Atmospheric carbon dioxide is one of four “planetary boundaries” that humanity has already exceeded, and could collectively prevent the Earth from being a “safe operating space” for humans, concludes a team of 18 authors in a paper published yesterday in the journal Science.
“What the science has shown is that human activities—economic growth, technology, consumption—are destabilizing the global environment,” said lead author Will Steffen of the Australian National University and the Stockholm Resilience Centre.
The four boundaries the world has already crossed are the extinction rate, deforestation, atmospheric CO2, and the flow of nitrogen and phosphorous into the oceans, the Post reports. The other five boundaries in the study include ozone depletion, freshwater use, ocean acidification, atmospheric aerosol pollution, and the introduction of exotic chemicals and modified organisms.
“These are not future problems, but rather urgent matters, according to Steffen, who said that the economic boom since 1950 and the globalized economy have accelerated the transgression of the boundaries,” Achenbach writes. “No one knows exactly when push will come to shove, but he said the possible destabilization of the ‘Earth System’ as a whole could occur in a time frame of ‘decades out to a century.’”