Threat Multiplier takes us onto the battlefield and inside the Pentagon to show how the US military is confronting the biggest security risk in global history: climate change. More than thirty years ago, Sherri Goodman became the Pentagon's first chief environmental officer. Indeed, for much of the twentieth century, the Department of Defense (DOD) was better known for containing the Soviet nuclear threat than protecting the environment. And yet, today, the military has moved from an environmental laggard to a clean energy and climate leader, recognizing that a warming world exacerbates every threat—from hurricanes and forest fires, to competition for increasingly scarce food and water, to terrorism and power plays by Russia and China. The Pentagon now considers climate in war games, disaster relief planning, international diplomacy, and even the design of its own bases.

What was the key to this dramatic change in military thinking? What keeps today's generals and admirals up at night? How can we safeguard our national defense and our planet? No one is better poised to answer these questions than Sherri Goodman, who was at the vanguard of environmental leadership among our armed forces and civilian representatives. In Threat Multiplier, she tells the inside story of the military's fight for global security, a tale that is as hopeful as it is harrowing.