Global warming is destroying ponds that have supported life in the Arctic for thousands of years – bad news for the North and an ominous warning to the rest of the world, says a new report by two Canadian scientists.

The small, shallow ponds on Ellesmere Island, high in Canada's Eastern Arctic, are drying up and could begin to release greenhouse gases that make the problem worse, says John Smol, a biologist at Queen's University in Kingston.

"What happens in the Arctic will affect us all, and not in good ways," says Smol, co-author of the report with Marianne Douglas of the University of Alberta in Edmonton. It is being published in the Proceedings of the National Academy of Sciences.

Their findings are the latest in a series of troubling studies that show how global warming is transforming the Arctic. The region is heating up further and faster than any other place on Earth, and "it's the first to show signs of change," Smol says. It's like the canaries that were kept in mines to warn of bad air: "The canary is singing – it's coughing and choking."

The Eastern Arctic is dotted by thousands of ponds – some just 30 or 40 metres long. Until now, they've been locked in ice most of the year and survived the brief, cool summers, bursting into life during that short open spell.

Smol has been visiting 40 ponds since 1983 on Cape Herschel, on the east side of Ellesmere Island, and Douglas joined the research three years later. They've also studied fossils in the pond sediments dating back 5,000 years. The fossil record shows the ponds were stable until 100 years ago, when industrial pollution put enough carbon dioxide into the atmosphere to launch the warming process.

Until recently, the alterations were subtle. Photos taken by others in 1959 and 1973 show the ponds were full of water in midsummer. But the mix of microscopic life was changing – evidence of the impact of higher temperatures and an ice-free season that's at least a month longer than two decades ago.

In 2005 and again last year – the two hottest years on record in the Arctic – many ponds dried up completely. So, too, did much of the tundra around them: Moss that was wet in July can now be set on fire.

"A key `tipping point' has now been passed. Arctic ponds that were permanent water bodies for millennia are now ephemeral," the report states. "The ecological implications of these changes are likely severe and will cascade throughout the Arctic ecosystem."

The ponds are drying even though the past two summers were wetter than average, the report states. Increased evaporation caused by the warmer temperatures and reduced ice cover far outstripped the extra precipitation. The result is that temporary ponds have vanished, permanent ponds are now temporary and bigger lakes are shrinking.

The wet areas are full of algae and are breeding pools for insects – major foundations for the Arctic's fragile ecosystem. Although little is known about how the food chain operates, the loss of these areas is bound to have a major impact.

The potential impact on global warming, though, is clear. The algae consume and store carbon. Without them, it's no longer absorbed. And, if the dry tundra burns, carbon dioxide will be released, adding to the greenhouse effect.

The new report adds to the evidence of Arctic warming, with the threat Greenland's massive ice cap will melt, raising sea levels and flooding coastal areas around the globe, and altering ocean currents.

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