Experts Agree (Sort of): 2011 Was One of the Warmest Years on Record

Depending on who you listen to, 2011 was either the 11th warmest on record — that’s according to the National Oceanic and Atmospheric Administration (NOAA) — or the 9th — according to the National Aeronautic and Space Administration — NASA.

According to scientists at NOAA, 2011 broke records for climate extremes, as much of the United States faced historic levels of heat, precipitation, flooding and severe weather.  This was driven in part by La Niña events at both ends of the year that impacted weather patterns in the United States and around the world.  NOAA’s annual analysis of U.S. and global conditions, conducted by scientists at NOAA’s National Climatic Data Center, reports that the average temperature for the contiguous 48 states was 53.8 degrees F, 1.0 degree F above the 20th century average, making it the 23rd warmest year on record.  Rain from coast to coast averaged near normal, despite record-breaking extremes in both drought and precipitation.

Kathryn Sullivan, assistant secretary of commerce for environmental observation and prediction and deputy NOAA administrator, described 2011 as an “extraordinary year.”  “It was extraordinary regarding major weather and climate disasters in particular in our country, from tornadoes to droughts to floods and extreme storms,” she said.  “America endured an unusually large number of extreme events causing damages totaling more than $55 billion dollars.”

By contrast, NASA research counters that 2011 was the 9th warmest year since records were first taken in 1880.  In fact, since that year, nine of the 10 warmest years on record have been in the decade since 2000, a rise in global temperature is evident. The only of the 10 warmest years that was not during the past decade was in 1998. Meanwhile, 2010 is still the warmest year on record overall.  The data was gathered from more than 1,000 meteorological stations across the globe.  NASA estimates that over the next few years we’ll see a year that will top 2010’s record breaking temperatures.  “It’s always dangerous to make predictions about El Niño, but it’s safe to say we’ll see one in the next three years,” James E. Hansen, director of NASA’s Goddard Institute for Space Studies, said. “It won’t take a very strong El Niño to push temperatures above 2010.”

According to NASA scientists, 2011 demonstrated a continuing strong trend linked to greenhouse gases.  NASA noted that the current warmer temperatures are primarily sustained by increased concentrations of greenhouse gases in the atmosphere, especially carbon dioxide. Carbon dioxide is created by a variety of human activities, such as coal-fired power plants to fossil-fueled vehicles to human breath.  At present, levels of carbon dioxide in the atmosphere exceed 390 parts per million (ppm), compared with 285 ppm in 1880 and 315 by 1960, according to NASA.

Writing in The Atlantic, Rebecca J. Rosen says that “In 1880, when the study’s temperature record-keeping begins, the concentration of carbon dioxide was 285 parts per million. Today it is more than 390 parts per million and rapidly rising. Many top climate scientists, including NASA’s James Hansen, have argued that a level not exceeding 350 parts per million is necessary ‘if humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted.’”