What Does It Take to Qualify as a Mass Extinction?

The World Wildlife Fund and the Zoological Society of London's current biennial 'Living Planet Report' makes unhappy reading (https://www.theguardian.com/environment/2022/oct/13/almost-70-of-animal-populations-wiped-out-since-1970-report-reveals-aoe). The 'Living Planet Report' is based on the monitoring of 32,000 populations of some 5230 animal species from all areas of the globe. The species are largely vertebrate species of fish, amphibians, reptiles, mammals and birds. The report notes an average decline of 69% in these populations, over the last 50 years. These declines are clearly linked to human activities such as forestry clearance; consuming beyond planetary limits and 'industrial scale' pollution. This 'Living Planet Report' may, however, underestimate the scale of what has been labelled 'the 6th Mass Extinction Event' for the Earth. We tend to focus on vertebrates (because we are vertebrates). The extinctions of plants, fungi and invertebrates (such as the insect pollinators/recyclers) may, however, have a more powerful impact on planetary health. The 'Living Planet Report' calls for the Cop15 Biodiversity Summit (in Canada) to press harder for reductions in anthropogenic (human-mediated) effects on the living world. One must support this call, as a severely denuded planet is of benefit to none of its residents, including humans.