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21: NORTHWEST <br />Insects and Fire in Northwest Forests <br />Recent <br />Disturbance <br />Fire area <br />Insect and <br />disease area <br />ifrojected lncreas <br />in Area Burned <br />600% to 700% <br />500% to 600% <br />WI 400% to 500°k <br />300% to 400% <br />200% to 300% <br />100% to 200% <br />Not modeled j <br />Change in <br />Probability of <br />Mountain Pine <br />Beetle Survival <br />114 40% to 100% <br />20% to 40% <br />-20% to 20% <br />-40% to -20% <br />-100% to <br />Figure 21.7. <br />(Top) Insects and fire have cumulatively <br />affected large areas of the Northwest and <br />are projected to be the dominant drivers <br />of forest change in the near future. Map <br />shows areas recently burned (1984 <br />to 2008)9798 or affected by insects or <br />disease (1997 to 2008).99 <br />(Middle) Map indicates the increases in <br />area burned that would result from the <br />regional temperature and precipitation <br />changes associated with a 2.2°F global <br />warmingloo across areas that share broad <br />Ill <br />climatic and vegetation characteristics. <br />Local impacts will vary greatly within <br />these broad areas with sensitivity of fuels <br />to climate.'' <br />(Bottom) Projected changes in the <br />probability of climatic suitability for <br />mountain pine beetles for the period <br />2001 to 2030 (relative to 1961 to 1990), <br />where brown indicates areas where pine <br />beetles are projected to increase in the <br />future and green indicates areas where <br />pine beetles are expected to decrease <br />in the future. Changes in probability of <br />survival are based on climate -dependent <br />factors important in beetle populatio i <br />success, including cold tolerance, <br />spring precipitation,1o3 and seasonal heat <br />accumulation.91,92 <br />Adaptive Capacity and Implications for Vulnerability <br />Ability to prepare for these changes varies with land ownership currently low severity fire systems, like drier eastern Cascades <br />and management priorities. Adaptation actions that decrease forests,111 but may be ineffective in historically high -severity - <br />forest vulnerability exist, but none is appropriate across all of fire forests, like the western Cascades, Olympics, and some <br />the Northwest's diverse climate threats, land -use histories, subalpine forests. It is possible toff se thinning to reduce tree <br />and management objectives.86,110 Surface and canopy thinning mortality from insect outbreaks, but not on the scale of <br />can reduce the occurrence and effects of high severity fire in the current outbreaks in much of the West. <br />Key Message 4: Adapting Agriculture <br />While the agriculture sector's technical ability to adapt to changing conditions can offset <br />some adverse impacts of a changing climate, there remain critical concerns for agriculture <br />with respect to costs of adaptation, development of more climate resilient technologies <br />and management, and availability and timing of water. <br />production systems contributed 3% and 11% of the region's <br />gross domestic product, respectively, in 2009.11' Although the <br />overall consequences of climate change will probably be lower <br />Agriculture provides the economic and cultural foundation <br />for Northwest rural populations and contributes substantively <br />to the overall economy. Agricultural commodities and food <br />U.S. GLOBAL CHANGE RESEARCH PROGRAM 496 <br />CLIMATE CHANGE IMPACTS IN THE UNITED STATES <br />