No civilization has survived the ongoing destruction of its natural support systems. Nor will ours.

Children whose developing lungs are particularly vulnerable suffer the most from air pollution. For children, breathing the air in cities with the worst pollution, such as Beijing, Calcutta, Mexico City, Shanghai, and Tehran, is equivalent to smoking two packs of cigarettes a day.

Another agricultural trend of growing concern is the increased nutrient content of coastal waters resulting from fertilizer runoff in agricultural regions. Augmented by urban sewage discharge in some situations, this results in huge algal blooms, which, as they die and decay, deplete the oxygen content in the water, leading to the death of the fish.

The foundation is being laid for the emergence of both wind and solar cells as cornerstones of the new energy economy. World wind generating capacity grew from 7,600 megawatts in 1997 to 9,600 in 1998, an expansion of 26 percent. At a national level, Germany led the way, adding 790 megawatts of capacity, followed by Spain with 380 megawatts, and the United States with 226 megawatts. In the past, U.S. wind generating capacity was concentrated in California, but in 1998, wind farms began generating electricity in Minnesota, Oregon, and Wyoming, broadening the new industry's geographical base.

Nuclear power, once regarded as petroleum's natural heir, has become less and less attractive as its numerous drawbacks come to light. Coal, the other fossil fuel, is ultimately as exhaustible as oil.

Each summer, for example, nitrogen and phosphate washing from farmlands in the Mississippi Valley enter the Gulf of Mexico, creating a massive algal bloom covering some 16,000 square kilometers. As the blooms die off, this area-roughly the size of New Jersey-is so deprived of oxygen that no fish survive.

We know what we have to do. And we know how to do it. If we fail to convert our self-destructing economy into one that is environmentally sustainable, future generations will be overwhelmed by environmental degradation and social disintegration. Simply stated, if our generation does not turn things around, our children may not have the option of doing so.