National report tracks huge costs of climate change in Southwest

A new national climate assessment paints a dismal picture of the Southwest over the next decade, as the rapidly warming climate drives food shortages, intensifies droughts, floods, wildfires, diseases, and jeopardizes public infrastructure like roads and dams. 

The Fifth National Climate Assessment — a congressionally mandated report due roughly every five years —found that although greenhouse emissions in the U.S. are slowly decreasing, it’s not happening fast enough to limit global warming to 1.5 degrees Celsius – a threshold beyond which scientists warn life on Earth will struggle to cope.

“We need to be moving much faster and we need to go much further,” said Allison Crimmins, the director of the National Climate Assessment, during a press conference last week. 

The climate breakdown isn’t just affecting the weather, say analysts. Every region in the U.S. is also facing far-reaching consequences to their economy and human health.

In the Southwest, home to more than 60 million people, drought and rising temperatures are expected to decrease agricultural productivity, creating food shortages and higher food costs.

California, a major crop producer for the West, is particularly susceptible to these disruptions. A major drought in 2021 cost California farming sectors an estimated $1.28 billion in losses due to crop failure.

Low-income urban communities are expected to be among the first to suffer food insecurity as climate change reduces food production in the West, according to the report. 

Infrastructure 

During the 1980s, the U.S. faced a billion-dollar disaster every four months when adjusted for inflation, according to the report. The average is now once every three weeks.

Between 2018 and 2022, climate-related extreme weather events cost the U.S. at least $150 billion a year, according to the federal report released last week.

“We were seeing an increase in the number of these billion dollar weather disasters, partly because of the increase in frequency and severity of multiple types of extreme events. But we’re also seeing several of these extreme events happening simultaneously,” said Deepti Singh, a climatologist and lead author for the report.

In Nevada, an increase in the frequency and severity of climate-related extreme events are estimated to have cost the state up to $5 billion in structural damage over the last five years, says the report. 

Cost of drought and floods

In 2017, devastating floods cost Nevada over $33 million in damages to state infrastructure. In 2018, the Martin fire alone cost the state $10.3 million in damages. Flooding in Nevada this summer caused a combined $20 million in damages to state infrastructure, according to the Nevada Division of Emergency Management.

The burden of those costs in Nevada often falls on rural and tribal communities with the least resources to adapt to climate-related extreme weather events. 

Drought has intensified in the Southwest, says the report. At the same time, flooding has also increased in the region due to more intense weather events, including extreme storms and rapid snowmelt.

“We’re seeing the changes manifest in multiple aspects of the climate system. The most obvious indicator is global average temperatures, which have increased by about 2.2 degrees Fahrenheit,” Singh said. “We’re also observing increases in the frequency and severity of heavy precipitation events.

“We understand to a greater degree now that as temperatures warm, we see an increase in the amount of moisture present in the atmosphere. And the more moisture that’s present results in heavier precipitation when there are storms,tropical cyclones, or atmospheric rivers,” she continued.

In Nevada, changes to the amount of precipitation and snowmelt are disrupting water infrastructure.

Record-breaking runoff from melting snow this summer caused potentially “life-threatening” structural damage to the Weber Reservoir Dam near Schurz in Northern Nevada. Other dams in Nevada, including the Lahontan Dam, struggled to hold more water than they were designed to this summer. 

This summer Hurricane Hilary — the first tropical storm to hit Southern California in 84 years — made its way to Southern Nevada as a sub-tropical storm, where it caused intense floods and structural damage. 

Reduced snowpacks and changes to the timing of precipitation have also had a deep impact on water management and infrastructure in the Southwest, says the report.

Receding water levels at the Lake Mead reservoir in Southern Nevada have threatened water deliveries and power production at the Hoover Dam. Shrinking water supplies in the Colorado River also means less water is available for heavily urbanized and populated cities in the Southwest, like Phoenix, Los Angeles, and Las Vegas. 

Although water levels have rebounded somewhat after heavy snowpack last year, climatologists say one good water year is not enough to ensure the long-term viability of the river amid a drier future exacerbated by climate change.

Health hazards

Between 2016 and 2020, 7,687 hospitalizations in the Southwest were due to heat and heat-related illnesses, compared to 5,517 the previous five years between 2011 to 2015, according to the report.

The Las Vegas metro area experienced the hottest July ever recorded this summer, with the last two weeks of July being the hottest 14-day stretch on record, marked by an average high of 112 degrees. That same month, emergency department visits related to the heat across Nevada more than doubled, compared to the same period last year, according to the Centers for Disease Control and Prevention. 

Nevada also saw a record number of heat-related OSHA complaints in July and August from employees working through the record heatwave, some even reporting that indoor employees were collapsing from the heat.

Overall, the report predicts the Southwest will continue to experience more extreme heat waves even under the best scenarios, contributing to more illness and premature death.

The Southwest can also expect more smoggy days under climate change, leading to higher air-pollution exposure. Drier soils from drought are expected to lead to more severe dust storms and doubling deaths attributed to fine dust during the final two decades of this century. Warmer and drier conditions are also creating hotter and more severe wildfires and increasing people’s exposure to deadly particulates in wildfire smoke. 

Nevada lags in adaptation

One damning fact revealed in the report is that among the Colorado River Basin states, Nevada has taken the least action to protect the public from the impacts of climate change.

Cities in Nevada have also taken the least amount of action to protect the public from the impacts of climate change when compared to other cities in the Southwest. 

Las Vegas, as well as Reno, are two of the fastest-warming metros in the nation. 

In Southern Nevada, the most populous county in the state, up to 30% of the population has three or more socioeconomic risk factors – high poverty rates, age, and low educational attainment, for example – that would make it difficult for them to absorb, endure, and recover from climate disasters, according to the report. In Nye County, home to the growing city of Pahrump, up to 40% of the population have three or more socioeconomic risk factors.

Jennifer Helgeson, a research economist who contributed to the report, said states and cities need to have strong adaptation plans in place to “put people and communities in the best position to thrive in the face of current and future climate change.”

States and cities should aim for a more transformational systems-level approach, including improving school district cooling systems design, and design infrastructure differently, so that indoor air temperatures don’t reach dangerous levels.

“We’re taking incremental actions, but we need to move towards more transformational actions to keep pace with extreme weather and climate impacts,” Helgeson said. “I just want to really highlight the fact that if we spend the money today, there are billions of dollars to be saved later.”

Nevada has, however, made reasonable efforts to mitigate climate change through renewable energy development, low-carbon technologies, and electrification. 

Rebecca Dodder, the federal coordinating lead author for the chapter on mitigation, said the increase in actions to mitigate and reduce climate change is an important positive among the report’s grim outlooks.

“Governments, organizations, and individuals can all act to reduce emissions, and they are acting. Businesses, cities, State, and tribal governments are stepping up. The key is to start scaling these up to get to net zero emissions.”