Fossil Fuel Emissions Worsen Western US Drought Crisis, Study Finds

Climate change has significantly worsened drought conditions in Western U.S. states, with a new report attributing 36 percent reductions in snowpack and 13 percent decreases in streamflow—along with one-tenth of groundwater loss in California’s Central Valley—to emissions from fossil fuel companies and cement manufacturers.

The findings, published Thursday by researchers at the University of California, Merced, and the Union of Concerned Scientists, highlight the disproportionate role of industrial pollution in accelerating water scarcity across the region. The report states that fossil fuel and cement industries have contributed to more than half of the observed climate impacts on Western water supplies.

Aaron Regunberg, director of Public Citizen’s Climate Accountability Project, emphasized the long-term consequences of corporate emissions. “Millions of Americans are facing historic water scarcity,” he said. “A small number of fossil fuel companies are responsible for a significant portion of this crisis—and they knew the risks decades ago.”

Internal company documents from as early as 1988 show that major corporations such as Shell recognized that burning fossil fuels would alter precipitation patterns and threaten water supplies, food security, and living standards. Despite this awareness, the industry spent years denying climate science and opposing regulatory action.

The report underscores the need for accountability, calling on fossil fuel companies to address the damage caused by their operations. Researchers estimate that emissions from these industries have directly led to measurable declines in critical water resources, threatening agriculture, ecosystems, and urban water systems across the West.

Meanwhile, water management experts warn that without rapid reductions in greenhouse gas emissions and stronger conservation measures, drought conditions will continue to intensify. The findings add to a growing body of evidence linking climate change to extreme weather events, including prolonged dry spells and reduced snowmelt, which are vital for replenishing rivers and reservoirs.

This study arrives as Western states grapple with persistent droughts, strained water supplies, and increasing pressure on agricultural and municipal systems. Scientists have long projected that rising global temperatures will reduce snowpack and alter precipitation timing, but this research quantifies the direct contribution of specific industrial sectors to those changes.

The report calls for stronger climate policies, including stricter emissions regulations and investment in sustainable water management strategies. It also highlights the broader public health and economic risks posed by water shortages, from food price inflation to ecosystem collapse.

In response to the findings, advocates are urging policymakers to hold fossil fuel companies accountable and accelerate the transition to renewable energy. Public Citizen and other environmental groups are pushing for legal action and regulatory reforms to address the documented harms.

“These companies knew what they were doing,” Regunberg said. “They lied to the public, delayed action, and profited from a system that is now pushing millions toward water insecurity. The time for accountability is long overdue.”