Global warming has made Arctic wetter and snowier

April 26th, 2008 - 12:28 pm ICT by admin  

National Geographic

Washington, April 26 (ANI): A new study has suggested that in addition to the Arctic heating up faster than almost anywhere else on the planet, it has also become wetter and snowier due to global warming.

According to a report in National Geographic News, the new study, conducted by the government agency Environment Canada, is the first to show that changes in precipitation in the Arctic are in part human-induced.

The extra precipitation, according to the research team, could freshen ocean water in the Arctic and North Atlantic, which might disrupt the so-called ocean conveyor belt, a current that runs through the Atlantic and carries warm water northward from the Equator.

The study also shows that previous computer models underestimated how much precipitation would change because of global warming.

Contrary to the simulations, Arctic rain and snowfall increased by 7 percent over the past 50 years. In just the Canadian Arctic, precipitation jumped 11 percent.

That might not seem very big, but a 10 percent change is quite a lot when it comes to precipitation, said study leader Francis Zwiers. The discrepancy means that models predicting future change may underestimate whats coming down the pipeline, he added.

For their work, Zwiers and colleagues considered whether changes in precipitation are due to human activities or are being caused by natural events such as volcanic eruptions or changes in the sun. The team also tested whether natural, chaotic variability in climate could be to blame.

Using computer models, the researchers could turn each of these forces on and off to see which contributed the most to the changes that have been observed.

Our conclusion is that, by a long shot, the best explanation for the change in Arctic precipitation is that its due to human influence, said Zwiers.

If you pull the natural forcing out, it doesnt change things much, said James McClelland of the University of Texas at Austin. The largest factor driving the changes weve seen turns out to be humans, he added.

According to Zwiers, increasing greenhouse gas emissions heat up the air, allowing it to hold more moisture. This means that the air blowing up from the tropics carries more water and thus creates more rain and snow when it reaches the Arctic.

One of the effects could be to shift the storm tracks closer to the Poles, he said. Extra precipitation could also make Arctic surface waters less salty, which would affect ocean circulation, he added.

Changes in Arctic rain and snow could also directly harm the people and animals that live in the far North, according to recent studies. (ANI)

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