Fire-Mediated Changes in the Arctic System: Interactions of Changing Climate and Human Activities

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Perhaps the most urgent challenge facing humanity is to understand the factors determining the limits to resilience of regional systems that are changing directionally in biophysical and social drivers. This research program will document the changing role of fire, particularly as affected by human activities, on the Arctic Climate System and its human residents. The research will focus on Alaska and Yukon Territory, a large regional system in which fire is the dominant disturbance mechanism. The proposed research has intellectual merit at several levels: 1. It will assess the changing role of human activities in the fire regime of the Alaska- Yukon region as this is determined by changes in the effects of people on fire (ignition and suppression) and the effects of fire on people, including economics (e.g., wages, property risk) and ecosystem services (e.g., game, berries, firewood, timber, climate feedbacks). 2. It will evaluate the consequences of climate- and human-induced changes in fire regime on land-surface properties that are important to climate. This is a critical link between research on human dimensions and research on climate feedbacks. 3. It will document the past and plausible future changes in climate feedbacks in the Alaska-Yukon region that result from climate warming and from climate- and human- induced changes in fire regime. It will compare the contribution to atmospheric heating that comes from (a) trace-gas fluxes vs. water/energy exchange and (b) arctic vs. boreal landscapes. This is the first comparison of the role of human activities within and outside the Arctic on the Arctic Climate System. This research has broad implications for assessment of both the short- and long-term consequences of the current policy of fire suppression near communities and roads. Fire management in North America is currently struggling with issues related to the wildland-urban interface. This modeling effort is one of the first to explicitly represent suppression in a dynamic landscape fire succession model and will provide a management tool for assessing the consequences of different fire management strategies (i.e., reactive versus preventative) for present and future fire regimes. Because of the importance of fire-fighting wages in the economy of rural communities, this has implications for the sustainability of subsistence activities. It will also assess the overall climate feedbacks caused by human activities outside northern regions (global warming) as compared to effects resulting from human interactions with the fire regime of northern regions. Because fire-induced changes in vegetation may be one of the few large negative feedbacks to high-latitude warming, fire management provides a potential tool to mitigate this warming. The utility of this mitigation strategy depends, however, on the net effects of fire on climate and on human welfare. This study is the first attempt to assess the potential impacts of such a radical regional-scale effort to reduce high-latitude climate warming. This research enhances interdisciplinary research by integrating natural and social sciences and including local residents in our research team. These are important steps in effective inclusion of human-dimensions research in Arctic System Science.