RACHEL Carson's ecological wake up call, "Silent Spring," initially appeared as a series of essays in The New Yorker in June, 1962. Her work launched America's modern environmental movement and set the stage for the Earth Day celebration of 1970

On April 10, 1995, just a few days short of the 25th anniversary of Earth Day, Greg Easterbrook published an article in the same New Yorker. Distilled from his recent book, "A Moment upon the Earth," the article focuses on "eco-realism." Easterbrook convincingly argues that we have greatly improved our environment since Earth Day, though few are ready to admit it.

Many fiscal conservatives, free-market aficionados and libertarians are unwilling to recognize our successes. They resist evidence that government programs are sometimes effective (though rarely efficient). Many modern liberals are reluctant to admit even partial victory. Some fear a relaxation of effort while others seek to profit by perpetuating the perception of crisis. Nevertheless, the gains are real.

Lake Washington, Puget Sound, Lake Erie, and many other bodies of water have made ecological comebacks. Airborne lead, carbon monoxide, sulfur dioxide, and automobile hydrocarbon emissions have declined from 24 percent to 96 percent, significantly improving air quality in America's cities. Some wildlife populations have rebounded. For example, the wild turkey, an important indicator species, was nearly extinct but is now more widely distributed than in colonial times.

Other environmental improvements have occurred without federal encouragement. The Atlantic Monthly's April feature story discussed the impressive and ongoing reforestation of the eastern United States. The much-maligned profit motive has spurred private enterprise to reduce consumption of natural resources and lower the generation of solid and toxic waste. And in the 1980s, private land trusts exploded as an important, local method for preserving millions of acres of land.

In spite of its successes, the post-Earth Day legacy of environmental protection has serious flaws. It emphasized rigid federal laws and regulations that are often monstrously inefficient and massively inequitable. The inefficiency, by wasting resources, means environmental protection is more likely to conflict with other important goals, especially when government budgets are tightening. Inequity, by imposing costs on a small number of people, encourages heated resistance to programs that are supposed to pursue worthwhile goals. For example, opposition to the Endangered Species Act continues to grow because the costs of species protection are concentrated on relatively few land owners.

Until recently, inefficiency and inequity were of little concern to single-minded seekers of environmental quality.

This is partly because we could achieve large gains in environmental quality for relatively little time, money, and inconvenience. But, as America grows cleaner, easy gains become more elusive. In economists' parlance, we encounter the problem of diminishing marginal returns. The next 5 percent of a specific environmental gain may cost more than the first 90 percent, the next 2 percent more than the previous 95 percent. Opportunity costs grow as we seek ever deepening shades of green.

In addition, environmental regulations often hide regulatory costs by placing them on businesses, and letting the businesses pass them on to consumers in the form of higher prices. With the public largely unaware of the monetary and social costs of environmental regulations, lawmakers and bureaucrats have little reason to worry about efficiency or equity.

Public indifference is complemented by political self-seeking and opportunism. Bureaucrats at EPA, OSHA and FDA, whose jobs depend on regulating even trivial or nonexistent risks, have powerful incentives to cast an ever wider net of ever tighter regulations, just to keep their people working and their budgets growing.

Legislators impede our movement toward environmental quality by carving out protections for powerful constituencies. For example, the 1977 Clean Air Act Amendments required smokestack scrubbers be installed at many coal-burning power plants rather than promoting low-sulfur coal. Scrubbers were chosen even though they did little for air quality because the use of low sulfur coal would have harmed eastern coal miners and the political careers of their congressmen.

Finally, many private environmentalists must share the blame for our misguided approach to environmental protection. They seek regulations that promote their narrow interests, frequently by foisting costs on less-organized or less-politically powerful groups. Public monies and state coercion are used to promote private or organizational interests at the expense of the public good.

Greenpeace, for example, has made efforts to restrict the industrial use of chlorine compounds, a class of substances very useful in a broad array of manufactures (which in turn contribute to America's health and welfare). Other organizations have supported legislation, such as log-export bans, that dramatically reduce property values and alienate the people who can best promote conservation.

As additional increments of environmental quality become more expensive and the costs of these increments become more visible, public resistance will stiffen. For example, the rise of the Wise Use movement partially reflects legitimate concerns with the concentration of environmental costs on rural landowners.

Much progress has been made since Earth Day 1970. But the easy solutions are behind us. To continue to improve our environment we must consider how we can minimize the burdens we impose on ordinary citizens as we pursue necessary environmental goals. This is the challenge for our next 25 years.