‘A wake-up call’: total weight of wild mammals less than 10% of humanity’s

A savanna elephant in Pilanesberg National Park, South Africa. The total biomass of savanna elephants was estimated in the study to be half that of the 2m tonnes cats collectively weigh. Photograph: Arterra Picture Library/Alamy

The total weight of Earth’s wild land mammals – from elephants to bisons and from deer to tigers – is now less than 10% of the combined tonnage of men, women and children living on the planet.

A study by scientists at Israel’s Weizmann Institute of Science, published this month, concludes that wild land mammals alive today have a total mass of 22m tonnes. By comparison, humanity now weighs in at a total of around 390m tonnes.