11 - Fire and Drought in the Western United States

Summary

Chapter 11 examines the rapid increases in wildfire extent and the role played by increased temperature-induced evaporative demand. The story begins in early November 2018, with the author clearing bone-dry brush in the woods behind his house, and discussing these incredibly dry conditions on a local radio show with his local volunteer firefighter friends. In dry regions, warmer air's increased ability to hold water increases its capacity to draw moisture from soils and plants. On November 6, the Community Alert show discussed the exceptionally dry conditions across California, and how these dry-fuel conditions were expected to combine with high winds to set the stage for potential conflagration. At sunrise on November 8, the Camp Fire, California's deadliest and costliest conflagration, broke out. Since the early 1980s, annual US wildfire extents have increased by more than 300 percent. In California, 2017 and 2018 wildfire extent, deaths, and damages were staggering. Increases in western US wildfire extent are tightly coupled with increases in aridity, which are related to both increases in air temperatures and atmospheric water demand. The 2017 and 2018 US wildfires were associated with more than $40 billion in damages and more than a hundred fatalities. Chapter 11 concludes with a firsthand account from Laura Eilerts, a ninety-one-year-old woman who lost her house in the Paradise Fire and drove herself to safety.