Here's a really great interview with the legend of the environmental movement, James Lovelock.  The full version can be found here in the New Scientist.  Some highlights:
On Carbon Emissions...

"Do we have time to do a similar thing with carbon emissions to save ourselves from climate change?

Not a hope in hell. Most of the "green" stuff is verging on a gigantic scam. Carbon trading, with its huge government subsidies, is just what finance and industry wanted. It's not going to do a damn thing about climate change, but it'll make a lot of money for a lot of people and postpone the moment of reckoning."

On Survival...
"Do you think we will survive?
I'm an optimistic pessimist. I think it's wrong to assume we'll survive 2 °C of warming: there are already too many people on Earth. At 4 °C we could not survive with even one-tenth of our current population. The reason is we would not find enough food, unless we synthesised it. Because of this, the cull during this century is going to be huge, up to 90 per cent. The number of people remaining at the end of the century will probably be a billion or less. It has happened before: between the ice ages there were bottlenecks when there were only 2000 people left. It's happening again.  I don't think humans react fast enough or are clever enough to handle what's coming up. Kyoto was 11 years ago. Virtually nothing's been done except endless talk and meetings.

It's a depressing outlook.

Not necessarily. I don't think 9 billion is better than 1 billion. I see humans as rather like the first photosynthesisers, which when they first appeared on the planet caused enormous damage by releasing oxygen - a nasty, poisonous gas. It took a long time, but it turned out in the end to be of enormous benefit. I look on humans in much the same light. For the first time in its 3.5 billion years of existence, the planet has an intelligent, communicating species that can consider the whole system and even do things about it. They are not yet bright enough, they have still to evolve quite a way, but they could become a very positive contributor to planetary welfare."

Sobering words, but it does make you look at things from the widest view possible.  We are on a rock spinning around the sun that's been here for millions of years.  Humans, while we like to think of ourselves quite centrically, are really small peanuts in the scheme of things.  I'd reckon any solutions we shoot for should really keep this reality in mind.  Though, how realistic might that really be...