If you are a longtime Boise-area resident, you might have noticed that the city is getting warmer.
Recent research quantifies this trend. Boise is warming at twice the rate of the nation as a whole.
A new report from Climate Central, a nonprofit climate science organization, reveals that from 1970 to 2018, Boise’s overall annual average temperature warmed 3.84 degrees Fahrenheit, ranking it No. 13 on the list of fastest-warming cities in the United States.
“A lot of locations are warming faster than the national average of 1.8 degrees Fahrenheit, especially in the more arid western U.S., because dry climates tend to warmer more easily than moist climates,” said Sean Sublette, one of the report’s authors, in an interview with the Idaho Statesman. Sublette is a meteorologist with Climate Central in Princeton, New Jersey.
To understand how America has warmed since 1970, Climate Central compiled data from the National Oceanic and Atmospheric Administration and looked at warming trends in 242 cities and 49 states. Hawaii was excluded.
According to the report, temperatures have risen at nearly 98% of U.S. cities since 1970. Ten cities have warmed by at least 4 degrees, and 59, including Boise, have warmed by at least 3 degrees.
“For places that are getting warmer, we need to think about what to do,” Sublette said. “In the West, droughts are a natural occurrence, but they have been getting worse, and a growing population in the West makes water resources even more important.”
To understand the impact of climate change to Boiseans, the city of Boise did a Boise Climate Adaptive Assessment in 2016. The two-page brief outlines the most significant climate change-related impacts for Boise in the next 60 years.
According to the assessment, effects Boiseans are likely to see by the middle of the century include:
The frequency of moderate risk heat stress days (days with a heat index above 91 degrees) will increase from a historical baseline of about 16 days to 66 days per summer.
The Treasure Valley will see moderate drought in roughly one of every two years, compared with one in every four now. Exceptional drought will occur in one of every three or four years, compared with one in every 12 now.
The odds of very large fires in the region is projected to increase by 400%, suggesting increased potential for chronic air-quality problems.
“The climate change picture being painted is a scary one, but what we want to know is what are the real world impacts for Boiseans,” said Colin Hickman, communications manager for Boise’s Public Works Department.
Boise is already seeing climate change effects. For example, the U.S. Department of Agriculture recently changed Boise’s gardening hardiness zone to a warmer zone because winters in Boise are likely to stay above freezing.
The city is working on a plan, to be released in 2020, on how Boiseans can do their part to mitigate local impacts.
City leaders encourage residents to do what they can to reduce their impact by considering how their daily decisions have a larger impact.
According to Haley Falconer, senior manager for the Boise’s environmental division, the average Boisean makes 10 transportation trips every day. Carpooling or chaining multiple stops into the same trip can reduce individual greenhouse gas emissions and improve trip efficiency.
“Individual actions do matter,” Falconer said. “Sometimes it feels like they don’t, but they really do all add up. We can make transformative change together, because it will take a balance of big and small changes to make greener progress.”
Said Hickman: “I have a sense of pride that our city can be a national leader for how we tackle climate change.”
Rachel Hager is writing for the Idaho Statesman this summer on a fellowship through the American Association for the Advancement of Science. She is a master’s student in ecology at Utah State University and earned a bachelor’s degree in biology at Bryn Mawr College.