Friday, January 16, 2015

Scientists: Human activity has pushed Earth beyond four of nine ‘planetary boundaries’

Clmate change: A severe drought plagued a third of Queensland, Australia in 2013. Destabilizing the global environment could make Earth less hospitable for humans. (David Gray/Reuters) At the rate things are going, the Earth in the coming decades could cease to be a “safe operating space” for human beings. That is the conclusion of a new paper published Thursday in the journal Science by 18 researchers trying to gauge the breaking points in the natural world. The paper contends that we have already crossed four “planetary boundaries.” They include the extinction rate; deforestation; the level of carbon dioxide in the atmosphere; and the flow of nitrogen and phosphorous (used on land as fertilizer) into the ocean. “What the science has shown is that human activities — economic growth, technology, consumption – are destabilizing the global environment,” said Will Steffen, who holds appointments at the Australian National University and the Stockholm Resilience Center and is the lead author of the paper...more