Pursuing Geoengineering for Atmospheric Restoration: Geoengineering Is Fraught with Problems, But Research on Three Approaches Could Lead to the Greatest Climate Benefits with the Smallest Chance of Unintentional Environmental Harm (Geoengineering) (Report‪)‬

A few decades ago, the notion of actively controlling Earth's climate resided primarily in the writings of science fiction authors such as Frank Herbert, Isaac Asimov, and Arthur C. Clarke. Today, planetary engineering is being discussed openly by scientists and policymakers in Congress, the UK House of Commons, and many other settings. Clarke's advice apparently struck a chord: "Politicians should read science fiction, not westerns and detective stories." Geoengineering can be thought of as intentionally manipulating Earth's climate to offset the warming from greenhouse gas emissions. Its activities can be divided into two loose groups. One set of options cools Earth by removing carbon dioxide ([CO.sub.2]) and other greenhouse gases from air, essentially reversing the process of fossil fuel emissions. The other cools the planet by blocking or reflecting sunlight, offsetting the consequences of increased greenhouse gases for temperature but leaving the buildup of greenhouse gas concentrations unchecked.