Researchers say Earth is entering a sixth mass extinction event
While there is still much conjecture about the causes of some mass extinctions, it is generally believed that they can occur when a biosphere under long-term stress is subjected to a short-term shock. In 1982, Jack Sepkoski and David M. Rauppublished a paper identifying five mass extinction events throughout Earth's history. Now a team of researchers claims that we are entering a sixth mass extinction event, which threatens our very existence.
As ever more speciesface extinction, we lose the vital ecosystem services they provide,such as honeybee crop pollination. For its continued existence,mankind is reliant upon an untold plethora of species that maintainthe status quo. As they disappear, that existence becomesincreasingly fragile.
The paper entitled Accelerated modern human–induced species losses: Entering the sixth mass extinction, which wasco-authored by Paul Ehrlich, a Professor of Population Studies inbiology and senior fellow at the Stanford Woods Institute for theEnvironment, draws on fossil records of vertebrate species and anabundance of data from other sources, combining them to create abaseline extinction rate for periods when there was no massextinction event underway. Predicated on this baseline, theresearchers were able to estimate that the current rates ofvertebrate extinction is up to 114 times greater than that of thebaseline.
According to the Union for Conservation of Nature, at this pointroughly 41 percent of amphibian species and 26 percent of mammalspecies are in serious danger of extinction. Alarmingly, extinctionrates are now at their highest point since the Cretaceous-Paleogeneextinction event some 66 million yearsago.
The paper's authorsstress that their findings are conservative in nature, and that thereality of the situation could be much worse. While conducting thestudy, the researchers even set the baseline extinction rate at twicethe value of estimates widely used in previous analyses. Amongst the causes for theincreased extinction rates are mankind'sdestruction of animals' natural habitats, and carbon emission drivenclimate change.
According to Ehrlichand his colleagues there is still hope, but in order to avoid direconsequences, we must embark upon a comprehensive regime of wildlifeand habitat conservation. The researchers also warn that the window for change isgrowing ever slimmer.
"If it is allowed to continue, life would take many millions of years to recover, and our species itself would likely disappear early on," said lead author Gerardo Ceballos of the Universidad Autónoma de México.
The study has been made available in the onlinejournal Science Advances.
Thevideo below, courtesy of Stanford University, highlights key aspectsof the research.