As the Rio+20 United Nations sustainable development summit opened in Rio de Janeiro on June 20, United Nations Secretary-General Ban Ki-moon said that progress against environmental degradation is too slow and warned world leaders and environmental ministers that “words must translate into action,” BBC News reported.
The admonition echoed conclusions drawn by scientists in separate reports warning that Mother Earth is approaching a tipping point of irreversible climate-related changes. The most recent, a paper published in the June 7 issue of the journal Nature by an international group of researchers, said such changes could wipe out much of the world’s biodiversity. So drastic would this be that it could cause calamitous change on a scale of that wrought by global mass-extinction events of bygone eras, said 22 scientists from the U.S., Europe, Canada and South America. And it’s mostly due to human pressures on the ecosystem.
“The net effects of what we’re causing could actually be equivalent to an asteroid striking the Earth in a worst-case scenario,” said the paper’s lead author, Anthony Barnosky, to the Los Angeles Times. “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.”
Barnosky, an integrative biology professor at the University of California at Berkeley, and his team compared past global changes and their biological impacts with today’s climate-change processes to extrapolate into the future. They published their findings in the June 7 issue of the journal Nature in advance of the United Nations Conference on Sustainable Development being held this week in Rio de Janeiro.
“The data suggest that there will be a reduction in biodiversity and severe impacts on much of what we depend on to sustain our quality of life, including, for example, fisheries, agriculture, forest products and clean water,” said Barnosky in a statement. “This could happen within just a few generations.”
At the same time there’s no telling how close Mother Earth is to such a tipping point, or how irreversible it would be, said the biologists, ecologists, complex-systems theoreticians, geologists and paleontologists involved in the study.
“We really do have to be thinking about these global scale tipping points, because even the parts of Earth we are not messing with directly could be prone to some very major changes,” Barnosky said. “And the root cause, ultimately, is human population growth and how many resources each one of us uses.”
The team’s warnings came on the heels of the United Nations’ own “report card,” the fifth edition of the Global Environmental Outlook (GEO-5), issued by the United Nations Environmental Programme (UNEP) on June 6. That, too, said that Earth’s ecosystem may very well be on the edge and that population, urbanization and consumption must be reduced in order to avoid irreversible, detrimental changes.
“My view is that humanity is at a crossroads now, where we have to make an active choice,” Barnosky said. “One choice is to acknowledge these issues and potential consequences and try to guide the future (in a way we want to). The other choice is just to throw up our hands and say, ‘Let’s just go on as usual and see what happens.’ My guess is, if we take that latter choice, yes, humanity is going to survive, but we are going to see some effects that will seriously degrade the quality of life for our children and grandchildren.”