Tuesday, September 25, 2012

100 million to die by 2030 if climate action fails: report

The Age, Date September 26, 2012 

More than 100 million people will die and global economic growth will be cut by 3.2 per cent of gross domestic product (GDP) by 2030 if the world fails to tackle climate change, a report commissioned by 20 governments said on Wednesday.

As global average temperatures rise due to greenhouse gas emissions, the effects on the planet, such as melting ice caps, extreme weather, drought and rising sea levels, will threaten populations and livelihoods, said the report conducted by humanitarian organisation DARA.

It calculated that five million deaths occur each year from air pollution, hunger and disease as a result of climate change and carbon-intensive economies, and that toll would likely rise to six million a year by 2030 if current patterns of fossil fuel use continue.

More than 90 per cent of those deaths will occur in developing countries, said the report that calculated the human and economic impact of climate change on 184 countries in 2010 and 2030. It was commissioned by the Climate Vulnerable Forum, a partnership of 20 developing countries threatened by climate change.

"A combined climate-carbon crisis is estimated to claim 100 million lives between now and the end of the next decade," the report said.

It said the effects of climate change had lowered global output by 1.6 per cent of world GDP, or by about $US1.2 trillion a year, and losses could double to 3.2 per cent of global GDP by 2030 if global temperatures are allowed to rise, surpassing 10 per cent before 2100.

It estimated the cost of moving the world to a low-carbon economy at about 0.5 per cent of GDP this decade.

Counting the cost

British economist Nicholas Stern told Reuters earlier this year investment equivalent to 2 per cent of global GDP was needed to limit, prevent and adapt to climate change. His report on the economics of climate change in 2006 said an average global temperature rise of 2-3 degrees Celsius in the next 50 years could reduce global consumption per head by up to 20 per cent.

Temperatures have already risen by about 0.8 degrees Celsius above pre-industrial times. Almost 200 nations agreed in 2010 to limit the global average temperature rise to below 2C (3.6 Fahrenheit) to avoid dangerous impacts from climate change.

But climate scientists have warned that the chance of limiting the rise to below 2C is getting smaller as global greenhouse gas emissions rise due to burning fossil fuels.

The world's poorest nations are the most vulnerable as they face increased risk of drought, water shortages, crop failure, poverty and disease. On average, they could see an 11 per cent loss in GDP by 2030 due to climate change, DARA said.

"One degree Celsius rise in temperature is associated with 10 per cent productivity loss in farming. For us, it means losing about 4 million metric tonnes of food grain, amounting to about $US2.5 billion. That is about 2 per cent of our GDP," Bangladesh's Prime Minister Sheikh Hasina said in response to the report.

"Adding up the damages to property and other losses, we are faced with a total loss of about 3-4 per cent of GDP."

Even the biggest and most rapidly developing economies will not escape unscathed. The United States and China could see a 2.1 per cent reduction in their respective GDPs by 2030, while India could experience a more than 5 per cent loss.

The full report is available at: http://daraint.org/


Read more: http://www.theage.com.au/environment/climate-change/100m-to-die-by-2030-if-climate-action-fails-report-20120926-26k4d.html#ixzz27WqMtLti

Saturday, September 22, 2012

Tipping into new climate territory as scientists put fears on ice

Ben Cubby, Environment Editor
Sunday Age, September 23, 2012
Earth may be approaching its points of no return.

AS ARCTIC sea ice hits a record low, focus is turning to climate ''tipping points'' - a threshold that, once crossed, cannot be reversed and will create fundamental changes to other areas.
''It's a trigger that leads to more warming at a regional level, but also leads to flow-on effects through other systems,'' said Will Steffen, the chief adviser on global warming science to Australia's Climate Commission.
There are about 14 known ''tipping elements'', according to a paper published by the US Proceedings of the National Academy of Sciences.
In the case of the Arctic ice cap, less ice means less white surface to reflect heat and more dark water to soak it up. This, in turn, leads to higher temperatures, which scientists say will unlock more ancient greenhouse gases frozen into ocean depths and permafrost, speeding climate change, interfering with ocean currents, rainfall patterns and weather.
Next to the Arctic ice cap, Greenland experienced melting across 97 per cent of its surface in June and July. It is unclear what the tipping point is for the melting of the Greenland ice sheet, and melts similar to this year's seem to occur every century or so. What is known is that if temperatures keep rising as they are, the ice sheet will start to disintegrate on a massive scale some time in the second half of this century. Tentative estimates from Australian and international studies say that another 1.5 degrees of warming would push Greenland across the threshold into irreversible melt, a process that would continue for centuries. There is enough ice in Greenland alone to raise sea levels off NSW and Victoria by four-to-nine metres.
Frozen methane trapped in pockets around the Arctic circle is also seen as a critical tipping element. Methane is a potent greenhouse gas, and as frozen earth thaws, more is leaking out. There are no exact measurements on the rate of leakage. Rough estimates suggest 30 to 60 billion tonnes of methane may leak by 2070.
Other potential tipping elements include monsoon patterns and the El Nino-Southern Oscillation cycle, which scientists expect will start to shift quite suddenly in response to global warming.
Changes in tree cover, especially in giant forests like the Amazon, are also expected in response to changing rainfall and more heat - and this would have the effect of amplifying global warming because fewer trees would mean less carbon dioxide was being soaked up out of the air.
As the polar ice cap shrivelled at unforeseen speed, Professor Steffen said he had changed his mind about the Arctic tipping point in past weeks. Existing predictions of an ice-free North Pole by 2050 were looking hopelessly wrong. ''I would say that, certainly, it is looking like 2050 would be an outlier now - I'm pretty certain that we have now passed the tipping point for Arctic sea ice.''
Sea ice reached a minimum size of 3.41 million square kilometres, down from an average of 7.4 million in the 1980s, 6.8 million in the 1990s and 5.7 million last decade. Professor Steffen believes that ''the most radical projection is about 2016, and probably the most conservative projection is about 2030, for when it will be ice free.''
The speed of events is why scientists are getting so worried. The only known way to stop these thresholds being crossed is to cut the human greenhouse emissions triggering these changes, and there are few signs of that taking place.
''Australians should see the vanishing Arctic sea ice as a warning sign that stronger action to cut greenhouse gas emissions is needed,'' the commission's chief, Tim Flannery, said this week. ''This is absolutely the critical decade for action. We're only seeing the beginning of rising sea levels; the real question is the rate - how fast will sea level rise? This poses risks for coastal communities, infrastructure and ecosystems right around the world including in Australia.''

Thursday, September 20, 2012

Arctic sea ice hits a new low

Justin Gillis   
The Age, September 20, 2012

The drastic melting of Arctic sea ice has finally ended for the year, scientists announced on Wednesday, but not before demolishing the previous record - and setting off new warnings about the rapid pace of change in the region.

The apparent low point for 2012 was reached on Sunday, according to the National Snow and Ice Data Centre, which said that sea ice that day covered about 3.41 million square kilometres, or 24 per cent, of the surface of the Arctic Ocean. The previous low, set in 2007, was 29 per cent.

When satellite tracking began in the late 1970s, sea ice at its lowest point in the summer typically covered about half the Arctic Ocean, but it has been declining in fits and starts over the decades.

"The Arctic is the Earth's air-conditioner," said Walt Meier, a research scientist at the snow and ice centre, an agency sponsored by the US government. "We're losing that. It's not just that polar bears might go extinct, or that native communities might have to adapt, which we're already seeing - there are larger climate effects."

His agency waited a few days before announcing the low to be sure sea ice had started to refreeze, as it usually does at this time of year, when winter closes in rapidly in the high Arctic. A shell of ice will cover much of the Arctic Ocean in coming months, but it is likely to be thin and prone to melting when summer returns.

Scientists consider the rapid warming of the region to be a consequence of the human release of greenhouse gases, and they see the melting as an early warning of big changes to come in the rest of the world.

Some of them also think the collapse of Arctic sea ice has already started to alter atmospheric patterns in the Northern Hemisphere, contributing to greater extremes of weather in the United States and other countries, but that case is not considered proven.

The sea ice is declining much faster than had been predicted in the last big UN report on the state of the climate, published in 2007. The most sophisticated computer analyses for that report suggested that the ice would not disappear before the middle of this century, if then.
Now, some scientists think the Arctic Ocean could be largely free of summer ice as soon as 2020. But governments have not responded to the change with any greater urgency about limiting greenhouse emissions. To the contrary, their main response has been to plan for exploitation of newly accessible minerals in the Arctic, including drilling for more oil.

Scientists said on Wednesday that the Arctic has become a prime example of the built-in conservatism of their climate forecasts. As dire as their warnings about the long-term consequences of heat-trapping emissions have been, many of them fear they may still be underestimating the speed and severity of the impending changes.

In a panel discussion in New York sponsored by Greenpeace, James E. Hansen, a prominent NASA climate scientist, said the Arctic melting should serve as a warning to the public of the risks that society is running by failing to limit emissions.

"The scientific community realises that we have a planetary emergency," Hansen said. "It's hard for the public to recognise this because they stick their head out the window and don't see that much going on."

A prime concern is the potential for a large rise in the level of the world's oceans. The decline of Arctic sea ice does not contribute directly to that problem, since the ice is already floating and therefore displacing its weight in water.

But the disappearance of summer ice cover replaces a white, reflective surface with a much darker ocean surface, allowing the region to trap more of the sun's heat, which in turn melts more ice. The extra heat in the ocean appears to be contributing to an accelerating melt of the nearby Greenland ice sheet, which does contribute to the rise in sea level.

At one point this summer, surface melt was occurring across 97 per cent of the Greenland ice sheet, a development not seen before in the era of satellite measurements, although geological research suggests that it has happened in the past.

The sea is now rising at a rate of about a 30 centimetres per century, but scientists like Hansen expect this rate to increase as the planet warms, putting coastal settlements at risk.

A scientist at the snow and ice centre, Julienne C. Stroeve, hitched a ride on a Greenpeace ship in recent weeks to inspect the Arctic Ocean for herself. Interviewed this week after putting into port at the island of Spitsbergen, she said one of her goals had been to debark on ice floes and measure them, but that it had been difficult to find any large enough to support her weight.

Ice floes were numerous in spots, she said, but "when we got further into the ice pack, there were just large expanses of open water."

The New York Times

Sunday, September 16, 2012

The staggering decline of sea ice at the frontline of climate change

John Vidal,  82.30 N,  25.80 E

Guardian.co.uk,  Friday 14 September 2012 

Scientists on board Greenpeace's vessel exploring the minimum extent of the ice cap are shocked at the speed of the melt

We are a few hundred miles from the north pole. The air temperature is -3C, the sea freezing. All around us in these foggy Arctic waters at the top of the world are floes – large and small chunks of sea ice that melt and freeze again with the seasons.

Arne Sorensen, our Danish ice pilot, is 60 feet up in the crow's nest of the Arctic Sunrise vessel. Visibility is just 200 yards and he inches the 1,000-tonne Greenpeace ice breaker forward at two knots through narrow passages of clear water. The floes are piled up and compressed in fantastic shapes and shades of grey and blue; they crack, rumble and groan as we nudge them aside or climb over them. Two polar bears on our port side lift their heads but resume hunting.

Sorensen has sailed deep into ice at both poles for 30 years, but this voyage is different, he says. The edge of the Arctic ice cap is usually far south of where we are now at the very end of the melt season. More than 600,000 square kilometres (sq km) more ice has melted in 2012 than was ever recorded by satellites before. Now the minimum extent has been nearly reached and the sea is starting to refreeze.

"This is the new minimum extent of the ice cap," he says, the "frontline of climate change".

"It is sad. I am not doubting this is related to emitting fossil fuels to a large extent. It's sad to observe that we are capable of changing the planet to such a degree."

The vast polar ice cap, which regulates the Earth's temperature and has been a permanent fixture in our understanding of how the world works, has this year retreated further and faster than anyone expected. The previous record, set in 2007was officially broken on 27 August when satellite images averaged over five days showed the ice then extended 4.11 million sq km, a reduction of nearly 50% compared to just 40 years ago.

But since 27 August, the ice just kept melting – at nearly 40,000 sq km a day until a few days ago. Satellite pictures this weekend showed the cap covering only 3.49m sq km. This year, 11.7m sq km of ice melted, 22% more than the long-term average of 9.18m sq km. The record minimum extent is now likely to be formally called on Monday by the US National Snow and Ice Data Centre (NSIDC) in Colorado.

The record hasn't just been broken, it's been smashed to smithereens, adding weight to predictions that the Arctic may be ice-free in summer months within 20 years, say British, Italian and American-based scientists on board the Arctic Sunrise. They are shocked at the speed and extent of the ice loss.

The Cambridge University Sea ice researcher Nick Toberg, who has analysed underwater ice thickness data collected by British nuclear submarine HMS Tireless in 2004 and 2007, said: "This is staggering. It's disturbing, scary that we have physically changed the face of the planet. We have about 4m sq km of sea ice. If that goes in the summer months that's about the same as adding 20 years of CO2 at current [human-caused] rates into the atmosphere. That's how vital the arctic sea ice is.

"In the 1970s we had 8m sq km of sea ice. That has been halved. We need it in the summer. It has never decreased like this before".

"We knew the ice was getting thinner but I did not expect we'd lose this much this year. We broke the record by a lot", says the NSIDC scientist Julienne Stroeve.

"The acceleration of the loss of the extent of the ice is mostly because the ice has been so thin. This would explain why it has melted so much this year. By June the ice edge had pulled back to where it normally is in September," she says.

"The 2007 record was set when you had weather conditions which were perfect for melting. This year we didn't have those. It was mixed. So this suggests the ice has got to a point where it's so thin it doesn't matter what the weather is, it's going to melt in the summer. This could become the new normal," says Stroeve.

In the past Stroeve has shown that ice melt has been happening far faster than the models predicted. Her new research, published last month in the journal Geophysical Research Papers, shows humans may have been responsible for most of the ice loss in recent decades.

"It suggests 60% of the observed decline in ice extent in Septembers from 1953-2011 was due to human activity. The decline is linked to the increase in temperatures," she says.

"This year is significant. At the moment the [ice extent] is below what the next Intergovernmental Panel on Climate Change (IPCC) report will show in 2014. We are on the extreme edge of the models, suggesting that ice loss is happening much faster than the models suggested," says Stroeve.

All over the Arctic the effects of accelerating ice loss and a warming atmosphere are being seen. The ecology is changing rapidly as trees and plants move north, new beetles devastate whole forests in Canada, Siberia and Alaska, and snowfall increases. Inuit and other communities report more avalanches, the erosion of sea cliffs and melting of the permafrost affecting roads and buildings. Whole coastal communities may have to be moved to avoid sea erosion.

With the ice loss has come a rush by industry for Arctic resources. Oil, gas, mining and shipping companies are all expanding operations into areas that until only 20 years ago would have been physically impossible. They bring new opportunities for trade, but new threats to the environment. On Monday, a historic first drilling operation by Shell in the Chukchi Sea off Alaska was halted after sea ice was seen moving towards the oil company's drill ship.

Other new research suggests that the loss of ice could be could be affecting the path and speed of the jet streams, possibly explaining why extreme weather in the northern hemisphere is lasting longer.

"There is evidence of stronger and more intense north Atlantic storms and extreme weather, says Stroeve. "We are thinking we are entering a new climate state. Until we get the next push and reach a new equilibrium."

From now on until June, the Arctic sea ice will refreeze. First it will be glassy, thin "shuga", "grease" or "pancake" ice, unable to bind the floes together. But within weeks, the whole icecap will visibly reform, growing up to 100,000 sq km a day until the melt season begins again next year.

But, says Toberg, because of the massive melt this year, there will be less old, or multiyear, ice which is thicker and less prone to melting. The new ice formed this winter will be weaker and more vulnerable to melt, hastening the loss of ice next year. "It is preconditioned to melt", he says.

Now, "feedbacks" are thought to be hastening the ice retreat. In recent summers, say ice experts, Arctic sea surface temperatures have been well above normal, partly because there is less ice to reflect heat back into the atmosphere. The darker open waters now absorb more solar radiation, accelerating the melt.

"The ice is weak so it opens up water and allows more sunlight in which warms the water more which makes the ice break up more – so it accelerates the melt. There is hardly any old, multi-year ice left, so first year ice is now dominant. We are seeing less and less old thick ice," says Toberg.

The longer term implications of the great melt of 2012 are hard to call, say climate scientists who caution that more research is needed. Sea ice plays a critical role in regulating climate, acting as a giant mirror that reflects much of the sun's energy, helping to cool the Earth.

What is suspected is that the formation of the sea ice produces dense salt water which sinks, helping drive the deep ocean currents. Without the summer sea ice, many scientists fear this balance could be upset, potentially causing major climatic changes.

"The Arctic ice cover is a lid on the planet that regulates the temperature. By taking it off you are warming it. Temperatures [everywhere] depend on it," says Toberg.

Sea ice extent has varied naturally over the decades with some Russian data suggesting similar or even greater ice loss in some local areas in the 1930s. But the models are clear, says Stroeve. If you omit the observed records, keeping CO2 levels at pre-industrial levels, then none show a decline of ice cover. When you do put CO2 into the models, they all show a decline, she says.

"Just because there was possibly less ice in some areas at other times, that doesn't mean it's not human-induced now".

"We can expect the Arctic to be ice-free in summer within 20 years, she says. "The ice won't go away the whole year. It will still be cold enough in the Arctic to freeze in winter. But by 2030 I'd say we will have an ice-free summer Arctic. That does not mean that natural ice variability cannot bring it back again, but the trend, we think, will be downward."

"This is a defining moment in human history," said Kumi Naidoo, director of Greenpeace International in Amsterdam. "In just over 30 years we have altered the way our planet looks from space and soon the north pole may be completely ice-free in summer.

"Fossil fuel companies are still making profits despite the fact that climate change is so clearly upon us. Our politicians are putting corporate interests above scientific warnings and failing in their duties to the public".

Time running out to save coral reefs, scientists say

The Age, September 17, 2012   

The chance to save the world's coral reefs from damage caused by climate change is dwindling as man-made greenhouse gas emissions continue to rise, scientists said in a study released on Sunday.

Around 70 per cent of corals are expected to suffer from long-term degradation by 2030, even if strict emission cuts are enforced, according to the study.

"The window of opportunity to preserve the majority of coral reefs, part of the world's natural heritage, is small," said Malte Meinshausen, co-author of the report published in the journal Nature Climate Change.

"We close this window if we follow another decade of ballooning global greenhouse-gas emissions."

Coral reefs are home to almost a quarter of the world's ocean species, they provide coastal protection and can support tourism and fishing industries for millions of people worldwide.

The rise of global average temperatures, warmer seas and the spread of ocean acidification due to greenhouse gas emissions, however, pose major threats to coral ecosystems.

The scientists from the Potsdam Institute for Climate Impact Research, the University of British Columbia and the universities of Melbourne and Queensland in Australia used climate models to calculate the effects of different emissions levels on 2,160 reefs worldwide.

World carbon dioxide emissions increased by more than 3 per cent last year and global average temperatures have risen by about 0.8 degrees Celsius over the past century.

Coral reefs face serious threats even if global warming is restricted to a 2 degrees Celsius limit, which is widely viewed as a safe threshold to avert the most devastating effects of climate change, such as drought, sea level rise or crop failure.

Warmer sea surface temperatures are likely to trigger more frequent and more intense mass coral bleaching, which is when reefs turn pale, the study said.

Although corals can survive bleaching, if the heat persists they can die. This happened in 1998 when 16 per cent of corals were lost in a single, prolonged period of warmth worldwide.

Ocean acidification can put even more stress on corals.

As more and more carbon dioxide is absorbed from the atmosphere, sea water turns more acidic which can hinder calcification which is crucial for corals' growth.

"Thus, the threshold to protect at least half of the coral reefs worldwide is estimated to be below 1.5 degrees Celsius mean temperature increase," the study said.

A separate report last week said Caribbean corals were under immediate threat and urgent action was needed to limit pollution and aggressive fishing practices.

Average live coral cover on Caribbean reefs has declined to just 8 per cent today compared to more than 50 per cent in the 1970s, according to the report by the International Union for Conservation of Nature.