Some researchers argued the one child policy was unnecessary in China, because fertility rates were already falling due to more education for women, the voluntary “Later, longer, fewer” campaign (later marriage, longer birth spacing and fewer children) and rising GDP. All the one child policy has done, apart from cause suffering for millions of people, is radically alter the age distribution of the population more quickly than would have happened naturally!
Fertility rates in most Western and East Asian countries are already below total replacement rates, except among migrants.
Chris Packham needs to focus his efforts on the countries with high fertility rates, like in Africa, etc - but rising education and prosperity for women would achieve that anyway.
As a biologist said to DH recently, it’s not the human population that’s the problem, it’s that everyone wants to be middle class!