2020-10-27_PERMIT FILE - C1981035 (22)

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rise will likely be in the ranges of 0.26 to 0.55 m for RCP2.6, and of 0.45 to 0.82 m for RCP8.5. It is very likely that the sea level will rise in more than about 95 percent of the ocean area,where about 70 percent of coastlines worldwide would experience a sea level change within ±20 percent of the global mean. All climate model projections indicate future warming in Colorado. Statewide average annual temperatures are projected to warm by +2.5°F to +5°F by 2050 relative to a 1971-2000 baseline under RCP4.5. Under the high emissions scenario (RCP8.5),the projected warming is+3.5°F to+6.5°F and would occur later in the century as the two referenced scenarios diverge. Summer temperatures are projected to warm slightly more than winter temperatures, where the maximums would be similar to the hottest summers that have occurred in past 100 years. Precipitation projections are less clear, with individual models showing a range of changes by 2050 of-5 percent to+6 percent for RCP 4.5 percent,and-3 percent to +8 percent under RCP8.5. Nearly all the models predict an increase in winter precipitation by 2050, although most projections of snowpack (April 1 Snow Water Equivalent) show declines by mid-century due to the projected warming. Late-summer flows are projected to decrease as the peak shifts earlier in the season, although the changes in the timing of runoff are more certain than changes in the amount of runoff. In general, most of the published research indicates a tendency towards future decreases in annual streamflow for all of Colorado's river basins. Increased warming,drought,and insect outbreaks,all caused by or linked to climate change, will continue to increase wildfire risks, and impacts to people and ecosystems. In 2018,the IPCC released a special report on the impacts of global warming of 1.5°C above pre-industrial levels and summarizes their conclusions from a number of key findings, several of which are excerpted here: • Human activities are estimated to have caused approximately 1.0°C of global warming above pre- industrial levels,with a likely range of 0.8°Cto 1.2°C, and warming is likelyto reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate. • Warming from anthropogenic emissions from the pre-industrial period to the present will persist for centuries to millennia and will continue to cause further long-term changes in the climate system, but these emissions alone are unlikely to cause global warming of 1.5°C (medium confidence). • Climate models project robust differences in regional climate characteristics between present- day and global warming of 1.5°C,8 and between 1.5°C and 2°C.These differences include increases in: mean temperature in most land and ocean regions (high confidence), hot extremes in most inhabited regions (high confidence), heavy precipitation in several regions (medium confidence), and the probability of drought and precipitation deficits in some regions (medium confidence). • By 2100, global mean sea level rise is projected to be around 0.1 meters lower with global warming of 1.5°C compared to 2°C (medium confidence). Sea level will continue to rise well beyond 2100(high confidence),and the magnitude and rate of this rise depend on future emission pathways. A slower rate of sea level rise enables greater opportunities for adaptation in the Dunn Ranch Area LBA and Mining Plan Modification 47 Technical Resources Report