To: Cautious_Optimist who wrote (86556 ) 3/31/2012 3:24:43 AM From: T L Comiskey Respond to of 89467 Friday, March 30, 2012 Seesawing weather patterns - Some people call what has been happening the last few years “weather weirding,” and March is turning out to be a fine example. Lurching from one weather extreme to another seems to have become routine across the Northern Hemisphere. Parts of the United States may be shivering now, but Scotland is setting heat records. Across Europe, people died by the hundreds during a severe cold wave in the first half of February, but a week later revelers in Paris were strolling down the Champs-Élysées in their shirt-sleeves. As a surreal heat wave was peaking across much of the U.S. last week, pools and beaches drew crowds, some farmers planted their crops six weeks early, and trees burst into bloom. Now, of course, a cold snap in Northern states has brought some of the lowest temperatures of the season, with damage to tree crops alone likely to be in the millions of dollars. Does science have a clue what is going on? The short answer appears to be: not quite. The longer answer is that researchers are developing theories that, should they withstand critical scrutiny, may tie at least some of the erratic weather to global warming. Specifically, suspicion is focused these days on the drastic decline of sea ice in the Arctic, which is believed to be a direct consequence of the human release of greenhouse gases. “The question really is not whether the loss of the sea ice can be affecting the atmospheric circulation on a large scale. The question is, how can it not be, and what are the mechanisms?” As the planet warms, many scientists say, more energy and water vapor are entering the atmosphere and driving weather systems. A strong body of evidence links global warming to an increase in heat waves, a rise in episodes of heavy rainfall and other precipitation, and more frequent coastal flooding. “A changing climate leads to changes in the frequency, intensity, spatial extent, duration and timing of extreme weather and climate events, and can result in unprecedented extreme weather and climate events." Some of the documented imbalances in the climate have certainly become remarkable. United States government scientists recently reported that February was the 324th consecutive month in which global temperatures exceeded their long-term average for a given month; the last month with below-average temperatures was February 1985.