The climate crisis is a kind of war, a violence that privileges some forms of life and eradicates others. It is, moreover, a long war, stretching back at least to the European invasions of Africa, Asia, and the Americas in the sixteenth century. Defined from an Indigenous perspective, anthropogenic climate change is “intensified colonialism,” as much as ongoing colonial warfare accelerates climate breakdown. It is the continuation of invasive regimes of terraforming and private property ownership meant to alienate—or eliminate—a land’s legitimate inhabitants. In this way, historical formations of empire and extractive capitalism laid the “groundwork” for the carbon-intensive economics that drive planetary crisis today.

Unearthed demarcates a critical juncture in this longue durée: a nineteenth-century moment of extraordinary intensification of the scale and violence of Euro-American schemes to govern large swathes of the planet. It was also, this book argues, a moment of corresponding intensification in sciences of earth and air, which then took on a planetary character. The two cannot, and should not, be disconnected. Telling here is the physique du monde or “global physics” of Prussian savant Alexander von Humboldt (1769–1859). A program of vast data collection and artful conjecture, physique du monde spanned four hemispheres in search of general laws of earth and environmental systems. The same claim to generality made global physics a key resource for aggressive European and settler states as they, in turn, sought to enclose frontier lands. Indeed, this is a history of the “groundwork” that made modern natures: an archaeology of environmental sciences assembled in the sphere of mineral extraction, first at the heart of Europe’s ore mining industry and then across empires east and west.

Perhaps most telling of all are historical accounts of climate as a conflict zone, the product of atmospheric surveys networked through diverse agencies of war and state building. From the North American frontier to the Eurasian steppe, physicists came to see the aridification of climate as a measure of “open war.” So said Gregor von Helmersen, a Baltic German, of a conflict he perceived at the southern rim of the Russian Empire in the 1830s. Helmersen charged Kazakh nomads with sabotaging the woodlands necessary for European settlement in the arid steppe, turning climate itself against the colonizers. There, as across northern Eurasia, imperial agents developed a model of meteorology drawn from another theater of environmental warfare, in North America. Early reports of the US Army’s meteorological program in the 1820s and 1830s are an unwitting record of the loss and damage of American woodlands and peoples. More than this, armed climate science was also a genocidal prophecy: said one US Army meteorologist, Joseph Lovell, “both these sons of the forest and the interminable wilderness they inhabited will, for all useful purposes, be as though they had never been.” US and Russian empires moved with remarkable symmetry thereafter, pressing deep into the continental interiors of the northern hemisphere. In 1848, as the United States laid claim to the trans-Mississippi West after the invasion of Mexico, Russian imperial forces seized great stretches of the trans-Caspian steppes that are now Kazakhstan.

Humboldt’s Prussia, a north German state seemingly removed from these empires, was actually central to them. Best remembered for his travels through Spain’s American colonies between 1799 and 1804, Humboldt also surveilled the northern Kazakh Steppe at Helmersen’s side in 1829. In fact, it was Humboldt who transmitted US Army meteorology to the Russian Empire. Central Europe was also embroiled in conflict in 1848: a popular revolution that Prussian meteorologists linked to climatic volatility caused by decades of deforestation. Soil became drier and rainfall scarcer amid the successive crop failures of the “Hungry Forties.” Still in 1859, the year of Humboldt’s demise, his followers warned that Germany stood on the brink of a forest-clearing, climate-altering war.

A great intensification was also taking place underground. Unearthed therefore has a profoundly vertical dimension, even as it moves across empires. Humboldt, after all, was a miner and “geognist” of the Saxon school. He trained at the famous Mining Academy in Freiberg and managed Prussian mines and manufactories in the 1790s. By the mid-nineteenth century, German miners began to unearth unprecedented quantities of mineral coal. German coal output more than doubled in the 1850s, outpacing even Britain, as the exploitation of the coalface from northern France and Belgium to Saxony and Silesia began to transform European society.

Carbonization was at once a global and a colonial process. By 1860, the same Helmersen as surveyed the steppe heralded a “new epoch” of energy in the Russian Empire: “one could call it a Carbon-period,” he told the Imperial Academy of Sciences. Helmersen was a major advocate for the exploitation of the Donetsk coal basin in modern Ukraine, which fueled imperial fantasies of a steam-powered, riverine assault on Central Asia. Also in 1848, Russian imperial troops carted two steamships nine hundred miles across the northern Kazakh Steppe. From the Aral Sea, they eyed the fertile headwaters of the rivers Amu Dar’ia and Syr Dar’ia, coveted for fossil fuels, silk, and cotton among other commodities. This, too, had a precedent in American imperialism. Armed steamers had already plied the Río Bravo during the US invasion of Mexico. Humboldt received direct reports from both fronts, having authored extensively mapped, multivolume works on colonial Mexico and Central Asia. Even from afar, the information order of global physics positioned the Prussian to advise on border surveys, coal prospects, and commodity production beyond the Río Bravo and Syr Dar’ia.

Humboldt’s apparent removal from these frontiers, and the language of liberation attached to his scientific project, warrants careful scrutiny here. It matters, in other words, that the agencies of state, empire, and capital that frame this story are also among the primary agents and beneficiaries of anthropogenic climate change. Studies of historic loss and damage attributions place the United States, nations of the European Union, and the Russian Federation alongside China and India in the top five contributors to global damages, a burden unevenly externalized. Germany joins Russia and the United States in reaping a net gain in GDP from fossil fuels, while poorer, often postcolonial nations from the Global South suffer disproportionately, unable to adapt and respond to a changing climate. The chapters that follow show how sciences practiced along Humboldt’s itineraries were formidable agents in the making of global asymmetries that still characterize our climate-changed world.

Sciences of the Humboldtian sort assembled models of the globe from far-flung industrial sites and frontier stations. But globalized geognosy and climatology did not merely measure or represent nature; nor can they be reduced to delocalized abstractions or imperious “visions.” Where others have focused on the intellectual and aesthetic program of “Humboldtian science,” this book shows the political and environmental agency of isotherms and geological profiles. Sciences of earth and air enacted new realities on (and under) the ground, operating through highly militarized and industrialized structures. At work across empires, those sciences had deep roots in the fiscal-military states and mining sectors of central Europe. After all, carbon surveys were already afoot in Germany in the 1790s, as steam engines drained the Silesian mines whence the Prussian “war-state” sourced iron for arms manufacture. Helmersen’s vision for fossil-fueled empire around 1860 amplified an argument from Humboldt’s earliest days as a miner: Both saw mineral coal as a solution to rampant deforestation and, by extension, to climate change. Unearthed therefore pursues history as reportage, accounting for an age of intensified extractivism and territorialization, an age whose legacy is still up in the air.