Earth Institute and School of International and Public Affairs, Columbia University, New York, NY 10027, USA.
Proc Natl Acad Sci U S A. 2012 Oct 23;109(43):17372-6. doi: 10.1073/pnas.1208417109. Epub 2012 Oct 8.
How does uncertainty about "dangerous" climate change affect the prospects for international cooperation? Climate negotiations usually are depicted as a prisoners' dilemma game; collectively, countries are better off reducing their emissions, but self-interest impels them to keep on emitting. We provide experimental evidence, grounded in an analytical framework, showing that the fear of crossing a dangerous threshold can turn climate negotiations into a coordination game, making collective action to avoid a dangerous threshold virtually assured. These results are robust to uncertainty about the impact of crossing a threshold, but uncertainty about the location of the threshold turns the game back into a prisoners' dilemma, causing cooperation to collapse. Our research explains the paradox of why countries would agree to a collective goal, aimed at reducing the risk of catastrophe, but act as if they were blind to this risk.
对“危险”气候变化的不确定性如何影响国际合作的前景？气候谈判通常被描绘为囚徒困境博弈；从整体上看，各国通过减少排放会更好，但自利心会驱使它们继续排放。我们提供了基于分析框架的实验证据，表明对跨越危险门槛的恐惧可以使气候谈判变成协调博弈，从而几乎可以确保采取集体行动来避免危险门槛。这些结果在跨越门槛的影响存在不确定性的情况下仍然稳健，但对门槛位置的不确定性会使博弈回到囚徒困境，导致合作崩溃。我们的研究解释了一个悖论，即为什么国家会同意一个旨在降低灾难风险的集体目标，但却表现得好像对这种风险视而不见。
