Re: IPCC Credibility
> Basically, as a scientific organisation, they should be comfortable saying that "this is the evidence for A"
They started out that way - the problem is the "nay" camp are vicious and IPCC people end up being the targets of highly personal public attacks on their credibility. This tends to back people into a corner and make them come out fighting.
Naysayers have a nasty habit of picking on several small periods in a trend which are slightly negative and when others point out that the values across much longer periods are vastly positive and that each "negative trend" has higher starting and finishing points than the last one, they again resort to personal attacks.
The diagram at http://www.skepticalscience.com/examining-the-latest-climate-denialist-plea-for-inaction.html illustrates this last point well.
The issues with human-accelerated global warming are these:
1: If it's true and we do nothing, things get worse (as in "extremely expensive" as well as other connotations)
2: If it's not true and we do nothing, things stay the same
3: if it's true and we do "something" - it's expensive but things either stay the same or don't get as bad (expensive) as they could do.
4: If it's not true and we do "something" - it's expensive but things stay the same.
Call it an insurance policy. Certain Arizona Sherriffs may decry such things but when bad shit happened he didn't have it to fall back on - and unlike him, if we do nothing and bad shit happens there won't be any other planets we can beg help from.
The same attitudes can be seen by those who refuse to insure their cars (or do it and whine about being forced to have insurance) - it's there for a reason and if you want to play the odds society doesn't have to bail you out. In the case of Global Warming denialists, most of the denialists either take the attitude of "if it happens I'm OK anyway" or digging a little deeper finds that they stand to make massive profits from what might happen if GW is true. (This is the same kind of thing as a pump-and-dump scam)