Samuel Alexander’s otherwise excellent critique of the failure of ecological economics to take proper account of rising energy prices contains a single, all too conventional flaw. He takes population growth as a ‘given’ to be accommodated rather than another important variable to be tackled. Total human impact on the planetary environment is, by definition, the average impact per person multiplied by the number of people; and natural resources per person are, by definition, total resources divided by the number of people. It is thus self-evident that stable or reducing populations are an essential, though far from sufficient, condition for bio-physical sustainability. This applies at any energy price or consumption level.
The UN projection for the global population in 2050 is somewhere between 8.1 and 10.6 billion people, depending largely on what we do about it in the meantime. I fully agree with Alexander that structurally declining energy return on energy invested (EROEI) heralds a grim future; but however grim it is, it will be less grim, the nearer to 8.1 billion we stabilise, and then start to reduce our numbers. Regardless even of energy, it is a fact that growth in anything physical on a physically finite planet will certainly stop at some point. It is also a fact that population growth can only stop either: by fewer births (the humane way – contraception backed by policy and resources for family planning and related, preferably voluntary, programmes to enable/encourage people to use it); or by more deaths (nature’s way – famine, disease and competition/war). As Maurice Strong (Sec-Gen of the first Rio Earth Summit in 1992) put it: “Either we reduce the world’s population voluntarily, or nature will do this for us, but brutally”. It follows that population stabilisation/reduction policies in all countries should be an essential part of any realistic degrowth soft landing strategy leaving some kind of civilisation intact.
My own paper, presented to the conference of the International Society for Ecological Economics in Rio in June, was entitled “Population Growth: Multiplier of Impacts; Divider of Resources; Creator of Conflict”. It identified the relevance of population growth to every theme and sub-theme at the conference. I hope Alexander will take account of population as a variable in future work.
Chair, Population Matters (UK)