Earth might be in the early stage of a sixth mass-extinction

Remember the mass-extinction event that wiped out the dinosaurs? Earth is apparently on the verge of another great biological extinction, and humans are solely to blame. The loss and decline of animals is contributing to what appears to be the early days of the planet’s sixth mass biological extinction event, scientists warn.

“Human impacts on animal biodiversity are an under-recognized form of global environmental change,” a team of ecologists and biologists warn in Science. “Among terrestrial vertebrates, 322 species have become extinct since 1500, and populations of the remaining species show 25% average decline in abundance.”

While previous extinctions have been driven by natural planetary transformations or catastrophic asteroid strikes, the current die-off can be associated to human activity, a situation that the lead author Rodolfo Dirzo, a professor of biology at Stanford University, designates an era of “Anthropocene defaunation.”

There may be unforeseen consequences, aside from the possible extinction of threatened species. “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,” Dirzo said in a statement.

While humans may be responsible for kickstarting another mass-extinction event, there might still be time to react. As Scientific American notes, current extinction rates suggest that humans still have a century or two to change course. Ben Collen, a lecturer at the University College of London and a co-author of the new mass-extinction analysis, says scientists need to focus on species that are thriving.

“Prevention of further declines will require us to better understand what species are winning and losing in the fight for survival and from studying the winners, apply what we learn to improve conservation projects,” Collen said in a statement. “We also need to develop predictive tools for modelling the impact of changes to the ecosystem so we can prioritize conservation efforts, working with governments globally to create supportive policy to reverse the worrying trends we are seeing.”

As David Biello writes in Scientific American: “To avoid the sixth mass extinction we will probably have to employ more aggressive conservation, such as moving species to help them cope with a changing climate. Think re-wilding: reintroducing species like wolves or beavers that were once present in a given ecosystem but have since disappeared. Aggressive conservation might also mean killing off newcomer species to preserve or make room for local flora and fauna.” Read more about the story here.