California Faces “Climate Whiplash” Without Systemic Change

At the Resilient California Summit in Sacramento last week, where approximately 1,400 people gathered, the mood was one of determination as attendees confronted a harsh reality: Life in the most populous state will change dramatically because of climate change, according to the state’s Fifth Climate Change Assessment report.

Summers are projected to grow hotter, with widespread consequences, including lingering heat and disappearing snow in a state that relies on its melt for agriculture and drinking water. Thousands of lives may be lost to exposure from wildfire smoke.

“The biggest point of alarm for me is that climate change is already exacerbating existing vulnerabilities,” said Elea Becker Lowe, a study author who works at the state’s Governor’s Office of Land Use and Climate Innovation and was at the summit. “We have more frequent extremes and these major fluctuations between wet and dry. The compounding effect could be pretty burdensome.”

The report, officially released on October 19, forecasts a series of drastic shifts throughout the state between dry and wet as “climate whiplash.” The side effects are already rippling unevenly across nearly every sector of life, including ecosystems, public health, and the economy. The authors also point out that the outcomes of this whiplash disproportionately impact Native American tribes, people living near the coast, and unhoused communities. 

The State of California has released four climate assessments in the last two decades, not including this year’s. California began tracking these threats in 2006, when former California Governor Arnold Schwarzenegger signed Executive Order S-03-05, calling for regular assessments of the consequences of climate change. Following the passage of Senate Bill 1320 in 2020, the assessment is now legally mandated every five years. 

Reports like these serve an essential purpose for informing both policymakers and the public on the risks and realities of an accelerating climate crisis. Extreme flooding, drastic wildfires burning back-to-back, and a super El Niño cooking California’s coast are just some examples of why climate assessments will be needed to help ramp down the greenhouse gas emissions responsible for these events. Yet soon after his return to power, President Donald Trump dismissed the nearly 400 authors and scientists who normally administer the federal government’s National Climate Assessment reports, the release of which have been mandated by Congress since 2000 and are supposed to publish every four years. The last report was published in 2023 by the Biden administration. 

For many years, scientists have understood that gases such as carbon dioxide and methane heat up the planet. Under the United Nations Paris Agreement, emitting nations agreed to keep global warming well below 3.6°F (2°C) above preindustrial levels and pursue efforts to limit it to 2.7°F (1.5°C). This year, the United Nations acknowledged for the first time that the planet will overshoot 1.5° and issued a call to all industrial nations to take action before the crisis gets worse. 

Temperature, water, and wildfires

In California, temperatures are forecasted to rise by 3.5°F (1.9°C) by 2050. The study also poses an even higher emissions scenario, with increases ranging upward to 5.7°F (3.2°C) in the next 70 years, far above the 2° barrier established by the Paris Agreement.  

Warming conditions place extra pressure on our bodies. There may be an additional 560 heat-related deaths each year should nothing change, according to the report, generating roughly $7.7 billion in annual economic impact. People living without shelter, roughly 0.5 percent of California’s population, also account for 13 percent of all hospitalizations of heat-related illnesses.  

Rising temperatures are already reshaping California’s landscapes, from the coastline to the mountains. As oceans absorb greenhouse gas emissions, water temperatures rise and consume more space. The report projects that by 2100, sea levels could rise by 3.3 feet, exposing $78 billion worth of property and 201,000 people to coastal flooding.  

Further inland, heat is also reducing the amount of snowpack available, which plays a critical role in replenishing water supplies. The report estimates there will be a 40 percent sharp reduction in snowpack by 2041. “Precipitation is so critical for California,” said Kristina Dahl, the vice president for science at Climate Central, who was not involved in the report.  

Trees and other fauna rely on snowpack melt and can die prematurely in its absence. Farmers and agricultural workers also draw from aquifers and ground water to grow their crops, as the state often goes for months at a time without rain. Over time, more precipitation is falling as rain rather than snow in the mountains, and drastic swings, from droughts to torrential downpours, are occurring.

Dahl did caution that exact precipitation is challenging to forecast, but the state already wrestles with water loss, “What we've been seeing is you have less and less water available during the summer season when you don't have the reservoirs filling up with additional rain,” she said. 

A diminished water supply in a state as large as California will impact more than just local  ecosystems. California has one of the largest economies in the US, accounting for nearly 14 percent of the nation’s gross domestic product, according to a recent report. The Golden State generated $23.8 billion in exports in 2024 and produces nearly half of the nation’s vegetables and over three-quarters of nuts and fruits.

The agricultural industry underpinning much of California’s economy depends on an increasingly strained water supply. Between 2007 and 2009, when California faced a three-year drought, farmers over-pumped groundwater; canals and other sources were greatly depleted; crops that didn’t require as much water took on higher demand. Farmers also turned to high-value crops on certain spaces of land, known as land fallowing. Farmers pumping from depleting ground water to sustain their crops contributes to land subsidence or the ground sinking. Long term, excessive groundwater extraction can disrupt an aquifer's ability to store water and can even lead to flooding risk.  

In California’s Central Valley, a study found that around 7.06 billion cubic feet of groundwater storage was lost annually between 2021 and 2022, a five-fold increase from years prior. The loss was equivalent to 30 percent of Los Angeles’s yearly water consumption. 

The state faces numerous other climate pressures as well. In the last decade, California has faced eight of the largest wildfires in its 100-year history. The analysis found that exposure to wildfire smoke may cause an estimated 5,000 excess deaths annually by 2050, costing nearly $68.8 billion each year. People of color, immigrants, and farmworkers will bear a larger burden of these excess deaths. Farmworkers specifically are estimated to experience a staggering 190 percent increase in smoke exposure days.  

“The more we learn about exposure to fine particulate matter, or PM2.5, the more it becomes clear that there's really no safe amount,” Dahl said.  

The Palisades Fire, which was ignited by arson, and the Eaton Fire together were among the most expensive natural disasters in US history, causing an estimated $250 billion in damage and economic loss. They burned more than 37,000 acres of land. The 2025 Los Angeles fires resulted in 31 direct fatalities, according to the report. 

Adapting to climate change

The complex challenge for California will be how the state evolves in the face of climate change. “I think the reality is there's no one size fits all, and each solution needs to be really catered to the community that it's about and for,” Becker Lowe said.  

California Native American tribes have conducted restoration and cultural burning, which can reduce the likelihood of catastrophic wildfires by up to 92 percent for a decade. These practices strengthen ecosystems, communities, and California’s overall adaptive capacity, according to the report.

In 2005, California was also the first state to pass an emergency outdoor heat illness prevention standard, which became permanent a year later. By law, employers must provide drinking water, one quart per hour per worker. Once temperatures breach 80°, there must be shade available and a five-minute break allowed upon request. In addition, employers must generate a plan for grappling with heat. 

“As the Trump administration turns its back on science, California is doubling down on climate action, on protecting our communities, and on building a safer future. We are putting the latest science to work so communities across the state have the tools to confront the climate crisis head on,” said California Governor Gavin Newsom in a statement. 

Leaving the summit, Becker Lowe hopes that reports like these will move people to implement change. “I’ve seen so many folks come forward to try to solve the problems and apply new solutions,” she said. “We're on that path towards resilience. There's big challenges, but I have a lot of hope.”