Earth's ecosystems nearing catastrophic 'tipping point,' warn scientists (+video)

Our planet is heading toward a sudden breakdown,?a group of international scientists warn, unless humans adopt more sustainable practices.?

By Stephanie Pappas,?LiveScience Senior Writer / June 7, 2012

This composite image uses a number of swaths of the Earth's surface taken in January 2012.

NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring

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Earth is rapidly headed toward a catastrophic breakdown if humans don't get their act together, according to an international group of scientists.

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Writing Wednesday (June 6) in the journal Nature, the researchers warn that the world is headed toward a tipping point?marked by extinctions?and unpredictable changes on a scale not seen since the glaciers retreated 12,000 years ago.

"There is a very high possibility that by the end of the century, the Earth is going to be a very different place," study researcher Anthony Barnosky told LiveScience. Barnosky, a professor of integrative biology from the University of California, Berkeley, joined a group of 17 other scientists to warn that this new planet might not be a pleasant place to live.

"You can envision these state changes as a fast period of adjustment where we get pushed through the eye of the needle," Barnosky said. "As we're going through the eye of the needle, that's when we see political strife, economic strife, war and famine." [Top 10 Ways to Destroy Earth]

The danger of tipping

Barnosky and his colleagues reviewed research on climate change, ecology and?Earth's tipping points?that break the camel's back, so to speak. At certain thresholds, putting more pressure on the environment leads to a point of no return, Barnosky said. Suddenly, the planet responds in unpredictable ways, triggering major global transitions.

The most recent example of one of these transitions is the end of the last glacial period. Within not much more than 3,000 years, the Earth went from being 30 percent covered in ice to its?present, nearly ice-free condition. Most extinctions and ecological changes (goodbye, woolly mammoths) occurred in just 1,600 years. Earth's biodiversity still has not recovered to what it was.

Today, Barnosky said, humans are causing changes even faster than the natural ones that pushed back the glaciers ? and the changes are bigger. Driven by a 35 percent increase in atmospheric carbon dioxide since the start of the Industrial Revolution, global temperatures are rising faster than they did back then, Barnosky said. Likewise, humans have completely transformed 43 percent of Earth's land surface for cities and agriculture, compared with the 30 percent land surface transition that occurred at the end of the last glacial period. Meanwhile, the human population has exploded, putting ever more pressure on existing resources. [7 Billion Population Milestones]

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