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Record high to record low: what on earth is happening to Antarctica's sea ice?

The Conversation - Thu, 2016-09-29 06:12

2016 continues to be a momentous year for Australia’s climate, on track to be the new hottest year on record.

To our south, Antarctica has also just broken a new climate record, with record low winter sea ice. After a peak of 18.5 million square kilometres in late August, sea ice began retreating about a month ahead of schedule and has been setting daily low records through most of September.

It may not seem unusual in a warming world to hear that Antarctica’s sea ice – the ice that forms each winter as the surface layer of the ocean freezes – is reducing. But this year’s record low comes hot on the heels of record high sea ice just two years ago. Overall, Antarctica’s sea ice has been growing, not shrinking.

So how should we interpret this apparent backflip? In our paper published today in Nature Climate Change we review the latest science on Antarctica’s climate, and why it seems so confusing.

Antarctic surprises

First up, Antarctic climate records are seriously short.

The International Geophysical Year in 1957/58 marked the start of many sustained scientific efforts in Antarctica, including regular weather readings at research bases. These bases are mostly found on the more accessible parts of Antarctica’s coast, and so the network – while incredibly valuable – leaves vast areas of the continent and surrounding oceans without any data.

In the end, it took the arrival of satellite monitoring in the 1979 to deliver surface climate information covering all of Antarctica and the Southern Ocean. What scientists have observed since has been surprising.

Overall, Antarctica’s sea ice zone has expanded. This is most notable in the Ross Sea, and has brought increasing challenges for ship-based access to Antarctica’s coastal research stations. Even with the record low in Antarctic sea ice this year, the overall trend since 1979 is still towards sea ice expansion.

The surface ocean around Antarctica has also mostly been cooling. This cooling masks a much more ominous change deeper down in the ocean, particularly near the West Antarctic Ice Sheet and the Totten glacier in East Antarctica. In these regions, worrying rates of subsurface ocean warming have been detected up against the base of ice sheets. There are real fears that subsurface melting could destabilise ice sheets, accelerating future global sea level rise.

In the atmosphere we see that some parts of the Antarctic Peninsula and West Antarctica are experiencing rapid warming, despite average Antarctic temperatures not changing that much yet.

In a rapidly warming world these Antarctic climate trends are – at face value – counterintuitive. They also go against many of our climate model simulations, which, for example, predict that Antarctica’s sea ice should be in decline.

Winds of change

The problem we face in Antarctica is that the climate varies hugely from year to year, as typified by the enormous swing in Antarctica sea ice over the past two years.

This means 37 years of Antarctic surface measurements are simply not enough to detect the signal of human-caused climate change. Climate models tell us we may need to monitor Antarctica closely until 2100 before we can confidently identify the expected long-term decline of Antarctica’s sea ice.

In short, Antarctica’s climate remains a puzzle, and we are currently trying to see the picture with most of the pieces still missing.

But one piece of the puzzle is clear. Across all lines of evidence a picture of dramatically changing Southern Ocean westerly winds has emerged. Rising greenhouse gases and ozone depletion are forcing the westerlies closer to Antarctica, and robbing southern parts of Australia of vital winter rain.

The changing westerlies may also help explain the seemingly unusual changes happening elsewhere in Antarctica.

The expansion of sea ice, particularly in the Ross Sea, may be due to the strengthened westerlies pushing colder Antarctic surface water northwards. And stronger westerlies may isolate Antarctica from the warmer subtropics, inhibiting continent-scale warming. These plausible explanations remain difficult to prove with the records currently available to scientists.

Australia’s unique climate position

The combination of Antarctica’s dynamic climate system, its short observational records, and its potential to cause costly heatwaves, drought and sea-level rise in Australia, mean that we can’t afford to stifle fundamental research in our own backyard.

Our efforts to better understand, measure and predict Antarctic climate were threatened this year by funding cuts to Australia’s iconic climate research facilities at the CSIRO. CSIRO has provided the backbone of Australia’s Southern Ocean measurements. As our new paper shows, the job is far from done.

A recent move to close Macquarie Island research station to year-round personnel would also have seriously impacted the continuity of weather observations in a region where our records are still far too short. Thankfully, this decision has since been reversed.

But it isn’t all bad news. In 2016, the federal government announced new long-term funding in Antarctic logistics, arresting the persistent decline in funding of Antarctic and Southern Ocean research.

The nearly A$2 billion in new investment includes a new Australian icebreaking ship to replace the ageing Aurora Australis. This will bring a greater capacity for Southern Ocean research and the capability to push further into Antarctica’s sea ice zone.

Whatever the long-term trends in sea ice hold it is certain that the large year-to-year swings of Antarctica’s climate will continue to make this a challenging but critical environment for research.

The Conversation

Nerilie Abram receives funding from the Australian Research Council.

Matthew England receives funding from the Australian Research Council.

Tessa Vance receives funding from the Australian government through the Cooperative Research Centres Programme.

Categories: Around The Web

Queensland's culling program is not the solution to New South Wales' shark problem

The Conversation - Thu, 2016-09-29 06:12
White sharks are one of the species targeted in shark programs, but are also threatened. White shark image from www.shutterstock.com

Sharks are back in the headlines this week following the attack of 17-year-old Cooper Allen off the coast of New South Wales.

In response there have been renewed calls for culling and even the establishment of a commercial shark fishery. Queensland premier Annastacia Palaszczuk offered to extend her state’s shark control program to include northern New South Wales beaches.

Any unprovoked shark bite is devastating for individuals and communities. Accepting Queensland’s offer of increased culling in New South Wales waters, however, will not automatically reduce the chance of these bites occurring.

So how does Queensland’s program stack up and should it be extended?

How does Queensland’s program work?

Queensland’s Shark Control Program relies on sharks being caught in large mesh fishing nets or drumlines, or a combination of both.

The program uses hundreds of hooked drumlines and tens of shark nets at popular beaches from Cairns to the Gold Coast. Equipment is checked every couple of days by government contractors, and target sharks that have been caught are killed with a firearm. The idea is to prevent sharks reaching the beaches and interacting with people.

The Queensland program has been running since 1962 as a public safety measure to reduce the risk of shark bites and attacks.

New South Wales already uses a similar program, which deploys nets set below the surface roughly 500m from the shoreline on 51 beaches from Wollongong to Newcastle between September and April each year.

The equipment is designed to target sharks of 2m or larger, but in reality indiscriminately kills animals of all sizes and species beyond the targets of white sharks, tiger sharks and bull sharks.

Do shark programs stop shark attacks?

A recent study has shown that unprovoked shark bites appear to have increased in recent years in eastern and southern Australia, but it is difficult to tease apart what environmental conditions are causing the increase, and even more difficult to predict when and where these conditions will next occur.

Important environmental conditions include sea surface temperature, freshwater runoff, turbidity (the cloudiness of water), currents and circulation patterns. While there are correlations between these factors and shark bites, that is all we know so far. Correlation does not mean causation.

The big problem is that there is currently no scientific evidence to link shark nets or drumlines to ocean safety.

It is not a matter of putting humans at the “top of the food chain” as Nationals president Larry Anthony (who represents the north coast in parliament) stated earlier this week.

It is a matter of whether (1) the strategies directly reduce the number of shark-related deaths, and (2) any reductions outweigh the ecological costs of these mitigation strategies.

Interestingly, shark-related fatalities have declined in Queensland since the state’s shark program began, but fatalities have declined in areas with and without shark mitigation equipment. The greatest decline actually occurred before deployment of nets and drumlines began.

And what about the sharks?

The dangers posed by Queensland’s shark program to shark populations are substantial. The vast majority of sharks that are caught by the program are threatened according to the International Union for Conservation of Nature. This includes target species such as white sharks and tiger sharks, and non-target species such as grey nurse sharks.

Some of these species are already listed by the New South Wales Fisheries Scientific Committee. The same committee has listed the state’s current program as a threatening process for marine wildlife. These species are in need of increased conservation and management rather than increased slaughter. Removing even a few of these larger predators can have unpredictable and cascading negative impacts on whole ecosystems.

Any removal of sharks are exacerbated by the slow growth and relatively low reproduction rate of these animals, which make them particularly vulnerable.

What Annastacia Palaszczuk is really offering New South Wales is to indiscriminately kill a large portion of species that should be protected by our state legislation.

What we should be doing is tagging and following the movements of these highly migratory species to understand where they go, and why.

Shark experts associated with the New South Wales government are trialling various forms of shark deterrent technology, some of which look are looking promising. Priority has been given to development of personal shark deterrents, such as electrical and magnetic devices, and protective wetsuits.

While things are progressing since the Shark Summit hosted by premier Mike Baird in September 2015, any solution is going to take time.

The Conversation

Jane Williamson has received funding from the Australian Research Council. She is Deputy Chair of the NSW Fisheries Scientific Committee.

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Fracking is a lousy way to create jobs | Letters

The Guardian - Thu, 2016-09-29 04:29

Gary Smith of the GMB says that Labour’s fracking ban is “an abdication of our environmental and moral responsibilities” (Report, 27 September). Clearly he hasn’t been reading the Guardian: otherwise he’d know that climate change is so serious that we need to leave most fossil fuel reserves in the ground. He also seems unaware of the Committee on Climate Change’s technical advice that fuels used by 2030 should produce an average of no more than 50g of CO2 per kilowatt hour. Natural gas generates nine times that and, with the risk of fugitive emissions, fracking is likely to produce more. If you want to deliver skilled jobs in an environmentally safe manner, look no further than investment in housing retrofit to deliver massive energy savings in our housing stock, the second leakiest in Europe. There’s also the option of reviving the growth of solar power, where 30,000 skilled jobs disappeared last year when the feed-in tariff was slashed.
John Rigby
Exeter

• Join the debate – email guardian.letters@theguardian.com

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Obama's climate change legacy at stake as Clean Power Plan has its day in court

The Guardian - Thu, 2016-09-29 03:51

Seven hours of legal argument on states’ right to allow carbon pollution may determine the fate of the centerpiece of US efforts to limit climate change

The future of the US’s centerpiece plan to tackle climate change hangs in the balance following nearly seven hours of legal argument over whether it tramples upon the right of states to allow carbon pollution.

Power utilities and business groups have joined 27 states in challenging the Obama administration’s Clean Power Plan, which would be the single largest tool in cutting greenhouse gas emissions to help avoid dangerous climate change.

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King's College London diverts fossil fuel endowments to clean energy

The Guardian - Thu, 2016-09-29 03:35

New investment policy will end the endowment fund’s exposure to fossil fuels and channel 15% of its £175m into low-carbon alternatives

King’s College London has endorsed a plan that would sink millions of its £179m endowment into clean energy, and drop investments in the most polluting fossil fuels.

Archbishop Desmond Tutu, a King’s alumni, has previously intervened in the university’s refusal to divest from fossil fuels after a campaign by students.

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Pangolins thrown a lifeline at global wildlife summit with total trade ban

The Guardian - Thu, 2016-09-29 01:10

World’s most illegally trafficked mammal wins total ban on international trade in all species under the strictest Cites protection possible

Pangolins, the world’s most illegally trafficked mammal, were thrown a lifeline at a global wildlife summit on Wednesday with a total trade ban in all species.

More than a million wild pangolins have been killed in the last decade, to feed the huge and rising appetite in China and Vietnam for its meat and its scales, a supposed medicine. The unique scaly anteaters are fast heading for extinction in Asia and poachers are now plundering Africa.

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New safeguards agreed for world's most trafficked mammal

BBC - Thu, 2016-09-29 00:53
A little known species driven to the edge of extinction by poaching, has gained extra protection at the Cites meeting in South Africa.
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Satellite Eye on Earth: August 2016 - in pictures

The Guardian - Wed, 2016-09-28 23:43

Ocean storms, California fires and an ice-free North-west Passage were among the images captured by European Space Agency and Nasa satellites last month

Composite image of an active Pacific and Atlantic storm season on 30 August 2016, with three hurricanes, two tropical depressions and a former typhoon visible from the ring of geostationary satellites in orbit high above above the Earth.

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Grass food crops facing climate change challenge

BBC - Wed, 2016-09-28 22:28
Projected climate change is set to happen too quickly for grass species, including major food crops, to adapt to the new conditions, a study suggests.
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US drives rainforest destruction by importing Amazon oil, study finds

The Guardian - Wed, 2016-09-28 22:00

The report found that California, despite its green reputation, is refining the majority of crude oil – with one facility accounting for 24% of the US total

US imports of crude oil from the Amazon are driving the destruction of some of the rainforest ecosystem’s most pristine areas and releasing copious amounts of greenhouse gases, according to a new report.

The study, conducted by environmental group Amazon Watch, found that American refineries processed 230,293 barrels of Amazon crude oil a day last year.

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Wildlife butchers of Belén: the town that serves up rare species for a few dollars

The Guardian - Wed, 2016-09-28 20:42

In this Peruvian shanty town endangered wildlife is sold daily at market, live or freshly cooked in gory detail by traders flouting lax enforcement. Stopping this growing illegal trade will be key to discussions at Cites this week

Where a confluence of rivers meet the Peruvian city of Iquitos, the world’s largest city to be inaccessible by road, lies Belén, a partially floating shanty town and market where endangered monkeys change hands for a few dollars and wildlife traffickers take orders to stock informal zoos or private collections with the abundant fauna from the world’s largest rainforest.

Wildlife is part of the town’s daily trade. A ban on selling bushmeat is openly ignored in Belén’s market. Deep-auburn slabs of the smoked meat of the endangered South America tapir (Tapirus terrestris) are stacked high on trestle tables. The protruding hoof of a peccary or the paw of an agouti betray the fact that there is hunted game on sale.

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New MIT app: check if your car meets climate targets | Dana Nuccitelli

The Guardian - Wed, 2016-09-28 20:00

In the US today, the most affordable and climate-friendly cars are electric

In a new study published in the journal Environmental Science & Technology, with an accompanying app for the public, scientists at MIT compare the carbon pollution from today’s cars to the international 2°C climate target. In order to meet that target, overall emissions need to decline dramatically over the coming decades.

The MIT team compared emissions from 125 electric, hybrid, and gasoline cars to the levels we need to achieve from the transportation sector in 2030, 2040, and 2050 to stay below 2°C global warming. They also looked at the cost efficiency of each car, including vehicle, fuel, and maintenance costs. The bottom line:

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The world passes 400ppm carbon dioxide threshold. Permanently

The Guardian - Wed, 2016-09-28 19:00

We are now living in a 400ppm world with levels unlikely to drop below the symbolic milestone in our lifetimes, say scientists. Climate Central reports

In the centuries to come, history books will likely look back on September 2016 as a major milestone for the world’s climate. At a time when atmospheric carbon dioxide is usually at its minimum, the monthly value failed to drop below 400 parts per million (ppm).

That all but ensures that 2016 will be the year that carbon dioxide officially passed the symbolic 400 ppm mark, never to return below it in our lifetimes, according to scientists.

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WHO releases alarming air quality report

ABC Environment - Wed, 2016-09-28 18:43
The latest World Health Organisation report on air quality finds one in nine people are at risk from pollution.
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Wave energy harnessed to power WA island

ABC Environment - Wed, 2016-09-28 18:35
Have you heard of wave power? This is a form of clean energy that is generated using the power of waves that move across the surface of bodies of water.
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Total trade ban for Gibraltar's monkeys expected

BBC - Wed, 2016-09-28 18:25
Europe's only non-human primate, the Barbary Macaque is likely to gain the highest level of protection at the Cites meeting in South Africa.
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Rare bird being driven to extinction by poaching for its 'red ivory' bill

The Guardian - Wed, 2016-09-28 17:48

Helmeted hornbills’ solid red beak sells for several times the price of elephant ivory due to soaring demand on the Chinese black market

A virtually unknown ivory poaching crisis is rapidly driving one of the world’s most spectacular birds to extinction, a global wildlife summit has heard.

The helmeted hornbill, found mainly in Indonesia, Borneo and Thailand, has a solid red beak which sells as a “red ivory” on the black market, for several times the price of elephant ivory. The huge birds have been caught for centuries for their tail feathers, prized by local communities, but since 2011 poaching has soared to feed Chinese demand for carving ivory, even though the trade is illegal, sending the hornbill into a death spiral.

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Frydenberg continues attack on state-based renewable targets

RenewEconomy - Wed, 2016-09-28 15:01
Frydenberg continues attack on state-based renewable energy targets, citing Grattan report that claims they are inefficient and too costly. But in the absence of any federal initiative, what choice do the states have?
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Gardeners may be spreading lethal frog disease throughout UK, study warns

The Guardian - Wed, 2016-09-28 15:00

Suburban homeowners stocking their garden ponds with frogs, fish or spawn from other ponds or aquatic centres are helping the ranavirus move around

British suburban gardeners may be unknowingly driving the spread of a lethal frog disease by stocking their ponds with exotic or wild aquatic species, research shows.

Scientists from ZSL and Queen Mary University of London say their findings could explain the rapid spread of ranavirus across UK amphibian populations in recent decades.

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Carnegie gets $2.5m ARENA funds for wave-based micro-grid

RenewEconomy - Wed, 2016-09-28 14:52
Carnegie gets grant and funding through convertible notes to put together the world's first micro-grid that combines wave energy, solar and battery storage.
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