Rate

 

The present rate of extinction of living organisms is exceptionally high, due to the activities of humankind. According to one estimate, species are becoming extinct at a rate about 1000 times higher than was the case in the late Pleistocene epoch, when the extinction rate was well above the average for geological time as a whole.

 

There are believed to be some 5 to 7 million species of animals, plants, fungi and micro-organisms (excluding bacteria and viruses) on Earth. Some authorities believe that about a quarter of these will be extinct by around 2025. Nearly 9000 kinds of trees, representing around 10% of the species known to science, are threatened with extinction. Over 34 000 species of plants face extinction. Among animals, mammals are now recognised to be much more endangered than birds.

 

The main cause of this loss of biodiversity on land is habitat destruction through various bioharvesting activities of humankind, including farming and logging. Other causes include the release of feral species into the environment and construction of buildings and roads. Serious and progressive loss of biodiversity in the oceans is the result of the increasing and unsustainable scale of the fishing industry.