There are two interesting pieces of news on the global temperature evolution.
First, today a paper by Grant Foster and Stefan Rahmstorf was published by Environmental Research Letters, providing a new analysis of the five available global (land+ocean) temperature time series. Foster and Rahmstorf tease out and remove the short-term variability due to ENSO, solar cycles and volcanic eruptions and find that after this adjustment all five time series match much more closely than before (see graph). That’s because the variability differs between the series, for example El Niño events show up about twice as strongly in the satellite data as compared to the surface temperatures. In all five adjusted series, 2009 and 2010 are the two warmest years on record. For details have a look over at Tamino’s Open Mind.
Meanwhile, the World Meteorological Organisation has recently come out with a Provisional Statement on the Status of the Global Climate for 2011. In addition to a discussion of some of the extreme events of 2011 this also comes with a first estimate of the 2011 global temperature, see their graph below:
They find – pretty much in line with the Foster and Rahmstorf analysis – that La Niña conditions have made 2011 a relatively cool year – relatively, because they predict it will still rank amongst the 10 hottest years on record. They further predict it will be the warmest La Niña year on record (those are the blue years in the bar graph above).
- G. Foster, and S. Rahmstorf, "Global temperature evolution 1979–2010", Environ. Res. Lett., vol. 6, pp. 044022, 2011. http://dx.doi.org/10.1088/1748-9326/6/4/044022