Is Earth Nearing an Environmental “Tipping Point”?

Humanity may be pushing the planet toward sudden, irreversible ecological changes

Human activities are pushing Earth toward a “tipping point” that could cause sudden, irreversible changes in relatively stable conditions that have allowed civilization to flourish, a new study warns.

There are signs that a toxic brew of climate change, habitat loss and population growth is dramatically reshaping life on Earth, an international team of researchers reported yesterday in the journal Nature.

Those pressures are greater than the natural forces that caused the end of the last ice age roughly 11,700 years ago, a time when half the planet’s large mammal species went extinct and humans migrated out of Africa.

“We are doing enough to cause one of these tipping points,” said lead author Anthony Barnosky, a paleobiologist at the University of California, Berkeley. “The question now is, how close are we? Is it inevitable? What are the changes that we see coming down the road that we should be aware of in order to make the best of it, essentially.”

The answer provided by Barnosky and more than 20 other experts in paleontology, ecology, geology, population biology and complex systems isn’t comforting.

The scientists say it’s likely — though not certain — that Earth is close to another wholesale transformation, but when that will happen and whether it will be irreversible isn’t clear.