When the dinosaurs disappeared 65 million years ago, the event is referred to by scientists as Earth's fifth mass extinction, the fifth such event in our planet's history. According to new research published in Science Advances a sixth mass extinction may well be underway and this time it is likely being caused by humans.
Previous mass die-offs of animals and plants were caused by large-scale natural disasters like meteors or multiple large volcanic eruptions. Such events killed between half and 96 percent of all living species within a relatively short amount of time.
This time, the researchers say, its being caused by man made changes to the environment including global-warming, poaching, deforestation and over-fishing.
Recent studies from around the world confirm hundreds of species are believed to have become extinct, such as the Desert Rat Kangaroo, the Emperor Rat, the Chinese Paddlefish, the Yangtze River Dolphin and the Skunk Frog, among countless others.
Gerardo Ceballos, senior ecological researcher at the National Autonomous University of Mexico, and Anthony Barnosky, a biology professor at Berkeley conducted research that found 477 vertebrate species have gone extinct since 1900, an extremely short period of time given our planet's long history.
Their model, based on fossil evidence, found that there should have only been nine species going extinct during the same time period if humans were not the primary cause of those extinctions.
The researchers fear that within just two generations' time 75 percent of the species we know today could disappear forever.
While "we have the potential for making massive change, the bottom line is that we can't be the generation responsible for wiping out three-fourths of life forms on the Earth," said Barnosky.
The diversity of wildlife on our planet provides critical functions, such as keeping air in the atmosphere and purifying drinking water, with life as we know it depending on having this diversity, the authors said.
"People think nothing bad will come from species loss, because scientists can't predict exactly how many need to go extinct before the world collapses," says Ceballos. "The problem is that our environment is like a brick wall. It will hold if you pull individual bricks, but eventually it takes just one to make it suddenly fall apart."
While the process of extinction is a natural part of the Earth's life giving process, the research marks the first time there is evidence humans of species loss at rates that are 1,000 to 10,000 times faster than the natural, historic rate of species decline.
The researchers say that its well within our power to change things, but action needs to happen quickly. They point to problems like pollution, deforestation, poaching and garbage in the oceans as simple things we can stop doing that will ensure the world's species stop dying off and our planet remains healthy for future generations.