I sometimes come across people who passionately deny that the world has any environmental problems, especially climate change.

Of course, this will always be the case and we can only hope that those in positions of influence are not deniers, or have their heads in the sand. The issue of peak oil, however, surely cannot be denied by anyone.

There is no doubt that oil will run out on this planet - there is a finite amount. George Monbiot's column in The Guardian raises this issue again in alarming fashion. The fact that whistleblowers from the International Energy Authority have now confessed to exaggerating the world's oil supply, in order to prevent spooking the markets, is scary.

How are we ever going to get our governments to be serious about working towards a world that has as little dependence on oil as possible if such key institutions are not telling the world the truth? Even the BBC drama Spooks recently ran a story based on the lack of coherent, long-term energy strategy for the UK.

Now, I don't know exactly when oil production will peak, I just know that it will. There are obviously lots of very scary consequences of a world with a shortage of oil, and Monbiot touches on one of the scariest. Food production is now totally dependent on petrochemicals.

With no oil, or very expensive oil, food prices will go through the roof. At a recent roundtable at the Cheltenham Literature Festival, Jonathan Porritt chaired a session on the future of food, which highlighted the 'perfect storm' that humanity is hurtling towards with depleted fossil fuels, climate change, loss of biodiversity, water and soil shortages.

The roundtable concluded that one potential outcome in the not too distant future would be the rationing of certain foods that are energy intensive. Peace-time rationing ?! Although, it may not be peace-time by the time oil starts to run out.

We have got to start acting now. We cannot keep putting off making tough decisions and significantly investing in renewable energy.

I spoke to a friend recently who told me not to worry - his view was that the human race is so smart that we will innovate our way out of these problems. I hope he's right, but I don't want to rely on hopes alone as we haven't had to face such a 'perfect storm' before in our history.

I'm off to plant some vegetables....