Earth nearing a catastrophic tipping point, scientists warn
- Blog Post by: Colleen Stoxen
- June 7, 2012 - 5:16 PM
A group of international scientists is sounding a global alarm, warning that population growth, climate change and environmental destruction are pushing Earth toward calamitous — and irreversible — biological changes.
In a paper published in the journal Nature, 22 researchers from a variety of fields liken the human impact to global events eons ago that caused mass extinctions, permanently altering Earth's biosphere.
"Humans are now forcing another such transition, with the potential to transform Earth rapidly and irreversibly into a state unknown in human experience," wrote the authors, who are from the U.S., Europe, Canada and South America.
If current trends continue — exploding global population, rapidly rising temperatures and the clearance of more than 40% of Earth's surface for urban development or agriculture — the planet could reach a tipping point, they say.
"The net effects of what we're causing could actually be equivalent to an asteroid striking the Earth in a worst-case scenario," the paper's lead author, Anthony Barnosky, a professor of integrative biology at UC Berkeley, said in an interview. "I don't want to sound like Armageddon. I think the point to be made is that if we just ignore all the warning signs of how we're changing the Earth, the scenario of losses of biodiversity — 75% or more — is not an outlandish scenario at all."
Global population just passed 7 billion and is expected to reach 9.3 billion or more by 2050. Increased carbon dioxide in the atmosphere from the burning of fossil fuels is making the ocean more acidic, and less hospitable to sea life. All this could produce a biologically impoverished Earth that would rob humans of vital ecological services such as insects that pollinate crops, forests that provide clean water, and tropical species that are the source of new drugs.
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