China's challenge to the United States and to the earth.

• Author: Brown, Lester R.

During the 1990s, China has emerged as an economic superpower, boasting the world's second largest economy. It is now challenging not only U.S. economic leadership, but the earth's environmental limits.

Using purchasing power parity to measure output, China's 1995 GNP of just over $3 trillion exceeded Japan's $2.6 trillion and trailed only the U.S. output of $6.7 trillion. If the Chinese economy continues to double every eight years, the pace it has maintained since 1980, it will overtake the United States by 2010, becoming the world's largest economy.

Over the last four years the Chinese economy has grown by 10 to 14 percent per year. As its population of 1.2 billion people moves into modern houses, buys cars, refrigerators and televisions, and shifts to a meat-based diet, the entire world will feel the effects. Already, China's rapidly rising [CO.sub.2] emissions account for one-tenth of the global total.

In recent decades, many observers noted that the United States, with less than 5 percent of the world's population, was consuming a third or more of its resources. But this is no longer true. In several areas, China has overtaken the United States. For example, China now consumes more grain and red meat, uses more fertilizer, and produces more steel than the United States.

Since China has 4.6 times as many people as the United States, its per capita demands on the earth's resources are still far less. To cite an extreme example, the average American consumes 25 times as much oil as the average Chinese citizen does.

Even with its still modest per capita consumption, China is already paying a high environmental price for its booming economy. Its heavy reliance on coal, for example, has led to air pollution nearly as bad as that once found in eastern Europe. As a result, respiratory disease has become epidemic in China, and crop yields are suffering.

As China, with its much larger population, attempts to replicate the consumer economy pioneered in the United States, it becomes clear that the U.S. model is not environmentally sustainable. Ironically, it may be China that finally forces the United States to come to terms with the environmental unsustainability of its own economic system. If China were to consume as much grain and oil per person as the United States does, prices of both commodities would go off the top of the charts. Carbon dioxide emissions would soar, leading to unprecedented climate instability. Together, these trends would...