Environmental problems occur because of either humans caused that or natural disasters in general. Several people believe it could be solved by all of countries around the world together but some people think it is easier to fix the problem started by make a concrete solution with their own country. I will explain both of these views and make personal opinion according this issue.
Making world agreement in committing protect this world is one of way to make some countries realize about the importance of prevent environmental promblems from early stage. From this project a lot of countries directly have promises to not crush their own environment and also there are sanctions for country that violate the agreement which have already agreed by other nations together. Thus, it makes some nations give respect to other countries and do not brave enough to make a disaster for their own benefits while they are actually do not want to obey the deal sometimes.
On the other side, the commitment from each nation to make environmental sustainability in their own country is very essential thing. all people who live in the country must get well education about this, so they can also take care the environment from a small thing such as not using plastic anymore. However, Government has most responsibility to fix ecological problems and they have to support ecological sustainability applied by their rules and policy for the nation.
In my point of view, they both are very crucial things and all of those could applied in all of countries, so the environmental problems will be solved together in large scale.
To sum up, those two ways of finishing environmental problems have each important role. Either in big scale or small scale, at the end that should be fixed together with high commitment from all of countries, including their own citizens.