When I moved back to Berkeley in August, I got a nosebleed every day for two weeks. It always happened at the most inconvenient moments — during lectures, while I was brushing my teeth, in the middle of dinner with friends. 

“Guys, I’ll be right back,” I would say, and then I’d sprint to the nearest bathroom with my hand clutched over my nose. 

“What is going on?” I asked my mom on the phone one afternoon, sitting on the floor of my room with a tissue up my nose. 

“It’s the dry air there,” she said. “You just need to get acclimated.” 

She was right. My weather-induced nosebleed days eventually ended, and have since become a brief blip in my memory. I had almost entirely forgotten about them until recently, when I attended Professor Eva Horn’s lecture, “A Sense of Air: For an Aesthesis of Climate.” Hailing from the University of Vienna, Horn is currently the Max Kade Visiting Professor in Berkeley's Department of German, and the author of the book The Future as Catastrophe: Imagining Disaster in the Modern Age (2018). Her interdisciplinary research focuses on the porous relationship between humans and the climates we inhabit. When we hear the word climate, Horn noted, our minds automatically associate it with climate change; however, the relationship between humans and our climates wasn’t always this contentious. What was climate, Horn asks, before it was something we could capture in a computer? 

To answer this question, Horn turns to the title of her lecture: the Greek word “aesthesis.” The word refers to a wholeness of perception, a way of being in the world that engages all the senses. The Greek physician Hippocrates was an early proponent of the relationship between aesthesis and climate: in his book “On Airs, Waters and Places,” he argues that people are profoundly affected by the climates they live in. Horn discusses his concept of the “open body,” the idea that our physical bodies are engaged in a form of radical communication with the forces of nature. Just as we cross through the air, the air crosses through us. Horn cited her own experience with the “open body”: she fell ill during her first time in the tropics, but has since grown to love the unique environment of a lush island climate. As she spoke, I couldn’t help but think about my nosebleeds. My body was open to different kinds of air, dry or not — and all I needed was time to adapt, time to let my body communicate with the world. 

We often associate air with nothingness, a blank field that our bodies pass through as we move from one place to another. Horn refuses to accept this notion: “Air is social,” she claimed, noting that we all share the same air in crowded urban landscapes. The state of the air mirrors the state of our bodies: it flows in and out of us, causing shared sensations. And indeed, we were sharing the same air that very moment: we were in the midst of a particularly strong October heatwave, and all the lecture-goers were wearing loose dresses and shorts. I rolled a cup of ice water over my forehead. It was as if we were experiencing Horn’s argument in real time. How could anyone believe that air is not shared, when there we were, dressed in flowy fabrics and fanning our faces? 

Horn’s work is both multidisciplinary and cross-historical, drawing upon art and literature to make sense of our changing relationship with weather. A pivotal moment in that relationship, Horn argues, was the Industrial Revolution. The period posed several threats to the natural world, filling the countryside with smog, steam and railroad tracks. J.M.W. Turner’s 1844 painting Rain, Steam, and Speed depicts this confusing relationship between nature and industry. In the image, a train is almost completely washed out by thick gushes of wind and air; it is unclear what are storm clouds and what is steam. The straight lines of the train tracks disappear into the blustery sky, almost as if the storm is swallowing them up. Horn called the air in the painting “a mixture of natural and industrial processes,” suggesting that perhaps air itself is an open body, where the natural and the industrial meet and churn into some strange, iridescent force. Turner’s work asks the question: can the two work together, fusing into something productive and beautiful? Or can these gusts of industrial force only be destructive, eventually gulping down the very machines that created them, like the train tracks in the painting? 

Much of Turner’s work understands climate as a sense of place. His paintings show an intense, embodied perception of his location, caught up in tumbling swirls of light, water and air. In her lecture, Horn argues that this keen sense of awareness towards climate has come to an end. After the emergence of meteorology in the late 18th century, climate became the study of averages, instead of feeling and perception. “You can’t perceive averages,” Horn said pointedly. As helpful as means are, they also deny us the ability to perceive normal variations in local climates. When we think of weather in terms of averages, its variety — its character — is flattened into a straight line. I thought of the swoops and billows of fog that fill the Bay in the summer, the way the clouds dissipate into hot, dry air in the fall, and the violent winds and diagonal streams of rain in the winter. It felt so painfully practical, so terribly unpoetic, to think of these wonderful quirks as data points. 

Our detachment from climate is deepened by what Horn calls a “culture of insulation.” Modern life coincides with the invention of heating systems, air conditioning, mini fans, freezers, heating pads, electric blankets, and hot tubs. Humidifiers, hot water bottles, heated pools, and ice skating rinks. It has never been so easy to escape one climate and cloak oneself in a simulation of another. Fossil fuels, Horn states, have allowed us to untie ourselves from “the rhythms of nature.” Her work calls for a return to aesthesis, a perspective that recognizes the flowing relationship between our bodies and our world. 

After the lecture, I walked past Strawberry Creek back to my building. There was a breeze in that part of campus, blowing along the water and gathering between the redwood trees. It felt wonderful. I thought about my nosebleeds again, how my body was more adaptable than I thought. But maybe air was adaptable too. Even on the hottest day of the year, it was settling into the creek bed and coming up cool, spreading over the ground like moss. The air was passing within itself, in and out, here and there. I thought about Horn’s definition of aesthesis: air is never this or that, hot or cold, gloomy or bright. It is textured, mobile, like a brushstroke in a Turner painting. Only our senses can capture it.