Why the greens hate me for telling the truth

Most (but not all) environmentalists locate themselves on the progressive left. Most (but not all) are therefore extremely apprehensive about contested causes that are not recognisably “progressive”.

Population comes top of that list. Because it is all too easy to caricature concern about population as the prerogative of racist, xenophobic and totalitarian interests, better by far to keep one’s distance. All the more so, as it’s impossible to address population with any integrity in isolation from immigration issues.

Once you have arrived intuitively at that conclusion, it follows that it is “rational” not only not to examine the evidence, but also to excoriate that small band of progressives who have – and who refuse to keep their distance. For instance, here’s dear old George Monbiot, winding himself up into a fury about people such as myself:

. . . why does such a large congregation of no ones keep banging on about this issue? Well I can’t help noticing that at least nine out of ten of them are post-reproductive, middle-class white men. They come from a group which is, in other words, more responsible for environmental destruction than any other class in history. Their consumption of just about every known resource outweighs that of most of the world’s people put together. There’s just one major issue for which they aren’t to blame: current increases in population. And – wouldya believe it? – this is the one they want to talk about.

That is quite polite in comparison to the kind of invective preferred by the right. In February, the Sunday Times carried a front-page story based on comments I had made that, as we head off into troubled times, it would come to be seen as “irresponsible” for families to have more than two children. You would have thought that I had advocated compulsory sterilisation, emasculation, euthanasia and baby-slaughtering all at once. The Daily Mail columnist Melanie Phillips likened me to Pol Pot and Hitler (who was “green” after all). When Fox News in the US picked up the story, every religious nutcase with nothing better to do crawled out from under his stone to suggest the best thing I could do to help address population pressure would be to top myself.

It should be a “badge of honour” for those on the progressive left to have set Phillips off on one of her paroxysmal rants. But it would still be good to keep this debate as rational as possible. It was Paul Ehrlich who provided the key to the underlying logic here more than 40 years ago. He reminded his fellow progressives that our impact on the environment should be seen as a function of three variables: population, consumption and technological efficiency. To reduce our impact, year on year, gains in technological efficiency must be greater than the combined increase in population and per capita consumption.

Right now, that looks like mission impossible. With efficiency gains running at less than 1 per cent per annum, continued population growth (of roughly 1 per cent per annum) plus continued economic growth (which was at roughly 3.5 per cent per annum before the recession) set humankind on a collision course with physical reality. Climate change hastens that moment. Billions of people’s lives will be affected – unless we change our behaviour and change course without further delay.

This will entail addressing economic growth, technological efficiency and population, all at the same time, and as determinately as we possibly can. On the issue of population, there is today no other place for progressives to locate themselves, if we are not to remain in reassuring but deeply dishonest denial. l

Jonathon Porritt is chairman of the UK Sustainable Development Commission