Global Warming in Perspective

I thank Coyote for noting the need to compare temperature anomalies to real temperatures.

We start with a view of global warming to date.  Current estimates for future warming vary, but are on the order of  0.11 degree C per decade.


The HadCrut4 chart shows warming beginning in 1900. Clearly CO2 cannot be the only source of warming.

Now lets look at some real data of the sort you might read on your thermometer.

Data is from Weather Underground,


The little circle contains a scaled version of the HadCrut4 chart with the same vertical scale (4 pixels per degree F).

Given that the range of variation on a daily basis is tens of degrees, and on an annual basis a 100 degrees, even multiples of the historical warming would be hard to observe in real data.