SWAN Village-to-Village Messaging System: Come to think of it! Can it be the same as mining?

Come to think of it! Can it be the same as mining?

Posted by Margaret on 11/26/2008, 3:14 pm
65.74.12.161

Alaska permafrost study reveals larger global warming problem
By Christi Hang

Published Tuesday, November 11, 2008
FAIRBANKS — Alaskans should watch where they step. University of Alaska professor Chien-Lu Ping and a team of researchers have dug more than 100 holes around the state, taking permafrost samples for a paper published in the October issue of the journal Nature Geoscience.

In the paper, Ping concluded frozen Arctic soil contains nearly twice as much organic material and greenhouse gases as previously thought. He based his conclusions on the information collected in Alaska and more than 10 years of research.

According to measurements by the National Oceanic and Atmospheric Administration, the Earth’s atmosphere contains about 387 parts per million of carbon dioxide — about 824 billion tons in total. Alaska tundra and the Canadian tundra zone holds one-sixth that amount — about 137 billion tons — and the amount in Russia is still unknown, Ping said.

If the permafrost melted, “it would release a big flux of gases into the atmosphere,” he said.

Permafrost is any material that remains frozen for two or more years. Most permafrost, however, has an active layer that warms and cools with changes in temperature while staying below the freezing point.

The greenhouse gases within the permafrost are contained in organic material — the semi-frozen remains of ancient plants — found on top of and in the upper layers of permafrost. When the organic material thaws, it begins to decompose, releasing carbon dioxide and methane into the atmosphere. As the Arctic grows warmer, more permafrost thaws, causing more organic material to decompose. And Ping’s study has revealed more organic material than ever just waiting to decompose.

A 2- to 3-degree rise in average air temperature could turn the Arctic tundra from a carbon sink to a carbon source. A carbon sink absorbs more carbon dioxide than it produces while a carbon source, does the opposite. Currently, dead plants in the Arctic tend to freeze faster than they can decompose, thus storing their carbon in the permafrost.

The groundwork for Ping’s study was created through several different projects for different agencies since 1992.

Ping is based at the University of Alaska’s Palmer Research and Extension Center. He said his team of researchers included students, biologists, hydrologists and soil scientists.

Ping and researchers used jackhammers to dig a meter into permafrost to obtain samples. He compared the permafrost to concrete and said it was hard to delve that deeply into the frozen ground.

Before his work, Arctic permafrost had not been widely sampled and the few measurements that did exist only studied the top 40 centimeters of permafrost areas, Ping said.

The top “50, 60 centimeters to a meter are (the layers) most likely subject to change,” he said.

After completing this study, Ping said the next step is to analyze the data and convert it into information that can be used by computer models to forecast how much greenhouse gas will be released if the permafrost melts.

Christian Beer of the Max Planck Institute of Biogeochemistry in Germany wrote in the same issue of Nature Geoscience that Ping’s findings give researchers a better idea of the situation, but the potential consequences of melting permafrost are still unknown.

One possibility is that the greenhouse gases released by melting permafrost could cause further warming of the Arctic, in turn melting more permafrost and creating a loop.

“The projected temperature increase of up to 6 degrees Celsius in the Arctic region of the active-layer ... could cause widespread degradation of permafrost within the next 100 years. As a result, some of the carbon stored within these soils may be released, potentially setting in motion a positive feedback loop of warming,” Beer wrote.

Contact staff writer Christi Hang at 459-7590.