Environmental reality: a tidbit from a Bradley Lecture at the American Enterprise Institute, in which Gregg Easterbrook previewed his forthcoming book The Progress Paradox. (Transcript: words worth repeating).

Despite the panic-stricken tone of environmental commentary and politics, all environmental trends in the U.S. except for greenhouse-gas accumulation are favorable.

Puget Sound, Chesapeake Bay, Lake Erie, the Hudson River and other important water bodies have gone from imperiled to mainly clean. Boston Harbor, whose filth was ridiculed in a commercial that was pivotal to the 1988 Presidential election, now has water so clear that revelers do ceremonial New Year's Day dips. The Chicago River, described in the Upton Sinclair classic The Jungle as so loaded with filth that chickens actually were seen walking across it, and as recently as the 1970s still badly polluted, today hosts art festivals, boat tours, and dinner cruises.

Since 1970, smog has declined by a third, even as the number of cars has doubled. Acid rain has fallen 65 percent, though the United States now burns twice as much coal. Airborne soot is down substantially. Airborne lead is down 98 percent. Emissions of CFCs have essentially ended.

During the 2000 Presidential campaign, much was made of Houston taking over from Los Angeles as the nation's "smog capital." Commentators did not add that this happened during a period when Houston smog diminished--it's just that L.A. pollution declined even faster, with Los Angeles prevailing in a race of positives. Twenty years ago, Los Angeles averaged 50 "stage one" ozone alerts per year; the city has not had one for the last four years running. This ability to make fantastic strides against pollution even during a period when the regional population was shooting up is a remarkable success story.

Other environmental measures are also positive. Toxic emissions by industry declined 48 percent in the last 15 years. And that's not because our pollution was shipped offshore--petrochemical manufacturers, the main industrial source of toxic emissions, actually increased domestic production during the period.

More than half of all Superfund toxic waste sites are cleaned up, and none imperil public health. Some Superfund sites are now sufficiently harmless to have been declared nature preserves. Rocky Mountain Arsenal outside Denver, where nerve gas was once made, has been a National Wildlife Preserve for 10 years. Eagle and other biologically delicate species thrive there.

Soil losses to agricultural runoff are declining. American ...