Climate Change Update

| Fri Dec. 26, 2008 12:28 PM EST

CLIMATE CHANGE UPDATE....My morning paper delivers some good news and some bad news on climate change. The bad news:

In one of the report's most worrisome findings, the agency estimates that in light of recent ice sheet melting, global sea levels could rise as much as 4 feet by 2100. The intergovernment panel had projected a rise of no more than 1.5 feet by that time, but satellite data over the last two years show the world's major ice sheets are melting much more rapidly than previously thought. The Antarctic and Greenland ice sheets are losing an average of 48 cubic miles of ice a year, equivalent to twice the amount of ice in the Alps.

I wouldn't be surprised to see this number grow further as more studies are done. But there's also good news:

The report is reassuring [] on the prospects for some potentially drastic effects, such as a huge release of methane, a potent heat-trapping gas, that is now locked deep in the seabed and underneath the Arctic permafrost. That is unlikely to occur in the near future, the scientists said.

"It's unlikely that we're going to see an abrupt change in methane over the next hundred years, but we should worry about it over a longer time frame," said Ed Brook, the lead author of the methane chapter and a geosciences professor at Oregon State University....By the end the century, Brook said, the amount of methane escaping from natural sources such as the Arctic tundra and waterlogged soils in warmer regions "could possibly double," but that would still be less than the current level of human-generated methane emissions.

The release of methane from melting permafrost is one of the worst of the feedback-loop scenarios that could cause climate change to spiral out of control during the middle part of the century. If we really have a hundred years or more before it gets out of hand, that's good news.

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