The emergence of the concepts of Environmental Impact Assessments (E.I.A.s) and Environmental Impact Statements (E.I.S.s) can be seen as the result of efforts to devise tools to steer planning and decision-making processes with impact on the environment, health, and safety of the people. 1 The arrangement of the cultures compared in this chapter is chronological according to when each adopted some form of these tools. Thus, the U.S.A. is discussed prior to the regional E.U., and the E.U. prior to international law, because that was the chronological order of their development. From that, we can observe an important lesson for Type I comparative law in practice, and that is that individual states cannot only influence other individual states directly, but also international public law. In turn, one can then make Type II comparisons of how states align themselves with common commitments under international law in this area.