In northern Vermont, where I live, old newspaper clippings show photos of people driving trucks across Lake Champlain. These icy and ephemeral corridors, however, seem to be relics of a bygone era.
About half a century ago, maybe more, the region began to warm. At first the change was imperceptible. The lake froze every year between 1850 and 1917 and almost every year until the late 1940s. However, in the last decade, the years of thaw have exceeded those of frost. Last February, the lake froze for the first time in seven years.
Technically speaking, a lake freezing or not is a small change. One degree too hot and you have running water, and one degree too cold and you have the local tourist ferry buried in ice. Exploit this split, says Grace Liu, a machine learning expert at Carnegie Mellon University in Pittsburgh. People pay more attention when they are shown black and white information — such as years when the lake froze versus years without frost — that continuous data, such as temperature increase over time, she and her colleagues reported in July 2025 in Nature Human behavior.
“People notice changes more frequently when they are presented with binary data,” says Liu.
Getting people to notice that something is wrong is a key first step in tackling climate change, Liu and others say. But it remains an open question whether this attention prompts action.
To freeze or not to freeze
New England, including Burlington, Vermont, is among the fastest warming regions of the world. This means that Lake Champlain, along Burlington’s western border, has gone from freezing almost every year, which translates to lake skiing, ice fishing, etc., to freezing every several years. Showing the increase in average temperature over time obscures this trend.
Putting the data in binary – years the lake froze versus years the lake did not freeze – makes the trend seem striking.
The boiling frog effect
Scientists believed that once hurricanes have become quite strong, forest fires are quite destructive, fairly frequent droughts and so on, to make people aware of the threat of climate change. Not so much, according to research.
When researchers analyzed more than 2 billion social media posts between spring 2014 and fall 2016, they found that people view normal temperatures as those that just happen two to eight years ago. People’s mental base is changing too quickly for even rapid climate change to be noticed, the team reported in March 2019 in the Proceedings of the National Academy of Sciences.
Researchers have called this apathy the boiling frog effect. According to tradition, a frog immersed in a pot of slowly boiling water does not notice the increasing heat until the moment of death. Likewise, this great pot known as Earth is now boiling, but many people remain oblivious to the impending disaster.
This rapid normalization of anomalies extends beyond rising temperatures. Another research team surveyed about 500,000 Americans exposed to some 15,000 natural disasters, including storms, floods, hurricanes, tornadoes and wildfires, from 2006 to 2022. little to change beliefs on climate change or the desire to support pro-environmental policies, the team reported during a seminar at the University of Barcelona.
“Nothing is moving things significantly,” says Toni Rodon, a political scientist at Pompeu Fabra University in Barcelona.
It’s problematic that people perceive climate change as slow, even though the pace of global warming over the past two decades is unprecedented, says Rachit Dubey, a cognitive scientist at UCLA. “We… trick ourselves into thinking it’s no big deal.”
If people so easily normalize climate change happening within a few years, imagine what happens from one generation to the next. My daughter, who was 4 years old the last time Lake Champlain froze, barely remembers crossing the icy expanse. Open water in late February, at least for her, is completely normal.
Our mental shortcut
Therapists and self-help writers are quick to note that thinking in a binary way is generally a bad idea. For example, a person with depression who tests just below the threshold for a formal diagnosis is not necessarily thriving.
“A lot of therapy is about helping people see the gray areas,” says psychologist Jeremy Shapiro, author of the book Looking for Goldilocksa screed against dichotomous thinking. Black-and-white thinking is a mental shortcut, he says. “It takes fewer neurons and less effort and energy to split things in two.”
In a distant past, characterized by scarce resources and numerous predators, quickly analyzing good from evil could mean the difference between the cruelest of binaries: life and death. Today, we remain, says Shapiro, “cognitive misers.”
Data patterns indicating climate threats tend to be more difficult to understand than the presence of saber-toothed big cats. In February, New York City was covered in more than 50 centimeters of snow. Yet snowfall, once the norm in the Big Apple, has become rare. In January 2024, snowflakes fell on the city after 701 days of snow drought. Most of the Northern Hemisphere, the researchers reported the same month in Natureseems to be heading towards a “snow loss cliff”, where even small increases in temperature will lead to ever-increasing snow loss.
Shapiro spends most of his time trying to get people out of the binary mindset. “Thinking in spectra… [is] more scientifically accurate in almost every situation,” he says. But given the ongoing challenge of breaking through people’s apathy toward climate change, he is intrigued by the idea that climate communicators might instead work with people’s miserly tendencies.
“I think it’s a brilliant turnaround,” he says.
When the climate becomes binary
What happens when you try to turn messy climate data into clear distinctions between two scenarios? Binarizing data is not always simple or even feasible – a truth we have learned to Scientific news when we tried to do it ourselves. By design, presenting the world in black and white is an oversimplification, an arbitrary bifurcation of a complex world. Click through the slideshow below to see where binary framing emphasizes the story – and where it doesn’t.
An illusion of change
As an undergraduate at Princeton University a few years ago, Liu first noticed what she and Dubey, then also at Princeton, call the “binary climate effect.” Tasked with studying local climate impacts as part of a research project, Liu looked through newspaper articles from the early 1900s. People frequently reported ice skating and playing hockey on the local body of water, Lake Carnegie, she discovered. And they reacted with surprise and dismay in odd years when the lake didn’t freeze.
Yet to Liu, a free-flowing Lake Carnegie in winter seemed normal. “I’ve never seen the lake freeze enough to ice skate,” she said. When, she wondered, did the surprise wear off? And could this feeling be restored?
For the article which finally appeared in Human behaviorshe and Dubey recruited nearly 800 participants online and presented them with data on freezing lakes in Townsville, a fictional town known for its frigid winters and ice skating on the local lake. They divided the participants into two groups. One group saw graphs showing the city’s winter temperature history from 1939 to 2019 as a time series of scattered points, and the other “binary” group saw graphs showing whether or not the lake froze during that same period.
On a scale of 1 to 10, participants rated the impact of climate change on Townsville. Participants who viewed the continuous charts gave the city an average climate change rating of 6.6, while those who viewed the binary charts gave it a rating of 7.5. The researchers repeated the experiment with real data from five U.S. lakes with nearly 250 people and obtained similar results.
The team then recruited nearly 400 additional participants to see if they perceived a specific moment, or change point, when weather conditions in another fictional city changed abruptly. In reality, this made no sense because the researchers set the rate of temperature increase or the probability of lakes freezing as constant. Yet about half of participants who viewed rolling data saw a year where things started to change. That perception increased to nearly 75 percent of participants viewing lake freeze data, the team found. According to Liu and Dubey, dichotomous data reinforces the illusion of sudden change.
Those who perceived a point of change also rated the impacts of climate change on the city as more severe than those who did not perceive such a point. The researchers did not track participants’ initial opinions on climate change. Still, the results suggest the possibility that such illusions could open people’s eyes to the severity of the climate crisis.
An oversimplified world
By design, presenting the world in black and white oversimplifies a complex world, Liu says. “Every time you binarize data, you lose information. The key, she says, is to present all the messiness of the real world with a more concrete model.
Concrete information, while reducing the world to something simpler and smaller, could help people identify ways to act, suspects anthropologist Julian Sommerschuh of the University of Hamburg. In Germany, people often encounter climate disasters on television and social media. Faced with the gargantuan data sets that the the mind can barely understandthey often perceive any action that fails to make a difference on a global scale as a failure.
“[German] people are apathetic because they feel overwhelmed,” says Sommerschuh.
Compare this with the farmers of western Kenya, a place where Sommerschuh spent decades conducting ethnographic research. Although unpredictable rains pose a palpable threat to farmers’ way of life, they keep hope for the futureSommerschuh reported in March in American anthropologist. And they talk about concrete solutions, like planting trees, that can prevent erosion and increase crop yields for future generations.
A frozen lake is, in this perspective, a palpable and concrete thing. A passerby can touch the icicles covering a sea cave and make sculptures from huge chunks of ice flaked off the glassy surface. But this irregular extent is also difficult to understand. At the top of this vast plain, one cannot help but feel small in a larger universe.
Now, with the arrival of spring, all these frozen details are melting and meteorologists are warning people to stay away from the lake. As birds herald spring, can those of us who live along the lakeshore hold on to the memory of winter?