Re: This is all you need to know
"CO2 levels are measured very accurately now; agreed? As is temperature?
Therefore, according to the IPCC, temperature should follow CO2. It doesn't!"
No you are missing the point that I made in my previous post. You can't look at temperature over a very short time span and simply say it's going up or down. This is because it is a noisy signal and affected by short term variations (such as El Nino etc.). So it's not simply a question of whether it is measured accurately. What you need to to is to look at the data over a long enough period to extract the signal from the noise. There are well understood techniques for doing this. One relatively simple approach is to take a rolling average of the data over a time period. This has the effect of smoothing out the short term ups and downs so that the long term trend is discernible.
Another approach is that it is actually possible to take the data from the time period in question and adjust it for known anomalies caused by such as El Nino and volcanoes and people have done that. The problem is that 'sceptics' would probably regard that as manipulating the data, even though the techniques in question are not out of the ordinary in science in general.
The point is that every study that has really looked properly at the data has detected a warming trend. The BEST study last year was initially supported by sceptics as it was expected to disprove warming but its basic finding was to support the previous studies.
"There are some very well qualified detractors listed there and if they can't agree what chance do we have?"
I agree - it's difficult. What you've got to remember though is that just because someone has a string of qualifications after their name, it does not necessarily mean that they know what they are talking about outside their area of expertise. This bloke Beck, for example, he was a biology teacher. Looking around the internet, it's easy to come away with the impression that there is a huge debate and lots of controversy. However, most of it is the same stuff repeated in different blogs. The amount of real scientific research underpinning the sceptical positions is quite small. People like Lindzen were reasonably well respected but his theories and predictions haven't stood the test of time and yet he is still feted on the sceptic sites. Ditto Roy Spencer, who has repeatedly been shown to be wrong.
Also, once you start to look into it you find that there are actually all sorts of different sceptical arguments and it is not possible to put them all together and come up with a coherent theory. For example, I've never seen a convincing sceptical argument that explains both how climate sensitivity is low and the Medieval Warming Period was a global phenomenon and yet those are both claims that a typical sceptic will try to make.
I'm no expert but, for me, the real sceptical position is to assume that there are no conspiracy theories that involve all climate scientists, all the major national science institutions, etc., and that the broad consensus on the science is there. On the other hand, there *is* past form for vested interests spreading misinformation to avoid environmental regulation etc. (e.g. see the tobacco industry and attempts to block control of CFCs). Very similar techniques are now being used by so called climate sceptics - spreading doubt about whether the science is solid, implying more controversy than there really is, repeating myths that have already been debunked, recruiting tame experts, and so on. Indeed it is not that hard to find links between organisations currently generating sceptical material on climate change and those fighting against CFC, acid rain and tobacco regulation in the past.