Discussed in this essay:

Nature’s Mutiny: How the Little Ice Age of the Long Seventeenth Century Transformed the West and Shaped the Present, by Philipp Blom. Liveright. 352 pages. $27.95.

Origins: How Earth’s History Shaped Human History, by Lewis Dartnell. Basic Books. 352 pages. $18.99.

The Fate of Rome: Climate, Disease, and the End of an Empire, by Kyle Harper. Princeton University Press. 440 pages. $35.

“Something’s changing,” said our dear leader, “and it’ll change back again.” This particular flavor of gaslighting dates back several decades. Like any canny half-truth, it grafts insinuations onto an unassailable fact. It is true, after all, that the global climate has changed drastically before, and that it will change again . . . some millennia from now. It is also true that many of these past changes brought on mass global death. Our concerns about climate change, to restate the obvious, are not for the climate itself. Our concerns are for our civilization, which has organized its infrastructure, trade, national borders, food production, and cities around specific climatic conditions under the assumption that they are permanent. Even a slight unsettling of these conditions will, like the shifting of tectonic plates, cause seismic upheavals. Unlike most matters of global political significance, there is no direct historical analogue for our situation—the unprecedented nature of the crisis is part of its horror. But human beings have endured climatic changes before. A growing historical subdiscipline (cli-hi?) has developed to examine how they managed it. With horrific suffering is the short answer, but Philipp Blom, a German translator and journalist who lives in Los Angeles, proposes in Nature’s Mutiny an artful corollary: that the hardships of a changing climate spurred the creation of what we think of as modern civilization, while at the same time inscribing within its genetic code the germ of its own demise.

The Fair on the Thames, Feburary 4th 1814, by Luke Clennell © The Trustees of the British Museum/Art Resource, New York City

Blom’s subject is Europe between the years 1570 and 1684, the height of what is commonly known as the Little Ice Age. “Europe was a frosted world,” two degrees Celsius colder than historical averages. Even its poetry shivered with frosted laments for a reprieve or, more cheerfully, merciful oblivion:

Just God, whence will things go
With these times of cold?
—Simon Dach

The sun no longer sends bright rays,
The clouds are raining like a fount,
The tears too plentiful to count.
—Paul Gerhardt

I can scarcely move or draw my breath?
Let me, let me freeze again to death.
—Henry Purcell

The sun dimmed in the sky; trees grew more slowly; birds fell to the ground like sleet, freezing mid-flight; wine regions migrated two hundred and fifty miles south; wheat harvests were insufficient for a century and a half; the seas were so choked with pack ice that at times ships could not enter or leave London; imperial armies marched across the frozen Danube; and forty sperm whales beached on the Dutch coast. The putrefaction of the rotting leviathans was so violent that several curious onlookers dropped dead after taking a whiff.

The anecdote that best stands for this cold century, however, is the Frost Fair. The Thames has not frozen for more than two hundred years, but at the end of 1683 it froze so thick that merchants extended the streets of London into the river, establishing a “carnival on the water.” Along the ice alleys they erected wooden huts selling all manner of supplies, as well as taverns, brothels, a printing press, and open fires over which whole oxen rotated on spits. Across the river children skated and horses raced. The gelid air blocked the coal smoke from rising, making it difficult to breathe or even see across the street. “Every moment,” observed the seventeenth-century diarist John Ev­elyn, “was full of disastrous accidents.” This was generally the way with the Little Ice Age: civilization went on, turning deprivation into opportunity, while enduring near-­constant cataclysm.

Blom acknowledges that the Little Ice Age is an imperfect stand-in for our current Big Warming Age. It was not a uniformly global phenomenon, after all, but concentrated in Europe; it was not mainly caused by human activity but by a still-mysterious conflation of geophysical events, which likely included deviations in ocean circulation and solar activity. Nevertheless, Blom proposes that it “provides an ideal case study of the subtle interactions between climate change and cultural change.” It was Roger Revelle and Hans Seuss who, in 1957, wrote that human beings, with our profligate consumption of fossil fuels, “are now carrying out a large-scale geophysical experiment of a kind that could not have happened in the past nor be repeated in the future”; Blom characterizes the Little Ice Age in the same terms, as “an experiment with an entire biological system”:

What happens if one changes a system’s parameters—the temperature, the weather, the climate? What will collapse and what will endure? Who will live and who will die? Will those creatures whose very existence is threatened . . . find some way, despite all that has changed, to establish themselves again, and to flourish?

It is this final suggestion—the flourishing­—that distinguishes Blom’s work from earlier accounts of the subject, particularly Brian Fagan’s The Little Ice Age: How Climate Made History, 1300–1850, to which Blom seems indebted; Sam White’s A Cold Welcome: The Little Ice Age and Europe’s Encounter with North America; and Barbara Tuchman’s 1978 classic of the subgenre, A Distant Mirror: The Calamitous 14th Century. In Blom’s telling, the prolonged cold, and the calamities it yielded, forced profound transformations of economic strategy, agricultural practice, political structure, educational systems, and philosophical thought.^* “New ways,” Blom writes, “had to be found in order to meet the challenges of a world that appeared to have become unnatural.” His thesis is Darwinian: under environmental pressures, the fittest adapted, and thrived. We are their descendants.

The general effect is of a concise primer on the European seventeenth century, digesting more than a hundred years of continental history into a bouncy survey of notable figures, battles, and social phenomena. “Finding coping mechanisms,” writes Blom, “was an existential challenge.” Faced with declining harvests, the argument goes, European farmers began to experiment with potatoes, tomatoes, and maize, consumed more beef and milk, and found that manure and crop diversification helped increase grain production. Unable to sustain their own citizens, nations relied more heavily on foreign trade, creating a new burgherdom of merchants, experts, and administrators—a rising middle class that sought to provide their children formal educations. With increased trade, faith in the Church was replaced, as society’s central organizing principle, by faith in the Market. A modern economy required strong laws, reliable institutions, impartial courts, and effective regulatory bodies. The cultural transformation Blom describes reaches its apotheosis in the final third of his book, in which he credits the climatic changes with bringing about, in a Rube Goldberg series of events, the birth of the Enlightenment and modern ethics: the Age of Reason. All thanks to two degrees.

It is a sympathetic argument—the contemporary reader, desperate for a silver lining to our own climate nightmare, warms to it easily. It is impossible to miss, however, that despite Blom’s having more than a century of history to draw from, his evidence has more hedges than the Boboli Gardens: we get verbal feints like “word had it” and “there were reports of,” a smattering of possiblys, arguablys, and perhapses, and, most deflatingly, after the wild theory that an increase in the salt content of the oceans might have led to a rise in volcanic activity: “This, however, is merely a hypothesis.” Another striking proposition, that the denser wood of stunted ice-age trees yielded stringed instruments of unusual resonance, unfolds for a page before we learn that it has been largely dismissed by scientists. To his credit, Blom even notes some caveats large enough to undermine his central thesis, such as the fact that severe winters in Russia, China, and the Ottoman Empire during the same period did not yield any comparable intellectual renaissance.

A third-century Roman mosaic depicting plowing and sowing from Saint-Romain-en-Gal, France © Erich Lessing/Art Resource, New York City

A more rigorous approach can be found in The Fate of Rome: Climate, Disease, and the End of an Empire, in which Kyle Harper, a classicist at the University of Oklahoma, draws on femur measurements, solar irradiance data, El Niño events recordedin ancient sedimentation, and charts of wheat prices between the reigns of Nero and Aurelian to argue that “bacteria, viruses, volcanoes, and solar cycles” were at least as significant to the Roman Empire’s decline and fall as were Alaric the Visigoth and Attila the Hun. The empire reached its apex during what paleoclimatologists have named the Roman Climate Optimum—­­a period, between 200 bc and 150 ad, during which the Mediterranean basin was consistently warm and humid. Though Harper reserves the greatest emphasis (and his best descriptive writing) for the influence of infectious diseases, he argues that climate change was the “wild card transcending all the other rules of the game,” heavily influencing the demographic patterns and the forms of agricultural production on which the structures of society rested. After the RCO, the Romans’ luck ran out. The next three centuries were marked by “raucous climate disorganization”; this was followed by its own cooling period, the Late Antique Little Ice Age, induced by a burst of volcanic activity and solar dimming, lasting until 700 ad—at which point Rome’s population had dropped from one million to twenty thousand, very few of whom likely had heard of the Roman Empire.

We can leave it to historians of antiquity to balance the significance of Stilicho’s military strategy against the volcanic winters of the late 530s, the crusades of Justinian against those of the bubonic plague. What is most valuable to nonspecialists about this new kind of narrative is its insistence on the centrality of environmental factors in human affairs. Historians have always considered the influence of climate on the fortunes of empires, dispositions, armies; even Gibbon refers frequently to climatic factors (“the keen air of Germany formed the large and masculine limbs of the natives, who were, in general, of a more lofty stature than the people of the South”). The difference in the last couple of decades is that scholars have been given the keys to a new permanent collection, what Harper calls our “natural archives”: the ice cores, bones and teeth, marine sediments, tree rings, glaciers, and lake deposits that preserve the planet’s medical records in exquisite detail. This new knowledge calls for a new kind of close textual reading. “The hard question,” writes Harper, “has become not whether, but how, to insert the influences of the natural environment into the sequence of cause and effect.”

Harper settles on a half-and-half approach—half plague and climate change, half political and military history. In Origins: How Earth’s History Shaped Human History, Lewis Dartnell, a British astrobiologist, takes a maximalist approach, in which human history is revealed as the inevitable outcome of celestial detonations, erosion, and solar flares. Beyond a certain point, this approach acquires a metaphysical sheen:

The water in your body once flowed down the Nile, fell as monsoon rain onto India, and swirled around the Pacific. The carbon in the organic molecules of your cells was mined from the atmosphere by the plants that we eat. The salt in your sweat and tears, the calcium of your bones, and the iron in your blood all eroded out of the rocks of Earth’s crust; and the sulphur of the protein molecules in your hair and muscles was spewed out by volcanoes.

The last ice age enabled humanity to populate the planet; climatic aridification some twenty million years ago led to our predilection for breakfast cereal; and British voting patterns correlate to the island’s deposits of carboniferous coal (the correlation is even stronger in the United States, though politically inverted—the UK coal counties vote Labour, the US coal counties vote overwhelmingly for the party of climate change denial). Like Philipp Blom, Dartnell argues that rapidly fluctuating climatic conditions favored those of us most able to adapt, thereby stimulating the advancement of human intelligence. What doesn’t kill us makes us smarter.

Such broad-stroke environmental determinism may wade into overcorrection, but it does at least have the virtue of correcting one of the most terrifying blind spots in the public discussion of climate change: its diminished political stature. This is one of the lesser-known byproducts of industry-funded climate denialism. Beyond sowing doubt and ignorance, denialism’s most impressive accomplishment is to turn an existential threat that touches every aspect of our civilization into a pet partisan issue, of equal, or more often lesser, stature than health care, economic inequality, immigration, civil rights, foreign policy, and the rest of the campaign season checklist. But climate change is not the equal of these issues. It encompasses them all. The climate crisis amplifies every problem it touches: it discriminates against the discriminated against, it sickens the frail, it goes easy on the rich and punishes the poor, it supercharges immigration, elevating regional tensions and the likelihood of war. The kind of action now necessary to avoid worst-case scenarios will require more than a consensus agreement among American voters to reduce carbon emissions. As the Intergovernmental Panel on Climate Change, a body not known for its audacity, has declared, for action to be effective it must entail “rapid, far-reaching and unprecedented changes in all aspects of society.” That means reducing carbon emissions must become the highest political priority—ahead of every other policy issue or, more conveniently, as a framework for addressing social inequality in all of its manifestations.

Philipp Blom is not particularly optimistic. “The rich Western societies of today are no more effective in combating climate change than those that existed around the year 1600,” he writes. “The occurrence of some kind of dramatic collapse seems to be only a question of time.” We are rapidly approaching the inevitable end point of an economic system that relies upon exploitation of resources, workers, the poor, he argues. We are too stubborn, too enraptured with the free market, to save ourselves in time.

Yet Blom’s own history suggests another possibility. If changes in climate spur profound changes in economic thought, philosophy, and the political and social order, might not such a profound shift occur again? It will have to. Blom thinks such a transformation can only occur if we abandon our faith in the invisible hand of the market—a faith “theological in nature”—and understand the degree to which our fate is tied to the protection of our physical environment.

An analogous intellectual transformation occurred in the 1670s in the Dutch provinces, where the Jewish lens grinder Baruch Spinoza overcame the ideological divide that had stymied Western thought for centuries. (Heinrich Heine: “All our modern philosophers . . . see through the glasses which Baruch Spinoza ground.”) Before Spinoza, intellectual thought had to square with the letter of the Bible, under the penalty of death; Blom recounts the cautionary tales of Giordano Bruno, burned at the stake for speaking of parallel worlds and an infinite universe, and Lucilio Vanini, the author of wily essays about the incompatibilities between Christian doctrine and rational thought, who was also burned, but only after having his tongue ripped out and being strangled.

In Blom’s telling, Spinoza’s Ethics marked the break between the medieval and modern worldviews. Spinoza’s method is to turn theological doctrine inside out, until it devours itself. Taking literally the notion that God is perfect and omnipresent, he deduces that God and nature are synonymous. (This is a convenient solution to the theology trap, for if God is everything we see, think, and feel, then He is also nothing.) It follows that an ethical life is one lived in accordance with nature. This requires liberating ourselves from ungoverned passions, which only cause suffering and confusion, and appealing instead to reason and the pursuit of knowledge. Spinoza does not call for the abandonment of self-interest but calls instead for an enlightened self-interest, which recognizes that we are most free when we act with shared purpose: “although men are generally governed in everything by their own lusts, yet their association in common brings many more advantages than drawbacks.” Blom, overlooking certain passages of the Ethics (such as those calling for human beings to exploit nature when it suits us), summarizes Spinoza’s conclusion this way:

if we analyze our situation, it becomes clear that our best chance to survive well, and with the least degree of restraint, lies in acting in solidarity with others in order to create a world in which people can live with dignity.

Activists, philosophers, and politicians are increasingly beginning to make this very claim about climate change: that inaction is not only irrational, a profound threat to our own sense of self-preservation, but immoral. It is immoral exactly because it threatens our self-interest. You hear a version of this argument in Bruno Latour’s insistence that favoring short-term interests over long-term human survival is not an instinctual behavior but one conditioned by economic and political factors. You hear the same argument when South Bend mayor Pete Buttigieg, likely the only millennial who will run for president in 2020, speaks of “intergenerational justice,” when the pope calls for solutions to climate change “not only in technology but in a change of humanity,” and when the sixteen-year-old Swedish activist Greta Thunberg tells world leaders that they are stealing their children’s future right in front of their very eyes. You will hear this argument grow louder and louder until, before very long, you won’t be able to hear anything else.