In 1900, the human population was 1.6 billion. Since then, it has exploded. We are on course for hitting 11 billion by the end of the century. Sir David Attenborough talks openly about the problem of overpopulation, and it was acknowledged even at the beginnings of conservation biology. The father of conservation biology Michael SoulĂ© said: "We're a species that when you add us, the diversity collapses. We can change everything, dictate everything and destroy everything." Human overpopulation is at the root of all of the problems facing our fellow species, in fact, human population density is a good predictor of the threats to biodiversity.

It is not just the space we take up, it is our relentless consumption of resources. Our natural resources are being diminished faster than they can be replenished. It is not sustainable - there is no Planet B. 

Wild animals now make up just 3% of total mammals on land - the other 97% is made up of 30% humans and 67% domesticated animals that feed us. Why do so few conservation organisations address, or even acknowledge, this issue?