Glorious, fluffy snow. We appreciate it for its beauty, fear its onslaught in blizzards, and rely on it for a lot of our water supplies, especially here in the mountain West.
In New Mexico, we’ve seen the Rio Grande dry up or surge, depending on what snow fell in the previous winter. Hmm, not even our snow, really; 75% of the Rio flow is snowmelt from the Rockies of Colorado.
Lots of snow means good flow here for our farms and cities, and too little means watering restrictions and some dying orchard trees. The snow amount goes up and down between years, and climate change is making the amount more erratic yet – or even just less.
There’s another effect of the warming of the climate – less snow and more rain, that is, a greater fraction of yearly precipitation as snow. That’s a problem. Snow stores itself and melts over months. Rain does not store itself. It runs down the rivers and gives us water to be dumped, or, worse, floods, landslides, and soil erosion.
The problem is global. Mohammed Ombadi and colleagues at Berkely and the University of Michigan studied rainfall extremes over the northern hemisphere above the tropics. They find that the risk of extreme rainfall events is growing. It will be about 5x higher almost everywhere by the end of the century relative to historical records. Their models at least can help us predict the risk and prepare ourselves.
This has been an outreach activity of the Las Cruces Academy, viewable at GreatSchools.org
