Despite the freezing (for the UK anyway) start to the year, NASA have confirmed that global average surface temperature in 2011 was the ninth warmest since 1880. The finding continues a trend in which nine of the 10 warmest years in the modern meteorological record have occurred since the year 2000.
NASA’s Goddard Institute for Space Studies (GISS) in New York monitors global surface temperatures have released an updated analysis that shows temperatures around the globe in 2011 compared to the average global temperature from the mid-20th century. The comparison shows how Earth continues to experience warmer temperatures than several decades ago. The average temperature around the globe in 2011 was 0.92°F (0.51°C) warmer than the mid-20th century baseline.
“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 first 11 years of the 21st century experienced notably higher temperatures compared to the middle and late 20th century,” Hansen said. The only year from the 20th century in the top 10 warmest years on record is 1998.
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 temperature analysis produced at GISS is compiled from weather data from more than 1,000 meteorological stations around the world, satellite observations of sea surface temperature and Antarctic research station measurements. A publicly available 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. This three-decade period functions as a baseline for the analysis.
The resulting temperature record is 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.
Hansen said he expects record-breaking global average temperature in the next two to three years because solar activity is on the upswing and the next El Niño will increase tropical Pacific temperatures. The warmest years on record were 2005 and 2010, in a virtual tie.
Cast your mind back to January 2010, when climate change sceptic Nigel Lawson was on UK’s BBC Question Time programme hinting that the unusually cold weather confirmed his views on climate change. This was despite at the time, Australia suffering a record heat wave and the Winter Olympics having to import snow due to unusually mild weather.
Anecdotes don’t prove anything, however the latest data show a worrying trend in warming of the planet.
Press release: http://www.giss.nasa.gov/research/news/20120119/
Data analysis: http://data.giss.nasa.gov/gistemp/2011/