Since the first half of the last century, environmental subjects directly or indirectly, have become part of multilateral policy cooperation. In the last few decades, globalizing environmental problems have also been addressed in the context of sustainable development by considering the complex interlinkages between socio-economic and environmental matters. The main factors driving this process are scientific knowledge about multiplying environmental hazards and their causes, the extreme and widespread environmental events, and moreover, the environment-related international conflicts and rapidly changing international political circumstances. The latter are a significant cause of the substantial fluctuation in the intensity of environmental and sustainable development cooperation over time and the fact that this has sometimes been more pronounced and sometimes less so. These ups and downs are reflected, for instance, in the concreteness of goals and commitments and the ‘ambition level’ of the resolutions, declarations, programs, and agreements thus adopted. The main stages of this process are reviewed and assessed below. It should be pointed out that while the main historical turning points between these stages can be rather unambiguously identified, the intermediate (sub)periods cannot be so clearly demarcated. Nevertheless, on the one hand, there are some tangible motives and signs of the favorable transitional (sub)periods, and on the other, specific causes of the ‘low points’ or stagnation in this multilateral cooperation.