more from the same article...
Today, modern agricultural practices diminish the wholesale drying experienced during the Dust Bowl, but extreme drought persists in the West. This is because the average temperature in the West has warmed at nearly twice the global average according to the Rocky Mountain Climate Change Organization. (8)
There are a few more things I need to mention to drive home the significance of the 10 percent reduction in stream flows. One is timing. The modeling shows that spring, summer and fall see a greater reduction in flows in most places than in winter. In many places, more mountain precipitation is now falling as rain in the winter, and this will increase. More runoff in winter means less snowpack, less water slowly percolating down into the aquifers, lower aquifer levels and a longer evaporation season as the snowpack disappears early. (9)
Compounding the increased length of the evaporation season, a little more warmth means a lot more evaporation. It is not a one-to-one relationship. The impacts are compounded in one more way. In the high country where most of the West gets its water, a little warming, and its corresponding evaporation, takes water that should slowly melt and feed aquifers or run off into reservoirs and evaporates it directly into the sky.
Another confusing aspect of this work is that numerous places in the press releases, and in the findings themselves, tell us and show us in graphic form that not all seasons in all areas experience drying and increased evaporation. The Columbia University press release tells us that, "The Colorado headwaters are expected to see more precipitation on average," and the NOAA Climate Variability and Predictability Program press release at Columbia tells us that, "Despite the fact that precipitation might increase in some regions and seasons (e.g. winter in northern California)." The most telling example of this climate confusion comes at the bottom of the Columbia University press release. This statement by Mingfang Ting, one of the paper's authors and a specialist in precipitation extremes, tells us: "For Texas, the models predict that precipitation will decrease and evaporation rates will also go down in spring and summer, but only because "there is no moisture to evaporate." (10)
Climate scientists have been pulling this alarm for 20 years. It is real - the building is on fire. To pull the fourth alarm on this one: Truthout wrote Professor Seager and asked him to confirm the assumption that natural drought cycles would add to or be on top of the projected megadrought drying. He confirmed, adding, "For the next one to three decades, results are not greatly different across the [different scenarios] because so much of what will happen is already in the pipeline, so to speak."
What does this mean? It means that even the best-case scenario that the IPCC is now considering results in an outcome that is the same, or "not greatly different," from the worst-case scenario of the new IPCC scenario family, for the next 10 to 30 years.