The Great Global Warming Swindle: Response

Richard Washington

15th March, 2007

In his documentary, ‘The Great Global Warming Swindle’, Martin Durkin presented the argument that the troposphere – Earth’s upper atmosphere – appeared to be cooler than climate models suggest. Durkin also argued that the global temperature fell in the post-war economic boom, despite rising levels of carbon dioxide.

We asked Dr. Richard Washington, Climatologist and Lecturer at Keble College, Oxford, whether the arguments hold water…

Is the troposphere cooler than it should be?

The two key sources of atmospheric temperature data above the surface in the troposphere are the temperatures derived from balloons (radiosondes) and those from satellite (e.g. using a Microwave Sounding Unit – MSU). These data sets differ in terms of their spatial coverage and also the methods of measurement. It is not surprising then that the temperature trends emerging from these data sets are different.

Satellites measure radiation not temperature. The radiation then has to be converted to temperature. The constants used in these calculations to connect radiation and temperature have been revised many times. Initially the constants were set so that a cooling appeared in the mid troposphere. But subsequent revision to more accurate constants effectively removed this cooling. These revisions were actually undertaken by Spencer and Christy who featured in the Channel 4 documentary. Corrections have also been made to the radiosonde data set so that there is now (in March 2007) much better...

To view the rest of this article - you must be a paying subscriber and Login