As the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) prepares to unveil a thorough diagnosis of the health of Earth's plant and animal species, this is what we already know:

– 2 species of vertebrate, animals with a backbone, have gone extinct every year, on average, for the past century. The global populations of 3,706 monitored vertebrate species -- fish, birds, mammals, amphibians, and reptiles -- declined by nearly 60 percent from 1970 to 2012.

– About 41 percent of amphibian species and more than a quarter of mammals are threatened with extinction.

– About half of coral reefs have been lost in the last 30 years.

– 25,821 species of 91,523 assessed for the 2017 "Red List" update were classified as "threatened". Of these, 5,583 were "critically" endangered, 8,455 "endangered", and 11,783 "vulnerable".

– African elephant numbers dropped to 415,000 in 2016, down about 111,000 over 10 years.

– 1,204 mammal, 1,469 bird, 1,215 reptile, 2,100 amphibian, and 2,386 fish species are considered threatened.

– Also threatened are 1,414 insect, 2,187 mollusc, 732 crustacean, 237 coral, 12,505 plant, 33 mushroom, and six brown algae species.

– Annual economic losses as a result of deforestation and forest degradation alone may be as high as $4.5 trillion (3.6 trillion euros).

– Scientists say Earth is undergoing a "mass extinction event", the first since the dinosaurs disappeared some 65 million years ago, and only the sixth in the last half-a-billion years.

– There are an estimated 8.7 million plant and animal species on our planet. This means about 86 percent of land species and 91 percent of sea species remain undiscovered.

SOURCE: AFP