An international team of scientists warn the Earth is amidst the early stages of what will be the sixth mass extinction in the history of life on Earth, and it was caused by humans.

Due to the impacts of industrialization on the natural environment, humankind has disrupted the entire global ecosystem, which in turn will ultimately forecasts a negative outcome for our own species as well.

Since 1500, 322 vertebrate species have gone extinct; of those that remain, there has been an average population decline of 25 percent. Invertebrate species fare worse, with 67 percent of monitored species seeing a 45 percent mean population decline.

“Such animal declines will cascade onto ecosystem functioning and human well-being,” says the article.

“Where human density is high, you get high rates of defaunation, high incidence of rodents, and thus high levels of pathogens, which increases the risks of disease transmission,” said Professor Rodolfo Dirzo at the Stanford Woods Institute for the Environment, and lead author of the study. “Who would have thought that just defaunation would have all these dramatic consequences, but it can be a vicious circle.”

Dirzo believes extinction should not be thought of merely as an event related to a single species, but rather a drop of water causing a cascading rippling effect that can compound and resonate.

“We tend to think about extinction as loss of a species from the face of Earth, and that’s very important, but there’s a loss of critical ecosystem functioning in which animals play a central role that we need to pay attention to as well,” said Dirzo in a University College London article. “Ironically, we have long considered that defaunation is a cryptic phenomenon, but I think we will end up with a situation that is noncryptic because of the increasingly obvious consequences to the planet and to human well-being.”

So far, life on Earth has experienced five mass extinctions. The most famous and latest, the Cretaceous-Tertiary mass extinction, killed off the dinosaurs, as well as about 75 percent of all life on Earth. The most devastating was the third mass extinction in Earth’s history, known as the Permian mass extinction. Ninety-six percent of species died out, crippling Earth’s biodiversity so much it took almost 10 million years for the remaining life on Earth to flourish again.

Luckily for humankind, this sixth mass extinction is wholly different from the others. Usually, mass extinctions are triggered by uncontrollable external environmental factors, such as flood basalts ejecting greenhouse gases into the atmosphere, or massive meteorite impacts causing chaos. However, this time, the primary cause is known and has the capacity to change, and scientists think there is still time to reverse the current trajectory.

An article in Nature from 2011 estimated that there was about one or two centuries before catastrophic impacts would be felt by society, just enough time to mitigate such effects. Scientific American reports that humans have physically saved 424 plants and animals from the brink of extinction, and continued environmental conservation efforts do have a major impact on the ecosystem.