2025

THE FLIP SIDE OF NEW ORLEANS:

The Case for Letting Malibu Burn: Many of California’s native ecosystems evolved to burn. Modern fire suppression creates fuels that lead to catastrophic fires. So why do people insist on rebuilding in the firebelt? (Mike Davis, Ecology of Fear)

From the beginning fire has defined Malibu in the American imagination. In Two Years Before the Mast, Richard Henry Dana described sailing northward from San Pedro to Santa Barbara in 1826 and seeing a vast blaze along the coast of José Tapia’s Rancho Topanga Malibu Sequit. Despite—or, as we shall see, more likely because of—the Spanish prohibition of the Chumash and Tong-va Indian practice of annually burning the brush, mountain infernos repeatedly menaced Malibu through the nineteenth century. During the great land boom of the late 1880s, the entire latifundio was sold at $10 per acre to the Boston Brahmin millionaire Frederick Rindge. In his memoirs, Rindge described his unceasing battles against squatters, rustlers, and, above all, recurrent wildfire. The great fire of 1903, which raced from Calabasas to the sea in a few hours, incinerated Rindge’s dream ranch in Malibu Canyon and forced him to move to Los Angeles, where he died in 1905.

From the time of the Tapias, the owners of Rancho Malibu had recognized that the region’s extraordinary fire hazard was shaped, in large part, by the uncanny alignment of its coastal canyons with the annual “fire winds” from the north: the notorious Santa Anas, which blow primarily between Labor Day and Thanksgiving, just before the first rains. Born from high-pressure areas over the Great Basin and Colorado Plateau, the Santa Anas become hot and dry as they descend avalanche-like into Southern California. The San Fernando Valley acts as a giant bellows, sometimes fanning the Santa Anas to hurricane velocity as they roar seaward through the narrow canyons and rugged defiles of the Santa Monica Mountains. Add a spark to the dense, dry vegetation on such an occasion and the hillsides will explode in uncontrollable wildfire: “The speed and heat of the fire is so intense that firefighters can only attempt to prevent lateral spread of the fire while waiting for the winds to abate or the fuel to diminish.”

Less well understood in the old days was the essential dependence of the dominant vegetation of the Santa Monicas—chamise chaparral, coastal sage scrub, and live oak woodland—upon this cycle of wildfire. Decades of research (especially at the San Dimas Experimental Forest in the San Gabriel Mountains) have given late-twentieth-century science vivid insights into the complex and ultimately beneficial role of fire in recycling nutrients and ensuring seed germination in Southern California’s various pyrophytic flora. Research has also established the overwhelming importance of biomass accumulation rather than ignition frequency in regulating fire destructiveness. As Richard Minnich, the world authority on chaparral brushfire, emphasizes: “Fuel, not ignitions, causes fire. You can send an arsonist to Death Valley and he’ll never be arrested.”

A key revelation was the nonlinear relationship between the age structure of vegetation and the intensity of fire. Botanists and fire geographers discovered that “the probability for an intense fast running fire increases dramatically as the fuels exceed twenty years of age.” Indeed, half-century-old chaparral—heavily laden with dead mass—is calculated to burn with 50 times more intensity than 20-year-old chaparral. Put another way, an acre of old chaparral is the fuel equivalent of about 75 barrels of crude oil. Expanding these calculations even further, a great Malibu firestorm could generate the heat of three million barrels of burning oil at a temperature of 2,000 degrees.