The UK’s political conference season was dominated by a debate over the ‘cost of living crisis’. Labour leader Ed Miliband blamed this on a lack of competition in energy markets and pledged to freeze prices should he take power in 2015. Right-wing Conservative MPs countered that the rise in energy prices has been due to the green taxes implemented by Miliband when he was energy and climate change Secretary and his Liberal Democrat successors.

Unfortunately neither claim stands up to much scrutiny – the evidence suggests the problem is much more fundamental than that.

First of all competition – the big 6 energy producers do not make excessive profits, at around 5-7% they are comparable to the big 4 supermarket chains which operate in a ferociously competitive market. Secondly, green taxes account for less than 10% of energy bills – and a proportion of that pays for energy efficiency programmes without which average energy bills would be even higher.

Look instead at the MGI commodity index (which includes energy, food and minerals) in the graph above. Having spent the 20th Century falling, commodity prices have soared in the 21st. Some blame this on speculation by investors, but prices have been on the up for over a decade now, a strong trend unlikely to be caused by short term financial manoeuvring in the markets.

I believe, the only explanation left for such an uptick is that supply is simply struggling to keep up with demand – our consumption is rubbing up against ecological limits. So maybe our politicians need to broaden their thinking and their policies – and the rest of us, too.