This chapter provides analysis on how to introduce ecological and environmental considerations within the global arena taking into account differences between nations, in terms of both economic development and biophysical conditions. The first section provides a background on the economics of international trade, and provides justification and criteria for gains from trade and some of the implications of international trade. Then we identify the market and institutional failures that give rise to the establishment of PES in the global arena, which is followed by a discussion of major issues of implementation in terms of efficient schemes of PES as well as some of the challenges in terms of government that it may entail. We conclude by identifying direction for future research.