Click the link to read the article on the Water Education Colorado website (Jerd Smith):
Colorado will certainly grow warmer between now and 2050, but whether it will become wetter due to this warming isn’t clear yet, according to a new state climate report due out next month.
The draft report, 2023 Climate Change in Colorado, shows that scientific models predict with high confidence that the state will see temperatures rise 2.5 degrees to 6 degrees Fahrenheit by 2050, but models looking at how this warming trend will impact water are much less clear. Some projections indicate the state could see more precipitation, and others show it will get less, according to Becky Bolinger, assistant state climatologist and an author of the new report.
“Some models are showing wetter, some drier, and we have a lot of uncertainty about which direction it is going to go,” Bolinger said.
“Since 2008 we have consistently experienced drier conditions. If you were to do a simple trend, it would appear we have gone drier, but there is a lot of variability. It is possible we will end this dry period and go into a wetter period. It is also possible that we could go into a drier period,” she said.
The Climate Change in Colorado report was produced by the Colorado Climate Center at Colorado State University, with support from the Colorado Water Conservation Board and Denver Water.
Bolinger said that this new third edition of the climate report, two previous editions were published in 2008 and 2014 respectively, is designed to serve as a guide for any community, or farm, or industry in Colorado working to prepare for a warmer future.
Despite the uncertainty about water, new modeling shows that snow, soil moisture and streamflows will likely decline, heat waves, fires and droughts will increase in frequency, and extreme rain storms and flooding are also likely to worsen.
Among the hardest-hit sectors will be agriculture, Bolinger said, in part because evaporation rates will rise as temperatures rise. As larger amounts of water are lost to the atmosphere, plants will need more.
In addition, because spring snows will melt and peak runoff will occur sooner, farmers will likely have to change planting schedules and figure out how to make their irrigation water last longer.
“It’s going to get harder to farm,” Bolinger said.
Out on Colorado’s Eastern Plains, at the Greeley-based Central Colorado Water Conservancy District, that’s not necessarily a surprise.
Randy Ray, executive director of the district, said farmers have already begun using comparatively new methods to stretch their water supplies and to help the soil retain moisture. These techniques, which include dramatically reducing the tilling of soils and using compost to help them retain water, are becoming more and more common, Ray said.
Irrigators also continue to call for more storage, whether it is in a reservoir or an aquifer, to give them more flexibility in how they manage irrigation water.
“I’m confident that the American farmer is going to be able to adapt,” Ray said. “It probably isn’t going to be easier and they are going to adapt with different crops and different methods of irrigation.”
Water utilities across the state have already begun analyzing what the dramatic warming trends mean for urban water supplies.
The City of Grand Junction has done forecasts that show worst-case drought scenarios could slash annual water supplies by more than half, to 6,400 acre-feet, down from the 15,000 acre-feet its system generates and stores each year. It also figures that long-term warming will drop the number by an additional 10%, according to Mark Ritterbush, Grand Junction’s manager of water services.
“By 2039, we may need to develop a different water supply in the event the worst-case scenario happens. We have the water rights, we would just need to upgrade our treatment technology to utilize those new sources,” he said.
Having more refined climate data and experts, such as those available at the Colorado Climate Center, is going to be helpful, he said.
“I feel good about [our forecast], but you never really know,” he said. “I’d like to know if that 10% we came up with is accurate.”
Jerd Smith is editor of Fresh Water News. She can be reached at 720-398-6474, via email at jerd@wateredco.org or @jerd_smith.
