Here's part of a new report from The Discovery Channel web site.

Quote:

Chien-Liu Ping and a team of researchers at the University of Alaska, Fairbanks spent the last 13 years meticulously sampling tundra soils across North America. In a study published this week in the journal Nature Geoscience, they estimate there may be almost 100 billion tons of carbon in the first meter of soil alone.

That's equivalent to about a quarter of the amount currently in Earth's atmosphere, or 10 years' worth of global emissions from human activity.

It also nearly doubles previous estimates of carbon content in Arctic soil. Despite decades of work, such approximations are rough at best, because land in the far North is vast, remote, and inhospitably cold. Even in the height of summer, soil scientists can rarely dig deeper than 50 centimeters before they hit rock-solid permafrost.

But worst-case scenario climate projections from the Intergovernmental Panel on Climate Change (IPCC) suggest Arctic temperatures could climb as much as 6 degrees centigrade by the end of the century.

If that happens, the Arctic region, which has already shown signs of thawing, will change dramatically. Already scientists have begun seeing areas where permafrost tundra has melted into muddy bogs called 'thermokarsts.' In other places, steep hillsides, no longer supported by rigid ice crystals, are giving way in landslides.

As the land melts bacteria intrude, decomposing the plant matter that has built up over thousands of years. They release methane and carbon dioxide into the air as byproducts, gases that warm the planet by trapping heat energy from the sun.

"Permafrost temperatures in Alaska have gone up about 1 degree Centigrade over the last 50 years," Ping said, pushing soils to within a fraction of a degree of freezing temperature. "In Russia, they've been monitoring permafrost for over a century. It has warmed 2 degrees Centigrade, so almost 5 degrees Fahrenheit."

It's not all bad news though. The warmer temperatures should allow plants to grow vigorously, and they can suck up huge amounts of carbon out from the atmosphere through photosynthesis -- perhaps even enough to cancel out greenhouse gas emissions from the soil.

In fact, many scientists say the jury is still out on whether or not the thawing Arctic could quicken the pace of global warming.



For the complete article, go here.