New West: We, and much of the West, are locked in a mega-drought

August 15, 2022

Montana Economy

Comments Off on New West: We, and much of the West, are locked in a mega-drought


By Todd Wilkinson EBS Columnist

We live in a time where some people would rather ignore the dots than start connecting them, or ponder the meaning of cause and effect, or believe that denying science is a less anxiety-inducing undertaking than seriously considering what which is before us.

Sometimes it’s hard to gauge what’s going on when you’re in the middle. Consider the indicators:

Regular and increasing summer tawny owl fishing and floating restrictions on our rivers; algae bloom on the lakes and even in the Gallatin. Although our immediate area has so far avoided large fires this summer thanks to a cool and wet late spring, we are by no means out of the woods.

Two years ago, a Labor Day weekend wildfire near the M Trail in Bozeman overtook the Bridgers and destroyed 68 structures, 30 of which were homes in Bridger Canyon. And this November, the Porcupine Fire burned down nearly 700 acres near Big Sky. Last summer the Shedhorn Fire up Taylor Fork south of Big Sky burned 75 acres and firefighters contained a burned tree on the South Fork loop. Currently, a dozen wildfires are burning in Montana.

Whitebark pines, whose cone seeds are an important source of nutrition for grizzly bears, continue to die off and are now being considered for listing under the Endangered Species Act. The melting of the mountain snowpack usually occurs earlier. Wetlands dry up and disappear. Average temperatures are rising.

Last summer, a peer-reviewed analysis published in the journal “Science” suggests that much of the West, including southwestern Montana and much of Wyoming, is not suffering the consequences of a drought, but mega-drought. The study is titled “Great Contribution of Anthropogenic Warming to an Emerging Megadrought in North America.”

While the impact is most pronounced in the desert and far western states, the tentacles reach right into our backyards in the Greater Yellowstone ecosystem.

“Severe and persistent 21stThe drought of the last century in southwestern North America motivates comparisons with medieval mega-droughts and questions about the role of anthropogenic factors. [human-caused] climate change,” write the nine authors. “We are using hydrological modeling and new reconstructions of 1,200-year-old tree rings, thus summer soil moisture, to demonstrate that the 2000-2018 drought was the second driest 19-year period since 800, surpassed only by a mega-drought of the late 1500s.”

Based on 31 different climate models, researchers believe that humans releasing more carbon dioxide into the atmosphere are changing weather patterns and ocean water temperatures, resulting in less humidity, lower humidity and warmer temperatures.

According to them, human-caused climate change has helped turn what would normally be a drought event into a prolonged mega-drought.

One of the tools used to compare hot, dry periods of the past with the present are tree rings that allow scientists to go back in time. Outside of deserts, and particularly in forested areas, the researchers note that drought conditions are aggravated by drying of soils in summer, driven by human-induced warming via increased water evaporation and early loss of snow cover.

One way to think about it is this: a ski area can have a lot of powder in February, but if warmer temperatures cause it to melt earlier and the summer humidity doesn’t materialize or the rains are offset by scorching temperatures, the soils are drying out.

When soils dry up, grasses and forests dry up and become very vulnerable to fire, whether caused by lightning or man-made. No forest thinning will stop the drying out of the soil; in fact, logging, other studies note, can make matters worse.

In Greater Yellowstone, including the foothills of the mountains around Bozeman, Big Sky, Paradise Valley, and in the Tetons, thousands of homes have been built on the edge or inside the forests. Policy experts say they are the equivalent of people building homes in the floodplains of rivers or along ocean coasts where hurricanes roar ashore.

In many areas, insurance companies are either requiring homeowners to pay extremely high premiums or have announced that they will no longer pay damage claims to homeowners who choose to build in at-risk areas.

On top of that, firefighting costs are often borne by all US taxpayers. In recent years, these costs have consumed half of the US Forest Service’s budget, with a huge percentage related to defending structures on private land.

At the same time, the agency has faced unprecedented reductions in staff responsible for scientific research and wildlife stewardship, backcountry management, trail maintenance, law enforcement, monitoring livestock grazing allocations and restoration work.

While climate change means huge challenges related to fires and loss of property (including health issues from smoke), water availability, rangeland for wildlife and livestock , to agricultural production and the economy of outdoor recreation, in the desert southwest, it can be even more serious.

Tens of millions of Americans depend on melting snow and precipitation that comes from the Rocky Mountains and then, via river systems like Colorado, is tapped into states like Utah, Arizona, New Mexico, Nevada and California downstream.

Lake Powell, a federal water supply project in southern Utah that was touted as an insurance policy against droughts and a source of economic prosperity through land development, crop irrigation and recreation, suffers from a “20-year drought” – the last 10 whose years have been described as extreme. This summer, water levels could reach 3,540 feet above sea level at Lake Powell, the lowest since 1968.

Experts say that today water has been over-allocated, meaning more has been allocated to different user groups than is generated in the system, especially during droughts. Although the transfer of agricultural water rights has bought the states of the Upper and Lower Colorado River Pacts time, many believe it is borrowed time.

Last summer, Montana State University’s Dr. Cathy Whitlock, Scott Bischke and others released the first-ever assessment that examines the ecological impacts of climate change on Greater Yellowstone. Look up. Analysis is another opportunity to connect the dots of scientific reality.

Todd Wilkinson is the founder of the Bozeman-based Mountain Journal (mountainjournal.org) and a correspondent for National Geographic and The Guardian. He is the author of numerous books, including his latest, “Ripple Effects: How to Save Yellowstone and America’s Most Iconic Wildlife Ecosystem”, available at mountainjournal.org.

This column has been updated from the original version published in EBS in April 2021.