Past the point of no return to a tolerable climate

From Mr J. Sinclair-Wilson, Oxford, UK

From Mr J. Sinclair-Wilson.

Sir, Martin Wolf lists many of the reasons for pessimism about the prospects for addressing climate change (“Why the world faces climate chaos”, May 15), but not all, and perhaps not the most intractable.

He omits “thermal inertia” – the fact that today’s emissions take 30-50 years to begin to have an effect on global warming. We are living in the past climatically, and by the same token, measures today will not begin to take effect for at least a generation into the future – far longer than governments or electorates can successfully plan for, particularly when the principal reasons for the investments (sacrifices) needed are not so much positive benefits as averting negative impacts, and ones that deniers are always ready to say would anyway never have happened.

Worse, however, the two main planks of climate policy – energy efficiency and emissions reductions – are arguably illusory. Efficiency can result in local savings, but at the macro level reducing the relative cost of energy inputs is more likely to result in higher aggregate energy consumption, making it counter-productive.

Reducing the flow of emissions is, of course, necessary. But emissions per se are not the problem. Climate change results from the stock of greenhouse gases in the atmosphere, and emissions reductions merely slow the rate at which that accumulates. Unlike debt, GHGs cannot be inflated away or worked off, and there are no effective proposals for dealing with the core of the climate problem. Moreover, and given how long CO2 remains in the atmosphere, scientists are not able to tell us where the cascading consequences and feedbacks of even the current 40 per cent increase since industrialisation will leave the world – they have neither the centuries nor the planets to conduct controlled experiments on the biosphere and their models of future impacts are not probative. As some including James Hansen argue, we may already be well past the point of no return to a tolerable climate envelope for our descendants.

Ours is a society that lives by consumption, the corollary to which may hold as well.

J. Sinclair-Wilson, Oxford, UK

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