For twenty-seven years, the world's average temperature has been hotter than the average during the second half of the 20th century. Last year, it was the ninth-warmest in recorded history — but still cold for the past ten.
The United Nations' World Meteorological Organization released its annual climate report this week. Compiled using data from NASA, the National Oceanic and Atmospheric Administration, and the UK's Met Office, the group's calculations show the global trend clearly: It's getting warmer.
Below is an approximation of that data, excluding the Met Office's set which wasn't available. The blue line is the NOAA data; the red, NASA. The average of the two is in gray. The zero line represents no deviation from the average global temperature between 1951 and 1980. Anything above zero, then, means the year was warmer than that average.
The WMO report also notes that "2001–2012 were all among the top 13 warmest years on record." As seen below. The numbers associated with each year indicate its rank out of the last 163. 2012 was the ninth-warmest year in the last decade — but only because we've just seen the hottest decade in recorded history.
The report — which can be read in full here — is replete with other unpleasant information about the state of the climate. Precipitation was up. Snow cover was down. But it's what we don't know that's disconcerting. "Climate change," the report says, "is aggravating naturally occurring climate variability and has become a source of uncertainty for climate-sensitive economic sectors like agriculture and energy."
If you're an optimist, we recommend you look at this news in another way: Only 154 years since 1850 were colder than 2012.
- Nature & Environment
- The United Nations