Another Year – More Evidence for Global Warming
A crumb of comfort for the skeptics is that there is a slight disagreement between the bodies which measure global temperatures: the UK Met Office, NASA, ECMWF and NOAA. Depending on which database you use, 2011 is going to be either the 10th or 11th warmest year in the last 150 years.
The global average temperature was 0.46 degrees Celsius above the long-term average. To prove that this is no fluke, the warmest 13 years on record have all occurred since 1997.
A figure of less than half of one degree may not seem like much, but most climatologists recognize that an increase of more than 2 degrees before the end of the century could lead to a runaway acceleration of global temperatures with catastrophic consequences.
The warmth of 2011 came despite an active La Nina event which continued until May. Such events are usually thought to reduce global temperatures by 0.1 to 0.15 degrees Celsius.
As another indicator of rising global temperatures, Arctic sea ice was well below average. The seasonal minimum ice extent, reached on 9th September, was 4.33 million square kilometres. This was the second lowest on record and both the Northwest and Northeast Passages were ice-free at times.
Hopefully, these findings will act as a spur to the delegates in Durban, but politicians seem to be more concerned about the state of the global economy than the globe itself.