It's obvious. Global efforts to combat climate change have failed. International summits are full of hot air and greenhouse gas pollution continues to rise. If a country bails on a climate commitment, they pay a price of, well, zero.

Turns out that's okay, at least according to game theory analyses by researchers at the University of Lisbon. Their models suggest that punishment by global institutions has no effect. They also say that global summits actually impede cooperation.

Now, in a new report, the researchers suggest that if punishment starts getting handed out at the local level, say city governments, what emerges is a much more cooperative global regime for combating climate change. The only other way for such collaboration to develop was for there to be a perception that the risks associated with climate change were devastating. The report is in the journal Nature Climate Change.

That's not the case at present, despite the reality of the environmental, economic and health threats posed by global warming. In fact, such threats are reminiscent of the risks associated with the ongoing financial crisis, as noted by the Organization of Economic Cooperation and Development. Nevertheless, the math of how people play games suggests that successfully curbing carbon pollution will rely on the old adage: think globally… act locally.

—David Biello

[The above text is a transcript of this podcast.]