Dust, Snow, and Water

Dust, Snow, and Water.

My last blog on population and land use was partially motivated by a recent paper in Geophysical Research Letters on the role of dust in accelerating snow melt in the Colorado mountains. The article is by Thomas Painter and co-authors, and here is a link to the abstract . The gist of the article is that dust landing on the snow can accelerate the melting of snow and reduce the annual snow cover duration by 18 to 35 days. This is a detailed study of the San Juan Mountains.

The source of the dust is convincingly linked to the Southwest U.S. and is related to the expansion of grazing, recreation, and agriculture. This is, of course, first and foremost a decision of land use, which is related to population pressure on the land. There are similar examples around the world, and the water supply of more than 1 billion people is directly linked to mountain snow packs.


The investigation by Painter and co-authors is the type of investigation that often gets wrapped up into the whole discussion on climate change. A warming globe would accelerate the spring snow melt. If you are predisposed to argue, this could evolve into climate change versus farm dust. In the spirit of scientific investigation, this becomes a course of study--how do you separate the potential climate change signal from the dust signal? (I'd be glad to hear reader proposals.)


Some of the responders to the last blog brought up the work of Jared Diamond . His two books Collapse and Guns, Germs, and Steel are provocative studies of how humans have evolved with their environment.


I want to try to combine the ideas from the paragraphs above. We are faced with many choices. We can use Diamond's work to show that what happens to us is, at least at times, related to the decisions of how we value our environment. We can use the work of Painter to see that if we were to change our practices of plowing and recreation and grazing, we could impact the stability of the water supply for billions of people. This might not stop climate change, but it would help us adapt--it would keep us from, essentially, accelerating the impacts of climate change. (It also opens up other paths for adaptation.)

It would be in the spirit of some of my readers, and perhaps me at times, to say that the pressure of population will ultimately overwhelm any efforts of adaptation. NPR is running a series called Climate Connections, and a recent entry was on the return to trees in Niger. Niger is one of places which suffers from severe desertification. The return of the trees can be directly linked to planting and the development of practices that allow the trees to grow.

We can make a difference. Again, we can argue over detection and attribution. We can argue about the economics of it all. We can recognize the role of population and standard of living. We can look at the past and decide that we are doomed. Or we can look at the past, and the fact that we have useful predictions for the future,meaningful ways of adaptation and mitigation, and decide that we can do something about it all.

Stabilizing Sand dunes: From United Nations Convention to Combat Desertification