blog.weather.us has a nice three-part article on the hydrometeorology behind the severe and likely long-term drought affecting the western U.S. I’ll admit I haven’t had time to read every word, but it looks to be well worth the read. It’s complicated if you want to get into the details, but it pretty much boils down to less rain and more evaporation.

I remember going to an American Water Resources Association specialty conference on climate change around 2011 or 2012, and listening to a speaker from Australia. The person showed data clearly showing that annual rainfall had slowly declined over the course of a decade or more and settled at a new normal. It took the political system there about a decade to accept the situation and begin to address it. The U.S. may be about where Australia was 10-15 years ago, but that is in a context of global trends that have been going downhill during that time.

I figure the west will turn to conservation and, if necessary, desalination to supply drinking water to large urban populations. Fires will just have to be accepted and dealt with. It seems to me that the long-term viability of agriculture in California and maybe across the Great Plains is in doubt, as the loss of rainfall and increased evaporation happen alongside loss of mountain ice and snowpack, and alongside a century of groundwater mining. Maybe we can move more agricultural indoors, maybe to coastal areas served by desalination plants, but we’ll have to harden those coastlines against sea level rise and increasingly severe storms. If all this comes to pass, it will cost a lot more than growing food outside in the sun, soil, and water and nature has provided mostly for free up until now. There is the question of where the energy required will come from. Food prices will go up, and unless our incomes go up along with them we will have less resources to spend on other things, making us poorer. Preservation of natural habitats will not be a priority if such a world comes to pass. And of course, in the United States and many other countries, we do not share the wealth we do have, so the poor and working class will suffer the most. Eventually this will lead to migration pressure and further strain our political system.