New report highlights how climate change may affect water in Colorado

August 5, 2014

Aug. 5, 2014                                                 Jeff Lukas

 

            Rising temperatures will tend to reduce the amount of water in many of Colorado’s streams and rivers, melt mountain snowpack earlier in the spring, and increase the water needed by thirsty crops and cities.

            That’s according to a new report on state climate change released today by CU-Boulder’s Western Water Assessment and the Colorado Water Conservation Board,

            CU-Boulder’s Jeff Lukas, lead author of the report, says Colorado has been getting much warmer the past three decades.

Audio Clips

Audio Script

New report highlights how climate change may affect water in Colorado

Aug. 5, 2014                                                 Jeff Lukas

            Rising temperatures will tend to reduce the amount of water in many of Colorado’s streams and rivers, melt mountain snowpack earlier in the spring, and increase the water needed by thirsty crops and cities.

            That’s according to a new report on state climate change released today byCU-Boulder’s Western Water Assessment and the Colorado Water Conservation Board,

            CU-Boulder’s Jeff Lukas, lead author of the report, says Colorado has been getting much warmer the past three decades.

CUT 1 “In the past 30 years, Colorado’s climate has warmed significantly by about 2 degrees Fahrenheit.  And with temperatures going up we’ve also seen in the last 30 years more heat waves, fewer cold waves and a lengthening growing season. And in fact, 2012 was the warmest year in recorded history in Colorado.” (:20)

          Lukas says he and his co-authors used the latest climate models for the report.

CUT 2 “The climate models tell us to expect continued warming with the continued emission of greenhouse gases and other human effects. (:10) So the effects from warming, like the streamflows shifting earlier in the year, we expect that to continue. (:19) It’s very likely that the warming is causing less of the precipitation that falls to reach streams as the size of the atmospheric sponge that can take up moisture from the ground, snowpack and plants increases with warming.” (:32)

            The authors also looked at how rising temperatures will affect streamflow in different regions of the state, says Lukas.   

CUT 3 “What we see is that there appears to be a greater risk of declining stream flow in the southwestern part of the state – the San Juan and Rio Grand basins. (:11) And that’s because there’s a little greater tendency across the climate models for the southwestern part of the state to have less precipitation in the future. It’s not a given but that’s a tendency we see for a little drier outcomes in the southwest part of the state.” (:30)

            Warmer temperatures the past three decades have lead to earlier snowmelt, which is causing problems for those who manage or use water in the state, says Lukas.

CUT 4 “Farmers and other water users around Colorado have seen this themselves, that the snowmelt and the peak runoff are occurring sooner by about one to four weeks verses 30 years ago.” (:12)

            But if there is a silver lining to the report it’s this: According to Lukas, because of Colorado’s high elevations and colder winter temperatures, the negative effects of rising temperatures will not happen as quickly here as it will in other western states.

CUT 5 “Because of Colorado’s high elevations, and thus colder temperatures in the winter, we are less subject to the effects of warming on our snowpack than say California with the Sierra Nevada and the Pacific Northwest where the snow is at a lower elevation and winter temperatures are warmer. (:19) But that doesn’t mean that we are immune to these effects. They will happen more slowly, but with continued warming they will occur. (:25) We should expect not only snowmelt to occur sooner but our spring snowpack will decrease over time.” (:35)

         Read the full report at http://wwa.colorado.edu/climate/co2014report.

 

-CU-

 

Give FeedbackSee More Photos View Photo