While air pollution is the most significant success story, major progress has been made in other areas, as well. Back in 1969, the nation was shocked when the Cuyahoga River in Cleveland caught fire, and the degradation of the Great Lakes was a scandal. Today, rivers no longer catch fire, and in most locations, the water of the Great Lakes is safe for fishing, swimming and drinking. Long-term data also show a major decline in chemical residues in wildlife in the Great Lakes region, and several bird species that were once in decline are now flourishing. Meanwhile, the decline in wetlands has been halted, and the national goal of restoring 100,000 acres of wetlands a year seems within reach.
Figures show that wetlands are already increasing in the western states.
Regulation has certainly played a role, but regulators can only command what is technically and economically feasible. Economic growth and technology are the key ingredients. As people get wealthier, they want more environmental improvement. None of this is to imply that our work is done, or that we don't have to worry about the environment, any more than the sharp decline in the crime rate means we can lay off police officers and stop fighting crime. There are two difficulties in solving these kinds of problems.