How hot was 2008?

2008 was the coldest year of the 21st century! 2008 was warmer than all but two years in the 20th century! 2008 was the 10th warmest year on record!

As National Aeronautics and Space Administration climate modeler Gavin Schmidt puts it in his blog, "The great thing about complex data is that one can basically come up with any number of headlines describing it – all of which can be literally true – but that give very different impressions."

So here's the data: According to the World Meteorological Organization (WMO), the worldwide average sea-surface and land-surface air temperature for 2008 was 57.76 degrees Fahrenheit.

That makes it the coldest year since 2000, and – for sticklers who waited until 2000 to party like it's 1999 – the coolest of the century, and of the millennium so far.

These lower temperatures were primarily the result of the La Niña that developed in the Pacific Ocean, reports the WMO. This period of cold ocean temperatures in the equatorial Pacific began in late 2007 and continued through May 2008. The last La Niña of this intensity occurred in 2000, a year that was significantly cooler. (All this was accurately predicted by climatologists a year ago.)

But the only reason that this year seemed so cold is that the rest of this decade has been so hot. The climate deniers who comment on this blog like to claim that "global warming stopped in 1998." While it's true that 1998 was the hottest year on record, none of these commenters have mentioned that the next seven hottest years were, in order, 2005, 2003, 2002, 2004, 2006, 2007, and 2001, according to Britain's Met Office.

As the Met Office points out, the years 2000 to 2008 now stand almost 0.36 degrees Fahrenheit warmer than the average for the years 1990 to 1999. Overall, this year was the 10th warmest since such measurements began in 1850. The only years in the 20th century that were hotter were 1998 and 1997.

The Guardian quotes Oxford professor Alan Myles. "For Dickens this would have been an extremely warm year," he told the British daily. The Guardian notes that, without human-caused global warming, the odds of getting a year as hot as 2008 are 1 in 100. Under today's climactic conditions, the odds are 1 in 10.

NASA, which also measures global surface temperatures, offers up slightly different numbers, but the big picture is the same: The globe is undergoing the warmest decade on record.