Anthropogenic climate change is usually portrayed as a recent discovery, with a genealogy that extends no further backwards than Charles Keeling sampling atmospheric gases from his station near the summit of Mauna Loa in the 1960s, or, at the very most, Svante Arrhenius’s legendary 1896 paper on carbon emissions and the planetary greenhouse. In fact, the deleterious climatic consequences of economic growth, especially the influence of deforestation and plantation agriculture on atmospheric moisture levels, were widely noted, and often exaggerated, from the Enlightenment until the late nineteenth century. The irony of Victorian science, however, was that while human influence on climate, whether as a result of land clearance or industrial pollution, was widely acknowledged, and sometimes envisioned as an approaching doomsday for the big cities (see John Ruskin’s hallucinatory rant, ‘The Storm Cloud of the Nineteenth Century’), few if any major thinkers discerned a pattern of natural climate variability in ancient or modern history. The Lyellian world-view, canonized by Darwin in The Origin of Species, supplanted biblical catastrophism with a vision of slow geological and environmental evolution through deep time. Despite the discovery of the Ice Age(s) by the Swiss geologist Louis Agassiz in the late 1830s, the contemporary scientific bias was against environmental perturbations, whether periodic or progressive, on historical time-scales. Climate change, like evolution, was measured in eons, not centuries.

Oddly, it required the ‘discovery’ of a supposed dying civilization on Mars to finally ignite interest in the idea, first proposed by the anarchist geographer Kropotkin in the late 1870s, that the 14,000 years since the Glacial Maximum constituted an epoch of on-going and catastrophic desiccation of the continental interiors. This theory—we might call it the ‘old climatic interpretation of history’—was highly influential in the early twentieth century, but waned quickly with the advent of dynamic meteorology in the 1940s, with its emphasis on self-adjusting physical equilibrium.footnote¹ What many fervently believed to be a key to world history was found and then lost, discrediting its discoverers almost as completely as the eminent astronomers who had seen (and in some cases, claimed to have photographed) canals on the Red Planet. Although the controversy primarily involved German and English-speaking geographers and orientalists, the original thesis—postglacial aridification as the driver of Eurasian history—was formulated inside Tsardom’s école des hautes études: St Petersburg’s notorious Peter-and-Paul Fortress where the young Prince Piotr Kropotkin, along with other celebrated Russian intellectuals, was held as a political prisoner.

The famed anarchist was also a first-rate natural scientist, physical geographer and explorer. In 1862, he voluntarily exiled himself to eastern Siberia in order to escape the suffocating life of a courtier in an increasingly reactionary court. Offered a commission by Alexander ii in the regiment of his choice, he opted for a newly formed Cossack unit in remote Transbaikalia, where his education, pluck and endurance quickly recommended him to lead a series of expeditions—for the purposes of both science and imperial espionage—into a huge, unexplored tangle of mountain and taiga wildernesses recently annexed by the Empire. Whether measured by physical challenge or scientific achievement, Kropotkin’s explorations of the lower Amur valley and into the heart of Manchuria, followed by a singularly daring reconnaissance of the ‘vast and deserted mountain region between the Lena in northern Siberia and the higher reaches of the Amur near Chita’,footnote² were comparable to the Great Northern Expeditions of Vitus Bering in the eighteenth century or the contemporary explorations of the Colorado Plateau by John Wesley Powell and Clarence King. After thousands of miles of travel, usually in extreme terrain, Kropotkin was able to show that the orography of northeast Asia was considerably different from that envisioned by Alexander von Humboldt and his followers.footnote³ He was also the first to demonstrate that the plateau was a ‘basic and independent type of the Earth’s relief’ with as wide ‘a distribution as mountain ranges’.footnote⁴

Kropotkin also encountered a riddle in Siberia that he later tried to solve in Scandinavia. While on his epic trek across the mountainous terrain between the Lena and the upper Amur, his zoologist comrade Poliakov discovered ‘palaeolithic remains in the dried beds of shrunken lakes, and other similar observations gave evidence on the desiccation of Asia’. This accorded with the observations of other explorers in Central Asia—especially the Caspian steppe and Tarim basin—of ruined cities in deserts and dry lakes that had once filled great basins.footnote⁵ After his return from Siberia, Kropotkin took an assignment from the Russian Geographical Society to survey the glacial moraines and lakes of Sweden and Finland. Agassiz’s ice-age theories were under intense debate in Russian scientific circles, but the physics of ice was little understood. From detailed studies of striated rock surfaces, Kropotkin deduced that the sheer mass of continental ice sheets caused them to flow plastically, almost like a super-viscous fluid—his ‘most important scientific achievement’, according to one historian of science.footnote⁶ He also became convinced that Eurasian ice sheets had extended southward into the steppe as far as the 50th parallel. If this was indeed the case, it followed that with the recession of the ice, the northern steppe became a vast mosaic of lakes and marshes (he envisioned much of Eurasia once looking like the Pripet Marshes), then gradually dried into grasslands and finally began to turn into desert. Desiccation was a continuing process (causing, not caused by, diminishing rainfall) that Kropotkin believed was observable across the entire Northern Hemisphere.footnote⁷

An outline of this bold theory was first presented to a meeting of the Geographical Society in March 1874. Shortly after the talk, he was arrested by the dreaded Third Section and charged with being ‘Borodin’, a member of an underground anti-tsarist group, the Circle of Tchaikovsky. Thanks to this ‘chance leisure bestowed on me’, and special permission given by the Tsar (Kropotkin, after all, was still a prince), he was enabled to obtain books and continue his scientific writing in prison, where he completed most of a planned two-volume exposition of his glacial and climatic theories.footnote⁸

This was the first scientific attempt to make a comprehensive case for natural climate change as a prime-mover of the history of civilization.footnote⁹ As noted earlier, Enlightenment and early Victorian thought universally assumed that climate was historically stable, stationary in trend, with extreme events as simple outliers of a mean state. In contrast, the impact of human modification of the landscape upon the atmospheric water cycle had been debated since the Greeks. For instance, Theophrastus, Aristotle’s heir at the Lyceum, reportedly believed that the drainage of a lake near Larisa in Thessaly had reduced forest growth and made the climate colder.footnote¹⁰ Two thousand years later, the Comtes de Buffon and de Volney, Thomas Jefferson, Alexander von Humboldt, Jean-Baptiste Boussingault and Henri Becquerel (to give just a short list) were citing one example after another of how European colonialism was radically changing local climates through forest clearance and extensive agriculture.footnote¹¹ (‘Buffon’, wrote Clarence Glacken, ‘concluded it was possible for man to regulate or to change the climate radically.’)footnote¹² Lacking any longterm climate records that might reveal major natural variations in weather patterns, the philosophes were instead riveted by the innumerable circumstantial reports of declining rainfall in the wake of plantation agriculture on island colonies. In the same vein, Auguste Blanqui’s older brother, the political economist Jerome-Adolphe Blanqui, later cited Malta as an example of a man-made island desert and warned that the heavily logged foothills of the French Alps risked becoming an arid ‘Arabia Petraea’.footnote¹³ By the 1840s, according to Michael Williams, ‘deforestation and consequent aridity was one of the great “lessons of history” that every literate person knew about.’footnote¹⁴

Two of these literate people were Marx and Engels, both of whom were fascinated by the Bavarian botanist Karl Fraas’s cautionary account of the transformation of the eastern Mediterranean climate by land clearance and grazing. Fraas had been a member of the impressive scientific retinue that accompanied the Bavarian Prince Otto when he became King of Greece in 1832.footnote¹⁵ Writing to Engels in March 1868, Marx enthused about his book: