Monbiot is still getting the basic environmental question wrong:

The formula for calculating people’s environmental footprint is simple, but widely misunderstood: Impact = Population x Affluence x Technology (I = PAT).

He then goes on to claim that people using higher technologies have greater environmental impact. This is wrong. The T should be used to divide, or perhaps the T should be a number less than one if we are to multiply.

This is, after all, the only way the equation makes any sort of sense at all. The base human technology is hunter gatherer - this existed in our ancestors before hom. sap. did. If there were 7 billion of us trying to be hunter gatherers then the entire environment, tree trunks, seaweed and grasses all, would be eaten within a month. We 7 billion of us using higher technologies than that base one are indeed having an environmental effect but rather less than that. T moderates the effect of P and A upon I, not multiplies it.

Getting this wrong means absolutely every conclusion drawn from the mistake somewhat suspect.

Still, there is comfort here:

But, as there are some genuine ecological impacts of population growth, how do we distinguish proportionate concerns about these harms from deflection and racism? Well, we know that the strongest determinant of falling birth rates is female emancipation and education. The major obstacle to female empowerment is extreme poverty. Its effect is felt disproportionately by women.

So a good way of deciding whether someone’s population concerns are genuine is to look at their record of campaigning against structural poverty. Have they contested the impossible debts poor nations are required to pay? Have they argued against corporate tax avoidance, or extractive industries that drain wealth from poorer countries, leaving almost nothing behind, or the financial sector in Britain’s processing of money stolen abroad? Or have they simply sat and watched as people remain locked in poverty, then complained about their fertility?

We point out - again correctly - that it is the rising incomes that enable that female economic emancipation. It’s only when human muscle power is not the energy source for production that women do indeed have an equal chance. Which is why we have, all along, gloried in that economic development of those poor places precisely because it leads to that emancipation - and, as Monbiot points out, solves that population problem if indeed there is one. You know, that neoliberal globalisation which has produced, in this past generation, the greatest reduction in absolute poverty in the history of our species.

Not that anyone will ever be able to convince Monbiot of that but the rest of us should take note.