Dust-laden snow May 19 on Rocky Mountain peaks south of Montrose, Colorado. Photo: Dennis DImick (click to enlarge.)
I've been in Colorado the past few days, participating in a symposium on food at Mountainfilm Telluride. Last year we discussed water, and energy was our focus in in 2007. Among speakers this year were writer Bill McKibben, soil scientist Jerry Glover of the Land Institute, plant geneticist Pam Ronald of UC-Davis, and Roz Naylor, who heads the food security and environment program at Stanford. A report on the forum from the Telluride Daily Planet is here: The Future of Food: Daunting but Doable.
The film Food,Inc., shown at the festival and scheduled for nationwide release in June, will get some attention here soon. Documentary filmmaker Ken Burns also premiered his elegant new 12-hour film on the National Parks at Mountainfilm. The series will air on PBS this fall.
One scene repeatedly mentioned indoors was on colorful display outdoors in the mountains above this southwest Colorado town. The snowpack, or what remains of it, looks pink. The color comes from repeated dust storms this past winter and spring.
Red-colored dust arrived as clouds from repeated blow-ups in the red rock areas of Utah and Arizona. The dust darkens snow and increases its melt rate. Early snowmelt and runoff from the mountains reduces the amount of water available in streams later in summer for irrigation and other uses.
The impact of dust on snow has gotten some attention in the scientific community. A study two years ago by the National Snow and Ice Data Center indicated that rising temperatures across the West are increasing the likelihood that dust storms will become more frequent, shorten the snowpack season, and affect timing of runoff in rivers and soil moisture in the mountains. The water will come off the mountains earier in the spring, and mountains soils will dry up sooner in the summer.
April 3, 2009 dust storm in northeast Arizona. From NASA Earth Observatory.