In anticipation of this week’s Rio+20 United Nations Conference on Sustainable Development, a group of 22 scientists from a variety of disciplines collaborated to complete a sobering—that is to say, terribly frightening—new study of the global ecosystem. Published in the June 7 issue of Nature, the study finds that the earth may be dangerously close to an abrupt tipping point or “state shift”: In short, the combined pressures of climate change, habitat transformation, and human population growth may soon culminate in sudden, calamitous ecological devastation and a precipitous decline in quality of life for human beings.

I spoke with lead author Dr. Anthony Barnosky, from the University of California, Berkeley, about whether the apocalypse is inevitable and how we should respond to it.

Your paper suggests the possibility that a state shift could occur by 2025. Do you think this scenario allows us enough time to reverse course?

I think the important thing to remember about the state shift is that it’s not necessarily a global catastrophe or an apocalypse…

Not a Day After Tomorrow scenario…

It will be a different world. The question is, will it still be a nice place to live? Or will we have reduced quality of life? Is that possible by 2025? I would say it is.

We’re already seeing signs with the current economic crisis, which to a large extent is related to natural resources. As natural resources become more constricted, I think we’ll see more economic problems. 

A question about the methodology of your study: your group relied heavily on models from epidemiology and demography. What makes these models useful for studying the global ecosystem?

We have recognized that state shifts takes place in many individual systems. All of these are complex systems where, if you tweak the wrong part at the wrong time, things fall apart. Our reasoning is that these sorts of state shifts can be recognized in just about any biological system at any scale. If you think big enough––on the planetary scale––they are not only possible, but we can recognize when they have happened. A big part of our study was comparing what’s going on today with what caused planetary state shifts in the past. The way humans are forcing the planet now is more intense than during the last state shift.

So how do you suggest that people adjust to the coming state shift?

New innovations are going to have to be part of this––for example, new batteries that allow us to store energy and use it when we need it, rather than when the sun is shining and the wind is blowing. For agriculture, the key is more efficient growing, instead of taking over more natural habitats. Lastly we have to keep our reservoirs of biodiversity stable rather than degrading.

And what sorts of progress do you anticipate coming from the Rio+20 conference?

One of the big contributions of the Rio conference is that it is focusing the world on sustainability issues, which are now more on people’s radars. I’m confident that, once enough people understand the issues we face with sustainability, that people are clever enough to come up with solutions. Humanity is at a crossroads where we have to make choices to drive the planet in a direction we want it to go. If we keep doing the same thing and wait to see what happens, that’s when we get ecological surprises.

This interview has been edited and condensed for clarity.