The 19th-Century Origins of Climate Science

How politics and azaleas gave rise to a modern understanding of the environment

Flowering azaleas
AI Project / Reuters

If you were to travel to the early 1800s and strike up a conversation with a European scientist about climate, they would begin by asking why you hadn’t read your Aristotle. First sketched by the philosopher in his fourth-century B.C. treatise Meteorologica, the model that sprang from the ancient Greek concept of klima divided the hemispheres into three fixed climatic bands: polar cold, equatorial heat, and a zone of moderation in the middle.

This understanding of climate as a static property of the Earth’s surface structured European thinking well into the 19th century, and it followed that the collection of atmospheric data, while perhaps useful for weather forecasting or navigation, had little to do with the planet’s overall condition.

Only in the 1850s did this ancient climatology began to lose its grip on the European scientific imagination. As the Yale historian Deborah Coen reveals in her inspiring and inventive new book Climate in Motion: Science, Empire, and the Problem of Scale, we owe the foundations of modern climate science to a forgotten cadre of Central European Earth scientists. The result of their research was a novel paradigm that Coen calls “dynamic climatology.” In this view, climate was not a stationary quality so much as a lively process of energy circulating through the atmosphere, the outcome of complex interactions over time among global and local forces. For the most part, this vision of climate is still our own.

It is not incidental that the Habsburg Empire, a once-grand and wide-reaching imperial state that unraveled in 1918, employed these pioneering researchers. Coen proposes that in response to the empire’s notoriously convoluted legal structure, its climatologists began to develop a modern, multi-scalar way of thinking about climate—as well as a powerful storehouse of tools for communicating their research to a vast imperial public. This is an arresting story about how politics can shape even the loftiest of sciences.

Azaleas played a surprisingly large role in the new conception of climatology. In the late 1800s, Anton Kerner Ritter von Marilaun spent a not-insignificant amount of his time studying the plants. Specifically, Kerner, a botany professor at the University of Innsbruck, wished to understand their distribution: why the flowers he found growing along an Alpine riverbank could also be found farther afield and at lower elevations. The most immediate explanation was that their seeds had been washed away by springtime snowmelt or carried by mountain winds.

Yet Kerner gradually came to believe something more radical. Isolated pockets of azaleas, he argued, were indicators of a changing climate: As the valleys had warmed over thousands of years, certain populations of Alpine flora had, over generations, colonized the mountainside in search of cooler temperatures and greater moisture. The plants left behind at lower elevations, or foundlings, hinted at “the advance of a given species in one or another direction,” Kerner wrote, “the retreat and extinction of others in historical times.” In his hands, flowers were a tool for slipping along scales of space and time, stepping outside the human frame of things to imagine how climate had slowly changed in the past—and might again in the future.

Dynamic climatology flourished in the Habsburg lands partly due to the empire’s exceptionally diverse natural environment. The state’s topography ranged from Kerner’s Alpine pastures to the shores of the Adriatic, from Carpathian peaks to the Hungarian steppe. As the Habsburg climatologist Julius Hann commented, “Nature has made it easy for the inhabitant of Austria-Hungary to cultivate climatic research.” Beginning in the 1850s, that research included government-sponsored weather stations and field studies in which intrepid scholars logged measurements of temperature, rainfall, wind speed, and seasonal growth. That data slowly fed into a new picture of the global climate.

The new field of climate science was also particularly well suited to the empire’s labyrinthine political and legal arrangements. This was not a unified nation-state, such as France or the United States, so much as a tangled web of nations, ancient sovereignties, and local principalities, assembled over centuries via smart marriages and successful wars. In ways that would have been foreign to their colleagues in other states, Habsburg climatologists were compelled by the empire’s hybrid structure to navigate different scales of time and space on a daily basis. As imperial-royal scientists, for example, Kerner and Hann were both civil servants and independent scholars. They were tasked with gathering new knowledge about local communities and regional landscapes while also contributing to the universal project of modern science—and to the empire’s global reputation. As a daily exercise in scaling, Coen writes, the Habsburg lands “proved good to think with” for field scientists keen on relating local climatic conditions to emerging models of global atmospheric circulation.

Dynamic climatology also promised to resolve a political dilemma for its imperial masters. As the 19th century drew to a close, the Habsburg empire struggled most of all with its own purpose. During an age of nationalism and democratization, what was this cosmopolitan, aristocratic empire for? To whom did it belong? Why should it deserve the loyalty of its citizens?

The Habsburgs needed to transform considerable linguistic and political diversity into a feeling of imperial unity, to make local experience meaningful as part of the whole. The state’s existential challenge was an intellectual quandary for climate scientists such as Kerner and Hann, who spent their careers explaining how and why flowering azaleas and other local phenomena mattered for the planet’s climate in general. In other words, and this is the hinge of Coen’s masterful argument, scaling was a salient political problem no less than a scientific one for the researchers and rulers of Habsburg Europe.

In the Habsburg view of climate, tiny details and local variations were part of a planetary system of exchange and balance. Interactions among air masses, for instance, were framed not as struggles or battles but as cases of atmospheric mixing and equilibration. In pamphlets, atlases, encyclopedias, and newspapers, new climatological maps of Central Europe allowed Habsburg citizens to see the full territory at a glance and appreciate how harmony could arise from local diversity. Offering a vision of the empire as a healthy and robust zone of circulation and flux, dynamic climatology became what Coen calls “the ecological justification for Habsburg unity.”

Today, our main climate challenge is not scientific understanding so much as storytelling: how to convey what climatologists are learning about our planet’s health in a way that is imminent and real for ordinary people. When the Intergovernmental Panel on Climate Change released its bombshell report in October, the Washington Post media columnist Margaret Sullivan challenged journalists to “tell this most important story in a way that will create change,” to find a way of translating technical or abstract climate science into human dimensions. We are, after all, creatures of relatively brief life spans and local attachments, reckoning with a process of global scope set into motion by those who came before us that mostly threatens those to follow.

From disastrous hurricanes born overnight to the asphyxiating smoke of uncontrollable wildfires, extreme weather is rendering our knowledge of the changing climate ever more immediate and experiential. But even this may not be sufficient. As The New York Times recently reported, the damage wrought in Georgia by Hurricane Michael left local climate skepticism intact.

We might look to the climate pioneers of Central Europe for help. After all, these men invented a bevy of new techniques for conveying the significance of climatology to the general public. Kerner’s ingenious use of Alpine azaleas to register profound but imperceptibly slow change is an obvious candidate. In a beautiful chapter titled “The Floral Archive,” Coen reminds us that living plants “bridge the temporal scales of human history and geohistory” by triggering sensory experiences as well as strong memories: the scent of cedar, the smoothness of an arbutus trunk, the warmth of autumn leaves.

The most inventive Habsburg creation was climatography: an interdisciplinary style of nature writing that combined information about overall climatic trends with an almost poetic attention to tiny details and a sense of physical motion. This was literature that tried to convey to nonexpert readers, as the poet Rainer Maria Rilke later observed, “how much splendor is revealed in the smallest things, in some flower, a stone, the bark of a tree, or a birch leaf  … The small is as little small as the big is big.”

In one sense, at least, we are still like the Habsburgs: Our environmental problems are not so easily separated from our political ones. It’s impossible not to sense the ebbing strength of facts and figures in our public life, the rise of feeling and instinct as our chief ways of knowing and acting. This, most of all, is what the climate scientists of Habsburg Europe have to tell us: not that we should start creating climatographies or floral archives (though it wouldn’t be a bad idea), but rather that any collective action depends upon our ability to manage what Coen calls “the emotional work of scaling,” the visceral responses generated by the business of understanding and responding to climate change. If we can channel the ingenuity of the Habsburg climatologists, we might just stand a chance.