In the case of California's Global Warming Solutions Act (AB 32), the answer flows directly from the very nature of the problem — global climate change, the ultimate global commons problem. (robertstavinsblog.org)
In any case, says Edenhofer, «climate change is a global commons problem. (e360.yale.edu)
Second, because GHGs mix globally in the atmosphere, anthropogenic climate change is a global commons problem. (metlink.org)