He is right to do so, although as US Senator John McCain has put it: For argument's sake, let's say that the science that we are relying on is wrong - yet we enact legislation to reduce greenhouse gas emissions. What harm will that action cause? Clean air and a more competitive industrial base.

(Or, as one debate participant puts it, Why wait for good science?).

Nevertheless, the argument persists that there needs to be more examination of the science. One person has written the following to [email protected]:

Since many of the issues are still fairly controversial, I would like [the debate] to include some reputable links for the arguments against climate change or at least against its deleterious effects e.g. websites that argue that climate change is a natural phenomenon that has occurred frequently in the history of the world without the intervention of mankind. In order to convince people that climate change is real and that something urgent must be done about it, we need to be able to counter serious arguments on the other side, so we need to know, in detail what those arguments are. I have not yet found them in your articles or links.

This request is welcome. But it compounds together different things that need to be distinguished

1. reputable links for the arguments against climate change

There are no serious scientific arguments against manmade climate change. It is the politics that is controversial.

2. or at least against its deleterious effects

This complex issue has been examined in depth in the scientific literature, including by peer reviewed authors contributing to the IPCC. It does not alter the balance of assessments.

3. climate change is a natural phenomenon that has occurred frequently in the history of the world without the intervention of mankind

No one disputes this.

4. we need to be able to counter serious arguments on the other side

Yes, if they actually exist. But read The Scientific Consensus on Climate Change (Science, Vol 306, Issue 5702, 1686 , 3 December 2004 - cited in an openDemocracy forum here).

Rational argument requires actual evidence and should not be confused with misleading and demonstrably false statements repeatedly made by climate sceptics, and well described by Chris Mooney here.

Countering serious arguments is one thing. Countering lies and distortions is quite another.

Here are a couple of links on the history of climate change: Brief Introduction and History of Climate Change. Please send ideas for more to climate @openDemocracy.net or, better, post directly to the forum.

Caspar Henderson