The man on the stage, it is quickly becoming clear, is not supposed to be there. “Just a moment madam,” he says to a steward attempting to wrest the microphone from him. He eyes the placard-toting crowd – and then begins. “Your children,” he says, “are going to die.” There is an ominous pause. “Your parents,” he continues, “are going to die.” And then he slopes off.

The fifth National Climate March, organised by the Campaign Against Climate Change, has been a rather staid affair up until this point. Speakers including Lib Dem leader Nick Clegg, Labour MP John McDonnell and Green Party leader Caroline Lucas have railed about the need for a green new deal, for an upsurge in civil disobedience, and for an immediate end to plans for a third runway at Heathrow. But it all feels a little lacklustre. Scheduled star speaker and president of the campaign George Monbiot doesn’t even bother to show up. It’s quiet. Chants that in previous years would be drowned out by the tumult can be clearly heard above just 5,000 pairs of marching feet. Climate change, it seems, has dropped from the agenda. The public has other worries now.

Protesters at the National Climate March on December 6

“In the last year the economy has really taken over people’s minds,” says Adam Johannes, 29, who organised the Cardiff bus up to the London march. “Climate change has slipped down in people’s consciousness. People are still worried about it, but it seems less immediate.”

With so many focused on scraping enough money together to pay increasing fuel bills and facing a fight just to find work, there is a real danger that the recession will be used as an excuse for inaction on climate change. “A lot of people when it comes to global warming just see it as a way that the government taxes them more,” says Adam. “We need to connect people’s concerns about the economy with the issue of the environment and the idea of a green new deal – the creation of green collar jobs, where people’s skills can be transferred to making wind turbines, working on renewable energy, and being part of a transition to a green economy.”

Connecting the demands generated by the environmental and economic crises is the goal of a group of South Wales activists who held a meeting in mid-December. Jonny Jones, 29, a socialist active in the Campaign Against Climate Change, says that it is imperative that the public sees fighting for a conversion to a greener economy as something which will benefit rather than harm them financially. “If at the moment the environmental movement turns to people and says what we need to do is cut back on building things, and we need to cut back on this, that and the other, it’s a recipe for absolute irrelevance,” he says.

The job cuts in South Wales over the last few months have been particularly severe. Budelpack in Maesteg. Bosch in Llantrissant. Hoover in Merthyr. All closed. “Every day you are seeing another big factory in the valleys shutting,” says Adam. In all, over 4,000 jobs were lost in the run up to Christmas, and it’s certain many more in South Wales will face a bleak, jobless beginning to 2009. “The economic crisis is going to get much, much worse,” says Jonny. “The spread of the financial crisis to the real economy is still going on. And it’s going to rumble on for months, if not years. It’s going to cause massive anger amongst ordinary people.”

For Jonny, it is vital that this anger is harnessed and moulded into a political force. “The Welsh Assembly is currently developing a plan with Hoover about what to do with its factory. What we did straight away when this closed was say that factory could hold five thousand workers building wind turbines and solar panels. The government has got the money to pay them. They’ve proved that by spending these enormous, insane amounts of money on bailing out bankers.”

Nelson Mandela and protesters in Parliament Square

What is needed, he says, is for the workers and the environmental movement to unite in demanding the government spend money on creating these environmentally essential ‘green collar’ jobs. “If the climate change movement is putting forward the same demands as the labour movement as a whole: we need massive investment; we need that money to be spent here, creating new jobs, making a better life for people and the planet – then it will have a massive resonance.”

Governmental protestations about lack of funds are now null. And discontent is growing. Will the economic crisis galvanise a generation of workers neutered by years of Thatcherite policy and inspire them to force the government to create green jobs? In response, Jonny recalls a quote of Antiono Gramsci: “Pessimism of the intellect; optimism of the will.”

“Can we stop climate change entirely? No,” he says. “Will it have a massive impact on millions of people? Absolutely. Will this sharpen people’s resolve to do something about it as it grows? Almost certainly. Can that fuse with people’s anger about every other aspect of how shit their life is becoming?” And here there is another one of those ominous pauses. “I really hope so,” he says.