The three ways in which the humans threaten the biodiversity are:
Pollution: Human beings tend to pollute the biodiversity in many ways, by polluting the soil, land and water. The oil spills, chemicals and pesticides from agricultural run off pollutes the water and land.
Deforestation: The cutting down of trees in huge amount can led to deforestation of trees. The use of timbers and log for commercial purposes increased the problem of deforestation.
Over exploitation: The use of fossil fuel and other resources more than the need which means to fulfill the greed of human being has led to over exploitation.