Nature & Environment

World Meteorological Organization Reveals Last Year was Ninth Hottest on Record

Catherine Griffin
First Posted: May 02, 2013 01:14 PM EDT

Last year, the Arctic sea ice melted at a frightening pace. It shrunk to record levels as 2012 was declared the ninth-hottest year since record keeping began in 1850. What is more worrisome is the fact that 2012 was actually experiencing cooling effects from the weather pattern known as La Niña.

Now, the World Meteorological Organization has announced that during the 2012 August to September melting season, the Arctic sea ice cover was just 3.4 million square kilometers. That's a full 18 percent less than the previous record low set in 2007. The melting itself has called quite a bit of attention to the current warming trend.

In fact, the WMO's annual climate report showed that the years from 2001 to 2012 were all among the 13 warmest on record--the hottest being 2010 when the average temperature was 58.2 degrees F. This trend is particularly worrisome considering that La Niña made an appearance in 2012.

La Niña is a coupled ocean-atmospheric phenomenon that is the counterpart of El Niño. They're both part of the broader Southern Oscillation climate pattern. During La Niña, the sea surface temperature across the equatorial Eastern Central Pacific Ocean is usually lower than normal. This, in turn, causes cooler temperatures and is usually associated with more rain in the Midwestern United States. Despite La Niña being present, though, there were above average temperatures in 2012.

The year 2012 wasn't only known for its warmer temperatures, though. In an interview with the Sydney Morning Herald, WMO Secretary-General Michel Jarraud dubbed the year a "disturbing sign of climate change" and went on to say that "The year 2012 saw many other extremes as well, such as droughts and tropical cyclones. Natural climate variability has always resulted in such extremes, but the physical characteristics of extreme weather and climate events are being increasingly shaped by climate change."

Although warming varies from year to year due to a large range of factors, above-average temperatures continue to persist across most of the globe's land surfaces. In addition, the melting sea ice in the Arctic could exacerbate the warming trend; ice reflects heat while the ocean absorbs it. Without the ice, the Earth will absorb more heat and more ice will melt.

"The continued upward trend in atmospheric concentrations of  greenhouse gases and the consequent increased radiative forcing the Earth's atmosphere confirm that the warming will continue," said Jerraud in an interview with the Sydney Morning Herald.

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