We rely on the world's ecosystems and rich biodiversity for everything we need to exist, from the regulation of our atmosphere and the pollination of plants to the creation of important new medicines and crops.
The value of biodiversity lies in both the range of species and the genetic differences within species.
We are reducing this crucial diversity through development, exploitation and pollution; our numbers and activity increasingly encroach on the natural world. Our impact on biodiversity takes many forms, and population growth significantly contributes to virtually all of them.
Climate change, itself arguably caused by humanity, is also playing a part in the rapid decline of global biodiversity.
In summary, the more of us there are, the greater is our impact on the environment.