Climate Change Is Shrinking the Colorado River

Predicted Growth of Drought in the U. S. Southwest

GR: Here’s a helpful article that explains the drought disaster that is spreading across the southwestern U. S. There’s nothing new here, but the discussion clarifies some issues and will help you prepare for the inevitable changes. The article has an optimistic message, but the science is clear, life will become steadily more difficult in the Southwest, people will move away, and most will be gone from Arizona and large areas of surrounding states by 2100. It is inescapably obvious that we need to redirect the energy devoted to development in the Southwest and the corresponding effort to conserve water to forcing an immediate end to fossil fuel use.

Projected Drought Intensity in the U. S.

Though I believe the future for the Southwest is bleak, there is one small hope that the article contains. The Southwest could become a solar power generator that might give some of the people the financial means to survive the drought. Of course, this does nothing to protect nature and wildlife in the region. I’ve posted 43 discussions of climate-change induced drought in this blog. Click here to scroll through stories about the coming megadrought that can no longer be avoided.

“The nation’s two largest reservoirs, Lake Mead on the Arizona/Nevada border and Lake Powell on the Arizona/Utah border, were brim full in the year 2000. Four short years later, they had lost enough water to supply California its legally apportioned share of Colorado River water for more than five years. Now, 17 years later, they still have not recovered.

“This ongoing, unprecedented event threatens water supplies to Los Angeles, San Diego, Phoenix, Tucson, Denver, Salt Lake City, Albuquerque and some of the most productive agricultural lands anywhere in the world. It is critical to understand what is causing it so water managers can make realistic water use and conservation plans.

“While overuse has played a part, a significant portion of the reservoir decline is due to an ongoing drought, which started in 2000 and has led to substantial reductions in river flows. Most droughts are caused by a lack of precipitation. However, our published research shows that about one-third of the flow decline was likely due to higher temperatures in the Colorado River’s Upper Basin, which result from climate change.

“This distinction matters because climate change is causing long-term warming that will continue for centuries. As the current “hot drought” shows, climate change-induced warming has the potential to make all droughts more serious, turning what would have been modest droughts into severe ones, and severe ones into unprecedented ones.

The Colorado River is about 1,400 miles long and flows through seven U.S. states and into Mexico. The Upper Colorado River Basin supplies approximately 90 percent of the water for the entire basin. It originates as rain and snow in the Rocky and Wasatch mountains (Courtesy USGS).

 

How Climate change reduces river flow

“In our study, we found the period from 2000 to 2014 is the worst 15-year drought since 1906, when official flow measurements began. During these years, annual flows in the Colorado River averaged 19 percent below the 20th-century average.

“During a similar 15-year drought in the 1950s, annual flows declined by 18 percent. But during that drought, the region was drier: rainfall decreased by about 6 percent, compared to 4.5 percent between 2000 and 2014. Why, then, is the recent drought the most severe on record?

“The answer is simple: higher temperatures. From 2000 to 2014, temperatures in the Upper Basin, where most of the runoff that feeds the Colorado River is produced, were 1.6 degrees Fahrenheit higher than the 20th-century average. This is why we call this event a hot drought. High temperatures continued in 2015 and 2016, as did less-than-average flows. Runoff in 2017 is expected to be above average, but this will only modestly improve reservoir volumes.” –Brad Udall and Jonathan Overpeck (Much more: Climate Change Is Shrinking the Colorado River – Indian Country Media Network.)

Bolivian Water Crisis as Glaciers Vanish, Population Grows

GR:  Many places will have to begin pumping groundwater.  That’s a temporary solution, however.  Here in the arid western United States, we’ve seen what happens as the depth to water falls and the cost of pumping rises. We’ve also seen how toxic metals concentrate in shrinking groundwater aquifers.

One glacier on Chacaltaya mountain… has already completely disappeared.

“Bolivia’s government was recently forced to declare a state of national emergency — a terrible drought, said to be the worst in at least the past 25 years, plus increasing demand in the form of population growth have left the country high and dry.

“As of now, the country is trying to drill their way out the predicament with “emergency wells.” In the city of La Paz, the three main reservoirs that provide the city’s water are almost dry. It is reported that five other major cities also face severe water shortages. Hospitals are working at half capacity and suspending non-emergency surgeries and dialysis. In some poor neighborhoods taps have run dry for three weeks. The Guardian has posted a photo-essay of the situation here.

“One key aspect of the trouble is that Bolivia’s glaciers have dramatically shrank, and so the dams that rely on continuously capturing glacial run-off are rendered somewhat worthless at this point. Bolivia’s population is expected to increase by 50% (to 15 million) by the early 2040’s.” —Joe Bish, Population Media Center (Read mre here:  Bolivian Water Crisis as Glaciers Vanish, Population Grows)

Drought breaks out this fall

GR:  I recommend that you follow the continue reading link.  The figures for the country and lots of specific cities are included.

“Drought has erupted in the Southeast United States in recent months, and emerged in the central plains in recent weeks. Forest fires have dotted the Southern Appalachians. Areas not directly threatened by the fires have dealt with the downstream consequences. Many places—including here in Asheville—have seen an almost uninterrupted run of air quality alerts. My part of the country now faces some of the same challenges many Californians have been battling for several years.

How we got there

“The short version of how we got there, and this isn’t meant to sound flippant, is that it’s been dry and warm.

“Take a look at October’s “percent of normal” precipitation map. The darkest brown color painted over much of the south—and nearly all of Alabama—and parts of the central and southern high plains represents less than 5% of normal rainfall. In other words, less than one part out of twenty of October’s average rainfall. In the south, October was an exclamation point at the end of a dry stretch dating to summer.” –Deke Arndt (continue reading:  Drought breaks out this fall | NOAA Climate.gov)

Is the Usual El Nino Pacific Storm Track Being Pulled North by Arctic Warming?

Will El Niño soften the mid-latitude droughts?

GR: Scribbler is suggesting that weakening of the polar high-pressure air mass is drawing the jet stream and El Niño enriched storms farther north away from the U. S. Southwest. Thus, the three-month forecast in the map below, based on past El Niño activity, may be inaccurate.

The 2014 Mule Deer Fawn Twins

The 2014 Mule Deer Fawn Twins Sampling Fallen Seeds From the Bird Feeder.

Three years ago, deer began visiting Coldwater Farm for the first time in 20 years. This might be related to drying springs in the uplands brought on by drought and the water-table-lowering wells of the homes in the foothills. A basalt dyke forces the normally belowground flow of the Agua Fria River above ground as it crosses the farm. Besides continuous year-round flow, there are several spring-fed ponds. For the past few years, homeowners have deepened their wells, and the water level in the ponds has dropped by about 10%. Last year, some precipitation softened the drought, and upland springs are flowing again. Nevertheless, the deer have remained and have increased.

Scribbler and others believe that precipitation events in February should tell us if this El Niño will break the Southwest drought, or a poleward shift of the storms will leave it intact.

seasonal-outlook-noaa Polar Amplification vs a Godzilla El Nino — Is the Pacific Storm Track Being Shoved North by Arctic Warming?

From robertscribbler.com 

“It’s an El Niño year. One of the top three strongest El Ninos on record. The strongest by some NOAA measures. And we are certainly feeling its effects all over the world. From severe droughts in Southeast Asia, Africa, and South America, to Flooding in the Central and Eastern US, Southern Brazil, and India, these impacts, this year and last, have been extreme and wide-ranging. During recent days, Peru and Chile saw enormous ocean waves and high tides swamping coastlines. Record flooding and wave height events for some regions. All impacts related to both this powerful El Niño and the overall influence of human-forced warming by more than 1 C above 1880s temperatures on the whole of the hydrological cycle.

“Amped up by a global warming related 7 percent increase in atmospheric water vapor (and a related increase in evaporation and precipitation over the Earth’s surface), many of these El Niño related impacts have followed a roughly expected pattern (you can learn more about typical El Niño patterns and links to climate change related forcings in this excellent video by Dr Kevin Trenberth here). However, so far, some of the predicted kinds of events you’d typically see during a strong El Niño have not yet emerged. A circumstance that may also be related to the ongoing human-forced warming of the globe.”