Average temp increase discussed at SRM meeting

Laramie – “To sum it up, we’re looking at something in the neighborhood of a three- to four-degree temperature increase by mid-century. The precipitation outlook is a toss up,” explained Wyoming State Climatologist and Director Steve Gray on the future of Wyoming’s climate and water situation.
Gray spoke during the 2010 Wyoming Section Society of Range Management (SRM) annual meeting on Nov. 8 in Laramie.
“In many cases, people use this low confidence in precipitation predictions as an excuse not to include climate change in what we do, or how we prepare for a changing climate. But, we need to focus on the fact that we know enough about temperature change alone to start planning and adapting to climatic change,” noted Gray. He added that it’s important to not look at the change as the end of the world.
“Saying that by 2050 we will, on average, have a three degree Fahrenheit temperature increase doesn’t seem like much. But, the fact of the matter is, these seemingly small increases in average temperature have the possibility for major impacts on ecosystems in Wyoming and the Rocky Mountain West.
“A big part of that is what you might think of as a statistical artifact. If you shift the average for a variable average temperature, what you wind up with is a situation where you’ve greatly expanded the potential for extremes on the high end, or more hot weather. That in and of itself has the potential to impact the ecosystems that we work in and try to manage,” explained Gray.
He noted the point can also be illustrated using real data from events that have occurred in the western mountain region in the last century.
“Focusing on what’s happened in western Montana, it’s about three degrees warmer now than it was at the beginning of the 20th century, for whatever reason. The three-degree increase in average temperature has really impacted what happens at the hotter end of the spectrum. There are more hot days, and more days over 90 degrees. You start to get those hot days much earlier in the spring, and they last much later into the fall. There are major potential impacts on the ecosystem due to the lengths of time you’re experiencing these hot days.
“Also in this case we looked at highest elevations, and the warming trend was much steeper up there than in the valleys. This is where the water comes from, and in terms of climatic change in the high country, that three-degree temperature increase results in 50 fewer days a year where the temperature gets below freezing. This has some major impacts on length of growing season, evaporative demand, fire impacts, pest outbreaks and other aspects of the ecosystem,” said Gray.
In terms of drought, Gray said it’s easy to see what the combination of warmer temperatures and possibly less precipitation can do in the future.
“There is the potential and physical possibility that, on average, we could be looking at conditions dryer than anything we ever experienced in the 20th century, and that may be the average by the mid to late 21st century,” said Gray. He added this will also impact water use and availability for irrigation, municipal, industrial and other uses.
“One case study looked at the Yellowstone River Basin and asked what would happen to the Palmer Drought Severity Index if the temperature increased by three degrees and the precipitation stayed the same as in the 20th century. It showed 15 percent less water in the river just because of the increase in temperature and the impact of the extra warmth and energy on the system.
“When you look at the study during the driest years, we looked at the 10 lowest snow years in the 20th century and increased the temperature by three degrees. According to the models we would be looking at between 20 and 30 percent less water in the streams than during the driest 20th century years,” said Gray.
“The fact that the climate has changed is not the end of the world. I suggest we look at it as a game changer for sure. We know enough to start preparing today. We have challenges coming down the pipes, and there’s no reason we can’t starting getting out in front of the problem today,” noted Gray.
“If we know the climate is changing, and that it will have an impact on how we live and make a living, it behooves us to do something in terms of adaptation if not mitigation. The fact of the matter is, if we’re planning for drought, we’ll also plan for climate change. If we’re better prepared to deal with the impacts of drought as we know we’ve always faced them in the past, then that will, in turn, help us prepare for climate change.
“Sound conservation and management practices put into place today will still have a value tomorrow. In terms of opportunities, preparing for climate change will also help us prepare for any number of challenges we’ll face in the future. If we’re monitoring climate, water availability, range conditions or whatever it might be, this will help us, regardless of what we’re talking about.
“The fact of the matter is that no matter what happens with climate change, you can’t go wrong if you can prove your ability to share information and data and get it to the people who need that information and data to make decisions and policy about the way we manage resources in a place like Wyoming,” concluded Gray.
Heather Hamilton is editor of the Wyoming Livestock Roundup and can be reached at heather@wylr.net