This isn't true. Democratic government is preferable under most circumstances. It is much easier to secure co-operation and deal with dissent if people have a genuine stake in society and the government exists by consent. Democracy has been successful for reasons of efficiency more than any other reason. It would very likely be much easier to restore democracy than you think.
But Lovelock is right. There are certain sorts of problems that democracies can't really deal with. That's why democracy and democratic freedoms are sometimes curtailed during war. In particular, democracies are poor at dealing with slowly developing, complex, and eventually catastrophic problems. WWII is a good example.
All I see is people crying like bitches about Lovelock's argument, or indulging in climate change denialism. None of this is addressing his argument. If democracy can't fix it and climate change is that big of a problem, it follows that we have to dispense with democracy (perhaps only in certain respects) until the problem is fixed. Crying like a bitch because you don't like the situation isn't solving anything.
In fact, all that needs to be done is for the political class to agree to fix the carbon problem no matter what the voters think. Such solutions are not unprecedented in democracies.
That seems reasonable. What's unreasonable is saying that you personally can live with the effects of climate change. I'm sure that the millions of people who would suffer terribly because of climate change would have a problem with your "choice". It's a global problem. If you just choose for yourself and screw everyone else, then you are justifying the use of force against yourself.
If rich countries think that they can ignore climate change and not suffer Al Qaeda x 100, then they are sadly mistaken. The world's poor aren't going to go quietly just so you can have "democracy".