The Earth’s temperature in 2013 tied for the fourth-warmest on record, the 37th straight year for above-average heat, according to a report released today by the National Oceanic and Atmospheric Administration.
The global temperature was 1.12 degrees Fahrenheit (0.62 degrees Celsius) above the 20th century average of 57 degrees Fahrenheit last year, the agency said today in a statement. The average tied the mark set in 2003.
“The long term trends in climate are extremely robust,” Gavin Schmidt, deputy director of NASA’s Goddard Institute for Space Studies in New York said on a conference call. “There is year-to-year variability. There is season-to-season variability. There are times such as today when we can have snow even in a globally warmed world but the long term trends are very clear. They’re not going to disappear.”
Climate change spurred by burning fossil fuels probably will take an increasing toll on the economy, food production, fresh water supplies and human health this century, according to the United Nations.
Including 2013, nine of the 10 warmest years occurred this century. Average temperatures last year were 0.07 degrees Fahrenheit below the 2010 record, according to the agency in its analysis of 133 years of data.
The warmest years, 2010 and 2005, were associated with a disruption of the atmosphere over the tropical Pacific known as El Nino that leads to warmer sea-surface temperatures. It’s counterpart, La Nina, is a cooling of the equatorial Pacific Ocean.
Last year was more neutral, Schmidt said. An El Nino trend likely to develop later this year may push average annual temperatures higher, he said.
“We’re looking at the likelihood of an El Nino starting that will help warm 2014 over 2013 and, depending on the size of the El Nino, is likely to push perhaps 2014 and more likely 2015 quite a way up the rankings,” Schmidt said.
Carbon emissions have been blamed for lifting the Earth’s temperature about 1.4 degrees Fahrenheit since the Industrial Revolution, triggering sea-level rise and extreme weather. Scientists say limiting average annual warming to 2 degrees above pre-industrial times would avoid some of the worst impacts of climate change.