In business as well as international politics, the best and ideal agreement is one that is credible and expected to be complied with. Compliance often necessitates trade sanctions or other sufficiently severe consequences for those parties that do not comply as promised.
So what explains the logic behind why most existing international environmental agreements are weak and without sufficiently strong sanctions? As an example, countries that emitted excessively under the 1997 Kyoto Protocol were asked to compensate by cutting emissions more in the future but faced no additional sanctions if they didn't. And in late December 2018, negotiators met in Katowice, Poland, to discuss the implementation of the Paris Agreement on climate change but failed to take advantage of the possibility to introduce sanctions on noncompliers.