Even for those lucky enough to get out in time, or to live outside the evacuation zones, there has been no escape from the fires in the Los Angeles area this week.

There is hardly a vantage point in the city from which flames or plumes of smoke are not visible, nowhere the scent of burning memories can’t reach.

And on our screens — on seemingly every channel and social media feed and text thread and WhatsApp group — an endless carousel of images documents a level of fear, loss and grief that felt unimaginable here as recently as Tuesday morning.

Even in places of physical safety, many in Los Angeles are finding it difficult to look away from the worst of the destruction online.

“To me it’s more comfortable to doomscroll than to sit and wait,” said Clara Sterling, who evacuated from her home Wednesday. “I would rather know exactly where the fire is going and where it’s headed than not know anything at all.”

A writer and comedian, Sterling is — by her own admission — extremely online. But the nature of this week’s fires make it particularly hard to disengage from news coverage and social media, experts said.

For one, there’s a material difference between scrolling through images of a far-off crisis and staying informed about an active disaster unfolding in your neighborhood, said Casey Fiesler, an associate professor specializing in tech ethics at the University of Colorado Boulder.

“It’s weird to even think of it as ‘doomscrolling,’ ” she said. “When you’re in it, you’re also looking for important information that can be really hard to get.”

When you share an identity with the victims of a traumatic event, you’re more likely both to seek out media coverage of the experience and to feel more distressed by the media you see, said Roxane Cohen Silver, distinguished professor of psychological science at UC Irvine.

For Los Angeles residents, this week’s fires are affecting the people we identify with most intimately: family, friends and community members. They have consumed places and landmarks that feature prominently in fond memories and regular routines.

The ubiquitous images have also fueled painful memories for those who have lived through similar disasters — a group whose numbers have increased as wildfires have grown more frequent in California, Silver said.

This she knows personally: She evacuated from the Laguna Beach fires in 1993, and began a long-term study of that fire’s survivors days after returning to her home.

“Throughout California, throughout the West, throughout communities that have had wildfire experience, we are particularly primed and sensitized to that news,” she said. “And the more we immerse ourselves in that news, the more likely we are to experience distress.”

Absorption in these images of fire and ash can cause trauma of its own, said Jyoti Mishra, an associate professor of psychiatry at UC San Diego who studied the long-term psychological health of survivors of the 2018 Camp fire.

The team identified lingering symptoms of post-traumatic stress disorder, depression and anxiety both among survivors who personally experienced fire-related trauma such as injury or property loss, and — to a smaller but still significant degree — among those who indirectly experienced the trauma as witnesses.

“If you’re witnessing [trauma] in the media, happening on the streets that you’ve lived on and walked on, and you can really put yourself in that place, then it can definitely be impactful,” said Mishra, who’s also co-director of the UC Climate Change and Mental Health Council. “Psychology and neuroscience research has shown that images and videos that generate a sense of personal meaning can have deep emotional impacts.”

The emotional pull of the videos and images on social media make it hard to look away, even as many find the information there much harder to trust.

Like many others, Sterling spent a lot of time online during the early days of the COVID-19 pandemic. Back then, Sterling said, the social media environment felt decidedly different.

“This time around I think I feel less informed about what’s going on because there’s been such a big push toward not fact-checking and getting rid of verified accounts,” she said.

The rise of AI-generated images and photos has added another troubling kink, as Sterling highlighted in a video posted to TikTok early Thursday.

“The Hollywood sign was not on fire last night. Any video or photos that you saw of the Hollywood sign on fire were fake. They were AI generated,” she said, posting from a hotel in San Diego after evacuating.

Hunter Ditch, a producer and voice actor in Lake Balboa, raised similar concerns about the lack of accurate information. Some social media content she’s encountered seemed “very polarizing” or political, and some exaggerated the scope of the disaster or featured complete fabrications, such as that flaming Hollywood sign.

The spread of false information has added another layer of stress, she said. This week, she started turning to other types of app — like the disaster mapping app, Watch Duty — to track the spreading fires and changing evacuation zones.

But that made her wonder: “If I have to check a whole other app for accurate information, then what am I even doing on social media at all?”

At the stroke of midnight on Dec. 31, Earth finished up its hottest year in recorded history, scientists said on Friday. The previous hottest year was 2023. And the next one will be upon us before long: By continuing to burn huge amounts of coal, oil and gas, humankind has all but guaranteed it.

The planet’s record-high average temperature last year reflected the weekslong, 104-degree-Fahrenheit spring heat waves that shuttered schools in Bangladesh and India. It reflected the effects of the bathtub-warm ocean waters that supercharged hurricanes in the Gulf of Mexico and cyclones in the Philippines. And it reflected the roasting summer and fall conditions that primed Los Angeles this week for the most destructive wildfires in its history.

“We are facing a very new climate and new challenges, challenges that our society is not prepared for,” said Carlo Buontempo, director of the Copernicus Climate Change Service, the European Union monitoring agency.

But even within this progression of warmer years and ever-intensifying risks to homes, communities and the environment, 2024 stood out in another unwelcome way. According to Copernicus, it was the first year in which global temperatures averaged more than 1.5 degrees Celsius, or 2.7 degrees Fahrenheit, above those the planet experienced at the start of the industrial age.

For the past decade, the world has sought to avoid crossing this dangerous threshold. Nations enshrined the goal in the 2015 Paris agreement to fight climate change. “Keep 1.5 alive” was the mantra at United Nations summits.

Yet here we are. Global temperatures will fluctuate somewhat, as they always do, which is why scientists often look at warming averaged over longer periods, not just a single year.

But even by that standard, staying below 1.5 degrees looks increasingly unattainable, according to researchers who have run the numbers. Globally, despite hundreds of billions of dollars invested in clean-energy technologies, carbon dioxide emissions hit a record in 2024 and show no signs of dropping.

One recent study published in the journal Nature concluded that the absolute best humanity can now hope for is around 1.6 degrees of warming. To achieve it, nations would need to start slashing emissions at a pace that would strain political, social and economic feasibility.

But what if we’d started earlier?

“It was guaranteed we’d get to this point where the gap between reality and the trajectory we needed for 1.5 degrees was so big it was ridiculous,” said David Victor, a professor of public policy at the University of California, San Diego.

The question now is what, if anything, should replace 1.5 as a lodestar for nations’ climate aspirations.

“These top-level goals are at best a compass,” Dr. Victor said. “They’re a reminder that if we don’t do more, we’re in for significant climate impacts.”

The 1.5-degree threshold was never the difference between safety and ruin, between hope and despair. It was a number negotiated by governments trying to answer a big question: What’s the highest global temperature increase — and the associated level of dangers, whether heat waves or wildfires or melting glaciers — that our societies should strive to avoid?

The result, as codified in the Paris agreement, was that nations would aspire to hold warming to “well below” 2 degrees Celsius while “pursuing efforts” to limit it to 1.5 degrees.

Even at the time, some experts called the latter goal unrealistic, because it required such deep and rapid emissions cuts. Still, the United States, the European Union and other governments adopted it as a guidepost for climate policy.

Christoph Bertram, an associate research professor at the University of Maryland’s Center for Global Sustainability, said the urgency of the 1.5 target spurred companies of all kinds — automakers, cement manufacturers, electric utilities — to start thinking hard about what it would mean to zero out their emissions by midcentury. “I do think that has led to some serious action,” Dr. Bertram said.

But the high aspiration of the 1.5 target also exposed deep fault lines among nations.

China and India never backed the goal, since it required them to curb their use of coal, gas and oil at a pace they said would hamstring their development. Rich countries that were struggling to cut their own emissions began choking off funding in the developing world for fossil-fuel projects that were economically beneficial. Some low-income countries felt it was deeply unfair to ask them to sacrifice for the climate given that it was wealthy nations — and not them — that had produced most of the greenhouse gases now warming the world.

“The 1.5-degree target has created a lot of tension between rich and poor countries,” said Vijaya Ramachandran, director for energy and development at the Breakthrough Institute, an environmental research organization.

Costa Samaras, an environmental-engineering professor at Carnegie Mellon University, compared the warming goals to health officials’ guidelines on, say, cholesterol. “We don’t set health targets on what’s realistic or what’s possible,” Dr. Samaras said. “We say, ‘This is what’s good for you. This is how you’re going to not get sick.’”

“If we were going to say, ‘Well, 1.5 is likely out of the question, let’s put it to 1.75,’ it gives people a false sense of assurance that 1.5 was not that important,” said Dr. Samaras, who helped shape U.S. climate policy from 2021 to 2024 in the White House Office of Science and Technology Policy. “It’s hugely important.”

Scientists convened by the United Nations have concluded that restricting warming to 1.5 degrees instead of 2 would spare tens of millions of people from being exposed to life-threatening heat waves, water shortages and coastal flooding. It might mean the difference between a world that has coral reefs and Arctic sea ice in the summer, and one that doesn’t.

Each tiny increment of additional warming, whether it’s 1.6 degrees versus 1.5, or 1.7 versus 1.6, increases the risks. “Even if the world overshoots 1.5 degrees, and the chances of this happening are increasing every day, we must keep striving” to bring emissions to zero as soon as possible, said Inger Anderson, the executive director of the United Nations Environment Program.

Officially, the sun has not yet set on the 1.5 target. The Paris agreement remains in force, even as President-elect Donald J. Trump vows to withdraw the United States from it for a second time. At U.N. climate negotiations, talk of 1.5 has become more muted compared with years past. But it has hardly gone away.

“With appropriate measures, 1.5 Celsius is still achievable,” Cedric Schuster, the minister of natural resources and environment for the Pacific island nation of Samoa, said at last year’s summit in Azerbaijan. Countries should “rise to the occasion with new, highly ambitious” policies, he said.

To Dr. Victor of U.C. San Diego, it is strange but all too predictable that governments keep speaking this way about what appears to be an unachievable aim. “No major political leader who wants to be taken seriously on climate wants to stick their neck out and say, ‘1.5 degrees isn’t feasible. Let’s talk about more realistic goals,’” he said.

Still, the world will eventually need to have that discussion, Dr. Victor said. And it’s unclear how it will go.

“It could be constructive, where we start asking, ‘How much warming are we really in for? And how do we deal with that?’” he said. “Or it could look very toxic, with a bunch of political finger pointing.”