Global Heating Will Make Colorado River Basin Drought More Severe

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A person can survive 30 days (or more) without food, 3 days without water, and 3 minutes without air. The latest climate research indicates all three will be in short supply as average temperatures on Earth increase. Hotter, drier conditions will reduce harvests, constrain water supplies, and make it more difficult to breathe. Great thinkers like Rex Tillerson say we will adapt, but he and his climate change denier friends fail to appreciate what that adaptation will involve.

For instance, some 50 million Americans rely on water from the Colorado River Basin. Cities like Las Vegas, Phoenix, and Los Angeles simply would not exist without it. Yet the amount of water flowing into the Colorado River from the surrounding watershed is decreasing year by year. According to AZCentral, Lake Powell, the body of water created by the Glen Canyon Dam, is now just 42% full. Downstream, Lake Mead, created by the Hoover Dam, is just 39% full.

Andy Mueller, general manager of the Colorado River Water Conservation District on the western side of the Rocky Mountains in Colorado, says the reduced amount of water flowing into the basin combined with the catastrophic forest fires that swept through the region offer a preview of what the region should prepare for in the future. “Climate change is drying out the headwaters and everybody in the Colorado River Basin needs to be concerned,” he says.

Mueller saw the effects while backpacking in Colorado’s Holy Cross Wilderness this summer with his 19-year-old daughter. Above the tree line they expected to see mushy green tundra. Instead, they found the ground was bone dry. When the fires erupted, they burned intensely, ravaging forests that once were dubbed “asbestos forest” because they stayed moist and historically didn’t burn. “That’s what this year wrought upon our natural systems up high. And what that meant is that down below that, the humans who depend upon the flow didn’t have the water that we need. We’re really seeing the effects of climate change hit locally in the Upper Basin incredibly fast and incredibly hard,” he says.

Water Rights And Contractual Priorities

Access to the water in the Colorado River is controlled by the Colorado River Compact which went into effect in 1922. That compact and subsequent agreements have created a hierarchy where some downstream users have greater rights to the water than those upstream who have so-called junior rights. The possibility that senior water rights holders could legally demand more water from upstream communities probably never occurred to the people who crafted those agreements long ago when LA, Phoenix, and Las Vegas where just small frontier communities but that is the prospect facing those junior water rights holders today.

One suggested solution is similar to the arrangements that are becoming common among electrical grid operators. In exchange for monetary considerations, some water users could agree to reduce or eliminate their usage for a few hours, a few days, or a few weeks. Managing the water in that way is a novel idea compared to earlier times when there was all the water anyone could ask for and more.

Critical water shortages were never fully anticipated and now that they are here, disputes among the communities who rely on the Colorado River for their drinking and irrigation needs are far more likely to occur. “We’re bound by that river,” Andy Mueller says. “All of us, regardless of our legal rights, regardless of what’s on paper, we need to consider how we can use less water. And we need to take action immediately.”

Temperate Zone Moves North

New research by the Rhodium Group and published by ProPublica projects that as average global temperatures rise, the temperate zone that currently covers most of the American Midwest — the place that grows much of the food America and the world consumes — will move north. Eventually the growing conditions that make corn the staple crop of Iowa may turn Ontario, Manitoba, and Saskatchewan into the “bread basket of the world.” Stop and think what that may mean for trade relations between the US and Canada and how Canada might react to an influx of immigrants from the US.

That study also predicts an increase in average daily temperatures and humidity could render many parts of the US uninhabitable by humans. Why? Because as humidity rises, the ability of the human body to cool itself by sweating decreases. At some point, the combination of those two factors will make it impossible for people to regulate their bodily temperatures enough to avoid heat stroke and cardiac stress.

The standard joke in Arizona is it’s hot but it’s a “dry” heat. Evaporative rooftop coolers are popular in an area where average humidity is often less than 10%. Once humidity levels start rising, those coolers will no longer provide the same degree of cooling and the people who rely on them will begin to suffer. According to Channel 12 News in Phoenix, the Rhodium Group report finds 6 counties in Arizona — including Maricopa County, home to the greater Phoenix megalopolous — may be uninhabitable within 30 years.

“One of the things that stands out in the Southwest, which I think we already know, is the heat being the overriding risk,” says Michael Crimmins, a professor of applied climatology at the University of Arizona. “It’s getting warmer, it’s largely attributable to climate change, and it’s something we’re going to have to deal with in the near future.”

Channel 12 News reports that numerous heat records were broken in Arizona last summer when the state recorded the hottest summer on record, one that had the most number of 110º  and 115º days. The Rhodium Group study projects that rising temperatures in Arizona will become more common, which will have an impact on its agricultural production. Some Arizona counties, including Maricopa County, will experience daytime temperatures above 95º for more than half the year, according to the study.

Back To The Future

Climate deniers like to trumpet the fact that the Earth has gone through many warming and cooling cycles and that drought conditions have prevailed in many places over time. They are correct. The Earth’s climate is not a static thing. There is evidence that Antarctica was once a verdant tropical rain forest — 90 million years ago. So if you’re comfortable waiting several million years for the Earth to stop heating up and return to the comfy temperatures prevalent a century ago, there’s absolutely nothing to worry about. If, on the other hand, you think your kids and their kids should be able to live and thrive where there parents and grandparents did, things are looking mighty bleak.

Matthew Lachniet, a paleoclimatologist at the University of Nevada in Las Vegas, has done a study of stalagmites found in caves in the Colorado Basin in Nevada. Uranium dating can identify the age of various levels of the icy fingers and further analysis can determine wet or dry periods in that historical record.

A report in the Mountain Journal, a content-sharing partner with InsideClimate News, says the research by Lachniet an his team validate a period of aridification between 9,800 and 5,400 years ago as the western Pacific warmed up and as sea ice declined in the Arctic because Earth’s orbit shifted. Lachniet says those same regional conditions — the warming Pacific and shrinking sea ice — could be expected to prompt a return to drought conditions in the Southwest because of the warming that results from burning fossil fuels. He adds that not only is Nevada expected to become warmer because of these trends but so are the Colorado Rockies and parts of the headwaters of the Colorado River. That loops back to the diminished amount of water in the Colorado River Basin reported by Andy Mueller.

Prior to the 4,400 year long drought, the Indigenous people in the area enjoyed a lifestyle that centered on abundant supplies of fresh water. As the drought progressed, they were reduced to subsisting on the seeds extracted from a desert plant known as pickleweed. So if you want your grandkids to subsist on pickleweed seeds, climate change need not concern you at all. Just keep voting for people who want to reduce government regulations and are more worried about using lots of hot water in the shower than preventing a climate catastrophe. By the time any of this happens, you’ll be dead, so why should you interrupt your comfortable lifestyle to benefit future generations? Let them solve their own problems. That’s the conservative way.

With these new studies confirming that hot, dry periods can last thousands of years, it may be time to rethink water use strategies for the more than 50 million people who rely on water from the Colorado River and the Rio Grande basins, Lachniet writes in his research report. “What we’re seeing is that temperatures are going to increase and that ends up producing much more evaporation, more loss of water from the reservoirs, a greater demand for water in agricultural systems where people are pulling in that water for use on their crops. So even in the absence of any change in the amount of precipitation, we would expect to have more water scarcity in the future under those warmer conditions.”

“Looking to the past to inform the future could help narrow uncertainties surrounding projections of changes in temperature, ice sheets and the water cycle,” says Jessica Tierney, an associate professor in the geosciences department of the University of Arizona, lead author of a new research paper published in the journal Science. “If your model can simulate past climates accurately, it likely will do a much better job at getting future scenarios right.”

Using past history to improve the accuracy of future predictions? Yes, please. More of that, thank you very much.