Carson had spent her life studying, observing, and writing about nature. She was a trained biologist and a talented writer who knew how to present scientific information in compelling stories. Before Silent Spring, she had written other books from the perspective of fish, birds, islands, and oceans. Carson knew that all things in nature exist in a delicately balanced ecosystem. In Silent Spring, Carson wrote that although the ecosystem can adjust to changes, it needs time. Carson believed that people in the 1950s were using pesticides carelessly. Nature didn't have time to adjust, wrote Carson, because so many pesticides had been used in such large quantities in such a short time.