NASA and the National Oceanic and Atmospheric Administration released their analyses of global surface temperature data for 2010. Both found that 2010 was slightly warmer than 2005, but that the difference was not statistically significant.
Combined land and ocean surface temperatures across the globe in 2010 were 0.62 degrees Celsius higher than the 20th century average, NOAA reported. In the continuous United States, temperatures were 0.6 degrees above normal, making it the 23rd warmest year on record for the country. The Northern Hemisphere experienced its warmest year on record, while the Southern Hemisphere saw its sixth warmest.
The NASA analysis uses the period from 1951 to 1980 as its baseline and found that, on a global scale, 2010 was about 0.74 degrees Celsius warmer than that average.
We have yet to hear from the Met Office Hadley Centre in Exeter, England, which is the third well recognized organization to undertake these types of assessments. All three groups use slightly different techniques to analyze a host of observations from ground stations, ships, buoys, and satellites. For instance, if there is a gap in measurements at a particular station (e.g., in the Arctic, where monitoring stations are few and far between) the Hadley researchers leave that station blank when doing their analyses. But NASA and NOAA, in slightly different ways from each other, use data from the closest stations to take an "informed guess" as to what the missing station data might be.
The key observation to be drawn from these assessments is that the baseline is getting warmer each year. For example, 2010 was the 34th year in a row in which global temperatures were higher than the 20th century average.
The NOAA assessment can be found at http://www.ncdc.noaa.gov/sotc/global/2010/12. The NASA assessment can be found at http://data.giss.nasa.gov/gistemp/. The link to the Hadley Center can be found at http://www.metoffice.gov.uk/.