http://www.washingtonpost.com/national/health-science/scientists-human-activity-has-pushed-earth-beyond-four-of-nine-planetary-boundaries/2015/01/15/f52b61b6-9b5e-11e4-a7ee-526210d665b4_story.htmlBy Joel Achenbach January 15 at 10:14 PM
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 are 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.
orest cover and land system change: Farming, mining and infrastructure projects are consuming the Amazon rainforest. According to data from Brazil’s space agency, deforestation increased by more than a third in 2013, wiping out an area more than twice the size of Los Angeles. (Nacho Doce/Reuters)
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