Today marks the arrival in London of Climate Camp 2009. Since it first started three years ago, when 600 campaigners gathered at Drax coal-fired power station in West Yorkshire, the camp has grown rapidly, seeing thousands converge during its protests at Heathrow in 2007, Kingsnorth in 2008, and at the G20 meetings in London earlier this year. It just grows and grows - with almost everyone seeming to now know someone who is attending!

The increasing popularity of the camp highlights a stark divergence in the response to climate change observable between civil society and the government. The announcement this month that dozens of new open-cast coal mines are planned for the UK is only the most recent example of the myriad of frankly unfathomable policies which highlight the Labour government’s continuing love-affair with fossil fuels.

Unsurprisingly, the barrage of criticism rightly faced by the British police – not just in response to the violence seen at the G20 in London which culminated in the death of Ian Tomlinson, but in the sleep deprivation and intimidation tactics at the Kingsnorth camp in 2008, some of which I witnessed first hand – has focused unprecedented levels of scrutiny on how the police operate during protests.

Today, with the beginning of this summer’s camp, we'll begin to see whether the Metropolitan police really have learnt a lesson (as they report they have by the appointment of new ground level commanders and a promise they'll be no repeat of the chaotic scenes played out at the last event. Will we see the legal right to peaceful protest upheld or will we witness another example of political-policing characterised – as in 2008/9 – by violence and intimidation?

But although many eyes will be on the policing, it's vitally important that the real story of the camp isn't overshadowed by it. Because the real message of climate camp is clear: that growing numbers of people are demanding that the government show far more ambition and leadership on climate change issues - and that time is fast running out. I'm looking forward to seeing old friends, and meeting new ones, when I join the camp at the end of the week, as we discuss how we can most effectively increase the pressure for urgent action.