Arctic sea ice disappearing

If the Artic ice cap keeps disappearing then children alive today will know a world without polar bears. Picture / Reuters

The melting of the sea ice in the Arctic, the clearest sign so far of global warming, has taken a sudden and enormous leap forward, in one of the most ominous developments yet in the onset of climate change.

Two separate studies by Nasa, using different satellite monitoring technologies, both show a great surge in the disappearance of Arctic ice cover in the last two years.

One, from the Jet Propulsion Laboratory in California, shows that Arctic perennial sea ice, which normally survives the summer melt season and remains year-round, shrank by 14 per cent in just 12 months between 2004 and 2005.

The overall decrease in the ice cover was 720,000 sq km - an area almost the size of Turkey - gone in a single year.

The other study, from the Goddard Space Flight Centre in Maryland, shows that the perennial ice melting rate, which has averaged 0.15 per cent a year since satellite observations began in 1979, has suddenly accelerated hugely. In the past two winters the rate has increased to 6 per cent a year - that is, it has got more than 30 times faster.

The changes are alarming scientists and environmentalists, because they far exceed the rate at which supercomputer models of climate change predict the Arctic ice will melt under the influence of global warming - which is rapidly enough.

The current estimate is that if climate change is not checked, the Arctic ice will all be gone by 2070, and people will be able to sail to the North Pole. But if these new rates of melting are maintained, the Arctic ice will all be gone decades before that.

The implications are colossal. It will mean extinction in the wild - in the lifetime of children alive today - for one of the world's most majestic creatures, the polar bear, which needs the ice to hunt seals.

It means the possibility of a lethal "feedback" mechanism speeding up global warming, because the dark surface of the open Arctic ocean will absorb the sun's heat, rather than reflect it as the ice cover does now - and so the world will get even hotter.

But most of all, the developments add to the growing concern that climate change as a process is starting to happen much faster than scientists considered it would, even five years ago when the UN's Intergovernmental Panel on Climate Change published its last report.

"These are the latest in a long series of recent studies, all telling us that climate change is faster and nastier than we thought," said Tom Burke, former government green adviser and now a visiting professor at Imperial College, London.

"An abyss is opening up between the speed at which the climate is changing and the speed at which governments are responding.

"We must stop thinking that this is just another environmental problem, to be dealt with when time and resources allow, and realise that this is an increasingly urgent threat to our security and prosperity."

The US climatologist James Hansen has issued a now-or-never warning to governments around the world, including his own, telling them they must take radical action to avert a planetary environmental catastrophe. He said it was no longer viable for nations to adopt a "business as usual" stance on fossil-fuel consumption.

"I think we have a very brief window of opportunity to deal with climate change ... no longer than a decade, at the most," he said.

Early in his first term the US President, George W. Bush, pulled the US out of the Kyoto Treaty that is meant to bind nations to lower emissions of warming gases. However, opinion in the US is starting to change, as evidenced by the huge success of the documentary on climate change, An Inconvenient Truth, narrated by the former US Vice-President Al Gore.

The two Nasa Arctic studies, released simultaneously, break fresh ground in dealing with the perennial, or "multi-winter" ice, rather than the "seasonal" ice at the edge of the icefield, which melts every summer.

Concern about the melting rate has hitherto focused on the seasonal ice, whose summer disappearance and retreat from the land masses of Arctic Canada and Siberia is increasingly obvious. In September 2005, it retreated to the lowest level recorded.

But such rapid shrinkage of the perennial ice has not been shown before.

"It is alarming," said Joey Camiso, who led the Goddard study. "In the past, sea ice reduction in winter was significantly lower per decade compared to summer sea ice retreat.

"What's remarkable is that we've witnessed sea ice reduction at 6 per cent per year over just the last two winters, most likely a result of warming due to greenhouse gases."

Dr Son Nghiem, who led the team that did the Jet Propulsion Laboratory study, said that in previous years there had been some variability in the extent of perennial Arctic ice.

"But it is much smaller and regional," he said. "However, the change we see between 2004 and 2005 is enormous."

Britain's Professor Julian Dowdeswell, director of the Scott Polar Research Institute in Cambridge, agreed that the changes shown in the American studies were "huge", adding: "However, it remains to be been whether the rate of change is maintained in future years."

The melting of the Arctic ice will not itself contribute to global sea-level rise, as the ice floating in the sea is already displacing its own mass in the water.

However, there are great volumes of land-based ice - the ice sheets of Greenland and Antarctica, and the ice locked up in mountain glaciers - which are subject to exactly the same temperature rises as the Arctic ice, and which have also started to melt. They most definitely will add to sea levels.

The West Antarctic Ice Sheet - characterised last year by Professor Chris Rapley, director of the British Antarctic Survey, as "an awakening giant" - would, if it were to collapse, raise sea levels around the world by 5m, submerging large parts of Bangladesh and Egypt.

Searing heat, drought, melting glaciers - what's world coming to?

Europe
In Greenland the barley is growing for the first time since the Middle Ages. In Britain gardeners were warned this week that the English country garden will be a thing of the past within 20 years. In Italy skiers were told yesterday that melting glaciers will mean an end to their pastime unless they can get above 2000m.

Even those enjoying the warmer temperatures in unpredictable bursts by venturing into the sea have been confronted by swarms of jellyfish, which have flourished in record numbers in Europe in the warmer waters. Those same waters are rising in Venice, prompting arguments over costly plans to seal off the lagoon from the sea.

The prospect of flooded squares on the scale of Venice's Piazza San Marco is driving plans to expand and reinforce the Thames flood barrier. In Holland the battle has been lost and 500,000ha, an area more than twice the size of greater London, will be strategically flooded instead and people will move to floating homes.

This summer prolonged drought in Spain and Portugal has expanded into central and northern Europe.

Africa
Natural disasters, extreme weather floods and droughts have always been common in southern Africa but the severity of the wet and dry periods is intensifying with disastrous results.

A barrage of meteorological studies have found a pattern of increasing climatic variability and unpredictability. Throughout the Horn of Africa debilitating droughts this year have culled the region's wildlife and disrupted the migrations across the Masai Mara and the Serengeti.

Human populations have been devastated by the soaring temperatures and freak dry seasons. Herdsmen in the north of Kenya have been driven to war over the few cattle that have survived the drought.

North America
In Alaska millions of dollars of damage has been done to buildings and roads caused by melting permafrost. Rising sea levels have forced the relocation of Inuit villages and polar bears have been drowning because of shrinking sea ice. The caribou population is in steep decline because of earlier spring and the west is suffering one of the worst droughts for 500 years.

In Louisiana about 400,000ha of wetlands have been lost to sea-level rise. In the northwest there has been dramatic shrinkage of glaciers in Glacier National Park and the South Cascade Glacier in Washington is at its smallest size in the past 6000 years.

Hawaii has seen first large-scale coral bleaching. And scientists now believe the strength of hurricanes that strike the southeast and the Caribbean is linked to climate change.

South America
Few images have offered such stark evidence of the advance of climate change as those of the dry bed of the Amazon River. Last year, the largest river in the world was reduced to a trickle by an unprecedented drought. This year sand banks have already appeared in the deltas of the Amazon and fears are rising that a drought cycle that was previously measured in multiples of decades may now be an annual event. As the most important carbon sink in the world, the Amazon's impact on global patterns of rainfall is only now beginning to be fully understood and scientists warned in July that this extraordinary planetary air conditioner could be malfunctioning critically.

The drying of the world's most biologically diverse forest has already been instrumental in a 1000-fold increase in the extinction rate of plant and animal species, says leading botanist Sir Ghillean Prance.

In the Peruvian Andes the alpacas that have for centuries provided indigenous farmers with a means of survival have died in cold snaps where temperatures plummeted to -30C.

Australia
Al Gore's documentary, An Inconvenient Truth, twice singles out Australia for lagging behind the rest of the world on climate change. It has, with the US, refused to ratify the Kyoto protocol. The Industry Minister, Ian Macfarlane, dismissed as "just entertainment" Gore's film, which documents the scientific consensus that climate change in Australia has increased the duration and intensity of cyclones, and prompted a drop in rainfall in agricultural areas.

Further evidence of climate change is to be found in the rising sea levels already starting to inundate Pacific islands, where the people, agricultural land, tourist resorts and infrastructure are concentrated on the coast. Temperature increases in the Pacific are killing off coral reefs.

Asia
In south India thousands of farmers have killed themselves after successive years of drought wrecked their crops. Most ominous of all, environmentalists are warning of disaster in the Himalayas, where glaciers are melting.

- INDEPENDENT