In February 1884, the English art critic and polymath John Ruskin took the stage at the London Institution to deliver two lectures on a topic that might have seemed unusual at the time: the weather. In his passionate speeches, titled “The Storm-Cloud of the Nineteenth Century,” Ruskin railed against a sinister “wind of darkness” and “plague-cloud” that, in his view, had recently begun to envelop Victorian cities. He claimed to have meticulously recorded meteorological changes and warned his skeptical audience of the “bitterness and malice” of this new weather. More than just an environmental observation, Ruskin believed that this shift in weather mirrored a societal “moral gloom.” He suggested that the same darkness afflicting the skies was also seeping into the human spirit.
Dismissing Ruskin: A Cautionary Tale
At the time, it was easy to dismiss Ruskin’s concerns as the ramblings of a troubled mind. Clouds, after all, were just clouds—how could they possibly reflect the state of the human psyche? As Brian Dillon pointed out in The Paris Review in 2019, it’s difficult to separate Ruskin’s observations of bad weather from his own melancholic mood. By 1886, Ruskin suffered a mental breakdown while delivering a talk in Oxford, and by the end of his life, he was widely regarded as insane. His musings on the connection between meteorology and the human spirit are not held in the same esteem as his works on J.M.W. Turner, the painter he so admired.
However, Ruskin’s clouds were more than mere atmospheric phenomena; they were, as he noted in his diary, infused with a “dense manufacturing mist.” These “plague-clouds” represented the miasma of the Industrial Revolution, a period marked by rapid societal and environmental change. The relentless transformation of pastoral landscapes into industrial hubs brought with it a host of sensory assaults: the stench of sulfur, soot-filled air, chemical and human waste, and the deafening clamor of machinery. These were not just physical nuisances; they were psychological burdens, shaping moods and behaviors in ways that were not yet fully understood.
The Psychological Toll of Industrialization
Ruskin believed that the relentless pace of industrialization, with its cacophony of tools, sprawling factories, and environmental degradation, undermined psychological well-being. He posited that the mind, much like the body, required a healthy social and physical environment to thrive—a somewhat novel idea at the time. (The concept of “mental hygiene,” a precursor to modern mental health, wouldn’t be formally defined by Isaac Ray, a founder of the American Psychiatric Association, until 1893.) For Ruskin, instability in the environment led to instability in the mind. One reflected the other.
Revisiting Ruskin in a Climate-Changed World
More than a century later, as we confront a new wave of rapid environmental changes, Ruskin’s “plague-clouds” have taken on a darkly literal meaning. Global average surface temperatures have risen by about 1.1°C (2°F) since the pre-industrial era, with most of this warming occurring in the past 40 years. Ice is melting, seas are rising, and storms are becoming more frequent and severe. Yet, the narrative of climate change remains largely one of external impacts: meteorological extremes, economic upheaval, and biodiversity loss. But perhaps it’s time to take Ruskin’s musings more seriously. As the climate crisis distorts weather patterns, acidifies oceans, and shatters temperature records with alarming regularity, one must wonder if our minds are also being reshaped by these changes.
The Unseen Impact: Climate Change and Human Behavior
The evidence is troubling. Immigration judges are less likely to rule in favor of asylum seekers on hotter days. Students’ academic performance suffers, with warmer school years corresponding to lower learning rates. Temperature has been shown to predict the incidence of online hate speech, domestic violence, and even suicide. In baseball, pitchers are more likely to hit batters with their pitches on hot days. The list goes on.
But you don’t need to be a scientist to know what this feels like. Perhaps you’ve noticed that you’re more irritable in the heat or that it’s harder to concentrate. You’re not alone. Extensive research in cognitive neuroscience and behavioral economics supports these observations. Drivers are more likely to honk their horns (and for longer periods) at higher temperatures. Heat predicts more aggressive behavior in sports, with baseball pitchers being more likely to retaliate against opposing players in hot weather.
Plague-Clouds Within: The Interconnectedness of Mind and Environment
These findings suggest that the “plague-clouds” are not just external—they are within us, too. They highlight the deep interconnectedness of our inner and outer worlds, revealing how environmental influences can shape our decision-making in ways far more profound than we might intuitively believe. As the climate changes, so do we.
The Brain’s Vulnerability in a Warming World
The London Institution, where Ruskin gave his lectures, closed in 1912. Today, when scientists seek to understand the connection between environment and mind, they publish their findings in prestigious journals like The Lancet. In May 2024, 24 neurologists, led by Sanjay Sisodiya, professor of neurology at University College London, published a paper arguing that the “incidence, prevalence, and severity of many nervous system conditions” can be affected by global warming.
In their survey of 332 scientific studies, Sisodiya and his colleagues demonstrated that climate change’s impact extends far beyond behavior, deep into the brain’s cortical folds. Temperature appears to influence conditions like migraine, stroke, seizure, and multiple sclerosis. In Taiwan, for instance, the risk of schizophrenia hospitalization increases with widening daytime temperature ranges. In California, hospital visits for any mental health disorder, self-harm, intentional injury, or homicide rise with broader daily temperature swings. In Switzerland, hospitalizations for psychiatric disorders increase with temperature, with the risk particularly pronounced for those with developmental disorders and schizophrenia.
The Expanding Reach of Climate-Induced Brain Maladies
Outside the hospital, climate change is expanding the habitable range of disease vectors like ticks, mosquitoes, and bats, leading scientists to predict an increase in vector-borne and zoonotic brain diseases like yellow fever, Zika, and cerebral malaria. Beyond the healthcare system, a changing environment affects our sensory systems and perception, degrading both the sensory information we receive and the biological tools we use to process it. As if that weren’t enough, warming freshwater increases the frequency of cyanobacterial blooms, which release neurotoxins that raise the risk of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease.
The Intergenerational Burden of Climate Change
Recent studies suggest that climate change may be exacerbating the already significant burden of neurodegenerative diseases like Parkinson’s and Alzheimer’s. In countries with warmer-than-average climates, more intense warming has been linked to a greater increase in Parkinson’s cases. The highest forecasted rates of increase in dementia prevalence are expected to be in countries experiencing the largest effects of climate change. Similarly, short-term exposure to high temperatures appears to drive up emergency department visits for Alzheimer’s patients. The air we breathe likely plays a role as well. In Mexico City, where residents are exposed to high levels of fine particulate matter and ozone from a young age, autopsies have revealed progressive Alzheimer’s pathology in 99 percent of those under the age of 30.
The risks are not limited to those alive today. In 2022, an epidemiological study revealed that heat exposure during early pregnancy is associated with a significantly increased risk of children developing schizophrenia, anorexia, and other neuropsychiatric conditions. High temperatures during gestation have long been known to delay neurodevelopment in rats. Other studies have shown that experiencing natural disasters in utero greatly increases children’s risk of anxiety, depression, attention-deficit/hyperactivity disorder (ADHD), and conduct disorders later in life. These findings cast the intergenerational responsibilities of the Anthropocene in a harsh new light, particularly given the global disparity between regions most affected by climate change and regions where the majority of studies are conducted. We don’t know what we don’t know.
The Brain: Climate Change’s Most Vulnerable Landscape
What we do know is that the brain is emerging as one of climate change’s most vulnerable landscapes. This understanding shifts our focus from the external world to the internal, offering new insights into how climate change may be affecting our minds.
The Weight of Nature on the Brain
Let’s revisit the example of horn-honking and baseball pitchers. By focusing on the brain, we can begin to understand the mechanisms behind these behaviors and avoid vague phrases like “wind of darkness.” Higher temperatures appear to shift functional brain networks—specifically, the coordinated behavior of various regions—toward more random activity. In extreme heat, scientists have observed an overworked dorsolateral prefrontal cortex (dlPFC), a brain region essential for rational decision-making. The dlPFC limits impulsive decisions; disrupted dlPFC activity suggests a relatively greater influence of limbic structures (like the emotionally driven amygdala) on behavior. More heat, less rational decision-making.
The Physicality of Environmental Influence on the Brain
The impact of environmental stress on the brain goes beyond the dlPFC and spans multiple levels of brain organization. For instance, heat stress in zebrafish down-regulates the expression of proteins crucial for synapse construction and neurotransmitter release. In mice, heat triggers inflammation in the hippocampus, a region necessary for memory formation and storage. While neuroinflammation often plays a protective role, chronic activation of immune cells—like microglia and astrocytes—can become harmful, as pro-inflammatory molecules may damage brain cells over time. In humans, hyperthermia is associated with decreased blood flow to this region. The observed decline in cognitive function and increase in aggression at higher temperatures align with these biological findings.
The Emerging Field of Environmental Neuroscience
The nascent field of environmental neuroscience seeks to “understand the qualitative and quantitative relationships between the external environment, neurobiology, psychology, and behavior.” This emerging discipline could be aptly named climatological neuroepidemiology or perhaps something catchier for a broader audience, like neuroclimatology or ecological neurodynamics. However, I prefer the term “the weight of nature.”
The Heavy Psychological Burden of Climate Change
The weight of nature constrains our choices, as evidenced by the behavioral changes mentioned earlier. When extreme heat reaches into your mind and tips your scales toward violence, it limits your options. By definition, impulsive decisions involve less reflection than considered decisions. Therefore, when a changing climate influences our reactions and decision-making, it can be seen as compromising our perceived free will. The weight of nature is heavy, and it displaces us.
It also imposes a heavy psychological burden. The term “climate anxiety” is likely familiar to you. It refers to a state of near-pathological worry and fear of impending environmental destruction. However, the term “anxiety” usually implies “excessive” worry. I’m not convinced that there’s anything excessive about recognizing the climate crisis and feeling a sense of doom. Perhaps those who experience climate anxiety are simply more attuned to reality, the true Cassandras among us.
Climate Anxiety: A Biological Perspective
I’m not entirely joking. Neuroscience has begun to study the brains of those experiencing climate anxiety, and for good reason. The midcingulate cortex, a central hub in the brain’s threat-detection circuitry, may hold clues to the biological basis of climate anxiety. In one 2024 study, researchers at Northern Michigan University found that people with higher levels of climate anxiety exhibited distinct patterns of brain structure and function in this region compared to those with lower levels of climate anxiety—regardless of their overall anxiety levels. The climate-anxious brain appears to have a smaller midcingulate cortex (in terms of gray matter) but one that is more functionally connected to other key hubs in the brain’s salience network. This network constantly scans the environment for emotionally relevant information. In people with climate anxiety, the midcingulate cortex works closely with limbic structures like the amygdala and insula to prepare the body to respond to these signals. This network may be particularly attuned to climate-related threats in those with climate anxiety.
The Adaptive Potential of Climate Anxiety
Rather than indicating a deficiency, a smaller midcingulate cortex may reflect a more efficient, finely tuned threat-detection system. The brain is known to prune redundant connections over time, preserving only the most useful neural pathways. The Michigan researchers suggest that this selective pruning allows the climate-anxious brain to process worrisome information more effectively, facilitating rapid communication between the midcingulate cortex and other regions involved in threat anticipation and response. In other words, the climate-anxious midcingulate cortex may be characterized by “more efficient wiring.”
This neural sensitivity to potential dangers could be both a blessing and a curse. On one hand, it may attune some people to the very real perils of the future. The midcingulate cortex is critical for anticipating future threats, and meta-analyses have shown that this region is consistently activated when people contemplate unpredictable negative outcomes. Given the looming specter of climate catastrophe, a highly sensitive threat-detection system could be an adaptive asset.
The Double-Edged Sword of Climate Anxiety
On the other hand, the complexity, uncertainty, and global nature of the climate crisis may lead individuals to deprioritize the risks associated with climate change or become overwhelmed and disengaged—a state sometimes referred to as “eco-paralysis.” An overactive midcingulate cortex has been implicated in clinical anxiety disorders, and the new findings suggest that climate anxiety shares some of the same neural underpinnings. It’s important to note that climate anxiety appears to be distinct from generalized anxiety, as the brain differences observed in the Michigan study could not be explained by overall anxiety levels.
A New Neural Cartography: The Brain and Climate Change
Ultimately, while speculative, these findings suggest that climate anxiety is not merely a sociocultural phenomenon but one with identifiable neural correlates. They provide a potential biological framework for understanding why some people may be more psychologically impacted by climate change than others. They raise intriguing questions about whether the brains of those experiencing climate anxiety are particularly well-suited to confront the existential threat of a warming world—or whether they are vulnerable to becoming overwhelmed by it. In all cases, these findings illustrate how the world is reaching inward.
Orienting Our Neurobiology Toward Climate Change
There is a flipside to consider. A changing climate is seeping into our very neurobiology. What might it mean to orient our neurobiology toward climate change?
This is the premise of a 2023 article in Nature Climate Change by neuroscientist Kimberly Doell and her colleagues at the University of Vienna. They argue that the field of neuroscience is well-positioned to inform our understanding of climate-adaptation responses and pro-environmental decision-making. In the decades since Ruskin’s time, environmental neuroscience has begun to explore the reciprocal relationship between organisms and their ecological niches. We now know that modern environments—whether green spaces, urban sprawl, or socioeconomic strata—leave their mark on the brain. Climate change is no exception.
Harnessing Neuroscience for Climate Action
Accordingly, Doell and her colleagues propose that scientists and advocates can integrate findings from neuroscience to improve communication strategies aimed at spurring climate action. They suggest taking advantage of insights from neurobiology and cognitive neuroscience to design climate solutions—both within ourselves and for society as a whole.
The Neuroscience of Climate Change: A Call to Action
The Anthropocene’s fever dream is already warping our mental “wetware.” Social and behavioral sciences have begun cataloging the psychological fallout of a planet in flux, but a neural taxonomy of climate change remains to be developed. The field’s methodological and conceptual tools are ready for the challenge, but honing them will require collaboration across disciplines, including climate science, medicine, psychology, and political science.
Some initiatives are already underway. The Kavli Foundation in Los Angeles recognized the need for answers and, in 2023, called for scientists to investigate how neural systems are responding to ecological upheaval. With a $5 million trial fund, the foundation aims to illuminate how habitat loss, light pollution, and other environmental insults may be influencing the molecular, cellular, and circuit-level machinery of brains, both human and non-human.
The Brain as Climate Change’s Black Box
The brain, that spongy command center perched atop our spinal cord, has always been a black box. As the climate crisis tightens its grip, and the ecological ground beneath our feet grows ever more unsteady, the imperative to pry it open and peer inside grows more urgent by the day. Already, we’ve begun to glimpse the outlines of a new neural cartography, sketched in broad strokes by the likes of Sisodiya and his colleagues. We know now that the brain is less a static lump of self-regulating tissue than it is a dynamic, living landscape, its hills and valleys shaped by the contours of our environment. Just as the Greenland ice sheet groans and buckles under the heat of a changing climate, so too do our synapses wither and our neurons wink out as the mercury rises. Just as rising seas swallow coastlines, and forests succumb to drought and flame, the anatomical borders of our brains are redrawn by each new onslaught of environmental insult.
Shaping the Future: Mind and Planet in Tandem
But the dialogue between the brain and the biosphere is not a one-way street. The choices we make, the behaviors we pursue, the ways in which we navigate a world in crisis—all of these decisions are reflected back onto the environment, for better or for worse. In seeking to understand how a changing climate molds the contours of our minds, we must also reckon with how the architecture of our thoughts might be renovated in service of sustainability.
Charting a Course Through the Gathering Plague-Clouds
The cartographers of the Anthropocene mind have their work cut out for them. But in the hands of neuroscience—with its advanced brain scans, gene-editing precision, and algorithmic might—there is something approaching a starting point. By tracing the pathways of environmental impact to their neural roots, and by following the cascading consequences of our mental processes back out into the world, we might yet begin to untangle the intricate web that binds the fates of mind and planet.
This much is clear: as the gears of the climate crisis grind on, our brains will be swept along for the ride. The question is whether we’ll be mere passengers, or whether we’ll seize the controls and steer toward a livable future. The weight of nature—the immensity of the crisis we face—is daunting. But it need not be paralyzing. Bit by bit, synapse by synapse, we can chart a course through the gathering plague-clouds.
As Ruskin once observed, “To banish imperfection is to destroy expression, to check exertion, to paralyze vitality.” Even if we could somehow eliminate the imperfections of environmental influence on the mind, we shouldn’t. Instead, we should recognize them as evidence of the intimate, vital relationship between self and world.
In this, climatological neuroepidemiology—young and untested though it may be—is poised to play an outsized role. By illuminating the neural circuitry of our planetary predicament, the field offers something precious: a flicker of agency in a world that often feels as if it’s spinning out of control. It suggests that, even as the weight of nature presses down upon us, we might yet find a way to press back.