Nature is in freefall and the planets support systems are so stretched that we face widespread species extinctions and mass human migration unless urgent action is taken. Thats the warning hundreds of scientists are preparing to give, and its stark.

The last year has seen a slew of brutal and terrifying warnings about the threat climate change poses to life. Far less talked about but just as dangerous, if not more so, is the rapid decline of the natural world. The felling of forests, the over-exploitation of seas and soils, and the pollution of air and water are together driving the living world to the brink, according to a huge three-year, U.N.-backed landmark study to be published in May.

The study from the Intergovernmental Science-Policy Platform On Biodiversity and Ecosystem Services (IPBES), expected to run to over 8,000 pages, is being compiled by more than 500 experts in 50 countries. It is the greatest attempt yet to assess the state of life on Earth and will show how tens of thousands of species are at high risk of extinction, how countries are using nature at a rate that far exceeds its ability to renew itself , and how natures ability to contribute food and fresh water to a growing human population is being compromised in every region on earth.