Grand Junction
Climate Change Daily Earth Science Repost

Climate Change Goes Local – Day 2: Hot and Dry

Grand Junction

The old adage “all politics are local” might be rewritten as “real climate change is personal.” The front line of climate change adaptation is formed in local communities as their way of life is challenged by environmental stress. They don’t have the luxury of pondering the grand scheme of global warming or rising sea levels because they are too busy coping with the fallout of climate change in their daily lives. We will take a look at three geographically and culturally different localities, and the breadth and scope of issues they face as the future arrives at their doorsteps. Yesterday was Miami and today is Grand Junction.

Grand Junction: Hot and dry

The confluence of the Gunnison and Colorado rivers marks the location of Grand Junction. Situated in Western Colorado, near the Utah border, the city lies in the bullseye of a regional heat anomaly. Maps showing global temperature changes highlight this area as a blister of heat stretching as far west as Moab, and north to the Wyoming border. While the planet has warmed by one degree Celsius since 1895, this area has seen temperature increases of up to 2.4 degrees Celsius.

The heat has consequences and starts its own feedback loop. Brad Udall, a scientist at Colorado State University, said, “Heating begets drying, and then drying further begets heating.” Hot and dry has been the trend for over two decades now, and a lack of moisture is stressing the whole region. The Colorado River is running dry. Winter snowpacks are becoming low to non-existent some years, and without the spring and summer meltwater, the complex system of irrigation for local farmers breaks down.

Paul Kehmeier, a local sixty-something farmer, has watched the changes. He notes his usual crop of 350 tons of hay was reduced to 35 tons in 2018. Without the snow, many farms will come to a standstill. This regional hotspot in western Colorado is one of the causalities from a two-decade megadrought, which is slowly bringing much of the American West to its knees. (See Juliet Eilperin’s excellent article “This giant climate hot spot is robbing the West of its water”)

Megadrought

The western USA is hot, dry, and parched after two decades of drought. But the situation may get worse before it gets better. The science behind the current drought research lies in counting tree rings. Dry years show up as patterns of thinner, compacted tree rings, so historic droughts appear in the natural records of tree growth. The rings tell us the last megadrought in western America ended before the Pilgrims landed in 1620.

Tree ring data takes us back 1200 years to the first recorded megadrought in the 800s, during the Medieval Era. This long period of severe drought was a harbinger to repeated dry spells in the 1100s, 1200s, and 1500s. These droughts tie into the collapse of the North American Anasazi culture, and the downfall of civilizations in Mexico.

The bad news is that megadroughts last for decades, and climate change is exacerbating the dry conditions. The current drought started in 2000, and the period between 2000 and 2018 was the second driest 18-year period on record since the 800s.

Colorado River

The Colorado River passes through Grand Junction on a 1450-mile journey from its headwaters in the Rocky Mountains to the Gulf of California. In its natural state, this river delivers about 22,500 cubic feet per second of flow. However, today, waters from the Colorado River are lucky to make it to their final destination in the Gulf of California.

The Colorado River provides water for some 40 million people. Also, it provides irrigation for 5.5 million acres, and 4,200 megawatts of hydroelectric power generation capacity. The dams for these hydroelectric power plants and other storage dams hold up to four years of average annual river flow and serve as a flow stabilization system. But the demands on this river now exceed its annual flow capacity.

From 1999–2004, Lakes Powell and Mead on the Colorado River (two of the largest reservoirs in the USA) lost half their water. This lost volume represented enough water to sustain Las Vegas for 80 years. When the rain and snow don’t fall, the impact on local farmers and residents disrupts their way of life and forces unwanted changes.


Sources:

This giant climate hot spot is robbing the West of its water (By Juliet Eilperin; Washington Post)

Megadrought Conditions Not Seen for 400+ Years Have Returned to the West, Scientists Say (By Kevin Stark; KQED)

The American West May Be Entering a ‘Megadrought’ Worse Than Any in Historical Record (By Brian Handwerk; Smithsonian Magazine)

About 40 million people get water from the Colorado River. Studies show it’s drying up (By Ian James; USA Today)

Climate change is drying up the Colorado River, putting millions at risk of ‘severe water shortages’ (By Drew Kann; CNN)

Feature Image: Grand Junction Skyline (Modified by ArcheanWeb) –   By Eleaf – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7026126

William House
William is an earth scientist and writer with an interest in providing the science "backstory" for breaking environmental, earth science, and climate change news.