The world consists of “195 countries, 72 dependent areas and other entities.” (CIA World Fact Book) and the corresponding peoples, different from each other in race, ethnicity or religion.
It is a coordination and measurement problem to design a global mechanism which must be enforced for the purposes of tackling climate change. National political and economic interests are the primary frictions which prevent cooperation. Moreover, if history is any indication, paradigmatic changes have not occurred because of premeditated, ex ante global cooperation. They have, without exception, always been a result of disruptive changes of significant impact in a few countries.
The problem of tackling the cumulatively increasing emissions of greenhouse gases in the earth’s atmosphere is similar. Change must occur in a few countries for it to diffuse and catch on elsewhere around the world.