Window Closing Down in Avoiding Earth’s Sixth Mass Extinction

Jun 20, 2015 By John Birks 4 Comments

A study done by a joint US-Mexican team of researchers seems to suggest that the Earth may be headed to its sixth mass extinction period due to human impact over the environment, which sees species disappearing at a rate 114 times faster than normal. The study’s finds were published Thursday in the Science Advances journal

This would be sixth such event in Earth’s history and the first since the disappearance of dinosaurs after a massive disaster 65 million years ago. The main argument in predicting the event is the abnormally high rate of extinction in species, with over 400 vertebrates having disappeared since 1900 alone, and the effects on human populations could possibly become visible in only three generations, whilst nature would take millions of years to recover.

Out of the over 400 species which have disappeared since the start of the the 20^th century, 69 of them were mammals, 24 reptile, 80 were bird species and more than 300 were amphibious or fish. Things are becoming worse as more than a quarter of all mammals and 41 percent of amphibians are threatened with extinction nowadays.

“Without any significant doubt … we are now entering the sixth great mass extinction event. There are examples of species all over the world that are essentially the walking dead. We are sawing off the limb that we are sitting on” said study lead researcher Prof. Paul Elrich.

The scientists have warned in the study that the high rate of extinction in species greatly disturbs the ecosystem, which in turn will have serious effects on human populations. For example, crop pollination by bees could be one benefit lost by our great-great-grandchildren.

They have also pointed out that their research and calculations are also based on a highly conservative method which was used to calculate a normal rate of extinction per species between mass extinction periods, pointing it out to be at two mammals per every 10,000 species each century. However, if applied to species which have disappeared over the last century, this rate would have seen the vast majority of them survive for periods between 800 and 10,000 years.

The study authors did say that avoiding such a dramatic event was still possible, but it would require massive and intense efforts to conserve species which are already threatened and curb the rapidly rising extinction rate. Limiting habitat loss, unnecessary exploitation and climate change are some of the measures which could help in this regard.

Image Source: Irish Times

Malcolm Mccallum

So why doesn’t this study get any credit?
Only a single news outlet has recognized this paper published 10 days earlier. Doesn’t anyone do a little journalistic research on press releases anymore? Its not like no releases were made from this study.

Published May 27, 2015,
Biodiversity and Conservation.
Vertebrate biodiversity losses point to sixth mass extinction.
http://link.springer.com/article/10.1007%2Fs10531-015-0940-6

The human race faces many global to local challenges in the near future. Among these are massive biodiversity losses. The 2012 IUCN/SSC Red List reported evaluations of ~56 % of all vertebrates. This included 97 % of amphibians, mammals, birds, cartilaginous fishes, and hagfishes. It also contained evaluations of ~50 % of lampreys, ~38 % of reptiles, and ~29 % of bony fishes. A cursory examination of extinction magnitudes does not immediately reveal the severity of current biodiversity losses because the extinctions we see today have happened in such a short time compared to earlier events in the fossil record. So, we still must ask how current losses of species compare to losses in mass extinctions from the geological past. The most recent and best understood mass extinction is the Cretaceous terminal extinction which ends at the Cretaceous–Paleogene (K–Pg) border, 65 MYA. This event had massive losses of biodiversity (~17 % of families, >50 % of genera, and >70 % of species) and exterminated the dinosaurs. Extinction estimates for non-dinosaurian vertebrates at the K–Pg boundary range from 36 to 43 %. However, there remains much uncertainty regarding the completeness, preservation rates, and extinction magnitudes of the different classes of vertebrates. Fuzzy arithmetic was used to compare recent vertebrate extinction reported in the 2012 IUCN/SSC Red List with biodiversity losses at the end of K–Pg. Comparisons followed 16 different approaches to data compilation and 288 separate calculations. I tabulated the number of extant and extinct species (extinct + extinct in the wild), extant island endemics, data deficient species, and so-called impaired species [species with IUCN/SSC Red List designations from vulnerable (VU) to critically endangered (CR)]. Species that went extinct since 1500 and since 1980 were tabulated. Vertebrate extinction moved forward 24–85 times faster since 1500 than during the Cretaceous mass extinction. The magnitude of extinction has exploded since 1980, with losses about 71–297 times larger than during the K–Pg event. If species identified by the IUCN/SSC as critically endangered through vulnerable, and those that are data deficient are assumed extinct by geological standards, then vertebrate extinction approaches 8900–18,500 times the magnitude during that mass extinction. These extreme values and the great speed with which vertebrate biodiversity is being decimated are comparable to the devastation of previous extinction events. If recent levels of extinction were to continue, the magnitude is sufficient to drive these groups extinct in less than a century.

http://link.springer.com/article/10.1007%2Fs10531-015-0940-6
Rick H

Can you post a list of the extinct vertebrate species since 1900?
Malcolm Mccallum

Its on the IUCN Redlist. It was updated in 2014, so might be a little bit different. I think its http://redlist.org
Malcolm Mccallum

Well, now I know. Most of these articles are automatically posted press releases sourced to the subject’s institution. They are not edited, rewritten, or even screened. Explains why the fake story on the Chocolate diet was spread all over. There is no quality control jut auto rss feeds.