Warm 2011 Weather Shows Climate Change Despite La Nina

Photographer: Scott Olson/Getty Images

Cracked mud at a water tank in a pasture on July 28, 2011 near Tulia, Texas. A severe drought in the region has caused shortages of grass, hay and water, forcing ranchers to thin their herds or risk losing their cattle to the drought. The past nine months have been the driest in Texas since record keeping began in 1895, with 75% of the state classified as exceptional drought, the worst level. Close

Cracked mud at a water tank in a pasture on July 28, 2011 near Tulia, Texas. A severe... Read More

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Photographer: Scott Olson/Getty Images

Cracked mud at a water tank in a pasture on July 28, 2011 near Tulia, Texas. A severe drought in the region has caused shortages of grass, hay and water, forcing ranchers to thin their herds or risk losing their cattle to the drought. The past nine months have been the driest in Texas since record keeping began in 1895, with 75% of the state classified as exceptional drought, the worst level.

Last year was among the 15 warmest since record keeping began in the late 19th century, despite a La Nina weather pattern that should have cooled global temperatures, according to an annual climate assessment.

La Nina’s failure to cause significantly cooler global temperatures is one of many indications of long-term climate warming, according to the U.S. National Oceanic and Atmospheric Administration’s State of the Climate report compiled by 378 scientists from 48 nations. La Nina was responsible for droughts in eastern Africa and North America, the scientists reported.

Last year “will be remembered as a year of extreme events, both in the United States and around the world,” Deputy NOAA Administrator Kathryn D. Sullivan said in a statement today. “Every weather event that happens now takes place in the context of a changing global environment.”

Texas had the hottest summer since data collection began in 1895 and extreme heat may be more common in the future.

“Conditions leading to droughts such as the one that occurred in Texas in 2011 are, at least in the case of temperature, distinctly more probable than they were 40-50 years ago,” according to the study. It used as a proxy 2008, another La Nina year, in which it found extreme heat was about 20 times more likely than in the 1960s.

Thailand’s 2011 floods weren’t the result of climate change because the amount of rain that fell “was not very unusual,” the report concluded.

Carbon dioxide emissions increased in 2011 and the yearly global average surpassed 390 parts per million for the first time since records started.

To contact the reporter on this story: Benjamin Haas in New York at bhaas7@bloomberg.net

To contact the editor responsible for this story: Tina Davis at tinadavis@bloomberg.net

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