Friday, July 13, 2012

The essence of the climate change debate

Again, over on WUWT there is a debate about the denial word. One of my posts got snipped by the moderator because I used the d-word, so I post a repeat of it here in case this one gets  snipped too.
Skeptical scientists like Lindzen, Spencer and Michaels all agree that the CO2 that we have added to the atmosphere commits Earth to a warming of ~0.8*C. They agree because it is standard textbook physics.
The debate is over the effects on climate sensitivity – the amplification of this 0.8*C by positive feedbacks.
The skeptic hypothesis is that negative cloud feedbacks will reduce the 0.8*C increase to ~0.5*C.
The consensus climatology position is that positive feedbacks will raise the 0.8*C to ~3+*C through increased water vapour, increased cloud, albedo changes, vegetation changes, methane releases from permafrost and clathrates, and secondary CO2 releases from soil and forest fires.
There are a number of separate lines of evidence, from study of past temperature changes, that arrive independently at the ~3*C figure.
Attempts to find evidence consistent with the 0.5*C figure have been few in number, and have been found to be flawed.
The weight of evidence therefore points towards the consensus position.


bbarna said...

Wether or not the climate is changing because of our influence or that of "mother nature" is somewhat irrelevant in my mind. What is important is that we have to stop living in our own filth and do what we can to clean up the air, water and land before it is too late. That is my concern.
Barb from Canada

DocRichard said...

I respect your approach. Otoh, there agw skepticism is being used to slow up an effective global response to protecting the biosphere, and this post is a tiny contribution to removing that handbrake to progress.

Thanks for commenting