Temperature Target May Doom Climate Talks, Study Says
By Andrew Freedman
Senior Science Writer
October 8th, 2012
At the much-heralded climate summit in Copenhagen in 2009, world leaders agreed to limit manmade global warming to less than 2°C (3.6°F) above preindustrial levels. The agreement at Copenhagen, however, and in multiple rounds of subsequent negotiations, hasn’t led countries to make actual commitments to the kind of emissions reductions that would put the world on a path to meeting that 2°C target.
According to a new study published in Proceedings of the National Academy of Sciences, however, this seeming inconsistency is not just unsurprising: it was inevitable. By focusing on the 2°C goal, negotiators inadvertently guaranteed that their efforts would fail, because there’s no hard evidence that any specific temperature target marks a dangerous threshold, with clear consequences for crossing it (instead, there is plenty of evidence that more and faster warming entails greater risks of major consequences, such as the collapse of the polar ice sheets). This uncertainty, the study argues, provides an incentive for countries to be free-loaders, jumping on board with the agreement without making potentially costly emissions reductions.
The main message, therefore, is that countries should not rely so much on the notion of a climate change “red line,” beyond which catastrophe could occur, as the basis for making emissions reduction commitments.