much as the ice sheets impeded human migratory routes, they also shaped the kind of people they would become. Surviving in the Arctic made the people tough; hunting big game and defending their kills against bears and lions could have infused hunters with edgy audacity and made them bold enough to go after the biggest game, at all costs. Eventually, some experts think, their experience north of the ice and in the ice-free corridors prepared them to hunt the American mammoth, the largest beast of all. This kind of prey required specialized lithic (stone-working) technology and may have spawned the iconic Clovis point. Much ink has been applied to papers debating these topics: Chapter 8 will add some more.
For the earliest American travelers, the ice must have seemed all encompassing, pervading their dreams and chiseling their angular features with blasts of Arctic wind. Coming down any route from Beringia, through icy defiles, the cold beauty of the glaciers would have dominated all landscapes. One could imagine the first Americans consciously aware of the growing, then shrinking glaciers, witnessing the melting white wilderness with a measure of alarm. Along the coast, the rising ocean would have haltingly inundated the forest, inch by inch. Climatic fluctuation, the retreat of the ice and the declining mass of the megafauna were not imperceptible changes to the first American explorers over the years. Beyond the daily struggle to survive, the wind was alive with the palpable scent of the regeneration of the earth—icy winds off the glacial front, the warm chinooks blowing up the Rocky Mountain Front and a wind bearing the fetor of dying beasts. How exciting, how terrifying a time to live: The last days of the Ice Age.
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The wide aim of this book is not so much to sort out the archaeological and other arguments (a great story) about people coming to America in the last days of the Pleistocene, but to inquire how people might have responded, bearing witness to radically changing environmental conditions. Though fundamentally unknowable, the question is worth some speculative consideration. Today, we approach a world we might not recognize by the end of this century. “Global warming”(often softened by the term climate change) is a catchword we can conveniently ignore with our modern technology and cultural insulation. Should our local weather warm up by a few degrees, who cares? But the extremes of global warming—widespread drought, floods, fierce storms, frigid winters in temperate zones and fiery heat—are the big enchiladas of global warming. These intense events can dramatically shift the limits of agriculture, create uninhabitable deserts the size of continents and break down the boundaries of what we call civilization. That this could happen within our lifetime does not seem to sharpen our perception of the threat. The climatic shifts of the Pleistocene might look quite mild in comparison to those of the 21st century.
What does it take to see the shadow of the sabertooth in the present day bush?
That particular conundrum is the challenge of this book.
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While writing a book about the past, our own crisis of climate runs through my head. Every day. I find myself grasping for comparisons that aren’t quite clear. I have a friend, old-fashioned in his communication technology, who sends me news clips from newspapers and magazines by mail. He knows I’m working on a book about the Pleistocene and he wants to keep my mind straight. To keep my nose to the grindstone, I post his worst scenario for today’s global warming disaster to the back of a map of Yellowstone Park, where I can’t avoid looking at it.
“By 2100, the Earth’s population will be culled from today’s 6.6 billion to as few as 500 million;” says James Lovelock, independent scientist and father of the Gaia theory, “billions of us will die and the few breeding pairs of people that survive will be in the Arctic where the climate remains tolerable.” Lovelock also thinks: “By 2040, the Sahara will be moving into Europe, and Berlin will be as hot as Baghdad. Atlanta will end up a kudzu jungle. Phoenix will become uninhabitable, as will parts of Beijing (desert), Miami (rising seas) and London (floods). Food shortages will drive millions of people north, raising political tensions. “The Chinese have nowhere to go but up into Siberia.” He hopes that “it doesn’t degenerate into Dark Ages, with warlords running things, which is a real danger.”
Yet Lovelock holds out a glimmer of light: “We are about to take an evolutionary step and my hope is that the species will emerge stronger. It would be hubris to think humans as they now are God’s chosen race.” Lovelock adds: “The human species has been on the planet for a million years now. We’ve gone through seven major climatic changes that are equivalent to this. The ice-ages were shifts in climate comparable with this one that’s coming. And we’ve survived. That series of glaciations and interglacials put the pressures on us to select the kind of human that could adapt. And we’re the progeny of them. And we’re just up against a new and different stress. Maybe we’ll come out better.”
My friend Scotch-taped to the bottom another scrap of newspaper:
“The Republicans are back in control of the House, and they’re bringing something with them: styrofoam cups. The cups, along with plastic forks and a number of other things seen as not eco-friendly, were done away with four years ago by Nancy Pelosi to reduce Congress’s carbon footprint.”
Green activists called the switch an insult to the environment, “Neanderthal” and a slap in the face to efforts to combat global warming.
My friend wonders if Lovelock is suggesting that the Pleistocene glacial fluctuations honed a more adaptable human, better able to cope with, say, the threat of modern global warming? These congressional folk not only don’t believe in global warming, they think it’s an environmental conspiracy. How does evolutionary pressure from the first (the Ice Age) select for the kind of person who seems indifferent to the second (climate change)? According to Lovelock, it should be the other way round. My friend finds grim humor here. Modern humans’ social tendencies paint the battles black and white in a world of friends and enemies; we focus on the fights that matter the least while ignoring what matters most.
A couple more clips, intrusive but closer to the heart of the matter:
The Los Angeles Times reports “Greenland’s Ice Sheet is Slip-Sliding Away.” By 2005, Greenland was losing more ice than anyone expected; the amount of freshwater ice dumped into the Atlantic had almost tripled in a decade. Summer meltwater, responding to recent warmer temperatures, also accelerated. The warm water on the top of the ice sheet made its way through a maze of tunnels, natural pipes and cracks in the ice to the bedrock below, lubricating the slip of ice over Greenland’s rock basement. The meltwater descended thousand of feet in weeks not decades. This was a surprise to scientists. If all glaciers draining the ice sheet slide too quickly, they could collapse suddenly and release the entire ice sheet into the ocean.
“Should all of the ice sheet ever thaw, the meltwater could raise sea level 21 feet and swamp the world’s coastal cities, home to a billion people. It would cause higher tides, generate more powerful storm surges and, by altering ocean current, drastically disrupt the global climate.”
Reuters: Arctic ice sheet may swamp U.S. coasts. The loss of the huge West Arctic Ice Sheet (WAIS) would cause sea levels to rise by 21 feet in North America and 16.5 feet worldwide.
Some scientists warn that the WAIS is fundamentally far less stable than the Greenland because most of it is grounded far below sea level. One expert considers the WAIS collapse is all but inevitable given the current business-as-usual projected warming of 5-7 degrees C.
Arctica’s Ross Ice Sheet is considered even more unstable than the WAIS because it had previously collapsed and could again at any moment. The Ross Ice Sheet collapse would result in an additional 15 feet of sea rise.
Fifty feet of sea rise would demolish the world’s coastal populations, flooding highly populated areas such as Washington, D.C., New York City and the California coastline, and deal disaster
