Not the End of the World: How We Can Be the First Generation to Build a Sustainable Planet

by Hannah Ritchie

In the Levantine – the Eastern Mediterranean – researchers have reconstructed the mass of mammals going back more than a million years and found that the mean mass of hunted mammals decreased by more than 98%.8 One and a half million years ago, our Homo erectus ancestors were roaming the Earth with mammals that weighed several tonnes. There were the ‘straight-tusked elephants’ (which weighed between 11 and 15 tonnes), the southern mammoth, and incredibly large hippos. Species by species, these majestic animals began to disappear. Nearly all the mammals that went extinct were big. If the climate alone was to blame, it wouldn’t make much sense that it was only the biggest mammals that suffered. Big mammals do have lower reproductive rates which make them more vulnerable, but we’d expect smaller mammals to be partly affected too. The climate doesn’t discriminate, but humans do.