Not only are the consequences global, but the causes are also widely distributed, making the coordination of responses complex. Unilateral actions by a single society considered in isolation are unlikely to have a significant direct impact on the danger represented by rising global average temperatures and the associated disruptions this brings. Responsibility for changing atmospheric chemistry is unevenly distributed, with some nations possessing a much larger per capita carbon footprint than others. And the persistence of carbon dioxide in the atmosphere and active carbon cycle (much of it for thousands or even tens of thousands of years) means that historical emissions further complicate the picture.
The necessity of international cooperation to address a serious threat is nothing particularly novel, though the mixing of atmospheric gases means that mitigation efforts by some subset of the globe brings no added climatic benefits to those bearing the costs of such action. Thus, the threat of freeloading is high. Every country hopes that other countries will do the heavy lifting.
This is the second in a series briefly outlining some of the distinctive features of climate change that makes ethical reflection upon our predicament more difficult. The first post can be found here.