Biodiversity Loss: How Accurate Are The Numbers? Can we tell how many species are becoming extinct? No-one knows how many species exist’
'Current estimates of number of species can vary from, let's say, two million species to over 30 or even 100 million species' -- 'The International Union for Conservation of Nature (IUCN) has listed 801 animal & plant species (mostly animal) known to have gone extinct since 1500. But if it's really true that up to 150 species are being lost every day, shouldn't we expect to be able to name more than 801 extinct species in 512 years?'