Earth at the Precipice

In the paper published this week in the journal Nature, "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," notes Boxall.

Equating human-caused impacts on the environment to mass extinctions of the past, the researchers warn that, "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."

"To avert a grim future, or at least make it less grim, the paper calls for significant reductions in world population growth and per-capita resource use, more efficient energy use, less reliance on fossil fuels and stepped-up efforts to protect the parts of Earth that have so far escaped human dominance."