The Next Great Migration: The Story of Movement on a Changing Planet
By Sonia Shah | Bloomsbury | $29.99 | 400 pages
The story opens and closes with butterflies. Checkerspots, to be precise: a sedentary, low-flying variety known as “the entomological equivalent of homebodies,” the study of which triggered a massive shift in scientists’ understanding of how wild species adapt to a changing planet more than two decades ago.
It is a fitting motif in a text that leaves no doubt about the butterfly effect. The Next Great Migration uncovers a living, moving, evolving planet in which all organisms are — and always have been — far more interconnected than believed. The smallest of changes sets in motion events that radically transform life on the other side of the world, or effects that are still felt centuries later.
Sonia Shah meticulously teases out these transformations and interconnections, taking readers not just to the science but to the very sources of scientific knowledge. The acclaimed author of Pandemic and The Fever, she is a veteran investigator of matters of history and science. Here, she turns her lens on two of the greatest challenges our future holds: climate change and migration. The result is a fascinating, sweeping and at times confronting audit of movement and survival — both human and “wild” — through history.
Shah’s central thesis is that movement is an inherent, constant and unstoppable feature of life on this planet. Movement isn’t an “anomaly,” an “aberration,” an “exception,” a “catastrophe” or a “violation of the natural order”; it is essential, and provides possibly our best and only chance at surviving the impending effects of a warming earth. It is potentially life-saving, not just for those who move but also for those receiving migrants into their midst.
The book’s greatest strength lies in how its stories, human and wild, are juxtaposed and interwoven. After opening with a series of vignettes depicting plants and animals on the move, Shah shifts her focus to migrants, refugees and people driven from their homes by disasters and climate. While the movements of wild species are constrained primarily by their own biological capacities and the geographic features they encounter on their journeys, the paths of human migrants are shaped (and often blocked) by abstractions — legal and political barriers to movement rooted, often, in historical racism and xenophobia.
Shah’s vivid storytelling brings to life enthralling revelations. Coral reefs, “literally stone walls,” are moving northward at a speed of fourteen kilometres per year. Forests are steadily climbing the Himalayas of their own accord, at a rate of nineteen metres each decade; their march brought the first known mosquitos to Tibet in 2009.
Other revelations will be more unsettling, even for the most enlightened of readers. Shah discredits much of the underlying work that has led to the classification of living things as being “from” certain places, debunking any notion of stability or stagnation among wild species. She also draws from science to argue that the arrival of “alien” species in established habitats can be positive, promoting biodiversity and filling “gaps” in existing ecosystems rather than destroying their delicate balances as once feared.
But the results of Shah’s investigation of anti-migrant sentiment make for the book’s most disturbing moments. She takes familiar narratives of migrants as national security threats, health risks, violent criminals and purveyors of social destruction and methodically debunks them. In doing so, she reveals how these narratives managed to take root in the first place. Her conclusions would be troubling at any time but are especially so in the “fake news” era. She demonstrates not only that such narratives run far wider and deeper than the populist Trump administration but also that they are the direct successors of a long line of bogus claims, dressed up as some of history’s most respected scientific truths.
As Shah traces the origins of scientific thought from eighteenth-century European naturalists through to their twentieth-century descendants, much of what she describes is grotesque. The abuse of African bodies in the name of “science” is appalling, particularly where it involved preoccupation with the sex organs of African women. Even after the focus shifts from “race” to global population control, the shocking stories continue, including one in which Indian police threatened to massacre a village of mostly poor Muslim families in the 1970s if the men and boys did not surrender themselves for forced vasectomies.
The common thread through the centuries is a crazed search for proof that humans can be divided into distinct groups, some biologically superior to others. Readers who don’t subscribe to such notions may be shocked to learn how certain words and concepts common to our modern vocabulary derive from these views. These insights are deliberately discomforting, forcing readers to acknowledge the extent to which apparently outdated notions of racial difference and disproven science still shape our lives in various ways.
In exposing the racist roots of anti-migrant sentiment and presenting scientific evidence that living creatures have always moved, Shah’s treatment of her subject matter is not always entirely dispassionate. At times she seems to be downplaying the very real threats that migration can pose. Moreover, some tensions between what she uncovers and prevailing beliefs about migration remain unresolved. Past and present attempts to classify all living creatures as from a fixed place and to stifle movement may be flawed, but that does not negate the fact that people, plants and animals are “from” certain places, and some migrations are exactly as destructively catastrophic as feared. Shah does not provide easy answers, and in some cases the existential and intellectual challenge she sets for her readers is compelling. But this tension is one with which an Australian readership in particular may feel unease.
Much of Australia’s native flora and fauna is unique, and a source of national pride. Far from promoting biodiversity, the introduction of “alien” species such as rabbits and cane toads has previously wrought great harm on our native ecosystems. Moving from the wild to the human, the attempt to uncouple people from specific places becomes outright problematic. Aboriginal and Torres Strait Islander peoples are from Australian lands, deriving from them identity, history and culture. Meanwhile, this country is still marred by the destructive legacy of British migration to Australia. Far from promoting biodiversity, that great migration resulted in genocide, the loss of language, culture and knowledge that can never be restored, and critical ongoing disparities between Indigenous and non-Indigenous Australians.
Nor do generalisations about migrant demographics hold true the world over, and certain aspects of Shah’s critique of barriers to human movement are misdirected. She is unduly disparaging of the Refugee Convention, and her explanation of its refugee definition is not entirely accurate. The book also makes only fleeting mention of the world’s 45.7 million internally displaced people, despite the fact that they far outstrip the number of refugees worldwide and potentially belie some of Shah’s conclusions about human movement.
But my biggest reservation relates to Shah’s engagement with the titular subject matter. “The next great migration is upon us,” she declares, early in the piece, but it is not until the second-last chapter that we get some idea of what that might be. Whereas human migration historically “flowed more rapidly from east to west,” Shah predicts that the pattern will “switch” in the new era, “flowing from south to north along the gradient of our warming planet.” The pace will be faster, she claims, with migrations unfolding over years and decades rather than centuries and millennia.
The evidentiary bases for these claims are neither articulated nor supported by reference material. Earlier, Shah writes that “a wild exodus has begun,” as animals and plants migrate towards the poles in search of cooler lands and waters. It is possible that she has extrapolated the future trajectory of human movement from scientific observations of other species. But even those movements are only northwards in the northern hemisphere. Surely, if humans were to follow our “wild cousins,” that would mean migration in both directions away from the equator.
Even then, does it necessarily follow that humans would move along the same routes, or deploy the same survival strategies, as other living creatures? As Shah herself documents, humans have long lived in and adapted to seemingly inhospitable climates and forbidding landscapes. Before modern political and physical barriers to movement were erected, all of humanity didn’t try to crowd into the most temperate patches of the earth’s surface.
With the adverse impacts of disasters and climate change intensifying, adaptation strategies must include mobility options; but, as Shah rightly explains, some of this mobility will involve temporary or seasonal movements, or follow opportunities for work rather than a cardinal direction. Preventative mitigation measures might even limit the need for migration at all and should be pursued as a priority for those communities that wish to remain in their homes as long as possible.
A massive and relatively fast displacement of human populations into the “Global North” in response to a warming planet is by no means a foregone conclusion. Nor is it in keeping with the recent history of forced migration, which has consistently seen displaced people remain close to home, overwhelmingly accommodated in developing countries.
But this failure to fully identify or provide supporting evidence for the “next great migration” doesn’t undermine the book’s value, for despite her title Shah’s purpose is to challenge readers to reflect deeply on the fundamental beliefs and supposedly incontrovertible “truths” that shape how we understand the living world more broadly. In this, she undoubtedly succeeds.
The “next great migration” may never eventuate, or not in the shape Shah predicts. But no readers will walk away from this book without a profound shift in their relationship with the world around them. •