Tuesday, August 7, 2007

Correcting global warming maps

The NOAA map below is in the format normally used to represent global temperatures. It is a Miller Cylindrical Projection which shows the entire earth in a single image. This format is convenient but greatly exaggerates land areas at high latitudes. The exaggeration can be calculated as 1/cos(latitude) .

There are two other problems with this map which make it misleading.

  1. The base period starts at 1971, which is a temperature minima. In the 1970s climatologists were warning of an impending ice age, due to rapidly cooling temperatures.
  2. The sensitivity is too high. The data set is not large enough to make meaningful comparisons within 0.5 degrees.

http://www.ncdc.noaa.gov/img/climate/research/sst/ani-weekly/5.gif

The maps below correct two of the three of the issues described above. They are equal area projections, and only temperatures which deviate by one degree or greater are shown. As you can see, ocean temperatures are generally close to normal and areas which deviate above and below the norm are about equal in size. Quite a different view of the world from what global warming alarmists would have you believe.



1 comment:

Gunnar said...

Excellent. That is a much more objective view of reality. Thanks.