Should we do anything about Lovelock?

James Lovelock finally demonstrates the example of unscientific, global warming alarmism that the denialists claim to see everywhere. His article has been taken apart elsewhere, and Tim Lambert has some good links. This statement is especially ridiculous:

We are in a fool's climate, accidentally kept cool by smoke, and before this century is over billions of us will die and the few breeding pairs of people that survive will be in the Arctic where the climate remains tolerable.

This is the same type of reasoning used by the denialists who claim that we're just in a natural warming cycle. In both cases, they come up with some kind of reasoning that sounds vaguely plausible to them (smoke to Lovelock, natural cycles to denialists), don't do the hard work of analysis to really test the idea, and then assume the idea is correct and draw all sorts of conclusions from it.

But here's where Lovelock stretches away from the scientific consensus in a measurable fashion:

...as the century progresses, the temperature will rise 8 degrees centigrade in temperate regions and 5 degrees in the tropics.

The IPCC says the rise will be between 1.4 to 5.8 degrees Celsius, and I have a hard time seeing how even 5.8C matches Lovelock's 5C in the tropics and 8C everywhere else.

Let's say though that Lovelock gives 50% probability to the 5.8C scenario, while the consensus suggests the probability is lower. Because the consensus says you get to 1.4 to 5.8 by starting at .1 to .2C per decade initially, then surely Lovelock must consider .2C/decade as his 50% probability to start with, while the mainstream position would more likely put it at .15C/decade.

In other words, there seems to be room for a bet, using 1:1 odds that temperatures will increase at less than .175C over the next 10 years or .35 over 20 years. Whether we should bet him isn't clear to me though. He wants to do the right thing in general (and it's interesting that he likes nuclear power), but exaggerations like his just get the environmentalists in trouble, even the people who don't exaggerate. How do we rein him in? Is it through a bet offer?