Climate Change and Fire Louisa Evers BLM Climate Change Coordinator Spring 2015 FALT Meeting

Climate Change Projections Warming year-round but especially for minimum temperatures and in summer Little change in annual precipitation but wetter winters and drier summers Increased frequency, intensity, and duration of drought Fewer but more intense storms, more dry days between storms Less snow and earlier snowmelt Increases in extreme heat, decreases in extreme cold

Observations Warming in most seasons with trends in some locations statistically significant Little change in annual precipitation, some shifts in seasonality Earlier snowmelt Earlier peak flows and lower base flows Fewer cold extremes, more warm extremes

Historical Droughts in Oregon and Washington

Types of Drought Very low winter precipitation with near normal seasonal temperatures – Dry Drought Warm winter with near normal precipitation followed by very warm, dry summer – Hot Drought Warm, dry winter followed by near-normal summer – Warm-Dry Drought Very warm temperatures through summer and near normal precipitation – Very Hot Drought

Drought Indicators Palmer Drought Severity Index – Not scalable – Values used not based on scientific significance – Does not capture drought onset – Performs poorly in mountainous terrain Standardized Precipitation Evaporation Index – Scalable – Based on climatological statistics – Captures drought onset – Performs better in mountainous terrain

SPEI Time Series Oregon-Washington Eastern Washington 3 months 6 months 12 months

Recommended Drought Sites: Drought Monitor

Recommended Drought Sites: UW Drought Monitor

Recommended Drought Sites: WestWide Drought Tracker

Energy Limited Fuel Limited Ponderosa Pine Fire Return Interval Cool-Moist Sagebrush Warm-Dry Sagebrush Juniper Woodland Salt Desert Scrub Dry Mixed Conifer Moist Mixed Conifer Lower Subalpine Upper Subalpine Implications of Climate Change Forests Rangelands

Observed Changes in 90 th Percentile ERC Values PSA Fire SeasonJuneJulyAugustSeptemberOctober NW NW NW NW NW NW NW NW NW NW NW NW

Projected Changes in the 90 th Percentile ERC Values

Questions?