“The Obligation to Endure” is the second chapter of Silent Spring. Rachel Carson observes that people have only recently “acquired significant power to alter the nature of the world,” especially in negative ways. Human beings have acquired this power through their careless misuse of science. She terms this negative—and usually long-lasting—alteration “man's assaults upon the environment" and claims that it occurs through “contamination.” Carson uses this umbrella term to refer to pollution caused by chemicals as well as to the effects of nuclear power.

Carson notes the drastically accelerating pace of human negative impacts in the 20th century. In particular, she points to the drastic changes that occurred in the early 1960s through the use (and misuse) of nuclear power. Chemicals and radiation work together to create negative effects in the natural and cultivated environment—such as agricultural crops—and in the “living tissues” and “bones of a human being.”

Chemicals used in agriculture, both pesticides and herbicides, contaminate the air, water, and soil in what Carson calls “a chain of poisoning and death.” While she notes that the natural world always contained some harmful elements, she argues that human actions have dramatically intensified the harmful qualities of such elements and accelerated the pace of their effects. She notes the long-lasting effects of Strontium 90—which is released through nuclear explosions—and more generally criticizes “man's tampering with the atom.”