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Climate Projections for Eagle County, Colorado

Eagle County, Colorado, will see many more extremely hot summer days by mid-century, with even larger increases later, unless global heat-trapping emissions are sharply reduced, according to a new analysis by the Rocky Mountain Climate Organization released on August 23, 2020.

As examples, in the Edwards/Avon area, the median projections with continuing high emissions are that days 85° and hotter per year:

  • In typical mid-century years, would average 16 days—compared to an average of one per year in a baseline period of 1970–1999.
  • In typical years late in the century, would average 60 days—two months’s worth.

The RMCO report also identifies the projected frequency of 85°-plus days in the hottest year in each 20-year period:

  • In the hottest year in mid-century, those hot days would occur 43 times—a month and a half’s worth.
  • In the extreme year late in the century, they would occur 88 times—a full summer’s worth.

Another measure of how much hotter Eagle County could get is the projected hottest day of the year. Also in the Edwards/Avon area, and also with high emissions, the hottest day of the year:

  • In typical mid-century years, would average 90°.
  • In the extreme year in mid-century, would be 95°.
  • In typical late-century years, would average 96°.
  • In the extreme year in late century, would get as hot as 101°.

There is good news, too, from this analysis—it also shows how completely the above changes can be avoided if global emissions of heat-trapping pollution are sharply reduced. With very low future emissions, 85°-plus days in the Edwards/Avon area are projected:

  • In typical years in 2020–2039 in typical years, to average five such days per year.
  • Then not to increase any further, also averaging five such days for the next 40 years, and dropping to four days a year in 2080–2099.

The report was commissioned by Eagle County and the Northwest Colorado Council of Governments Water Quality/Quantity Committee (QQ).

Kathy Chandler-Henry, Eagle County Commissioner and QQ Chair said, “Our last couple summers have been unlike any we’ve seen here before, with record-breaking heat, wildfires, and mudslides.”

Matt Scherr, Chair of the Eagle County Commissioners added, “This report confirms the importance of the work we continue to do in Eagle County to promote sustainability, because if we don’t bring down emissions things could get an awful lot worse.”

Stephen Saunders, the president of RMCO, said, “These numbers show both how much Eagle County has at stake as humans continue to change the climate and how much difference climate protection actions can make to head off unacceptable changes. And this will be of interest in other Colorado mountain communities with similar elevations, because they can expect similar changes, again depending on future emissions.”

In addition to identifying projected changes in summer heat, the report details how many fewer days below freezing there could be in winters, how many more 40° days there could be at the end of the snow/ski season, and how much more frequent intense rainstorms and snowstorms could become. The report, “Climate Projections in Eagle County, Colorado,” is one of the most detailed studies yet done of how climate change may affect a particular locality. It analyzes 24 million individual projections of daily high temperatures, low temperatures, and precipitation amounts:

  • using four different scenarios, ranging from continued high emissions of heat-trapping pollution to very low future emissions;
  • derived from 12 to 20 global climate models per emission scenario;
  • downscaled to produce local results for three specific areas in Summit County; and
  • covering four 20-year periods (2020–2039 through 2080–2099).

RMCO today also released a companion report with similar analyses of climate projections for locations in Summit County.

Explanation of above figure

The figure above shows the projected average number of days 85° or hotter in the Edwards/Avon area in Eagle County, Colorado. On the left for context is shown the average number of such days in 1970-1999, which was one day per year. On the right are climate model projections for four 20-year periods, and within each period for four possible levels of future emissions of heat-trapping pollution. The columns show the range of the middle 80 percent of projections from multiple climate models (the brighter colored portions of the columns) and the medians (the numerals) of all projections.

Links

The full report on the Eagle County climate projections.

A 4-page summary of the projections report.

A news release on the release of the report.

Spreadsheets of full results on both heat and precipitation projections from the analysis, for each of the three individual grids in Eagle County considered in the analysis: