The Brief

Climate change is expensive, deadly and preventable, according to the new National Climate Assessment, the most sweeping, sophisticated federal analysis of climate change compiled to date.

Released every five years, the National Climate Assessment is a congressionally mandated evaluation of the effects of climate change on American life. This new fifth edition paints a picture of a nation simultaneously beset by climate-driven disasters and capable of dramatically reducing emissions of planet-warming gasses in the near future.

This is the first time the assessment includes standalone chapters about climate change's toll on the American economy, as well as the complex social factors driving climate change and the nation's responses. And, unlike past installments, the new assessment draws heavily from social science, including history, sociology, philosophy and Indigenous studies.

The new approach adds context and relevance to the assessment's robust scientific findings, and underscores the disproportionate danger that climate change poses to poor people, marginalized communities, older Americans and those who work outdoors.

"Climate change affects us all, but it doesn't affect us all equally," says climate scientist Katharine Hayhoe, one of the authors of the assessment. But threaded throughout the report are case studies and research summaries highlighting ways "climate action can create a more resilient and just country," she says.

This is also the first time the National Climate Assessment will be translated into Spanish, although the Spanish-language version won't be available until the spring, according to the White House.

The National Climate Assessment is extremely influential in legal and policy circles, and affects everything from court cases about who should foot the bill for wildfire damage, to local decisions about how tall to build coastal flood barriers. "It really shapes the way that people understand, and therefore act, in relation to climate change," says Michael Burger, the director of the Sabin Center for Climate Change Law at Columbia University.

Hundreds of scientists from universities, industry, and federal agencies contributed to the report. They reviewed cutting-edge research published since the last report and contextualized it in decades of foundational climate research.

The fifth edition of the assessment arrives as millions of Americans are struggling with the effects of a hotter Earth. Dramatic and deadly wildfires, floods and heat waves killed hundreds of people in the United States in 2023.

And, while federal spending on renewable energy and disaster preparedness has increased, the U.S. is also investing in new fossil fuel infrastructure that is not compatible with avoiding catastrophic warming later this century.

Here are the three big takeaways from the Fifth National Climate Assessment. More information about the specific effects of climate change in your area can be found in the assessment's regional chapters.

Climate change makes life more expensive

Food, housing, labor – it all gets pricier as the Earth heats up, according to the National Climate Assessment.

Climate-driven weather disasters, like heat waves, floods, hurricanes and wildfires, are particularly expensive. They destroy homes and businesses, wreck crops and create supply shortages by delaying trucks, ships and trains. Such disasters make it more likely that families will go bankrupt, and that municipal governments will run deficits, the authors note.

Weather-related disasters in the U.S. cause about $150 billion each year in direct losses, according to the report. That's a lot of money – roughly equal to the annual budget for the Energy Department – and it's only expected to go up as the Earth gets hotter.

And that's all before factoring in the less obvious or tangible costs of climate change. For example, healthcare bills for people who are sicker because of extreme heat, or have respiratory illness brought on by breathing in mold after a flood. Exposure to wildfire smoke alone costs billions of dollars a year in lost earnings, the assessment notes – a burden that falls disproportionately on poor people who work outdoors.

"The research indicates that people who are lower income have more trouble adapting [to climate change], because adaptation comes at a cost," says Solomon Hsiang, a climate economist at the University of California, Berkeley and a lead author of the assessment.

For example, one of the simplest ways to adapt to severe heat waves is to run your air conditioner more. But "if people can't pay for it, then [they] can't protect themselves," explains Hsiang.

And the hotter it gets, the more profound the economic harm, assessment warns. Twice as much planetary warming leads to more than twice as much economic harm, the assessment warns.

A roadside memorial to those who died in the wildfire that swept through the town of Lahaina, Hawaii in August. The latest National Climate Assessment underscores the many ways that climate change is already making Americans sick, and even killing them.

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Claire Harbage

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NPR

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Climate change makes people sick and often kills them

Since the previous NCA was released five years ago, the health costs of climate change have gone from theoretical to personal for many Americans.

The most obvious risk? Extreme weather, particularly heat, says Mary Hayden, the lead author of the chapter examining human health. Heat waves have become hotter, longer, and more dangerous, and they're hitting areas that aren't ready for them–like the "record-shattering" heat dome that descended on the Pacific Northwest in 2021 and caused hundreds of deaths.

But it's not just heat. Wildfire smoke can send people thousands of miles from the fires to hospitals with respiratory problems and heart disease complications. Hurricanes can disrupt people's access to healthcare: when a clinic is flooded or people are displaced, for example, kidney patients can't get dialysis treatment.

In most cases, the people who bear the brunt of the disasters are those already at risk: poor communities, communities of color, women, people with disabilities, and other marginalized groups. Temperatures in formerly redlined neighborhoods in cities across the country can soar nearly 15 degrees Fahrenheit hotter than wealthier areas just blocks away, putting residents at much higher risk of heat exposure.

The assessment also homes in on research tracking less-obvious health impacts. Living through climate disasters, for example, can leave lasting emotional scars. "We're not just talking about [people's] physical health–we're talking about their mental health. We're talking about their spiritual health. We're talking about the health and well-being of communities which are being affected by this," Hayden says.

That means recognizing the long-term effects on communities like Paradise, California, where people still deal with deep emotional trauma five years after their town burned in the 2018 Camp Fire. The report also flags the growing emotional toll on children and young people, for whom anxiety about the future of the planet is bleeding into all parts of their lives.

A lobsterman paddles out to his boat in a harbor in Maine. Climate change is disrupting ways of living with, and from, the ocean.

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Ryan Kellman

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Climate change threatens people's special, sacred places and practices

The places, cultural practices, and traditions that anchor many communities are also in flux because of climate change.

Fishing communities are seeing their livelihoods shift or collapse. The Northeast's iconic lobster fishery, the single most economically valuable in the country, has withered as marine heatwaves sweep through the regional seas. Shrinking snowpack and too-warm temperatures are interrupting opportunities for beloved recreational activities, like skiing or ice fishing.

Indigenous communities are being forced to adjust to new climate realities, which are disrupting traditional food-gathering traditions. In Palau, a monthly tradition of catching fish at a particularly low tide has been upset by sea level rise, which keeps water levels too high to trap fish in the historically-used places. Sea level rise is also forcing coastal communities to re-think their very existence, pulling apart the social fabric that has developed over generations.

But many communities – Indigenous people, farmers and fishers, groups that have lived tightly connected to their environments for a long time – have deep stores of resilience from which to draw, says Elizabeth Marino, a sociologist and the lead author of the chapter on social transformations. "There is quite a lot of wisdom in place to adapt to and even mitigate climate change," she says. "It allows people to come up with solutions that fit the lives that they lead, and that's also a place of hope."

The fixes to climate change can make Americans' lives better

The fifth assessment lays out a stark picture of the climate challenges the U.S. faces. Keeping planetary warming to "well below" 2 degrees Celsius (3.6 degrees Fahrenheit), the goal of the international Paris Agreement, will require immediate, enormous cuts to fossil fuel emissions in the U.S and beyond. Keeping warming below 1.5 degrees Celsius (2.7 degrees Fahrenheit), an ambitious target written into the Agreement, will be even harder, the report says.

But it also points out many successful efforts underway to adapt to the new reality and to prevent worse outcomes.

"It's not the message that if we don't hit 1.5 degrees, we're all going to die," says Hayhoe. "It's the message that everything we do matters. Every 10th of a degree of warming we avoid, there's a benefit to that."

Addressing fossil fuel-driven climate change can also help people live healthier lives, stresses J. Jason West, the lead author on a chapter on air quality. Dialing back fossil fuel emissions would help prevent further climate change and also lessen the kinds of air pollution most harmful to human health." There really is a lot of opportunity to take action that would resolve both of those problems at the same time," West says.

There's been a subtle shift in the report's perspective since the last one, says Candis Callison, a sociologist and author of the report. There's now a clear acknowledgement, developed through years of rigorous research, that the fossil fuel-powered society the U.S. built over generations was profoundly unjust. Many pollution-producing coal or gas power plants were sited in communities of color rather than white communities, affecting people's health outcomes for generations. And decisions about land and water use for energy extraction often excluded tribal communities, with consequences still playing out today.

The transition forward can look different, she says. "Climate change actually provides us with an opportunity to address some of those inequities and injustices–and to respond to these impacts," Callison says. "That's really a powerful thing."

Nithya Raman turned the tide in the L.A. mayoral race by winning over large swathes of the city that voted for Karen Bass in 2022, according to an LAist analysis of election data.

Bass was a favorite in many areas that voted for Rick Caruso when she faced him in 2022. She held onto a majority of voters across South L.A., but lost much of her previous support.

The switchup came after Bass — a veteran in progressive politics — took a relatively-conservative approach on issues like policing and high-density housing developments compared to Raman, a member of the Democratic Socialists of America.

The Los Angeles Homeless Services Authority told its employees Friday to stop work, shut down their computers and stay off agency systems while it looked into “a potential security issue affecting our systems,” its chief executive confirmed to LAist.

That shutdown order was still in place Monday evening, according to a LAHSA official not authorized to speak on the record.

Gita O'Neill, the agency’s interim CEO, told LAist on Friday evening that the agency did not “yet have enough information to say definitively whether any sensitive or confidential personal information was accessed.”

She has not answered questions about whether or not services for unhoused people are disrupted.

Gita O’Neill, interim CEO of LAHSA, speaks ahead of the annual homeless count on Jan. 20, 2026.

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Jordan Rynning

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LAist

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LAHSA holds highly sensitive information collected from people experiencing homelessness in the region. The agency oversees the Homeless Management Information System, or HMIS, which includes unhoused people’s names, dates of birth, Social Security numbers and disabilities, as well as self-reported mental health and substance abuse history, income sources and domestic violence history.

In a statement Monday, LAHSA said it had taken its internal computer systems offline “as a precaution” and “engaged outside cybersecurity specialists to investigate the nature and scope of the incident.” The statement, sent on O'Neill's behalf by outside public relations strategist Trevor Daley, continued to call it “a potential cybersecurity incident.”

The agency is “taking steps to maintain essential operations,” the statement added, saying LAHSA “remains open” while the investigation continues. It said the agency is working with its technical and legal teams.

What staff were told

Friday’s email to "Team LAHSA" carried the subject line "URGENT: Log Off and Shut Down for the Week." LAist obtained a copy, and O'Neill confirmed by text message that she had sent it.

“As a precaution while we look into a potential security issue affecting our systems, we're asking all staff to stop work and take their machines offline for the remainder of today and through the weekend,” the email said.

It told employees to “Log off and shut down your LAHSA computer” and not to log back in or connect to LAHSA systems, including email, “until you receive an all-clear from us.”

The email also told staff to report anything “unusual” before shutting down, such as “files renaming on their own, unexpected pop-ups or messages.”

What LAHSA leadership has said

In a texted response to LAist on Friday evening, O'Neill said she asked staff to take their computers offline “out of an abundance of caution” while the agency’s IT team assessed the situation.

“Our IT team is actively reviewing the situation now and working to understand exactly what occurred and whether any information was affected,” she wrote. “Protecting people’s personal and confidential information is a top priority in that review.”

Leaders of three LAHSA-funded service providers told LAist on Monday afternoon that they had not received any communications from LAHSA about the potential cybersecurity issue. All three use the HMIS system that holds unhoused people’s personal details.

Previous attacks against another LA housing agency

Another L.A. housing agency was previously hit by cyberattacks. The Housing Authority of the City of Los Angeles — a separate agency known as HACLA — has said hackers got inside its network in 2022 and may have accessed people’s names, Social Security numbers, financial accounts numbers and medical information.

Two years later, HACLA was breached again, according to an official notice, with hackers potentially accessing names, dates of birth, Social Security numbers and phone numbers.

LAist reporter Aaron Schrank contributed reporting to this story.

Los Angeles County Supervisor Lindsey Horvath announced Monday that she is running to be the county’s first elected chief executive. Horvath is the only candidate so far to enter the race, which is set for 2028.

The new executive post will take the place of the county’s appointed CEO and implement key priorities of the county Board of Supervisors. The executive will oversee the county budget, which is currently roughly $50 billion, and labor relations with more than 100,000 employees.

Horvath was first elected to the Board of Supervisors in 2022 and was re-elected in June to another four-year term. She represents the county’s 3rd District, which covers the San Fernando Valley and parts of the Westside and Central Los Angeles. She is a former mayor of West Hollywood.

The supervisor made her announcement Monday via social media and her campaign website. She called the race a “once-in-a-generation opportunity.”

The backstory

Voters created the position in 2024 when they approved Measure G, which was proposed by Supervisors Horvath and Janice Hahn.

Among other changes, the measure allowed the Board of Supervisors to expand from five to nine members by 2030 and established an independent Ethics Commission, which held its first meeting last month.

The pushback

On Monday, Supervisor Kathryn Barger issued a statement saying she believed it was “premature” to campaign for the new county executive position when it remained unclear whether “the office itself is constitutional.”

Barger pointed to questions raised by former federal judge Stephen Larson about whether California’s Constitution allows an elected county executive to veto board decisions, control county contracts and take on powers state law currently gives the Board of Supervisors.

“Moving forward with an office that would fundamentally change how Los Angeles County is governed, without first resolving these questions, is putting the cart before the horse,” Barger said in her statement. “We need clarity.”

The primary election is scheduled for March 7, 2028.