Countries who go it alone by refusing to take meaningful steps on emissions reduction could soon be forced to pay in other ways.
As the 2030 deadline for the Paris Climate Agreement targets creeps closer, countries who are meeting more ambitious targets are thinking about other ways to motivate those who aren't.
One measure that is starting to gain traction, particularly in Europe, is the creation of a so-called "Carbon Club".
The carbon club idea is simple: countries who are meeting their climate targets as set out under the 2030 Paris Agreement will form a coalition, and impose border tax adjustments on those who aren’t.
Currently, the plans would involve several EU countries.
The notion of a carbon club likely offends President Donald Trump's isolationist worldview, but it appears Democratic hopeful Joe Biden could be open to the idea.