How would I explain to my children how we let the last of these animals die? I cannot imagine what it would feel like if the last elephant or rhinoceros in the wild died — and I then had to explain to my children how we let it happen. It would be impossible to reassure them with a straight face that we could still reverse climate change or end intractable conflicts.

The global agenda is full of challenges demanding attention. We live on a warming planet that is home to increasingly unequal societies confronting new and unsettling forms of conflict and extremism. So why spend energy on tackling the multibillion-dollar illegal wildlife trade? At a time when the threats to human health and security are so great, why should any president, prime minister or chief executive prioritise concern about poaching in Africa?

My riposte is that conservation is about people, not just animals: the 1,000 park rangers who have been killed by poachers in the past decade; the victims of the militia organisations that use the profits of poaching to fund conflict and massacres; the millions of Africans whose economic security relies on a wildlife tourism industry but whose livelihoods are being destroyed. About 80% of revenue received in Africa from tourists comes from watching wild animals, which are the ones most often threatened by poaching. The criminals who plunder the world’s natural resources are trapping fellow human beings in poverty, denying future generations the right to economic and social development. It is a vicious circle.

At least 26 elephants, their faces hacked off and their tusks removed, lay in congealing blood on Botswana’s Chobe National Park floodplain. Poachers had killed them within sight of tourist camps.