It is May nineteenth and about fifty degrees in the shadow of Eklutna Glacier in Alaska’s Chugach State Park. My companion
and I bicycled in on a rough gravel road for twelve miles. The gravel road was lined with birch and aspen and poplar in their
full spring foliage, no longer simply budding but truly leafed out. At the end of the gravel road, we abandoned the bicycles
and walked another mile through patches of snow and across shattered rocks and boulders as big as cars. We scampered over
bedrock carved out by ice and smoothed by meltwater. Throughout, our dog trotted along behind, but here, just below the glacier,
we surprise a mountain goat. The goat lures our dog along, staying just ahead of him, moving up toward the glacier. Both dog
and goat ignore our calls.
Where we stop, waiting for our dog, the glacier has resided recently, probably within our lifetimes. A few wind-borne seeds
have taken hold. Dryas, not yet in bloom, lines cracks in the rocks. Here and there, saxifrage has gained a toehold in dirt-filled
depressions — its lavender flowers are open — but most of the ground is bare rock. A steady wind blows off the glacier and
across the rock. Up the valley, what is left of the glacier is profiled with steep ridges and crevasses of white snow and
blue ice. It looks distinctly like a glacier on its way out. Just below us, meltwater paints a pond azure. A quagmire of wet
glacial flour surrounds the pond. Farther down, where glaciation is a somewhat more distant memory, patches of shrubs and
even trees grow along the slopes. In places, the ground has collapsed, liquefied by melting snow and failing under its own
weight or carried away in avalanches. Along the edges of the collapses, the young soil stands exposed, a fragile veneer, a
thin skin creeping in behind the glacier. Far down the valley, past the collapses, the landscape is similar to that of Scotland,
scarred by long-gone ice but more or less healed.
The goat reappears a quarter of a mile up the valley. Our dog comes limping back. The pads of his feet have been torn open,
and he trembles in pain and fear. Out of sight, something happened. The goat butted him, or he tripped and slid on rocks and
ice.
This is the sort of scene that would have been common when the Pleistocene ice pulled back: bare rock, patches of snow, struggling
vegetation, constant wind, unstable soil, and animals that do not know how to behave.
I
t is June second and just over sixty degrees in London. My taxi driver talks of plans for an afternoon on a Brighton beach
after he has dropped me at Heathrow Airport. He insists on pointing out the sights. When he points out Kew Gardens, I ask
if he knows that a polar bear skull was found there. During the Pleistocene, I tell him, polar bears roamed through what would
become downtown London. “The bears,” I say, “were as big and white as German and American tourists visiting Westminster Abbey.”
We ride the remaining twenty minutes in silence.
I fly for six hours above seas recently thawed and land that was glaciated only yesterday, and then I sit in Boston traffic.
The thermometer stands north of eighty degrees. Cars battle for position, each belching carbon dioxide at an ice-age-killing
rate of something like eight tons per year. In my midsize rental, I turn on the air conditioner. Prior to this, I have not
turned on a car air conditioner in at least ten months. The temperature drops abruptly. As abruptly, my clothes turn clammy.
King James would have felt this same sudden clamminess upon entering Cornelis Drebbel’s air-conditioned Westminster Abbey
four centuries ago. For the king, a sweaty king unaccustomed to air-conditioning and bearing the weight of royal clothes,
this feeling of clamminess must have been overwhelming.
I stop at an old house south of Boston, a Cape built for cold weather. A sign outside says maritime museum. Inside, it is
as much a museum of shipwrecks as a museum of ships. The curator, an elderly woman full of energy and enthusiasm about ships
and shipping, has never heard of Frederic Tudor. She knows nothing of the Boston ice trade to the Caribbean and India. The
Ice King means nothing to her. She seems hesitant to believe that ice was commercially harvested from Walden Pond and sold
in the tropics.
She shows me a sketch depicting a wreck on a sandbar. Four men are perched atop the splintered remains of a mast. A fifth
man is in a life ring of sorts, riding a cable stretched to shore. “They save the youngest first,” the old woman tells me.
“They have longer to live.” The sketch, even without color, captures blowing snow and sleet. The hair of one of the men clinging
to the mast is blown forward, hiding his face. In conditions like these, their clothes would have been stiff against their
skin. Since they were wet and poorly protected, their core temperature would have quickly dropped, their hands numbing and
their grip on the mast loosening, their will to live diminishing.
Outside, I am struck by the reality of Boston: traffic and heat and people in cars as big as fishing dories, all doing their
level best to pump the atmosphere full of carbon dioxide, all doing their part to warm the planet. They are killing what little
is left of their ice age. I stand by my own car for a moment thinking about my plane ride across the Atlantic and knowing
that my one seat was responsible for something like half a ton of carbon dioxide. I’ve already dumped another ten pounds from
my rental car’s tailpipe in Boston.
“It’s my ice age,” I say to myself, “and I’m killing it.”
The Frenchman Joseph Fourier, orphaned at the age of eight, was active during the French Revolution. As a result, he was awarded
an appointment at the École Normale Supérieure and eventually a chair at France’s prestigious engineering school, the École
Polytechnique. He probably knew something about the volcanic eruptions that caused the Year Without Summer. He served under
Napoleon and would have heard of the devastations of frostbite suffered by the French army in Russia. He would have heard
of soldiers burning themselves while rewarming frozen digits and limbs over open fires. He would have known something of the
death of Vitus Bering and of early British attempts to navigate the Northwest Passage. He likely knew that ammonia could be
liquefied at temperatures well below freezing. He may have read of early refrigerators.
In 1827, Fourier published an essay in which he recognized that certain gases in the atmosphere contributed to the warmth
of the earth. Carbon dioxide, water vapor, and methane blanketed the earth, allowing visible light to pass through but absorbing
warmth that was reflected back up. This was early in the Industrial Revolution, and these were for the most part naturally
occurring gases. What Fourier described would later be called the greenhouse effect. Without the greenhouse effect, the average
temperature of Miami might approximate that of Bangor, Maine. New York City would be as cold as Fairbanks, Alaska. Barrow,
Alaska, would be substantially less inhabitable. On the whole, the earth without the greenhouse effect would be only marginally
more tropical than Mars.
Fourier harbored a strong aversion to cold. He believed that wrapping up in blankets would improve his health. In 1830, wrapped
in blankets, he tripped down a flight of steps. The fall killed him.
The Swede Svante Arrhenius was not born until 1859, almost a decade after the end of the Little Ice Age. By then carbon dioxide
had been frozen, Agassiz had become famous for his belief in the great Pleistocene Ice Age, and Lord Kelvin had developed
a temperature scale with zero set at the limit of molecular motion. Arrhenius probably rode, or at least saw, an early bicycle,
a direct descendant of the Draisine, invented when the Year Without Summer pushed the cost of grain and hay beyond reach and
rendered horses unaffordable. In the April 1896 edition of the
London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science,
Arrhenius wrote of the greenhouse effect. “Is the mean temperature of the ground in any way influenced by the presence of
heat-absorbing gases in the atmosphere?” he asked. “Fourier maintained that the atmosphere acts like the glass of a hothouse,
because it lets through the light rays of the sun but retains the dark rays from the ground.” Arrhenius went on to estimate
that a doubling of carbon dioxide in the air would lead to a five-degree increase in average temperature. He believed that
natural increases in carbon dioxide levels might have melted the great ice sheets of the Pleistocene. He speculated, for the
first time, on how carbon dioxide released into the atmosphere from the smokestacks of the Industrial Revolution would warm
the planet. Like Fourier, he appears to have harbored a certain aversion to cold: he welcomed the greenhouse effect and looked
forward to a warmer world.
For some time, no one worried much about climate change. The predictions were interesting but not relevant. It was a time
of exploration and of scientific and technical revolution. The Franklin expedition, freezing and starving, probably resorted
to cannibalism before perishing on a windswept gravel coast. Greely, after leaving a wake of corpses in the Arctic, failed
to predict the School Children’s Blizzard. Hydrogen was liquefied, and then helium, at only seven degrees Fahrenheit above
absolute zero. Einstein and Bose described a new state of matter, a condensate that would exist only near absolute zero. Onnes
discovered superconductivity at seven degrees Fahrenheit above absolute zero. Clarence Birdseye marketed frozen foods. There
were other distractions: the rise of communism, a deadly flu epidemic, a world war.
And then, in the late 1930s, an English steam engineer named Guy Callendar found that the world’s temperatures had been increasing
over the past century. Digging a bit more, he found that carbon dioxide levels also had increased. But the historical data
were suspect. Old thermometers had precision problems. Carbon dioxide measurements changed every time the wind changed direction.
Conventional wisdom suggested that carbon dioxide would dissolve in the world’s oceans. Callendar became a footnote in climatology
textbooks.
By the 1950s, scientists were measuring atmospheric carbon dioxide more accurately. A gifted oceanographer named Roger Revelle
was writing about climate change and sea level rise. His key point was that carbon dioxide unleashed from fossil fuels would
not simply dissolve in the oceans and disappear, as had been previously believed. “Human beings,” he wrote, “are now carrying
out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future.”
Coupled with a new understanding of world population growth and its implications, the prophets warmed up to the idea that
the world’s temperature might increase as a result of human emissions. They did not like the world they envisioned. They began
to worry.
For a time, climate change became something of a religious cause. One either believed or did not believe. The data were far
from certain. The implications were huge. Industry representatives talked of climate change kooks and global warming crazies.
Right-wing politicians ridiculed scientists. With each summer heat wave, the media recycled stories of a warming earth. With
warming winters, the papers reran the stories from a slightly different angle. Often reporters botched the facts. People talked
of a climate change debate, as if the reality of increased carbon dioxide and warmer temperatures could be discussed onstage,
as if science could somehow be conducted under parliamentary rules.
The confusion left the science vulnerable. Naysayers pointed to events of fifty-five million years ago, to the Paleocene-Eocene
Thermal Maximum, noting that the Arctic Ocean had warmed to seventy degrees, that global average temperatures had shot up
five or ten degrees in a few thousand years, that the world had been hotter then than now. Yet the world had not ended. In
fact, warming also had occurred in the midst of an ice age, in the heart of the Pleistocene. The climate change kooks and
the global warming crazies pointed out that temperatures were rising quickly. Temperatures were rising much faster than they
had fifty-five million years ago. The world, they said, did not end fifty-five million years ago, but habitats were flooded
by rising sea levels. Animal and plant communities changed quickly. Today’s warming would be more abrupt. And today we call
those habitats cities. Among the plant communities likely to change quickly are fields of grain and corn and okra and broccoli.
Among the animal communities likely to change quickly are those that include cows and chickens and humans.