As we approach this Earth Day on Friday, Americans have plenty to celebrate. Air pollution has fallen to the lowest level ever recorded. Wildlife is thriving. The bald eagle can finally be taken off the Endangered Species List. Forestland in the eastern half of the United States is increasing at a net rate of 1 million acres a year. And after three centuries of decline, wetlands are now making a rapid comeback.

Clearly, the commitment Americans have made to improving the environment is showing huge results. But the key word is Americans, not — as many would have us believe — the mandates imposed by the American government. There's a huge difference, and the implications for the future of environmental policy are likewise huge.

The successes we celebrate today are not a vindication of government intervention. Quite the contrary: Much of the progress we've made has been due to grass-roots efforts and private organizations working for the good of our society. In many cases, their attempts to improve the environment are more hindered than helped by the tangle of government regulations.

In California, for example, kelp has been receding for years. Retired French aquaculture entrepreneur Rodolphe Streichenberger came up with a plan for seeding kelp forests on property leased from local and state authorities, with their permission. After Streichenberger's idea was implemented with the planting of a 10-acre kelp reef, the Coastal Commission mandated that it be removed for jurisdictional reasons.

Over the last few years, market incentives have been shown to be much more effective in environmental cleanup than the blunt paperwork mandates and endless lawsuits which for so long were the working tools of government regulators.

A small group of ranchers took some of the American bison off the open range where they were dwindling. From a low of fewer than 1,000, there are now as many as 350,000 bison in North America, according to the National Buffalo Association. And the species is no longer endangered. The California condor, peregrine falcon, bald eagle and Mauritius kestrel have been similarly helped by privately funded efforts.

Meanwhile, trash entrepreneurs have invented a new way to recycle waste cheaply. Known as "dirty MRFs" — materials recovery facilities — these new low-tech trash mills sort recyclables from regular trash. This eliminates extra trips for garbage trucks and makes recycling hassle-free.

Costly government-run programs, on the other hand, intentionally push presorting of trash back on individual households. This is monstrously inefficient by comparison to MRFs.

Private-sector conservation and individual initiative can be easily encouraged by market incentives. The response is more flexible and adaptable to local conditions. Also, market-based approaches cost far less to administer than government attempts at command and control. Harnessing free-market forces is a method that has been proven successful time-and-again. Properly structured, it works beautifully in the environmental arena.

Environmental progress is a wonderful thing. So this Earth Day we should make a special effort to acknowledge the accomplishments of the private sector in improving our precious ecosystem. Voluntary, uncoerced cooperation in solving common problems is part of what has made America great. Let's keep up the good work.