I’ve always felt that logic and sound evidence provide a pretty solid foundation for good policy-making. But some issues are more amenable to logic than others, and population is clearly the least amenable of all.

I’m in the population doghouse yet again. On 1st February the Sunday Times carried a front page story based on comments I had made that as we are heading off into some very troubled times, it would come to be seen as “irresponsible” for families to have more than two children.

You’d have thought I’d advocated compulsory sterilisation, emasculation, euthanasia, and baby-slaughtering all in one fell swoop. Melanie Philips likened me to Pol Pot and Hitler (who was “green” after all!), and when Fox News in the US got hold of the story, every religious nutcase with nothing better to do crawled out from under their stones to suggest the best thing I could do to help address population pressure would be to top myself. Instantly. Logic and sound evidence were not much in evidence.

So let’s just start all over again – here’s the logic, in 12 easy steps.

1. The more human beings there are on the planet, the bigger our collective impact. There were about 3 billion of us in 1950, and there will be about 9 billion by 2050 – if we just carry on as usual. That’s an extra 6 billion in 100 years!

2. Our impact is felt in many different ways – in terms of soil erosion, over-fishing, deforestation, water shortages, loss of species and habitats, and so on. Most particularly, it’s felt in terms of the rising emissions of C02 and other greenhouse gases that we’re putting into the atmosphere, with the prospect of horrendous consequences by the end of the century if we can’t turn this around.

3. Each individual is responsible for their own carbon footprint. Here in the UK, it’s about 12 tonnes per person per annum. In China, it’s about 4 tonnes per person per annum. It soon mounts up. Were it not for China’s ‘one child family’ policy (which is certainly very controversial), there would be as many as 400 million additional Chinese alive today – with a combined annual carbon footprint of around 1.6 billion tonnes of C02!

4. Population and environmental impact are therefore inextricably intertwined. New technology (around energy efficiency and renewables) can do a lot to help reduce that impact. But at the moment, the efficiency gains it gives us are not even keeping up with the combined increase in human numbers and economic growth.

5. Here in the UK, we have adopted some extremely ambitious targets to reduce emissions of C02 and other greenhouse gases by 80% by 2050. On a per capita basis, that means going from around 12 tonnes per person per annum today to around 2.5 tonnes per person per annum by 2050 – if our population remains the same in 2050.

6. But it’s not going to! Current projections indicate that our population is going to grow from 61 million today to 77 million by 2050. Logically, that means there’s a lot less C02 to go round (in terms of our per capita allocation), making it all the harder to achieve that 80% target. (A target, incidentally, which many scientists now see as the absolute minimum which will be required in rich countries like ours).

7. It also means a lot more overcrowding, a lot more pressure on housing, on water supplies, on our trains, on our already congested roads and so on.

8. If you accept that this is a not very attractive proposition, and that it would be better to aim for a lower, rather than a higher population, there are two things that have to happen here in the UK.

9. The first is to allow into our country no more people than leave it on an annual basis. That’s called “net zero immigration”. This is not xenophobic, let alone racist. It’s just common sense.

10. The second is to see if we might persuade (please note, persuade, not coerce!) the 26% of women in the UK who are currently expected to have more than two children to ‘stop at two’. (The other 74% already do stop at two, or have one child or none.) If we did this, we would be able to cut our forecast population by around 7 million people.

11. Combine both policies (neither of which, I think you’ll agree, are that extreme, let alone threatening, let alone totalitarian!), and the consequences are enormous: instead of a population of 77 million, we’d have a population of around 55 million – 6 million fewer than we have today.

12. Amazingly, if we then applied ourselves to doing more or less the same for women the world over, during the course of the next 20 years or so, by the tried and tested means of improving education for all (but particularly for girls), including healthcare for all (but particularly for women), and ensuring a choice of contraception for all women so that they are free to manage their own fertility, without fear of oppressive religious and male-dominated constraints, then we might just be able to stabilise world population to something closer to 7.8 billion instead of 9.2 billion. And just work out what that means for climate change, the planet and all future generations.


So that’s the logic. Of course, it isn’t as easy as that. The barriers are still huge.
Many religious people still think the use of any contraception other than abstinence or the ‘natural method’ runs counter to the will of God. Many economists still think that a declining population will create an increasingly problematic imbalance between those at the end of their working lives and those whose taxes will be needed to support them.

But there seems to be little reason, on either count, to declare that population must remain for ever a taboo subject, beyond rational discourse, worthy only of the rantings of Daily Mail columnists and religious extremists.

So I shall stick to my guns on this one! As a Patron of the Optimum Population Trust, I shall be keenly supporting their ‘Stick at Two’ campaign. And as an environmentalist with a bit of a track record, I shall continue to point out to many of my colleagues that their continuing silence on the links between population, climate change and social justice is actually a betrayal of everything that they stand for – however ‘politically correct’ they may imagine it to be.