There is a news article with the header Not just March, but start of 2012 shatter US records for heat, worrying meteorologists by Seth Borenstein
Excerpts from the article read [with my comments inserted]
It’s not just March.
“It’s been ongoing for several months,” said Jake Crouch, a climate scientist at NOAA’s National Climatic Data Center in Asheville, N.C.
Meteorologists say an unusual confluence of several weather patterns, including La Nina, was the direct cause of the warm start to 2012. While individual events cannot be blamed on global warming, Crouch said this is like the extremes that are supposed to get more frequent because of man-made climate change. Greenhouse gases come from the burning of fossil fuels such as coal and oil.
My Comment: The highlighted text is yet another example where unsubstantiated claims are made to infer that these extremes are a result of added CO2. Yet what Mr. Crouch ignored is that in March, the global average lower tropospheric temperature anomalies were only +0.11C above the 30 year average for March (see)! The lower tropospheric anomalies are ~0.4C cooler than in early 2010.