April 22, 2000, the 30th anniversary of the first Earth Day, provides us with a good opportunity to take a step back and assess what strides we have made toward a cleaner and better environment in which to live, work, and play.

If Americans want the environmental improvement that has occurred over the past generation to continue, they will embrace policies that encourage economic growth.

If you asked most Americans, they would say that we are losing ground, that the air we breathe is dirtier and the water we drink more polluted than ever. Polls, in fact, consistently find majorities who believe that environmental quality in the U.S. is declining. But in this case, perception does not match reality.

This report presents decades of government facts and figures on Michigan and U.S. air and water quality, land use, and other environmental factors to show that, far from worsening, environmental conditions have actually improved substantially—and are likely to continue improving.

Air quality, for example, has improved dramatically over the past generation. The U.S. Environmental Protection Agency reports that nationwide, 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. Michigan cities monitored by the EPA are below the health-based thresholds set by the Clean Air Act for thes pollutants and are experiencing downward trends. Most Michigan cities not only meet the national standard, but are below the national average.

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 by 98 percent.

There also have been large improvements in water quality and wildlife health in and around the Great Lakes over the past 30 years. Today it is once again possible to fish in the Great Lakes, and even to drink their water in most locations. In fact, the environmental challenge facing the Lakes today no longer comes mainly from industrial pollution or toxics, but from biological threats: Nearly 145 non-native or "exotic" species now found in the Great Lakes are crowding out the habitat of other indigenous species in the Lakes.

Unfortunately, monitoring water quality is much more difficult and costly than monitoring air quality, and the measures currently used are seriously defective. Nevertheless, Michigan has a superior record in monitoring water quality and has impressive results to report. While all 50 states taken together assessed only 17 percent of their rivers and streams in the 1996 National Water Quality Inventory, Michigan assessed 40 percent and found 93 percent of assessed rivers, streams, and lakes to be "fully supporting," which means they are safe for swimming and fishing.

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. In Michigan, roughly 44 percent of the state is covered in forest, while only 10 percent of the state's land area is considered "developed."

U.S. wetlands development also has 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.

What accounts for these and other environmental gains? The seemingly obvious conclusion is to give all credit to such regulations as the 1970 Clean Air Act and Clean Water Act. A longer-term look, however, reveals a more complicated picture. For example, 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 Clean Air Act.

Why? While government regulations undoubtedly play a role, research suggests that the "wealth effect" of a growing economy is the key to an improved environment. As the Michigan and U.S. economies grow, so does their ability to control pollution and protect resources. Economic growth also means improved technology and, therefore, more efficient uses of raw materials and natural resources. Data suggest that it is this growth, combined with an increasing public demand for a clean environment, that has driven many environmental improvements over the past 30 years.

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 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.