Leading article: The green light, hopefully...

In his first newspaper interview since the G20 summit, Gordon Brown makes it clear that he will not be spending his time hoping that the Government's position in the polls is about to be magically transformed by good economic news.

But, although the Prime Minister will not be looking for green shoots, he seems keen to plant a few. He has signalled that the Budget being prepared by the Chancellor, Alistair Darling, for later this month will have a strong emphasis on the environment. He suggests it will contain an electric car pilot scheme, plus measures to hurry along wind farm developments and to support carbon capture technology.

Mr Brown is certainly right when he argues that Britain will need to find some way of creating jobs in a post-recession world in which the City, our dominant employer of late, will be much diminished. Furthermore, we will need to expand our renewable industry rapidly if we are to meet our EU target of producing 15 per cent of our energy from low carbon sources by 2020. There is plainly scope for growth in the labour-intensive green economy.

So it makes sense for the Government to shape its economic policy to fit a low carbon future for Britain. Yet there are some caveats.

In his many years at the heart of power, Mr Brown has never seemed particularly animated by the need for urgent action on climate change. This raises questions of credibility about his sudden conversion now. The second problem is affordability. The deterioration in the public finances outlined by the Institute for Fiscal Studies this week shows how little room for manoeuvre the Government has. A shift to green energy will pay for itself over time. But there are upfront costs. Does the Government have the means to pay them?

Neither of these two obstacles is insurmountable. Mr Brown can demonstrate that he is finally serious about the environment. And sending clear signals to the market can be as important as the investment of public money. But if the Prime Minister imagines the public will be fooled by a handful of half-hearted measures pulled out of the bag to distract us from grim economic news, he needs to think again.