**updated June 2025**
Lack of fresh water for agricultural use and for human consumption is a growing and very serious problem globally–including in rich countries.
Read this article (Henry Fountain, New York Times, May 24, 2018) for a look at how climate change is affecting rivers in the western United States. The Rio Grande and the Colorado, two major western U.S. rivers, are experiencing significantly reduced flows due to warmer temperatures, longer and more frequent droughts, less snow and less winter precipitation overall, and the need to serve more people. By May, stretches of the Rio Grande are often already completely dried up. “Both of these rivers are poster children for what climate change is doing to the Southwest” U.S.
These events are not a theory or a future projection, it is happening today. How can we as a society and as individuals mitigate and adapt?
See this source behind this story:
*Udall, B., & Overpeck, J. (2017). The twenty-first century Colorado River hot drought and implications for the future. Water Resources Research, 53(3), 2404-2418. [PDF] [Cited by]
“Between 2000 and 2014, annual Colorado River flows averaged 19% below the 1906–1999 average, the worst 15-year drought on record. At least one-sixth to one-half (average at one-third) of this loss is due to unprecedented temperatures (0.9°C above the 1906–1999 average), confirming model-based analysis that continued warming will likely further reduce flows. Whereas it is virtually certain that warming will continue with additional emissions of greenhouse gases to the atmosphere, there has been no observed trend toward greater precipitation in the Colorado Basin, nor are climate models in agreement that there should be a trend. Moreover, there is a significant risk of decadal and multidecadal drought in the coming century, indicating that any increase in mean precipitation will likely be offset during periods of prolonged drought. Recently published estimates of Colorado River flow sensitivity to temperature combined with a large number of recent climate model-based temperature projections indicate that continued business-as-usual warming will drive temperature-induced declines in river flow, conservatively −20% by midcentury and −35% by end-century, with support for losses exceeding −30% at midcentury and −55% at end-century. Precipitation increases may moderate these declines somewhat, but to date no such increases are evident and there is no model agreement on future precipitation changes. These results, combined with the increasing likelihood of prolonged drought in the river basin, suggest that future climate change impacts on the Colorado River flows will be much more serious than currently assumed, especially if substantial reductions in greenhouse gas emissions do not occur.“
Questions? Please let me know (engelk@grinnell.edu).
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