This week, two thousand people will gather at London's Heathrow airport with tents and sleeping bags - not to EasyJet to the beach, but to alert their fellow citizens to the Weather of Mass Destruction we are unleashing.
If you need to know why this is necessary, take a look at the world the deniers are so glibly averting their eyes from. The two countries doomed to drown by global warming in my lifetime have already begun to disappear beneath the waves. Almost half of Bangladesh is under water as you read this, following monsoons four times more ferocious than they should be. Ten million people are now homeless in the region. In the Maldives, a series of massive swell waves stretching to 4.5 metres drowned 68 islands this spring. The residents know the waves are getting bigger every year, and soon they will swallow their homes forever.
We are living at a time when the most politically important part of any news broadcast is the weather forecast. I have just been out on the borders of Darfur, meeting some of the survivors of the first global warming- triggered genocide. For decades, the Arab nomads and the settled African farmers of the region got along fairly well, with elaborate procedures to share the region's water. But then, as the UN Secretary-General Ban-Ki Moon recently explained: "Two decades ago, the rains in southern Sudan began to fail. According to UN statistics, average precipitation has declined some 40 percent since the early 1980s." This was, he said, almost certainly the result of global warming.
With the water supplies swiftly disappearing, Darfur's fragile Arab-African relations broke down - and one side decided the only way they could survive was to drive their thirsty rivals away, or into a mass grave.
It is not only the poor world that is being shafted by the destabilisation of the planet's climate into chaos. Britain has just been battered by the kind of floods that should only happen every 200 years - except they have happened twice in a six-year stretch.
The protesters at Heathrow are trying to shake us awake, so we do not sleepwalk into more and more of this. Over the next week they will be smeared and slandered as "vandals" and "eco-terrorists". (The Government has disgracefully encouraged the police to use powers introduced to deal with jihadi murderers against them.) But far from being "violent", they are trying to prevent the vast and growing violence of global warming, without hurting a single human being.
Last year, the protesters targeted the Drax coal-fuelled power-station in Yorkshire. This year, they have chosen Heathrow, an airport with a fifth terminal opening in March and demands for a sixth already in, for a simple reason. The current expansion in flying is, on its own, a guarantee that Britain will fail to meet even the most modest of its environmental targets.
Look at the figures. Flying currently accounts for nearly 20 percent of Britain's impact on global warming - and unlike the other factors, it is growing rapidly. The Tyndall Centre for Global Warming, one of the world's most distinguished scientific bodies, has calculated that air travel alone will take up 134 percent of the Government's greenhouse gas targets by 2050. That means that even if we stopped every car and shut every factory, flying alone would guarantee we fail. If Britain - one of the richest countries in the world - can't do it, we cannot pressure anyone else to.
Rather than deal with this real and persuasive argument, the right has been inventing straw-men to savage the protesters with. You want to keep the poor world poor! No, it is global warming that will keep people poor - just ask the people of Darfur.
You are snobs, who sneer at working class people flying to Ibiza! No, we would love people to be able to take more cheap holidays, and to take them ourselves, if it wasn't for the fact it will contribute to global disaster. You are, The Times jeered, "dogmatic flat-earthists" opposed to science! No, we are acting on the overwhelming scientific consensus.
And, finally they splutter - but you are so impractical! Actually, the group Plane Stupid!, whose organisers have been absurdly banned from the camp, has a very practical agenda to reduce these air-emissions. The first is easy: stop the Government from handing the airline industry vast sums of taxpayers' money. They pay no VAT, no tax on their fuel, and have the Government pick up the tab for much of their construction and maintenance work. The former Treasury economist Brendan Sewell has calculated that this is worth £10bn a year. Transfer this cash to cleaner, greener forms of transport.
Gordon Brown is doing the opposite: he has just appointed Digby Jones, straight from his job as spokesman for big industry, including the airlines, to the Government. As Chancellor, Brown championed the Heathrow expansion. Only hard political pressure - showing that further expansion plans will stir public rage - can change his course.
The Plane Stupid! agenda has two other demands: halt all expansion of airports, and ban short-haul flights. It's astonishing to realise that the most popular destinations from Heathrow are Manchester and Paris, both of which can be reached easily on trains which are almost as fast and 10 times less polluting. Currently, half of all flights within Europe go less than 500km - the distance from London to Scotland. Flying needs to become the very last travel option, after every alternative has been exhausted.
Since so much environmental reporting by the right has turned into a game of gotcha! against greens like Al Gore, I should explain my attitude to my own carbon emissions. I don't drive, and I never take short-haul flights. I only take long-haul flights for work, where I kid myself that reporting on human rights abuses makes it worth spending some carbon. I know the atmosphere does not hear my excuses, and nor do the victims of global warming.
But it is not enough for a few people to voluntarily restrain ourselves, while everyone else carries on. We need to all be restrained, by law, or we will all face spiralling climate chaos. That's why joining the climate camp is even more important than changing your lightbulbs or recycling or shifting to a hybrid car: it is collective pressure on government, not dulled and dispersed consumer choices, that the world needs now.
Leila, a London admin assistant helping to prepare the camp, said this weekend: "I realised that if I don't take action, I'm going to spend my old age watching more floods, more droughts and more death, in the knowledge I could have done something." To find out how to join her, go to www.climatecamp.org.uk. How will you explain it to the drowned people of Bangladesh - and the North of England - if you don't?
© 2007 The Independent