In 2000, when we did the artwork for our album Kid A, our designer Stanley Donwood and I spent a disproportionate amount of time on the net. We came across the Worldwatch Institute's website, which was full of scary statistics about icecaps melting, and weather patterns changing. At the time these things were being talked about a little, but they weren't the obsession they are now. We became obsessed with it, and it ended up inspiring us to use an image of a mountain range on the cover of the record.
I got involved with Friends of the Earth after the UN report on climate change was published in 2003 and decided to support their Big Ask campaign for a strong climate change law.
At first I told Friends of the Earth that I was absolutely the wrong person to be associated with their campaign. I've based my life on touring, and the rock industry is a high energy-consuming industry. But they persuaded me that that was exactly why it was a good idea for me to be involved; that they didn't want to present a holier-than-thou message.
I've not made a habit of meeting many politicians. That said, I was impressed with Ken Livingstone - he was very clued-up on the technical side of things, almost to the point of geekdom. One of the interesting things Ken said to me is that lots of business people really want some laws laid out so they can plan long-term. They think further ahead than the next opinion poll.
Ken is best known for the congestion charge, and he's just introduced incentives for Londoners to own low-emission cars. But my difficulty with the car issue is the motor industry's attitude to the whole problem. I went to Brussels last week and learnt how car companies are lobbying frantically against emission-reduction targets. My generation was brought up with the idea that speed, horse power and cylinders were king, but owning a fast car will soon become naff.
In Freiburg, an amazing green city in Germany, they have done a huge amount to make it easier for people to get around without the car, and generally live low-carbon lifestyles. It's not without its problems, but it shows that a bit of political leadership can get you a long way, and that green living can be good living, too.
With the Big Ask, we started campaigning from the grass roots, asking people to persuade their own MPs that we needed a law to limit carbon emissions, and then asking them to put pressure on the prime minister. The government has said it will introduce a law, which is fantastic news.
Now we just need to make sure it is strong enough. One big problem is that the UK's share of international aviation emissions isn't covered at the moment. The government is also hiding behind old science figures that a 60% reduction in carbon dioxide emissions by 2050 will be enough, even though the science community is saying at least 80% cuts will be needed. I'm disappointed with Gordon Brown. It's a good thing the climate change bill is still going through, but other than that they seem to be going in the opposite direction - nuclear power, new coal-fired power stations, new airports, chucking out road pricing.
With Radiohead, the most shocking yet obvious thing we discovered was that the way people travel to our shows has the biggest impact. So we now play in venues that are supported by public transport. We have a new lighting rig that is, hopefully, powered by super-efficient generators, and we've made deals with trucking companies to cut their emissions.
These changes might be small, but they are in the right direction. Unlike pessimists such as James Lovelock, I don't believe we are all doomed. It was good to hear Sir David King recently saying he was an optimist and human behaviour is changing.
As I heard George Monbiot saying not long ago, isn't it funny how in the space of a year we went from listening to sceptics who denied this was happening to suddenly saying we're all doomed - how interesting that both scenarios demand that we do nothing. That can't be right.
You should never give up hope.
· To see Thom talking more about the campaign click here or here, or watch our video of his CO2 campaign here