Earth Protect Blog

CLIMATE CHANGE ASSESSMENT

By Suzie Romig

Pilot & Today

When State Climatologist Russ Schumacher presented a preview of the Climate Change in Colorado assessment update to a conference audience in late August in Steamboat Springs, he said the statewide annual temperature has warmed by 2.9 degrees Fahrenheit since 1895 and could warm by 5.5 degrees total by 2050.

“Observations in the past decade have only affirmed the long-term trends as described in the 2014 report, more warming everywhere, in all seasons,” Schumacher presented in his take-home messages.

“The observed warming alone is already imposing reductions on snowpack, soil moisture and stream flows,” Schumacher said. “Some climate extremes and hazards have already become more frequent and intense due to warming: heat waves, drought, wildfires. Heat waves, droughts and wildfire will worsen with the additional warming. Heavy and extreme precipitation and flooding are likely to worsen as well.”

Precipitation trends and future precipitation change are less clear and certain, but the early 21st century will be drier than late 20th century, the state climatologist noted. Snow, soil moisture and streamflows are “very likely to decline further,” reported Schumacher, the director of the Colorado Climate Center and professor in the Colorado State University atmospheric science department.

Schumacher’s presentation was part of the annual summer Colorado Water Congress hosted in Steamboat. He told the audience of water professionals and guests that scientists have a “very high confidence in change” that evaporative demand in Colorado will continue to be higher and a “high confidence in change” that summer soil moisture will continue to lower, and runoff timing will be earlier. Scientists have a “medium confidence in change” that annual stream flow and spring snowpack will continue to lower in the future.

In terms of climate-related hazards and extremes in Colorado, climate scientists have a “very high confidence in change” that heat waves will continue to be more frequent and intense. Scientists have a “high confidence in change” that cold waves will be fewer, droughts will be more frequent and intense, and wildfire threat will be higher.

In an overview of 2023 so far, Schumacher noted that snowpack, or peak snow water equivalent, measured on April 1 was above average in all river basins across the state, and by May 1 the snowpack remained above average in all basins except the Arkansas. He said the winter was a top-10 snow year at most Colorado measuring stations west of the Continental Divide.

“Snowpack accumulation was especially huge at lower-elevation sites. Columbine Pass on the Uncompahgre Plateau at approximately 9,200 feet destroyed their previous record for snow water equivalent,” peaking at 46 inches from a previous high of 36.7 inches in 1993, he noted.

He said a large part of northeast Colorado experienced a record wet May, June and July. This year, Colorado stream flows were good and reservoirs recharged. “But not nearly enough water to solve the large problems in the Colorado River system,” he noted.

“The monsoon has been lacking in southern and western Colorado thus far, meaning that despite the snowy winter, drought has started to return, and irrigation needs have been high,” Schumacher noted during the Aug. 24 presentation.

The state’s 2023 Climate Change in Colorado report, which was last updated in 2014, is expected to be released in October and available at ClimateChange.colo state.edu.

The report is a synthesis of climate science relevant for management and planning for Colorado’s water resources and focused on observed climate trends, climate modeling, and projections of temperature, precipitation, snowpack and streamflow. The 2023 report will focus on the release of new climate models and how the models compare to models used in the 2008 and 2014 reports.

“The core mission of the report is to describe recent trends in Colorado’s climate and hydrology and interpret the model-based projections of future climate and hydrology,” according to the report website. “Proportionately more of this report is devoted to extreme climate-driven events — including heat waves, droughts, wildfires and floods — than the previous reports. The overall societal impacts of climate change will be driven by changes in these extreme events as well as by changes in the average climate.”

Schumacher also encouraged people to help collect precipitation data for the 25-year-old CoCoRaHS, or Community Collaborative Rain, Hail and Snow Network, by visiting the website cocorahs.org to help with the citizen scientist effort. CoCoRaHS started on the Front Range as a grassroots volunteer network of backyard weather observers of all ages and backgrounds working together to measure and map precipitation. The collaborative now has some 26,000 active observers in the U.S., Canada, Puerto Rico, U.S. Virgin Islands, Guam and the Bahamas.