Hilary Bambrick, Head of School, School of Public Health and Social Work, Queensland University of Technology

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

Maybe we can, but should we? Deciding whether to bring back extinct species



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Immortalised on a stamp, New Zealand’s stout-legged wren went extinct in the 1990s.
Boris15/www.shutterstock.com

Gwenllian Iacona, The University of Queensland and Iadine Chadès, CSIRO

De-extinction – the science of reviving species that have been lost – has moved from the realm of science-fiction to something that is now nearly feasible. Some types of lost mammals, birds or frogs may soon be able to be revived through de-extinction technologies. The Conversation

But just because we can, does it mean we should? And what might the environmental and conservation impacts be if we did?

Prominent conservation biologist Stuart Pimm has been one of the vocal opponents of de-extinction because, among other concerns,

Without an answer to “where do we put them?” — and to the further question, “what changed in their original habitat that may have contributed to their extinction in the first place?” — efforts to bring back species are a colossal waste.

These are valid concerns, and difficult to consider in light of the many competing factors involved.

We’ve recently outlined a deliberate way to tackle this problem. Our new paper shows that an approach known as “decision science” can help examine the feasibility of de-extinction and its likely impact on existing environmental and species management programs.

Applied to the question of possible de-extinction programs in New Zealand, this approach showed that it would take money away from managing extant (still alive) species, and may lead to other species going extinct.

Solving complex problems

The potential to reverse species extinction is exciting from both a science and a curiosity perspective. But there is also great concern that in the passionate rush to implement new technology, we don’t properly consider environmental, economic and social issues.

Balancing these multiple objectives requires decision makers to understand how various project endpoints relate to all the different project goals.

Decision science methods simplify complex problems into parts that describe the benefit, cost and feasibility of the different possible solutions. They allow for “apples to apples” comparisons to be made about different but essential aspects of the projects being considered.

Decision science in action

When applied to de-extinction projects, decision science lets researchers:

  • compare different possible outcomes of de-extinction approaches
  • better understand future expected costs and benefits, and
  • see impacts of using de-extinction technology on other species that we care about.

New Zealand and New South Wales are home to more than 1,100 threatened species of conservation concern between them.

Over the past decade their management agencies have built on a decision science approach to prioritise their conservation efforts, and increase the number of species they are able to put on the road to recovery.

New Zealand in particular is a prime candidate for considering de-extinction because they have had many recent extinctions, such as the huia.

The New Zealand native bird ‘huia’ went extinct in 1907.
Photographed by Kendrick, J. L. and with thanks from NZ Department of Conservation, Author provided

These lost species fit many of the criteria for species appropriate for de-extinction technologies.

A recent study took the process that was developed to rank New Zealand species according to priority for action, and included 11 possible candidates for de-extinction in the ranking process. These were birds, frogs and plants, including the little bush moa, Waitomo frog and laughing owl.

By applying a decision science process, the authors found that adding these species to the management worklist would reduce their ability to adequately fund up to three times the number of currently managed species, and essentially could lead to additional species going extinct.

The study also showed that private agencies wishing to sponsor the return of resurrected extinct species into the wild, could instead use the money to fund conservation of over eight times as many species, potentially saving them from extinction.

Crucially, this study could not examine the initial costs of using genetic technology to resurrect extinct species, which is unknown but likely to be substantial. If it could have included such costs, de-extinction would have come out as an even less efficient option.

The laughing owl went extinct in New Zealand in 1914.
Photographed by Kendrick, J. L. and with thanks from NZ Department of Conservation, Author provided

Could de-extinction ever be the right option?

The New Zealand example is not a particularly rosy picture, but it may not always be the case that de-extinction is a terrible idea for conservation.

Hypothetically, there are situations where the novelty and excitement of a de-extinct species could act as a “flagship species” and actually attract public interest or funding to a conservation project.

There also is an interesting phenomenon where even just the possibility of having a management action such as de-extinction may change how conservation problems are formulated.

Conservation management currently aims to do the best it can, while operating under the constraint that biodiversity is a non-renewable resource. With this constraint we can apply theory that is used for managing the extraction of non-renewable resources like oil or diamonds to determine the best strategy for management.

However, if extinction was no longer forever, the problem could be considered as one that would be managing a renewable resource, like trees or fish.

Of course, the ability to revive species is nowhere near as simple as regrowing trees, and a species being revived does not necessarily equate to conservation.

But changing the way that conservation managers think about the problem could present conservation gains in addition to losses.

Theoretically, different methods may be used for conservation benefit and there may be different strategies to produce the best outcomes. For example, species that could easily be de-extinct may get less funding attention that the ones for which the de-extinction technology isn’t available, or are too costly to produce.

This research does not advocate for or against de-extinction, rather, it provides strategies to deal with alternatives from the start with a clear representation of the trade-offs.

This work aims to step back and take a realistic look at the implications of new technology, including its costs and its risks, within the context of other conservation actions. Decision theory helps to do just that.

Gwenllian Iacona, Postdoctoral Research Fellow, The University of Queensland and Iadine Chadès, Leader of the Conservation Decisions Team and Senior research scientist, CSIRO

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

Writing the WA wheatbelt, a place of radical environmental change


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A message ploughed in the land calls on the federal government to help drought-affected farmers near the wheatbelt town of Kondinin in 2001.
Liza Kappelle/AAP

Tony Hughes-D’Aeth, University of Western Australia

What can creative literature tell us about radical environmental change? Most people accept that literature can be closely connected to places. Whether it is Dickens’s London or Hardy’s Wessex, we also accept that imaginative works deliver something about the nature of place that does not necessarily come to us by any other means. The Conversation

How then does this work in Australia? I have spent the past decade writing a literary history of the Western Australian wheatbelt and have sought in various ways to answer this question.

It is a regional literary history that nevertheless encompasses some of the nation’s finest writers — Albert Facey, Dorothy Hewett, Peter Cowan, Jack Davis, Randolph Stow, Elizabeth Jolley, Tom Flood, John Kinsella. Facey’s A Fortunate Life (1981) is a landmark in Australian autobiography; Hewett, Cowan and Stow helped define literary modernism in Australia; Jack Davis was a leading figure in the Aboriginal literary renaissance; and Jolley’s The Well (1986) and Flood’s Oceana Fine (1990) both won the Miles Franklin literary award.

What unites these works? Is it simply a quirk of fate that a sparsely populated hinterland in Australia’s most isolated state produces a body of literature that rivals in many ways the literary outputs of the great Australian metropolitan centres in Melbourne and Sydney?

For the answer to this question one has to understand the history of the WA wheatbelt. In two 30-year periods (1900-1930 and 1945-1975) an area of land roughly the size of Britain was stripped of its native vegetation for the production of grain and livestock. It is a crescent of land that begins just north of Geraldton on the west coast and sweeps south and east to Esperance on the south coast.

When the Swan River Colony was founded in 1829, six years before Melbourne, it was with the intention of forming an agricultural colony of closely settled yeoman farmers, who would own their own land and congregate in small, nicely spaced villages.

The clearing of the wheatbelt during the 20th century.

However, the antique soil of WA bore almost no resemblance to the fertile soils of recently glaciated northern Europe. Four to five more or less rainless months, where dry desert winds blow steadily across the vegetation was also an unprecedented challenge to farming methods learned in the British Isles. Lastly, there were almost no rivers to speak of, and permanent summer water was a rare commodity.

WA Government land advertisement from 1904.

For all these reasons, the agricultural dream of WA remained largely unrealized. The game-changing event was the goldrush of the 1890s. The population of the colony trebled between 1889 and 1896, from 44,000 to 138,000.
Knowing that the gold would be dug out before too long but wanting to capture this new cache of colonists, the colonial government passed the Homesteads Act in 1893 to parcel out land, and established an Agricultural Bank in 1894 to finance farmer-settlers. An army of land surveyors fanned out through the southwest and provisions for water, fertilizer and rail transit were quickly put into motion. Towns were gazetted, one-teacher schools popped up and WA took the lead in distance learning.

Albert Facey’s uncle Archie McCall had come over from South Australia to work the goldfields and was one of those who leapt at the land offer. Dorothy Hewett’s grandparents had made their money selling goods to diggers heading out to the goldfields at Kalgoorlie and Coolgardie and with this they purchased an extensive parcel of prime land at Yealering not far from McCall’s farm at Wickepin.

The dream refracted

What we get in both of these very different writers is a distinct picture of the dream of the wheatbelt. It is this dream — a settler-colonial ideology of farming independence — that we see refracted through the wheatbelt writers all the way through the 20th century.

The animating vision of the wheatbelt was an amalgam of ideals. On the one hand, it appealed to the basic material prospect of upward mobility. In the late 19th and early 20th century, opportunities for advancement through education were not generally available.

But the wheatbelt vision seemed even more deeply situated than this, offering itself as an antidote to the ills of modern city life. As the various states all moved to convert low-yield pastoral production to high-yield cash-cropping, there emerged a veritable ideology of wheat in the post-Federation years, and right through to the Depression.

C.J. Dennis joined the chorus in his bouncy ballad simply called Wheat from 1918:

Tho’ it ain’t a life o’ pleasure,

An’ there’s little time for leisure,

It’s contentin’, in a measure, is the game of growin’
Wheat.

Dennis and others helped to drag crop-farming away from its associations with European peasant drudgery and into the noble task of nation-building and feeding the “bread-eating” (i.e. European or European-derived) countries of the world.

Dorothy Hewitt, 1965.
University of Western Australia archives.

For Facey, even though his memoir was not published until 1981 (the year before he died), the dream of the wheatbelt and the ideology of wheat remain preserved as if in amber. The basic tasks of “clearing” the wheatbelt — particularly the regimes of annual burning and cutting — are remembered with particular pride by Facey.

Born a generation and a half later, Hewett grew up in a farm that was already in place. Although she left Lambton Downs (as it was dubbed) at the age of 11, Hewett’s writing returned again and again to the wheatbelt. Hewett’s wheatbelt had a mythic, gothic flavour in which the dream of it is present but often in inverted form. This wheatbelt is beset by a pernicious fatality and mired in the sexual miseries of her extended family.

Hewett deserves credit for being the first writer to take seriously the fact that the wheatbelt was built on land whose traditional owners had not disappeared but were still there, either impoverished in fringe-camps or incarcerated in government or church institutions.

The other side of the farming frontier

But it was the emergence of Aboriginal writing in the generation politicized by the citizenship referendum that brought a powerful voice from the other side of the wheatbelt frontier. Jack Davis had spent time in the notorious Moore River Native Settlement on the edge of the mid-northern wheatbelt, and then (after the untimely death of his father), with relatives of his mother’s sister at the Brookton reserve in the Avon valley. There he did the usual itinerant work that Aboriginal families did in the wheatbelt’s early years — clearing, fencing, shearing, rabbiting.

What Davis gives us in his poetry of the 1970s and the great plays of the 80s is a completely alternative vision of the wheatbelt. It doesn’t look like wheatbelt literature for the simple reason that it does not proceed either positively or negatively from the wheatbelt dream. Instead, it proceeds from Aboriginal presence in the land.

The tragedy of the Noongar is shown in all its woeful extremity, but tempered by Davis’s astringent sense of humour—his black humour if you like. But really Jack Davis is writing about survival. His example has provided a platform for a writer like Kim Scott to foster new forms of Noongar creative re-emergence, and also new forms of penetrating critique.

At the same time that a consciousness of Aboriginal dispossession began to force its way into the understanding of the wheatbelt, a much sharper sense of its ecological cost was also starting to emerge. Certainly, right through my literary history of the wheatbelt there was a realization that the waving fields of wheat were planted on lands stripped of their native ecosystems.

Everyone knew this because everyone spent a considerable part of each year toiling to clear the land. But the view tended to be that there was always more bush. Each bit of clearing was a merely local matter. Likewise, as rising salinity became directly associated with the clearing of native perennial vegetation, it was repeatedly explained away as a small, local, confined phenomenon.

Environmental destruction

But in the writing of Peter Cowan and that of the naturalist, Barbara York Main, the full picture of environmental destruction began to appear without the customary euphemism. It would be wrong to say that public opinion, particularly in the wheatbelt, changed decisively in the 1960s or even the 1970s. The cart-blanche denial, however, of environmental value — that the natural world of the wheatbelt had a value — became harder and harder to maintain.

By the 1980s, the wheatbelt had become uncanny. No longer the sign of the natural cycles of life replenishing the earth with seasonal regularity, but a vast and even repellent monocultural expanse. The wheatbelt was something profoundly unnatural in the eyes of writers like Elizabeth Jolley, Tom Flood and John Kinsella.

Of these, it has been Kinsella who has proved to be both durable and prolific. His poems, stories and other writings specify a wheatbelt that exists in strange cross-currents of science, tradition and avarice. The natural world is prised out of its familiar romantic categories and, in his remarkable work, exists in eerie counterpoise to the techno-scientific mania of modern agribusiness.

The central fact of the wheatbelt is radical disappearance. On one hand there was the destruction of the sovereign culture of the Noongar, custodians for millennia. Noongar people continue to practice and uphold their culture in spite of everything and the land continues to speak through them.

But on the other hand we must also contend with the fact that in the central wheatbelt shires, at least, only something like 7% of the natural vegetation (and the animal habitat it provides) remains. This, in a place that has a biodiversity as stunning as a rainforest canopy.

Charred timber after the ‘burn’.
State Library of Western Australia

Literature cannot, in and of itself, make these losses good. A thousand novels cannot replace one extinct species. But in human terms there is hope. The Noongar language is being revitalized. And here literature certainly does have a role to play. Jack Davis used Noongar in his plays and provided his own glossaries. Kim Scott’s fiction, and occasional poetry, gives its readers Noongar — in fact teaches its readers Noongar and the deft sonics of a language adapted to country. And many of today’s farmers are now at the forefront of conservation initiative and Landcare groups.

The role, though, that I see for literature in coming to terms with the facts of the wheatbelt lies in its capacity to continuously disabuse us of the complacent certitudes by which we think we know the world. It need not require the experimental bravura of Kinsella’s postmodern verse to do this unsettling. Even the older writing does it in surprising ways.

Only 7% of the central wheatbelt’s natural vegetation is left.
Google Earth.

What Dorothy Hewett and Jack Davis do within the broad parameters of theatrical realism nevertheless succeeds in unpicking the simple pouches we tend to pack our conceptions in. Barbara York Main’s natural histories throw open the dazzling singularity of wheatbelt life forms, and at the same time their intricate interconnections. Peter Cowan’s quietist studies of disillusioned loneliness, defamiliarises the wheatbelt just as certainly as Facey’s childhood glee at burning the bush to smouldering ashes.

It is not a particular kind of literature that gets to the “heart” of the wheatbelt. It is the fact that the wheatbelt falls into the prism of literature that allows us to see this place in terms other than the ones it gave itself via its animating dream of agricultural plenitude and generational continuity.

Creative writing is not blind to the natural or economic forces that determine the fate of the wheatbelt, but it will always approach the matter through the medium of human subjectivity. In this sense, it is only literature that allows us to see inside the wheatbelt that was created, geologically speaking, in the blink of an eye.

Tony Hughes-D’Aeth, Associate Professor, English and Cultural Studies, University of Western Australia

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

The lengthy childhood of endangered orangutans is written in their teeth



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A young Bornean orangutan nursing.
Erin Vogel, Author provided

Tanya M. Smith, Griffith University

Orangutan populations in the wild are critically endangered, and one of the things that may hamper their survival is the time they take to rear new offspring. The Conversation

An orangutan mother will not give birth again until she’s finished providing milk to her previous offspring. Nursing can take a long time and vary across seasons, as we found in research published today in Science Advances.

Primate mothers, including humans, raise only a few slow-growing offspring during their reproductive years.

Differences in infant development have a profound effect on how many children a female can have over the course of her life – the key marker of success from an evolutionary vantage point.

Great apes have a high-stakes strategy. Chimpanzee mothers nurse their offspring for five years on average, twice as long as humans in traditional small-scaled societies.

Orangutans have been suspected of having even longer periods of infant dependency, although determining just how long has been a particular challenge for field biologists.

Wild orangutan from Gunung Palung National Park, Borneo, Indonesia with her one month old infant. (Gunung Palung Orangutan Project)

Living high up in dwindling Southeast Asian forests, these apes are adept at evading observers. Their nursing behaviour is often concealed, particularly while juveniles cling to their mother or rest together in night nests.

Maintaining continuous field studies to track their development is expensive, and efforts are hindered by frequent forest fires and devastating deforestation for palm oil plantations.

Teeth tell the story

I have spent the past few decades studying how orangutans and other primates form their teeth. Amazingly, every day of childhood is captured during tooth formation, a record that begins before birth and lasts for millions of years.

Teeth also contain detailed dietary, health and behavioural histories, allowing biological anthropologists an unprecedented window into the human past.

I’ve also teamed up with researchers Manish Arora and Christine Austin, at Icahn School of Medicine at Mt Sinai in New York, who have pioneered methods to map the fine-scaled elemental composition of teeth, as well as primate lactation expert Katie Hinde at Arizona State University.

We have shown in a previous study that tiny amounts of the element barium are an accurate marker of mother’s milk consumption. Like calcium, barium is sourced from the mother’s skeleton, concentrated in milk, and ultimately written into the bones and teeth of her offspring.

Tooth growth creates daily lines (indicated by short white lines), as well as a neonatal line (NL) at birth. Growth starts at the junction between enamel and dentine, and progresses away from the junction and towards the root (arrows).
Christine Austin and Tanya Smith

Once animals start nursing after birth, their teeth show increases in barium values, which begin to decrease when solid food is added to the diet. These values drop further to pre-birth levels when primates stop nursing and are weaned.

We’ve recently used this approach to explore the nursing histories of wild orangutans in collaboration with orangutan expert Erin Vogel at Rutgers University. In order to do so, I borrowed teeth housed in natural history museums from individuals that had been shot many years ago during collection expeditions.

Wild Bornean orangutan mother and suckling 19-month old infant.
Paige Prentice, Author provided

Orangutan teeth show a gradual increase in barium values from birth through their first year of life, a time of increasing consumption of their mother’s milk. After 12-18 months, values decrease as infants begin eating solid foods consistently.

But surprisingly, barium levels then begin to fluctuate on an approximately annual basis. We suspect that this is due to seasonal changes in food availability. When fruit is in short supply, infants appear to rely more on their mother’s milk to meet their nutritional needs.

Light microscope image (left) of a wild orangutan molar contrasted with an elemental map of the same tooth (right) showing the distribution of barium. The timing of barium incorporation was determined from accentuated lines (in days of age on the left), which form during enamel and dentine secretion. Approximately annual bands of enriched barium are apparent in the dentine after the first year, likely due to seasonal increases in mother’s milk intake.
Smith et al. (2017) Science Advances

Hanging around

Another surprising finding is that nursing may continue for more than eight years, longer than any other wild animal.

This information is the first of its kind for wild Sumatran orangutans, as they have been especially difficult to study in their native habitat. Previous estimates from two wild Bornean orangutans suggested that juveniles nurse until about six to eight years of age.

Rather than spending so much time and energy breastfeeding their children, human mothers in traditional societies transition their infants onto soft weaning foods around six months of age, tapering them off milk a few years later.

Humans also benefit from having help such as older siblings and grandparents who lend a hand with childcare and enable women to energetically prepare for having their next child.

Orangutan mothers have it hard by comparison. They live alone in unpredictable environments with limited nutritional resources. In order to survive they use less energy than other great apes, raising their young more slowly.

Wild orangutan mother and 11-month old infant.
Tim Laman, Author provided

Vulnerable orangutans

Female orangutans begin reproducing around age 15 and can live until 50 years old in the most favourable of circumstances. They bear new offspring every six to nine years, producing no more than six or seven descendents over their lifetime.

Having a long nursing period and slow maturation makes orangutan populations especially vulnerable to environmental perturbations.

Recent work has also implicated poor habitat quality and the pet trade as additional factors in their rapidly declining numbers, which is underscored by their critically endangered status.

Research on collections housed in natural history museums provides timely evidence of how remarkable orangutans are, how much information we can retrieve from their teeth, and why conservation efforts informed by evolutionary biology are critical.

Tanya M. Smith, Associate Professor in the Australian Research Centre for Human Evolution, Griffith University

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

This South Pacific island of rubbish shows why we need to quit our plastic habit


Jennifer Lavers, University of Tasmania

A remote South Pacific island has the highest density of plastic debris reported anywhere on the planet, our new study has found. The Conversation

Our study, published in the journal Proceedings of the National Academy of Sciences, estimated that more than 17 tonnes of plastic debris has washed up on Henderson Island, with more than 3,570 new pieces of litter arriving every day on one beach alone.

Our study probably actually underestimates the extent of plastic pollution on Henderson Island, as we were only able to sample pieces bigger than two millimetres down to a depth of 10 centimetres. We also could not sample along cliffs.
Jennifer Lavers, Author provided

It is estimated that there are nearly 38 million pieces of plastic on the island, which is near the centre of the South Pacific Gyre ocean current.

Henderson Island, marked here by the red pin, is in the UK’s Pitcairn Islands territory and is more than 5,000 kilometres from the nearest major population centre. That shows plastic pollution ends up everywhere, even in the most remote parts of the world.
Google Maps

A 2014 paper published in the journal PLOS One used data from surface water all over the world. The researchers estimated that there are 5.25 trillion pieces of plastic in the top 10 centimetres of the world’s oceans.

Plastics pose a major threat to seabirds and other animals, and most don’t ever break down – they just break up. Every piece of petrochemical-derived plastic ever made still exists on the planet.

Jennifer Lavers, Research Scientist, Institute for Marine and Antarctic Studies, University of Tasmania

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

Why 2℃ of global warming is much worse for Australia than 1.5℃


Andrew King, University of Melbourne; Ben Henley, University of Melbourne, and David Karoly, University of Melbourne

Australia is a land of extremes. We’ve experienced all manner of climate extremes over the past few years, from heatwaves (both on land and over the Great Barrier Reef), to droughts and flooding rains. The Conversation

We can already link some of these recent extreme events to climate change. But for others, the link is less clear.

So far we have had about 1℃ of global warming above the average pre-industrial climate. So how will extreme weather events change with more warming in the future? Will they become more frequent? Will they become more severe?

We have investigated these questions in our new research, published today in Nature Climate Change.

Climate targets

The Paris Agreement, brokered in 2015, committed the world’s governments to:

Holding the increase in the global average temperature to well below 2℃ above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5℃ above pre-industrial levels, recognising that this would significantly reduce the risks and impacts of climate change.

It is vital that we understand how climate extremes in Australia might change if we limit global warming to either 1.5℃ or 2℃, and what the implications might be of pursuing the more lenient target rather than the more ambitious one.

In our study we used state-of-the-art climate model simulations to examine the changing likelihood of different climate extremes under four different scenarios: a natural world without any human-caused climate change; the world of today; a 1.5℃ warmer world; and a 2℃ warmer one.

Heat extremes are here to stay

First, we looked at hot Australian summers, like the record-breaking “angry summer” of 2012-13.

We already knew that human influences on the climate had increased the likelihood of hot summers. Our results show that this trend would continue with future warming. In fact, in a world of 2℃ global warming, even an average summer would outstrip those historically hot ones like 2012-13.

Australian summer temperatures are strongly related to the El Niño-Southern Oscillation, with hot summers more likely to occur during El Niño events, and cooler ones during La Niña episodes.

In the past, a summer as hot as 2012-13 would have been very unlikely during a La Niña. But our modelling predicts that with either 1.5℃ or 2℃ of global warming, we could expect similarly angry summers to occur during both El Niño and La Niña periods.

We already know that the sea surface temperatures associated with mass bleaching of much of the Great Barrier Reef in early 2016 would have been virtually impossible without climate change. If the world continues to warm to either the 1.5℃ or 2℃ levels, very warm seas like we saw early last year would become the norm.

High sea temperatures linked to coral bleaching in Great Barrier Reef will become more likely in a warmer world.
Author provided

In fact, our research suggests that with 2℃ of global warming, the future average sea temperatures around the Great Barrier Reef would be even hotter than the extremes observed around the time of the 2016 bleaching.

Less change for heavy rains and droughts

In December 2010 Queensland was devastated by severe flooding following very heavy rainfall. Our analysis suggests that this kind of event is highly unusual, and may well continue to be so. There isn’t a clear signal for an increase or decrease in those events with ongoing climate warming.

Natural climate variability seems to play a greater role than human-driven climate change (at least below the 2℃ threshold) when it comes to influencing Australian heavy rainfall events.

The Millennium Drought across southeast Australia led to water shortages and crop failures. Drought is primarily driven by a lack of rainfall, but warmer temperatures can exacerbate drought impacts by increasing evaporation.

Our results showed that climate change is increasing the likelihood of hot and dry years like we saw in 2006 across southeast Australia. At 1.5℃ and 2℃ of global warming these events would probably be more frequent than they are in today’s world.

Heat extremes are much more common at 2℃ than 1.5℃
Author provided

Not a lost cause

It is clear that Australia is going to suffer from more frequent and more intense climate extremes as the world warms towards (and very likely beyond) the levels described in the Paris Agreement.

If we miss these targets, the warming will continue and the extremes we experience in Australia are going to be even worse.

With either 1.5℃ or 2℃ global warming, we will see more extremely hot summers across Australia, more frequent marine heatwaves of the kind that can cause bleaching of the Great Barrier Reef, and probably more frequent drought conditions too.

The more warming we experience, the worse the impacts will be. The solution is clear. To limit global warming, the world’s nations need to reduce their greenhouse gas emissions – fast.

Andrew King, Climate Extremes Research Fellow, University of Melbourne; Ben Henley, Research Fellow in Climate and Water Resources, University of Melbourne, University of Melbourne, and David Karoly, Professor of Atmospheric Science, University of Melbourne

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