Most Americans regard the environment with both pessimism and anxiety. A 1999 U.S. poll on environmental issues by the Wirthlin Group confirms this sentiment: three-quarters of those polled believe that environmental problems will get worse during their lifetime. Such fears are largely unfounded, however, because any way one looks at it, U.S. environmental quality has improved dramatically since the first Earth Day in 1970.

Moreover, research reveals that advances in technology and economic growth have led to this environmental improvement and will most likely lead to even greater improvements in the future. Thus, Earth Day 1999 should be a day for celebration and optimism rather than woe.

Consider, for example, air quality, which has improved dramatically over the past generation. The Environmental Protection Agency reports that ambient levels of all six pollutants thought to adversely affect outdoor air quality have declined significantly since the 1970s.

Between 1976 and 1997, ambient levels of ozone—the major contributor to urban smog—decreased 30.9 percent. Sulfur dioxide levels—the primary component of acid rain—decreased 66.7 percent, while nitrogen oxides decreased 37.9 percent, carbon monoxide decreased 66.4 percent, and lead decreased a dramatic 97.3 percent. Particulate matter, commonly known as dust and soot, decreased 25.5 percent since 1988, the first year for which particulate data are available.

National water quality shows similar improvement trends. Due to wastewater treatment facilities, all sewage generated in the United States had been treated before discharge by 1992. This treatment means that since 1970, discharge of toxic organics has declined 99 percent, and toxic metals has declined by 98 percent.

Natural resources, including forests and wetlands, are making a comeback as well. U.S. forests now cover nearly 30 percent of the nation’s total land area, and have remained stable for most of this century. Each year the United States plants more trees than it harvests, and has done so since 1950. A full two-thirds of the deforestation experienced in North America took place between 1850 and 1910, and there is about three times more forestland in North America today than there was in 1920.

Wetlands conversion has also decreased dramatically. For every 60 acres of wetlands converted to cropland annually from 1954 to 1974, only 3 acres were converted annually from 1982 to 1992. Since 1980, the United States has experienced no net loss of wetlands.

The seemingly obvious conclusion is to give the government credit for these marked improvements due to such regulations as the 1970 Clean Air Act and Clean Water Act. A more detailed and long-term look, however, reveals a more complicated picture.

Although the data for air pollution are not well quantified prior to 1970, studies indicate that air quality was improving rapidly before the passage of the 1970 Clean Air Act. For example, Paul Portney of Resources for the Future writes that it is “extremely difficult to isolate the effects of regulatory policies on air quality, as distinct from the effects of other potentially important factors,” because “some measures of air quality were improving at an impressive rate before 1970.”

Portney points out that the historical data available show that ambient levels of particulates declined more than 20 percent during the 1960s, while ambient levels of sulfur dioxide fell by almost 50 percent.

In addition, the Organization for Economic Cooperation and Development notes in a 1991 report on the U.S. environment that “emissions have also fallen in other OECD countries, sometimes by as much or proportionally more than in the United States,” but with less stringent regulation.

While regulations have undoubtedly played a role, it is also important to realize that they are not the root cause of air quality improvements. Rather, they are the mechanism that the United States has chosen to use in response to the public’s demand for a cleaner environment.

As income levels rise, people begin to demand higher environmental standards. As a society, this effect is cumulative—thus, we expect even better environmental quality as our economy grows. Until now, environmental policy has relied almost entirely on command-and-control regulation. While such regulation has had its successes, it also hinders the very economic growth that has allowed for environmental improvements.

Further, the marginal cost of pollution reduction is continually rising. Stated another way, a smaller aggregate amount of pollution means that each further reduction is more costly than the last, and the health benefits produced are less significant and felt by fewer people.

For this reason, environmentalists should not regard economic concerns as a hindrance to effective policy, but should embrace economic growth as the key to further environmental improvements. Moreover, if Americans want the improvement that has occurred over the past generation to continue, they will look to innovative new policies that incorporate and even promote economic growth. Such policies not only best address today’s environmental situation, but provide the most promising future for tomorrow’s environment as well.

Erin Schiller is a Public Policy Fellow at the California-based Pacific Research Institute.