Should the environmental issues raised by megacities be dealt with on a city level , , country level,,=regional level or global level?

There are almost 20 megacities all around the world. Despite their undeniable contribution to the global economy, megacities have caused ferocious environmental problems. I believe there needs to be a global approach to extract these issues. Coping with megacities’ environmental problems could not be on a city level. Firstly, megacities affect all regions around the […]