William K. Stevens

Many scientists envision an environmental apocalypse in the twenty-first century if current ecological trends continue. In the following viewpoint, New York Times science writer William K. Stevens describes the profound impact humanity has had on the biosphere, particularly during the twentieth century. Stevens examines the depletion of natural resources and other critical environmental concerns that could lay the groundwork for an environmental apocalypse.

As you read, consider the following questions:

1. What is the Green Revolution, according to Stevens?
2. What role do trees play in the maintenance of the biosphere, according to the author?
3. In Stevens’s opinion, why is global warming the most consequential environmental concern"

Humans have always exploited nature in the belief that the all-encompassing biosphere—the seamless, wondrously resilient fabric of life, land, water and air—was so...