Earth headed for catastrophic collapse: Study

Writing in the journal Nature, the team warned 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 author Anthony Barnosky of the University of California, Berkeley, told LiveScience.

To reach the conclusion, Barnosky and 17 other scientists from US, Canada, South America and Europe reviewed research on climate change and ecology to assess evidence for what the future holds.

The results could cause some plant and animal species to disappear, new mixes of remaining species and huge disruptions to crops, leading to global political instability, they found.

At certain thresholds, putting more pressure on the environment leads to a point of no return, Barnosky said.

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 per cent covered in ice to its present, nearly ice-free condition.

Most extinctions and ecological changes occurred in just 1,600 years. Earth's biodiversity still has not recovered to what it was. But humans are causing changes even faster than the natural ones that pushed back the glaciers -- and the changes are bigger, Barnosky said.

Driven by a 35 per cent increase in atmospheric carbon dioxide since the start of the Industrial Revolution, global temperatures are rising faster than they did back then, he pointed out.

Likewise, humans have completely transformed 43 per cent of Earth's land surface for cities and agriculture, compared with the 30 per cent land surface transition that occurred at the end of the last glacial period, Barnosky said.

In addition, the human population has exploded, putting ever more pressure on existing resources, he added. (More)