The Arctic could alter the Earth's climate if it becomes a net source of carbon dioxide. The Arctic to capture or currently absorbs 25 percent of this gas, but climate change would alter that amount, according to a new study.
David McGuire of the USGS (U.S. Geological Survey, the U.S. geological survey service) and the University of Alaska at Fairbanks, and colleagues show that the Arctic has been a major carbon sink since the end of last Ice Age, but that may change drastically. On average, the Arctic has represented between 10 and 15 percent of all global carbon sink. However, the rapid rate of climate change in the Arctic almost twice as large as at lower latitudes, could remove the sink and turn the region into a net source carbon dioxide.
usually goes carbon in the oceans and land masses from the Arctic atmosphere and accumulates in large quantities in permafrost, frozen soil layer below the surface land. Unlike active land in permafrost carbon is not broken. As a result, carbon is trapped in the frozen earth. The surface cold conditions also slow the rate of decomposition of organic matter, allowing the absorption of carbon in the Arctic exceeds what it produces.
But
Recent warming trends could change this balance. Warmer temperatures than those of yesteryear could accelerate the rate of decomposition of organic matter from the surface, releasing more CO2 into the atmosphere. Is of greater concern that the permafrost has begun to thaw, exposing previously frozen soils to decomposition and erosion. These changes could reverse the historical role of the Arctic as a sink for carbon dioxide.
Within a few decades, the melting permafrost could also leave the swampy terrain, a situation that could promote the activity of methane-producing organisms.
Currently, the Arctic is a substantial source of methane emitted to the atmosphere: the amount released each year is up as much as 50 million tonnes. The figure of 400 million tonnes of carbon dioxide annually catch the Arctic is certainly higher. But methane gas is a very potent greenhouse, approximately 23 times more potent than carbon dioxide. From accelerating the Arctic methane discharge into the atmosphere, global warming could be accelerated significantly.
November 20 of 200 9
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