Climate and environment updates: Fires would have been extreme without climate change

In a new quick-turn analysis, UCLA climate scientists found that climate change could be responsible for roughly a quarter of the extreme vegetation dryness present when the Palisades and Eaton fires began. But they say the fires would still have been extreme even without that moisture deficit.

"We believe that the fires would still have been extreme without the climate change components noted above, but would have been somewhat smaller and less intense," the team noted.

The climate scientists at UCLA's Climate & Wildlife Research Initiative considered what contributed to the fire "to quantify how unusual these factors are, in the context of the natural weather and climate variability."

The researchers examined the intense summer heat, drought and extreme precipitation that impacted the region in recent years. They concluded that the unusually warm temperatures during the summer and fall of 2024 are the most likely way climate change could have helped intensify the wildfires by lowering fuel moisture in the region.

However, the analysis found that this stretch of unusually warm weather was likely not the primary driver of the extreme vegetation dryness that was in place at the time of the wildfires.

Researchers point to the lack of early wet season precipitation as the main contributor of the extremely dry fuels, estimating that about 75% of the dryness was due to lack of rain and roughly 25% attributed to the stretch of anomalous warmth. They say the current rain deficit is more likely due to California's highly variable natural climate rather than human-amplified climate change.

"As I've often said, no one claims that climate change directly causes natural disasters. Instead, we highlight that human-caused climate change amplifies these events. As this issue becomes more pronounced, it's essential that we focus on mitigation, adaptation, and planning for the warming that is already inevitable," explained Ginger Zee, ABC News chief meteorologist and chief climate correspondent.

Based on their findings, the research team recommends aggressively suppressing fire ignitions when extreme fire weather is forecast, making homes more fire resistant, and building new units in low wildfire risk zones.

The analysis has not been peer-reviewed and additional findings are likely to emerge as new studies are completed.

-ABC News Climate Unit

The devastating wildfires in Southern California were fueled by a perfect storm of weather and climate factors. While the exact causes of the fires are still under investigation, the conditions that led to their rapid spread are a combination of a lots of rain followed by extreme dryness and powerful winds. We also know that climate change is amplifying the intensity and destructiveness of wildfires in general.

After a period of massive amounts of rain and flooding, Los Angeles has only seen 0.16 inches of rain since May 6, leaving the region exceptionally dry and filled with fuel for potential fires. But dryness alone wasn’t enough to create the chaos. An extraordinary mountain wave wind event, with gusts reaching 100 mph, spread the flames uncontrollably. At that point, firefighters were not going to be able to stop them.

The National Weather Service had warned of these conditions 36 hours before the fires began, calling them “life-threatening and destructive.” Unlike a similar wind event in 2011, this year’s extreme dryness and a unique atmospheric setup made the winds even more devastating, spreading fires to areas not typically impacted by those weather conditions.

While climate change’s exact impact on these fires is still under study, scientists agree that along with rapid urbanization, human-amplified climate change is intensifying dry-wet cycles that increases vegetation growth followed by extreme drying. This hydroclimate whiplash, along with more extreme heat, is contributing to wildfires being larger and more destructive.

-ABC News Chief Meteorologist and Chief Climate Correspondent Ginger Zee, ABC News meteorologist Dan Peck, ABC News Climate Unit’s Matthew Glasser and ABC News meteorologist Dan Manzo

Scientists know that human-amplified climate change is increasing the frequency and intensity of many extreme weather events, but our changing climate could also be making wild weather swings more common and more extreme, according to new research published in Nature Reviews Earth & Environment and the Fifth National Climate Assessment.

For example, moving from devastating drought to record-breaking precipitation, or vice versa.

Parts of the world, like the southwestern U.S., historically experience highly variable weather and climate conditions, typically shifting from periods of very dry to very wet weather. However, in recent years, the rapid succession of extreme droughts, wildfires and floods has significantly impacted these regions, prompting scientists to look closely at how global warming affects climate variability.

The new research, which involved UCLA and UC Agriculture and Natural Resources, further investigated this variability, focusing specifically on hydroclimate volatility. Hydroclimate volatility is sudden, large and/or frequent transitions between arid and very wet conditions.

Researchers found that this volatility, also known as "hydroclimate whiplash," has become more frequent and will increase significantly as global temperatures rise.

The analysis found that since the mid-20th century, inter-annual hydroclimate volatility has increased by 8% to 31% over land areas, meaning more frequent shifts from dry to wet conditions in recent decades.

"This increase in hydroclimate volatility likely underpins a good portion of the societal perception that the impacts from climate change are accelerating," Daniel Swain, lead researcher and climate scientist with UCLA and UC Agriculture and Natural Resources, said in a statement.

To better illustrate their findings, the authors formally introduced the analogy of an "expanding atmospheric sponge," saying that the underlying physical processes driving the increase in volatility can be compared to using a kitchen sponge.

With each degree of global temperature rise, the hypothetical sponge becomes 7% larger, and, therefore, can hold more water. -- just like a larger kitchen sponge can soak up more water from the countertop compared to a smaller one. And when you wring out the bigger sponge, more water will pour out. A larger sponge will also require more water to become fully saturated.

A warmer atmosphere will also want to soak up more water vapor to achieve this through processes like evaporation, which can enhance dry conditions. These changes in atmospheric water vapor capacity will not only increase the chances of moving from very dry to very wet conditions, but it could fuel droughts and more extreme rainfall.

And as hydroclimate volatility continues to increase, more rapid swings between extreme weather events will amplify many of the associated hazards and potentially require changes to how we manage them.

-ABC News meteorologist Dan Peck

Just days before he leaves office, President Joe Biden is taking executive action to ban offshore oil and gas drilling in more than 625 million acres of ocean.

Using a provision in the 1953 Outer Continental Shelf Lands Act that gives the president the authority to ban drilling in the Outer Continental Shelf ocean zone, Biden declared the entire U.S. East Coast, the eastern Gulf of Mexico, the coasts of Washington, Oregon, and California and portions of the Northern Baring Sea in Alaska off limits to future oil and natural gas leasing.

"My decision reflects what coastal communities, businesses, and beachgoers have known for a long time: that drilling off these coasts could cause irreversible damage to places we hold dear and is unnecessary to meet our nation's energy needs. It is not worth the risks," Biden said in a statement.

The decision is not unprecedented. President Barack Obama used the act to ban oil and gas production in parts of the Arctic and North Atlantic oceans. And President Donald Trump used it to prohibit drilling off both Florida coasts and the coasts of Georgia and South Carolina. Trump also tried to overturn the Obama decision in 2019, but a U.S. District Court judge ruled that it would require an act of Congress to undo the ban. With that ruling, Trump may have difficulty ridding himself of the ban.

Environmental groups are praising the decision, and one senior administration official told ABC News that the ban is "one of the most significant climate actions the president could take" regarding climate protection and natural resource protection.

The American Petroleum Institute panned the move, saying, "American voters sent a clear message in support of domestic energy development, and yet the current administration is using its final days in office to cement a record of doing everything possible to restrict it."

The group, which represents America's natural gas and oil industry, is urging "policymakers to use every tool at their disposal to reverse this politically motivated decision and restore a pro-American energy approach to federal leasing."

But Biden is pushing back on the criticism, and the White House says hundreds of municipalities and thousands of elected officials have formally opposed offshore drilling in these areas because of health, environmental and economic threats.

"We do not need to choose between protecting the environment and growing our economy, or between keeping our ocean healthy, our coastlines resilient, and the food they produce secure and keeping energy prices low. Those are false choices," Biden added in his statement.

While the eastern Gulf of Mexico is considered a lucrative region for drilling, the oil and gas industry has not shown much interest in developing some of the other areas receiving the new protection. And there's been bipartisan pressure to protect many of these locations as many legislators don't want oil platforms near their beaches.

-ABC News Climate Unit's Matthew Glasser and ABC News White House Correspondent MaryAlice Parks