Summary of Debate on the Greenhouse Effect

Here is a summary of the recent debate about the existence or non-existence of a physical phenomenon named "greenhouse effect", including the following groups:

1. Alarmists: There are "ghosts" and they are dangerous.
2. Inside Skeptics: There are "ghosts" but they are not so dangerous.
3. Outside Skeptics/Deniers: No real "ghosts" have been identified.

Lindzen, Spencer, Singer, Monckton and Watts belong to group 2, and myself to 3.

There are many possible incarnations as "ghosts" besides "greenhouse effect", like "terrorists", "viruses", "marsians", "islamists", "jews", "drugs", "comets", "aliens"...

Note that from scientific point of view, 3 is the position which is best or easiest to defend, since it puts the burden of proof on 1 and 2 who claim that ghosts exist. Position 2 is most difficult to defend since it both requires identification of ghosts and quantitative assessment of their degree of dangerousness. Position 1 has the advantage of connecting danger and ghost and compensating lack of proof of existence by inflating danger.

One may argue that good science has good defense, and that bad defense gives bad science.