Answer: -
The five things that can reduce the biodiversity are
1) Climate change : -
Most species have adapted themselves through out the course of evolution to their natural climate. A sudden change in the climate like the melting of the polar ice caps can greatly lower the biodiversity.
2) Deforestation and Habitat loss
Forests to many species are not only their homes but a source of food. Deforestation leads to the destruction of both their homes and food source. This sudden change in habitat reduces biodiversity.
3) Over exploitation
Over exploitation of species like excessive hunting or excessive fishing leads to the death of many species, leading to decrease in biodiversity.
4) Invasive species
The introduction of non-native species into an ecosystem can threaten local wildlife. Invasive species like predators or species with which competing for resources occurs leads to loss in biodiversity.
5) Pollution
Pollution causes a number of detrimental effects like acid rain, green house effect etc. They lessen the biodiversity as well.