Global Temperature Chart – April 2010

Posted on May 17, 2010


The above map, produced by the US National Oceanic and Atmospheric Administration (NOAA), compares global temperatures in April 2010 to a 1970-2000 base period.

In the chart, the larger the dot, the greater the departure from the established base period.  Red dots mean warmer, blue dots mean cooler.

It is important to keep in mind that the 1970-2000 base period was a time when global temperatures had already begun to accelerate upwards.

If an earlier base period had been used, the chart would have no blue dots, or almost none, and the red dots would be larger still and closer together.

The chart above, in effect, compares warming this year with warming earlier.

The proportion of red to blue dots thus tells us whether warming has slowed or stopped this April, as some of the loonier climate change denialists have been merrily saying.

It hasn’t.