Each of the previous extinctions wiped out between 50 and 90 percent of all species on the planet.
The most recent occurred about 65 million years ago, when an asteroid ended the reign of the dinosaurs.
A 2016 study published in the journal Science suggests this sixth mass extinction is killing off large ocean dwellers (like sharks, whales, giant clams, sea turtles and tuna) in disproportionately greater numbers than smaller animals. That’s a reversal from past extinctions, when there was a slight correlation between smaller size and going extinct.
The 6th extinction is man made
Previous extinctions were often linked to asteroids or volcanoes, but this one is man made.
Species are disappearing up to 114 times more quickly than they did during previous mass extinctions.
Extinction is a natural part of evolution, having already claimed an estimated 99 percent of all species in Earth’s history, but when too many species die out too quickly, it creates a domino effect which is capable of bringing down entire ecosystems.
Loss of habitat
The main cause of wildlife declines is loss of habitat and fragmentation which is the primary threat for 85 percent of all species on the IUCN Red List. That includes deforestation for farming, logging and settlement, but also the less obvious threat of fragmentation by roads and other infrastructure.
Invasive species now threaten a variety of native plants and animals around the world, either by killing them directly or by beating them to food and nest sites.
Pollution is pervasive on land, in the air and in our oceans – from chemicals like mercury that accumulate in fish to plastic waste that is strangling our oceans.
Vertebrates are disappearing fast
Earth’s entire vertebrate population has fallen 52 percent in the last 45 years, and the threat of extinction still looms for many including an estimated 41 percent of all amphibian species and 26 percent of mammals.