
San Francisco bears the nickname City of Fog for good reason. The fickle yet frequent summer fog impacts everything and everyone it touches. It makes the season notoriously chilly and orchestrates people’s daily routines. Fog toys with housing prices and clouds visibility for commuters, mariners, and pilots. But it also nourishes redwood forests along the otherwise parched California coast. Fog permeates San Francisco’s charm and culture. Residents have even given it a name: Karl.
Ever since Pulitzer Prize–winning New York Times journalist John Branch moved to the Bay Area a little over a decade ago, he has wondered how climate change might affect Karl’s regular visits. Collaborating with freelance photographer Nina Riggio and NYT graphics editor Scott Reinhard, Branch delved into that seemingly simple question in his multimedia feature “The Elusive Future of San Francisco’s Fog.” The answer, he finds, is far from straightforward.
Branch isn’t the first journalist to ponder this question. But while others mostly forecast doom and gloom for San Francisco’s meteorological mainstay, Branch takes time to marvel at the miracle of fog in the first place, and how the region’s topography and climate make it possible. Despite its familiarity, fog remains an enigma. Scientists lack a robust definition and a means to measure it, let alone a way to track its changes. The foggy notion of fog led Branch to talk to unexpected sources for his article, imbuing the piece with idiosyncratic characters and details. He also sows wonder for the weather pattern with lyrical prose amid the hard scientific facts. Reinhard’s interactive animations and Riggio’s photos of an iconic cityscape painted over by fog complement Branch’s lush descriptions, making the piece a sensory feast.
Branch has made a career of rendering beautiful, unexpected stories from topics that might seem mundane or amorphous. His fog article offers a shining example to writers hoping to break out of the news cycle and chase their curiosity, even if just about backyard phenomena. Science journalist Shi En Kim spoke with Branch about his methods for navigating uncertainty and sparking wonder within stories that don’t have tidy conclusions. (This interview has been edited for length and clarity.)
What sparked your initial idea to do a story about fog?
I have a love affair with the fog. [And] I have a lot of friends who have lived here for a long time and who grew up in the city, who swear that fog is declining. I’d seen stories that that was true, but those stories were [from] 10 or 12 years ago.
My initial pitch was: It seems that fog is declining. And that would seem to have a lot of potential impact on everything, from the environment to the culture of this area. Once I started doing the reporting, I realized, well, it might actually have ticked back up recently, for reasons we don’t quite understand.
I’m sure there was pause [among my editors]: Do we still have a story? Maybe that is the story. We don’t really know what to make of this, but let’s talk about it.
Why is the science of fog so cloudy?
I thought it was actually fitting that fog is one of the most elusive parts of climate change. It’s more interesting to me that way, than to have a real obvious answer. It’s nice that there’s something that still fools us. Even people that live in it, work in it, study it aren’t sure what to make of it.
A lot of different parts of science have researched different aspects of fog. But there aren’t very many people whose whole expertise is fog. There are people who study clouds, people who study oceanography. Some of the most interesting research about fog came from somebody who studies redwoods. People who study salmon in the creeks or amphibians along the coast … suddenly now they’re interested in fog, because they realize [it] plays a role.
Fog is [also] regional. Fog in San Francisco is different from fog even in central California, which is different from fog in Southern California, which is different from fog in other parts of the world.
Since you couldn’t lean on solid scientific evidence, how did you decide where to focus your story?
The big question is, why does this matter? It’s great to have scientists tell me what they think about fog and what they found. [But] I know from living here, people have opinions about it. They either love the fog or they hate the fog. I wanted to go find the men and women that live in the fog and maybe have some history because they’ve been doing it for a long time. [This] is why I went out and tried to find painters on the Golden Gate Bridge, people in the Coast Guard, or gardeners out in Golden Gate Park.
I wanted some humanity in this. The best stories are stories about people. Because there was no event we had to describe, it gave us freedom to talk about this in a different way. It’s more like, “Let’s talk about fog; how does fog affect your life?” It allowed for these expansive, unpredictable conversations.
How did you get from these conversations to the final structure of the story?
As Nina was taking photos and Scott was starting to work on the graphics, I told editors I’ll write up the scenes of people I had talked to, to give an idea of the kinds of things that I was thinking about. I sent them to editors, and they ended up using them. As photos and graphics came in, we started cutting and pasting these and rewriting transitions and trying to blend them together. But they were really written as six or seven vignettes that we then sandpapered to make look like and read like one pretty coherent thought.
How did you come up with your vivid descriptions of fog—playful, whimsical, shifty—and how do you capture these types of details when you’re out reporting?
I’m very much a fan of details and metaphors. None of this comes naturally in one brain dump. As I’m out, on the Coast Guard ship, for example, I’m taking notes and talking to people. I might see something and be like, “Oh, that’s a good way to describe it.” And I’ll write in the margins of my notes a metaphor or a simile just as a descriptor. I will take my notes from the day and plug them into a Google Doc. That way, they’re searchable. Sometimes I’ll look back at them and be like, “Well, that was ridiculous,” and sometimes I’ll say, “That was pretty—let’s see if we can fit that in somewhere.”
If there [are any lines] that make it into a story that I’m proud of, usually those thoughts come to me in the shower or when I’m driving a car. They rarely come to me as I’m writing while sitting at the keyboard.
One of the exercises I’ve done over the years is that, when I’m at places like the airport, I will sit at the gate and think, “How would I describe the scene right here?” You just try to put up your antenna and think, “If I had to paint the scene with words, how would I do it?” It’s a muscle I try to train.
Like this fog story, many of your pieces take an unexpected look at a seemingly mundane topic. What’s your advice for early-career journalists on cultivating this approach?
[In the newsroom], sometimes [editors] would send interns out to cover the Veterans Day Parade. What a great opportunity for a reporter to take a rote assignment and realize that it is full of color and fresh angles, if [they] enthusiastically pursue them. To an editor, it’s just one of the things we have to cover. You turn that into something, and they’re going to be like, “Holy crap, you turned a Veterans Day Parade into a great little story.” That’s the goal: To offer readers (and editors) more than they ever expected.
I spent the early years of my career covering sports. And sports is an area where there’s a lot of packed journalism. You go into a locker room and 15 reporters are on a quarterback. And you think, well, I could go join the pack and try to write a better version of those 15 stories, or I could go over and talk to that guy who’s by himself and write the one good story that nobody else is expecting. But that’s always been my philosophy—when I see a bunch of journalists, I go the other way.
I like the offbeat. And how I see the world is like, “I want to take something that you think is mundane, maybe barely worth your time, and I’m going to surprise you and show you that there’s a story everywhere.”
This story is also an example of reporting on topics wrapped in uncertainty. Why do you think these stories are important to tell even if the science is unsettled?
If the bar to clear is that we need to have definitive proof that this is happening before we write about it, then we might never write about it. Just because something hasn’t happened, just because there hasn’t been a new study that says this is why it’s going up or down, it’s still worthy of conversation, still worthy of education.
[This piece] certainly sparked a lot of opinion and a lot of conversation. I hope that people who live here have a different kind of appreciation for fog, or at least notice it more than just that it’s a weather phenomenon. I want people to think about things in new and different ways. And to me, that’s the point of journalism. Whether you come up with an answer, I think it’s mostly to spur a thought.

Shi En Kim is a life sciences reporter at Chemical & Engineering News and a TON early-career fellow sponsored by the Burroughs Wellcome Fund. Her work has appeared in Popular Science, National Geographic, Scientific American, Hakai Magazine, Science News, and Smithsonian Magazine, where she was a AAAS Mass Media Fellow in 2021. She recently earned her PhD in molecular engineering from the University of Chicago. Follow her on Twitter @goes_by_kim.