Modest global warming has resulted in fewer Idaho climate extremes and has brought significant additional benefits, a review of Idaho climate data reveals. The climate data should reassure Idaho legislators who have expressed concern about local impacts of asserted climate change.
NOAA data show the greatest impact of Idaho warming has been to reduce temperature and climate extremes. For example, days with temperatures above 95 degrees remain less frequent than was the case during the 1920s and 1930s. NOAA reports there were only 35 days with temperatures above 95 degrees during the 1995–2014 period (the latest 20-year period for which NOAA has published data), compared to 43 such days between 1920 and 1939. On the other end of the spectrum, Idaho averaged approximately 10 nights per year between 1910 and 1950 when temperatures plummeted below 0 degrees F. By contrast, Idaho has averaged only 5.5 such brutally cold nights per year since 1990.
NOAA data also reveal there has been a modest increase in Idaho precipitation since the late 1800s, which should alleviate concerns that global warming is causing droughts in the state. Since the early 1900s, average precipitation in Idaho has increased from approximately 1.9 inches per month to just over 2 inches per month. Idaho precipitation is also becoming less extreme. There has been a declining trend in the average amount of precipitation in the wettest month of the year, while there has been an increase in the average amount of precipitation during the driest month of the year. This is good news for Idaho farmers and ranchers.
Aside from agriculture, Idaho will likely continue to benefit from modest warming in other ways. Satellite measurements of global vegetation intensity show Idaho is benefitting from global greening more than almost any other region of the planet. Idaho, like the rest of the nation and globe, will also likely continue benefiting from fewer cold-related deaths, which occur much more frequently than heat-related deaths. Moreover, a warmer climate will provide greater opportunities for tourism, exercise, and recreation, with longer seasons for hiking, camping, fishing, golfing, bicycle riding, and myriad other outdoor activities.
Idaho legislators have prudently kept an eye on climate change impacts specific to Idaho. Climate and temperature data reveal a reassuring reality.