The policing at the climate camp today is very hands-off. I walk my bike under the rope without so much as making eye contact with a cop, let alone being stopped, questioned or searched. But there are still no vehicles allowed onsite, so the business of building the camp goes on by hand, with supplies and tents being carted to and fro in wheelie bins.

The atmosphere is relaxed and co-operative. Everyone lends a hand to right a gazebo the wind has upended. A bike tool doubles up to fix some plumbing. Clowns entertain the children, leading them in a ramble round the perimeter fence for the Forward Intelligence Teams to photograph.

Apart from the planes taking off and landing, the most disruptive element at the workshop I'm giving is a middle-aged lady who lives in nearby Harmondsworth. Her home will be knocked down if the third runway goes ahead (along with 700 others, two churches and a Grade-I listed, 14th-century tithe barn), and she is angry, very angry. I say disruptive but, in fact, she does my job for me, welcoming the campers to her neighbourhood and telling the story of the decades of doublespeak that she and other residents have endured.

All through the Terminal 5 inquiry, BAA maintained it would not need a third runway. As the ink dried on the permission letter, which capped aircraft movements at 480,000 (that's one every 90 seconds), BAA announced that it would, after all, be seeking another runway. Before T5 even opens next spring, the government will be consulting on plans to scrap that movement limit.

So, the campers learn about the locals' problems, and everybody (I hope) learns a bit more about aviation's contribution to climate change (13% of the UK's climate damage and rising fast, with no technofix in sight). We run through government policy: support for expansion at airports up and down the country, centralisation of the planning process to ensure this happens, a belief that the carbon problem will go away once emissions are within the EU trading scheme. And we're left with the usual question: what can we do about it? The campers, of course, have pledged to take direct action, but the crucial question is what form this will take.

Probably thanks to BAA's heavy-handed injunction attempt, I get the feeling Middle England is largely on the campers' side. Sure, there are get-a-job rants on the Telegraph comment pages, but if we can calibrate public opinion using a Times leader as just centre of centre, the mood seems to be that the camp should go ahead: the campers have a point, their dedication is impressive, but they'd better not disrupt anyone's holiday. This line of argument reveals the same missing link as today's survey into environmental behaviour - people accept that climate change is a problem, but are unwilling to change their lifestyles to help solve it.

I'm not saying disrupting the airport is the best way to cement the connection between flying and the damage it causes. But neither can we commend the climate campers without accepting the need for all of us to fly less.

 http://commentisfree.guardian.co.uk/peter_lockley/2007/08/carry_on_climate_camping.html