The natural world has gifted humanity with untold health benefits, and it is believed that it harbours many more undiscovered health breakthroughs. However, we risk losing these benefits, if we continue to degrade the environment.

The UN biodiversity conference, COP15, is due to wrap up on 19 December. This weekend, we are looking at some of the ways that humanity is reliant on a healthy and thriving global ecosystem.

One million species are now said to be at risk of extinction, and if species losses continue to mount, ecosystem functions vital to human health and life will continue to be disrupted.

Ecosystems provide goods and services that sustain all life on this planet, including human life. While we know a great deal about how many ecosystems function, they often involve such complexity and are on a scale so vast that humanity would find it impossible to substitute for them, no matter how much money was spent in the process.