The Voluntary Human Extinction Movement (VHEMT) is an environmental movement that calls for all people to abstain from reproduction in order to cause the gradual voluntary extinction of humankind. VHEMT supports human extinction primarily because it would prevent environmental degradation. The group states that a decrease in the human population would prevent a significant amount of human-caused suffering. The extinctions of non-human species and the scarcity of resources caused by humans are frequently cited by the group as evidence of the harm caused by human overpopulation.
https://en.wikipedia.org/wiki/Voluntary_Human_Extinction_Movement