By 2050, the world will not be able to feed itself and a worsening environment will threaten our children's future, according to the Millennium Ecosystem Assessment, a U.N.-commissioned study released last month.The report paints a gloomy picture that ignores an important reality. On the environment, there is abundant cause for optimism.

Ozone air pollution in the United States has fallen to the lowest level ever recorded, according to the Environmental Protection Agency. Over the past decade, the areas of the nation with the highest pollution levels have shown the greatest improvement. The EPA also notes that mercury emissions in the United States declined by 45 percent in the 1990s.

The EPA's Toxics Release Inventory for the years 1998 to 2002 shows a cumulative decline of 37 percent since 1998. While the U.N. study predicts hard times for species, the number of bald eagles increased during 2004, along with the number of whales. The latest National Resources Inventory finds that between 1997 and 2002, wetlands on private land expanded by 131,400 acres. The report raises the specter of global warming, but here caution is due.

Scientists agree that global temperatures have risen about 0.6 degree Celsius over the past century. But the famous "hockey stick" graph claiming to prove that the past 25 years have been the warmest in the past 1,000 years cannot be taken seriously. Experts have shown that the computer algorithm used to generate the graph would produce similar results from any series of random numbers.

Despite continued alarmist rhetoric, 47 percent of Americans, according to Gallup, say they worry "only a little" or "not at all" about global warming. According to a Harris poll, 71 percent of Americans claim to be happy with the state of the environment where they live. Still, the default position of most Americans remains that of the U.N. report - that the environment is getting worse everywhere.

Based on the data, the default position should be that real progress has been made. In areas such as air quality, improvements over the past 30 years are of greater magnitude than those in reducing crime and welfare dependency. The U.N. report is to be applauded for advocating free-market incentives to reduce farm pollution and gas emissions. But its aversion to development is troublesome because economic growth is the cornerstone of environmental protection.

A milestone in understanding the role of economic growth is "The Real Environmental Crisis: Why Poverty, Not Affluence, is the Environment's Number One Enemy," by University of California physicist and energy expert Jack Hollander. If emerging nations follow those guidelines and the best data on the environment, today's children will have plenty to eat. Contrary to the U.N. report, they will also be living in a steadily improving environment rather than under a cloud of gloom.