Nature in danger: facts and figures

Humans are changing nature at such a rate that species may no longer be able to adapt, leading to a major extinction crisis, scientists say. Some numbers:
- One in four mammals, one in eight birds, one in three amphibians and nearly half of freshwater turtles are threatened, according to the “Red List” of the World Conservation Union (IUCN).
- At least 15.589 species are facing a risk of extinction, according to the 2004 red list, ie 7.266 animal species and 8.323 species of plants and lichens.
- The rate of disappearance of species is 100 to 1.000 times greater than the natural rate (ie the rate measured over geological time and due to the normal renewal of ecosystems).
- In total, since 1500, 784 animal and plant species are considered extinct, and 60 more survive only in captivity or in culture.
- Next to emblematic species, such as the dodo (a kind of large pigeon incapable of flight), which disappeared after the arrival of the first settlers in the islands of the Indian Ocean around 1740, the great penguin in the northern hemisphere, the Galapagos elephant turtle or the Tasmanian wolf, thousands of unknown species disappear every year.
- Man has described only 1,75 million species out of an estimated total of 10 to 30 million.
- For every tropical plant that disappears, it is estimated that around 30 associated species disappear. For each tropical tree, 400 species disappear.
- Average global warming could lead to the disappearance of 15 to 37% of species, according to modeling carried out on a thousand plants and animals in 6 regions particularly rich in biodiversity around the world (Thomas, Nature of January 8, 2004).
- Three quarters of the world's population are treated with plants, and 70% of our medicines are derived from plants (Nicole Moreau, CNRS)
- Systematicians discover more than 10.000 new species each year, mostly insects, and above all beetles which represent almost a quarter of the species described.

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sources: International mail

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