Scientists have identified five major episodes of mass extinction in the past 550 million years. These episodes were rare but extremely deadly, and at least 76 percent of species were lost forever. The last mass extinction happened about 65 million years ago when an asteroid destroyed dinosaur life.
Many scientists now say the planet is experiencing its sixth great mass extinction, and the greatest acceleration in the loss of animal life has happened in the past century. A 2022 study in Nature found that about 40 percent of amphibians, 25 percent of mammals, 21 percent of reptiles and 13 percent of birds now face extinction.
Climate change is a driving factor in animal extinction. A May 2023 study in Global Change Biology found the environment has significantly degraded in the past 50 years. Animals have lost their habitat to deforestation, disease, fire and flooding. Others are dying off simply because ...
