There have been 5 mass extinctions, and that's about to turn into 6.
A mass extinction is a "widespread rapid decrease in biodiversity on earth". Mass extinctions are usually caused by volcanoes, or meteoroids. Like how dinosaurs become extinct. 3/4 of all species could vanish.
35% of all mammals and 13% of all birds are threatened by extinction because of human causes. Human activity has greatly decreased biodiversity not only on land, but in the oceans as well. Plants are involved in mass extinction as well. In the past 500 years, we know of about 1,000 species that have gone extinct. Global warming is causing the loss of many exotic species. Diversity in the ecosystem helps with resilience, and we are losing so much diversity that our ecosystem is becoming less and less stable.
Why is it happening?
Over Hunting, poaching, pollution, loss of habitat, invasive species, overpopulation and overconsumption are most likely the causes of this event. People are killing plants and animals faster than they can reproduce. We are destroying the habitats and food sources of animals. The limited resources decreases the carrying capacity of the environment and therefore is the reason why animals and plants population is decreasing at such an alarming rate.
How can we fix it?
Protecting habitats, changing our diets to less land-intensive food, and other forms of conservation. We can stop burning fossils fuels which releases gases that warm our environment. We need to start using renewable forms of energy, such as solar or wind power. We should protect the earth land and oceans... Only 15% of land and 4% of the oceans are being protected. over 40% of the earth land is used for crops and livestock. We need to fight illegal wildlife trafficking. People are slaughtering exotic species, specifically rhinos and elephants, just to illegally sell their body parts. Slowing human population growth could help because we can limit the amount of garbage produced and the amount of fossil fuels being burned.