The other day I started reading The Geek Manifesto, by Mark Henderson, and, given my particular interests, I started near the end with the chapter on Geeks and Greens before starting properly at the beginning.
I strongly suggest reading it, but to summarise, the traditional green movement is generally unscientific and deeply political, and this has led to counterproductive politicisation and scepticism of scientific issues like climate change.
The greens latched onto a few things correctly by accident, like climate change research, but are still vastly wrong on many others. They come with too much junk science to be credible, and this leaks into the real science that they accidentally picked up. The association of the Green Party, for instance, with homeopathy and other alternative medicine approaches, is just sad in this day and age (although I believe it changed recently, it wouldn't surprise me if the party still includes many who do believe this junk).
Add to that that many traditional greens have far-left politics which puts a lot of people off, and you end up with the conclusion that they *cannot* be trusted to be the main voice on important matters of science like climate change, which should essentially be an apolitical issue.
Whether it's NGOs like Greenpeace or Friends of the Earth, or political parties like the Green Party here in the UK, they are just too embedded in their history to be able to deal with this properly. They can't give up their hatred of nuclear power, for instance, or their opposition to GM science, both of which are probably going to be essential tools for our future, without alienating their core membership.
I agree with Mark that a new approach is needed, but I don't think those organisations can be rescued ‘from the inside' as he suggests. They can carry on if they like, but even in the unlikely event that they change their views, the public's perception of them would still be the same. We need something new, something reality-based, something that aims to have the clean high-tech future that I personally want.
Even the word ‘green' is now rendered useless by these viewpoints, so we have to just drop it and talk about ‘sustainability' and ‘clean' instead. If someone could come up with a catchy name for it that's half as good as ‘green' though, that would be lovely.