Last year’s adoption of the Paris Agree- ment signaled widespread political will to reach net-zero greenhouse gas emis- sions by midcentury while aiming to keep the rise in global average tempera- tures to well below 2°C above preindus-
trial levels. More than 100 nations ratified
it, and the mood was optimistic as countries
reconvened this year to talk implementation.
That is, until the U.S. election put climate
change denialism back on the table.
As political momentum slows, perhaps
there is no better time to glance at the “rear-
vision mirror of history,” as suggested by
Anthony McMichael in Climate Change and
the Health of Nations. The book’s goal is not
to make predictions but to motivate change,
which McMichael does by bringing into focus
humanity’s sensitivity to fluctuations in the
natural climate system throughout history.
McMichael, an epidemiologist, published
prolifically on the relationship between
changing climates and human health during his four-decade-long career. This is the
last full-length work he completed before
his unexpected death in 2014. True to his
legacy, McMichael puts people front and
center in the story.
The book weaves together historical
threads, multiple fields of science, and refer-
ences to art and literature, as if McMichael is
gathering the strands of his knowledge. Its
power derives from synthesis.
Our journey through Earth’s evolutionary
phases begins in the Cambrian explosion
540 million years ago and continues through
the Pleistocene to the beginning of our current epoch, the Holocene, aka our “climatic
comfort zone.” Cue the spread of farming
and, as more food begets more people, the
rise of towns, cities, and civilizations. Along
the way, the book describes climate-enabled
developments in agriculture, environmental
pressures that caused the rise and collapse
of empires, and the increase in natural resources demanded by ever-more-prosperous
and complex societies.
We see how cooling temperatures forced
early Europeans to abandon settlements
and make do with less-productive farming
and how unusually cool and humid condi-
tions ushered in the bubonic plague and
contributed to the fall of the Roman Em-
pire. The Mayan civilization, we learn, met
a similar fate, in part as a result of severe
drought that brought food shortages, con-
flict, and migration. As we reach modern
times, the information gets richer and
more familiar: food and water shortages,
extreme weather disasters, the first cholera
Food shortages emerge as the greatest
recurring risk. But McMichael is careful
to note that climatic variation does not act
alone in major crises. More often than not,
it gives an “extra punch” to other forces,
such as environmental degradation, social
unrest, and displacement.
Just 6°C separates the emergence of early
farming 11,000 years ago from the end of
the glacial period that preceded it, McMi-
chael notes, giving context to the 3° to 4°C
increase expected this century if current
emission rates are maintained. And it’s not
just ecological systems that are vulnerable
to small variations in temperature: Human
biology evolved in times of stability, slowly
adapting to climatic variations through nat-
ural selection. The book calls on a frame-
work for understanding the vulnerability of
species and systems to climate change, cat-
egorizing the evidence according to expo-
sure, susceptibility, and adaptive capacity.
Here, McMichael is at his most critical.
He sees naiveté in arguments that human
ingenuity will get the world out of trouble
and laments the pursuit of incremental
technical fixes. An instance of optimism
about the rise of renewable energy soon
fades under the weight of an array of per-
ceived structural and scientific barriers.
Ultimately, the book traces our failure to
adapt and respond to climate change to an
economic paradigm that equates material
growth with progress, overlooking the value
of natural wealth.
Scepticism, doubt, and denial don’t es-
cape McMichael’s attention. He argues that
not believing in climate change originates
from a human tendency to favor urgent,
survival-enhancing reactions over respond-
ing to gradual changes. Can the brainpower
we evolved in times of climatic stability be
channeled toward changing the behavior
that undermines this stability? he asks.
McMichael concedes that change is not
easy. He focuses on motivating action by
speaking to the public about climate change
not in the abstract but in terms that are
closer to home, akin to everyday experience.
Through education and informed discussion,
let’s talk of debilitating heat, not emissions;
parched crops, not scenarios; infectious microbes in the water we drink, not targets.
This way, he says, there may be a chance to
activate a “fight or flight” response that befits this threat to our survival. j
Back to the future
An epidemiologist takes a long view of our fraught
relationship with the environment
BOOKS et al.
The reviewer is a freelance writer and editor based in London.
By Anita Makri
Just 6°C separated the last glacial period from the
era in which early farming began, notes McMichael.
Climate Change and
the Health of Nations
Famines, Fevers, and the
Fate of Populations
Anthony J. McMichael
Oxford University Press,
2017. 390 pp.