There are several major threats to biodiversity.
- Loss of habitat is a direct cause of extinction and therefore a threat to biodiversity. Loss of habitat is related to human population growth. Loss happens world wide, as cities push out into what was once wilderness habitats are lost or damaged, it also happens in areas where deforestation is taking place.
- Invasion of Non-native species is important as a threat to biodiversity. Introduction of non-native species in any area - either intentional or accidental - is one of the most difficult to control with our life styles of global travel and movement around the planet.
- Pollution is not usually a direct cause of extinction, but it can have a significant effect on any given species' habitat.
- Climate change itself is a normal process. However it is rapid climate change, influenced by humans, that is a threat to biodiversity. Rapid climate change does not give ecosystems or species the time to adapt.
- Over-Hunting has in the past been more of an issue as a threat than it is today. Most hunting of endangered species is monitored now, although it still occurs when animals are poached.