Climate Change - Visualized

New Scientist has put together one of the best visualizations on Global Warming that I've seen
You really should play around with this.  You can

• Pick a 20 year period to look at global trends in that period - from 1893 to 2012
• Pick a location to look at the specific trend in that location
• Drill down into a specific area

There is a whole lot more - it really packs a ton of information into a clear and intuitive interface.   (The above is just a screen grab.  Go to the original for the Visualization) 

From the writeup on the site

This interactive graphic displays results from a global analysis of surface temperatures from 1880 to the present called GISTEMP, produced by a team at NASA’s Goddard Institute for Space Studies in New York City.

The graphs and maps all show changes relative to average temperatures for the three decades from 1951 to 1980, the earliest period for which there was sufficiently good coverage for comparison. This gives a consistent view of climate change across the globe. To put these numbers in context, the NASA team estimates that the global average temperature for the 1951-1980 baseline period was about 14 °C.

The analysis uses land-based temperature measurements from some 6000 monitoring stations in the Global Historical Climatology Network, plus records from Antarctic stations recorded by the Scientific Committee on Antarctic Research. Temperatures at the ocean surface come from a measurements made by ships from 1880 to 1981, plus satellite measurements from 1982 onwards.

Surface temperature measurements are not evenly distributed across the globe. So the NASA team interpolates from the available data to calculate average temperatures for cells in a global grid, with each cell measuring 2 degrees latitude by 2 degrees longitude. The analysis extrapolates up to 1200 kilometres from any one station, which allows for more complete coverage in the Arctic – where monitoring stations are sparsely distributed, but where the warming trend is especially strong.

The NASA team also corrects the data to remove local heating caused by dense human settlements – a phenomenon known as theurban heat island effect. Temperature stations in urban areas are identified by referring to satellite images of the light they give off at night, and their records are adjusted to reflect the average trend of nearby rural stations.

The global picture is frightening enough, but there is some really bad shit going on at the poles...