This may be boring. I am using it as a repository for my contributions to the debate on WUWT, so that if moderated, my efforts will not be entirely wasted.
Tony G asks if wobble is in denial, in my opinion. I have no opinion on that, and if I did, I would not express it here, as the one thing I have learned here is that the d-word is not PC.
David Ross argues that current temperatures are not unprecedented. I accept that. The Eemian waqrm period was 114k years ago. To put that in context, anatomically modern humanity began 200k y/ago, and became behaviourally modern 50k years ago, Civilisation began about 12k y/ago.
OK, part of northern Greenland was ice free 4k y/ago. However, the Vostok core goes back 420k yrs. We cannot extrapolate from one region of Greenland to the whole world. We have to spread the net of data as wide as possible.
David then helpfully refers to evidence of forest fires in the MWP, supporting my point that increased forest fires are to be expected in warm times, and that this will unfortunately provide another positive feedback. In providing this argument, David contradicts Smokey and Crispin. Wikipedia : http://en.wikipedia.org/wiki/Forest_fires#Effect_of_weather says "Heat waves, droughts, cyclical climate changes such as El Niño, and regional weather patterns such as high-pressure ridges can increase the risk and alter the behavior of wildfires dramatically."
I have to confess that I am not sure what turnedoutnice is arguing. Which is a big pity, since he is addressing the key point of my argument, which is that the effect of anthropogenic CO2 on climate is generally agreed, since it is derived from basic physics (as Rob Dekker has set out).
Is there anyone on this list who can summarise what turnedoutnice is saying? Is it agreed by all, or the majority on this list? Because if it can be sustained, it represents a revolution not just in climate science, but in physics.
If it is not, we must all accept as fact that (1) CO2 is a greenhouse gas, (2) that it is increasing, (3) that this increase commits the earth to a modest increase in temperature, and therefore (4) we must debate climate sensitivity and decide on the importance of this increase on the climate as a whole.