ABSTRACT

Three United States environmental laws and one European environmental law demonstrate the difficulties in implementing strict system-based limits under environmental law. The first example is Total Maximum Daily Loads (TMDLs) under the United States’ Clean Water Act, which establish the maximum amount of a pollutant that can be emitted to a water body without exceeding the federal water quality standards for the pollutant. The second is the authority to regulate greenhouse gases under the United States’ Clean Air Act. The third is critical loads and levels in the European Union’s air pollution regulation and the Convention on Long-range Transboundary Air Pollution (LRTAP). The last is the Acid Rain Program in the United States Clean Air Act, which establishes a cap-and-trade program for emissions of sulfur dioxide. These mechanisms have failed to achieve the ecological systems-based objectives that underlie them. By contrast, the Montreal Protocol on Substances that Deplete the Ozone Layer is a relatively successful example of a regulation based on broad, global-scale ecological limit, but a model unlikely to apply easily to climate change and other global ecological problems.