Not exactly. He does say that we shouldn’t run out wildly doing things that make no sense economically. He says that we should think carefully about where to put those billions.

As far as 50 years out goes, we have absolutely no possible way of knowing what the climate will be like after 50 years. Current trends simply do not extrapolate linearly (or even logarithmically). Cycles happen – consider the Maunder minimum.

If one accepts Lomberg’s argument, then all previous anti-anthropogenic arguments cannot be made, and the debate moves to what should be done.

One criticism of Lomberg is that he argues few lives will be lost if we don’t act environmentally, but spend the money on other things. The problem is that projections put the highest loss of life after Lomberg’s 50 yr limit. So while we may lose fewer lives over the next 50 yrs, after that the loss will greatly increase.

It’s a gamble but based on all the evidence we’ve seen so far (the 90% IPCC figure, for example, which is about as close you can come to a scientific consensus without the theory being 50 years old) leans the outcome very strongly towards us needing to make big changes. So although the more information we can glean from new research to clarify exactly how much warming (or even if none) is there, large volumes of data say there is going to be at least some damage so it’s logical to start working to negate some of that even as we work out whether it’s 0.3 degrees or 7 degrees we need to worry about. Once it moves into the political and economical realm it needs to be less about “my paper vs your paper” and more about “consensus of every paper suggests this is the most prudent response”.

I really hope that readers of this blog find that a compelling argument as that’s how a lot of science works and I feel the general public misunderstands the fact that whilst theory is being devised, it is by its very nature varied in opinion and magnitude of effect, and that the combined analysis of all of these data is more important than any one particular paper whether it leans towards one way or another.

Almost every article rings with “we don’t know enough about this”.

And your argument seems to come across as “we don’t know enough about this, so we don’t need to do anything about it until we do”; I’ll admit this may be an oversimplification, but feel free to clarify.

The scientific method, by design, always implies that we never know as much about anything as we need to, and hence drives further research. I can accept arguments much easier from people who say “OK, we don’t know everything, but we’ve got a lot of evidence that points to [conclusion x]” than from someone who says “there are elements of conjecture in [hypothesis y], therefore [conclusion x] can be ignored completely and considered bunk”. As Tomas and other commenters here have pointed out, the cost of applying solutions and finding them unnecessary would be far smaller than the cost of doing nothing and later discovering we should have acted.

Re: Lomberg; I’ll agree that CO2 programs are not the “only possible response”, but the alternative of “more direct things” seems a little nebulous – can you expand on that for us a bit (in the absence of a copy of the book)? I’d be interested to know what could be a more direct solution to an overabundance of CO2 than cutting down the amount of it we release.