December 12, 2008

Greenhouse Gas Warming Uneven In The US

Government researchers said on Thursday that climate changes caused by greenhouse gases are warming the United States.

"The continent as a whole is warming, mostly as a result of the energy sources we are using," William J. Brennan, acting administrator of the National Oceanic and Atmospheric Administration, said at a briefing on the nation's climate since 1951.

However, there is a "warming hole" where no change occurred in the center of the country, roughly between the Rocky Mountains and the Appalachians, according to Martin Hoerling of NOAA's Earth System Research Laboratory.

Last year, it was concluded by the International Panel on Climate Change that global warming is "unequivocal, is already happening, and is caused by human activity."

The report on Thursday localized the analysis, concluding that average surface temperatures over the United States have increased 1.6 degrees Fahrenheit since 1951, nearly all in the last 30 years.

"We see a cause-effect relationship in data," Hoerling said.

Human-induced warming is the overall driving factor and also is the main cause of changes in sea-surface temperature, he said.

Climate experts have learned a lot about how sea temperatures result in uneven changes over land by affecting wind and storm movement.  This effect was learned in recent years by studying the periodic El Nino and La Nina patterns of unusual warming or cooling of the tropical Pacific Ocean and how those changes after weather.

The Pacific, currently, is in a neutral condition between the two extremes, and in a separate report on Thursday, the NOAA's Climate Prediction Center said neutral conditions are likely to continue through early next year.

Also, on Thursday, a third report was released by NOAA's National Climactic Data Center saying that November's average temperature for the contiguous United States was 44.5 degrees, 2.0 degrees warmer than average.  It was the warmest November on record for the Western states.

The January-November period has an average temperature of 54.9 degrees F which was 3.0 degrees above the 20th century average.

The nation's January-November temperature increased at a rate of 0.12 degrees per decade since 1985, and at a rate faster of 0.41 degrees each decade during the last 50 years.

Precipitation across the United State in November averaged 1.93 inches, which is 0.20 inch below the 1901-2000 average.

U.N. Secretary-General Ban Ki-moon said on Thursday that the world will have to fight against climate change during the financial crisis, or otherwise it will be overlooked.  He called for a renewed sense of urgency in facing "the defining challenge of our era."

Some 145 environment ministers and other top officials gathered to help push to secure agreement next year on a new worldwide treaty to cut greenhouse gas emissions, which would take effect in 2013.


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