Climate Expert: Jackson has greatest warming in short time span

In the last 50 years the average of the coldest temperatures in Jackson increased by 15 degrees Fahrenheit. It’s the largest rise in temperature climate expert Steve Running has ever seen in such a short time span.

Running, a professor of ecology and director of the Numerical Terradynamic Simulation Group at the University of Montana, averaged the temperatures of the five coldest days in each of the last 50 years and then compared the averages. It is an unusual way to look at climate change, but it’s the way it should be evaluated, instead of the more common method of looking at annual average temperatures, he said.

“(Annual temperature average) is probably the least dynamic part of the entire record because it changes so slowly because it is an average,” Running said.

Looking at the extremes — both temperature highs and lows — shows how quickly and how much things are changing, he said. It is the extremes that cause the most impact.

“Living and dying happens at the extreme events,” he said.

Running took the five coldest days, instead of just the single coldest, in his calculations, in case the coldest day in any one year was an anomaly.

There are plant and animal species that can adapt to a few degrees shift in temperature, but can’t survive major swings. Running uses mountain climbers that can scale Mt. Everest as an example. They can be hyper-fit, the top specimens physically of the human population, able to make the extreme and arduous trek up the mountain. But if they are climbing and a major cold snap hits, no matter how fit they are, they can die within an hour, he said. The same results happen on the other end of extremes. Ultra-marathon runners who train and race in the desert are physically strong and acclimated to heat, but no matter how fit they are, or how much they train for heat, if they encounter an extreme heat event, they can still die.

Running looked at Jackson’s data before presenting to the Yellowstone Business Partnership in Grand Teton National Park in May.

Running’s data was important, but not surprising to Janice Brown, executive director of the group. A long-time Idaho resident she’s noticed the brutal winter days old-timers talk of in stories have actually become legend.

For business owners it’s important to think about the future, especially if the extremes increase another 15 degrees in the next 50 years, she said.

“There could be some very big implications for business and investments,” she said.

Some impacts could be good — longer growing and tourism seasons, while other consequences, like less snow and a shorter winter sports season, could hurt some businesses. Plus there are all the unknowns that climate change creates, she said.

Running believes the highs and lows are changing elsewhere, too, but not many people are analyzing the extremes of particular areas.

Research is showing places at higher latitudes and higher altitudes are warming more and warming faster than other areas, he said. While global climate data isn’t incorrect, area-specific analysis gives a better idea of what is happening in a person’s own backyard, Running said.

Analysis similar to Running’s evaluation of Jackson’s extremes has been performed on Missoula, Mont., where the past two winters temperatures haven’t dropped below zero degrees, Running said. There has been little change in overall average temperatures in Missoula, but the extreme events, like cold below zero degrees, is changing significantly, he said.

The world is changing, Running said. There are species that thrive in warmer weather while other species will struggle to survive. The warming in Jackson may have some positives for the tourism industry, he said. It could mean longer summers and fewer days in the winter that are too cold to ski. But it’s too difficult to know exactly the overall impact of warming on the broader ecosystem that includes Jackson Hole. The next piece of analysis, Running said,  is to look at extreme heat events, average the hottest days, or how many days climb to 100 degrees or more each year.