Green Right Now Reports
Warmer than average global surface temperatures in 2011 added up to make the year the 9th warmest on record, or since 1880, when modern record-keeping began, according to NASA.
The finding, according to NASA scientists at the Goddard Institute for Space Studies (GISS), confirms that the Earth’s temperatures are warming overall, with 9 of the 10 warmest years occurring since 2000. The only 20th Century year in the top ten was 1998. (2005 and 2010 tied for the hottest year(s) on record.)
“We know the planet is absorbing more energy than it is emitting,” said GISS Director James E. Hansen. “So we are continuing to see a trend toward higher temperatures. Even with the cooling effects of a strong La Niña influence and low solar activity for the past several years, 2011 was one of the 10 warmest years on record.”
The rise in temperatures can be attributed to increasing greenhouse gas emissions from energy production, industry and vehicles, according to NASA. These emissions trap heat as they accumulate in the atmosphere, or as the scientists put it:
Higher temperatures today are largely sustained by increased atmospheric concentrations of greenhouse gases, especially carbon dioxide. These gases absorb infrared radiation emitted by Earth and release that energy into the atmosphere rather than allowing it to escape to space. As their atmospheric concentration has increased, the amount of energy “trapped” by these gases has led to higher temperatures.
The carbon dioxide level in the atmosphere was about 285 parts per million in 1880, when the GISS global temperature record begins. By 1960, the average concentration had risen to about 315 parts per million. Today it exceeds 390 parts per million and continues to rise at an accelerating pace.
The GISS temperature analysis was compiled from weather data from more than 1,000 meteorological stations around the world. Those include satellite observations of sea surface temperature and Antarctic research station measurements. A computer program is used to calculate the difference between surface temperature in a given month and the average temperature for the same place during 1951 to 1980, which serves as a three-decade baseline for the analysis.
The GISS group notes that their conclusions are “very close” to analyses by the Met Office Hadley Centre in the United Kingdom and the National Oceanic and Atmospheric Administration’s National Climatic Data Center in Asheville, N.C.
The trend has no end in sight, says Hansen, who expects record-breaking global average temperature in the next two to three years because solar activity is increasing and the next El Niño will raise tropical Pacific 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,” Hansen said. “It won’t take a very strong El Niño to push temperatures above 2010.”