Climate change and western wildfires.

Abstract

This feature explores topics of enduring ecological concern: fire regimes, climate change and forest management of the North American West. The authors describe the dual challenges of past forest management legacies and fire exclusion confronted by a changing fire regime due to the coupling of stark climatic changes and abundant fuels. They argue for intentional management to create more drought- and fire-resilient forests, emphasizing key forest characteristics that conserve biodiversity and ecosystem values, while recognizing that this implies the use of mechanical thinning, prescribed burning and managed wildfire as tools. The debate, therefore, involves disparate views of how North American forests functioned a century or more ago, historical variation in climate and fire interactions, and the costs of not increasing the pace and scale of climate adaptation. Conversely, the debate also involves values and aspirations, recognition of the role of indigenous fire stewardship, conflict between preservation of wild forests and rural livelihoods, and social acceptance of the tools available for building resilience. The toolkit for rebuilding landscape resilience involves hard choices. These include changes to management of the wildland/urban interface, the risks and benefits of prescribed burning and managed wildfire policies, and the benefits and consequences of active timber harvesting and burning to reduce fuels. The stakeholders are many, including indigenous peoples, rural communities whose livelihoods depend on natural resources, wilderness advocates, fire professionals who put their lives on the line, and all those individuals and livelihoods impacted by wildfire smoke and the increasing burned area. The financial stakes are also high. The cost of firefighting in the USA alone is in the billions each year and growing, the value of real estate and other key infrastructure in the “red zone” is far higher than that, and the value of the lives at stake and treasured ecosystems are priceless. As a result, the substantive scientific discussion intersects fundamental human issues and, ultimately, the conversation must address scientific knowledge, values and social choices. The authors of this feature tackle the challenge of creating resilience to fire in a changing climate in each of these dimensions. They identify what is known and what remains uncertain so that the management of western North American forests can be upheld on the basis of strong evidence while informed by core social values. The significance of this work goes beyond the specific problem of western North American wildfire and speaks to the management of ecosystems in a no-analog future, in which the Earth’s systems reflect a history of intensifying exploitation and management under a changing climate. The intellectual challenge to ecology and ecologists is to imagine an ever-changing human-dominated world, where ecosystems are dynamically resilient to a warmer, more fire-prone world. In this new reality, the past may inform the future, but it no longer provides simple archetypes to restore toward; systems resilient to Holocene variation may be starkly vulnerable in a warmer, drier and more variable Anthropocene climate. This set of papers directly addresses one very large region but has implications for ecosystems globally.