Save Our Species: Earth's Current Biodiversity

There is a valid argument, as stated in my last post, that extinction is entirely natural, and has been happening for hundreds of millions of years before human evolution. It is certainly the case that extinction is a natural process taking place before human evolution, but sources estimate current loss of species to be between 100 and 10,000 times higher [1, 2] than the expected natural rate!

Base rates of extinction are something that meddling cannot help – competition and lack of needed adaptations will result in loss of a species, and this is necessary for the proliferation of other species. However mankind is clearly increasing this rate of extinction to a level that has serious consequences for the planet.

Here are some fairly shocking statistics that demonstrate Earth’s current biodiversity:

· 19,817 of the around 53,000 species so far assessed on IUCN Red List of Threatened Species are vulnerable, to critically endangered. This is likely much higher, compared to the estimated almost 9 million species on the planet [5].

· Abundance of species declined by 40% between 1970 and 2000 [2].

· Since 2000, 6 million hectares of primary forest have been lost each year [2].

· 1/4 mammals, 1/8 birds and 1/3 amphibians are in danger of extinction (as of 2008! [1]).

Last Chance to See BBC [1] is an informative, but depressing, read on the worrisome state of Earth’s biodiversity, as seen in 2008.

As a quick warning on the above, don’t necessarily believe these figures – there are many assumptions associated with working out extinction rates, which can mean the figure under or overestimates. It is important to remember that background extinction rates (without humans) vary, most species likely haven’t yet been discovered (see [4]) and estimates have to be calculated, not observed ([3] for more criticisms).