Scientists set boundaries for survival

PHOENIX, Sept. 24 (UPI) -- A group of European, Australian and U.S. scientists say humans have pushed the Earth system beyond three of the planet's biophysical thresholds.

The 29 scientists say the consequences of those actions might be catastrophic for large parts of the world.

The group says scientists have been warning for decades the explosion of human activity since the industrial revolution is pushing the Earth's resources and natural systems to their limits. Now data confirm 6 billion people are capable of generating a global geophysical force the equivalent to some of the great forces of nature -- just by going about their daily lives.

That force has given rise to a new era -- Anthropocene -- in which human actions have become the main driver of global environmental change, the scientists said.

"On a finite planet, at some point, we will tip the vital resources we rely upon into irreversible decline if our consumption is not balanced with regenerative and sustainable activity," said report co-author Sander van der Leeuw, director of the School of Human Evolution and Social Change at Arizona State University.

The lead author, Professor Johan Rockstrom of Stockholm University, said human pressure on the Earth system has reached a scale where abrupt global environmental change can no longer be excluded.

The report appears in the journal Nature.