By Jaclyn Lopez
There have been five mass extinctions – times when the Earth has lost more than three-quarters of its species in a relatively short timeframe – during the past 540 million years.
Today, almost 20,000 species of animals and plants worldwide are at a high risk of extinction, and it is estimated that 0.1% of the world’s species go extinct annually.
If these 20,000 species were to go extinct, and that rate of extinction continued, we would lose at least three-quarters of all species on Earth within a few centuries. We will have created the sixth mass extinction.
There is a background, or “normal” rate of extinction of about one to five species per year. Scientists estimate we are losing 1,000-10,000 times that background rate. Historically, mass extinctions have been due to natural events.
Meanwhile, the current extinction trend is largely the result of climate change and other human activities. It is estimated that we are outstripping the earth’s renewable resources, land, and waste absorption capacity by 50%.
Species like the majestic West African lion that once roamed freely are now a trophy hunt away from extinction.
Of course the extinction rate is difficult to calculate. We do know that extinctions have ripple effects, whereby one extinction can create an imbalance that leads to other extinctions.
We know there are about 1.7 million species, and suspect that there are at least twice as many species we have not yet discovered. Therefore, it is impossible to know the status of those species, or which species have recently gone extinct.
However, not all is gloom and doom.
A new study substantiates the theory that biodiversity supports biodiversity by protecting it against human impacts. Basically, having a high concentration of different species in an area allows ecosystems to withstand human disturbance and avoid catastrophe.
Also, a new set of objective measures to help countries measure and monitor biodiversity were recently prepared to help meet the United Nation’s Convention on Biological Diversity’s goal of halting the loss of biodiversity by 2020. The measures are intended to aid nations in providing evidence-based information on biodiversity.
Finally, we do have at least one tool to prevent species extinction: the Endangered Species Act.
The Act is a groundbreaking piece of federal legislation aimed at affording our Nation’s most imperiled species VIP status by creating protections from the very threats that jeopardize their survival.
The Act has been nearly 100% effective in preventing extinctions since its inception in 1973. This year marks the 40th Anniversary of the Act – celebrate it by letting your elected officials know you support its full implementation and funding.
Jaclyn Lopez is a staff attorney with the Center for Biological Diversity. This article reflects her opinions and does not represent those of the Center.