over ruined suburbs, bombed factories, and narrow ancient streets.
With “shock and awe,” the US military had unleashed the end of the world on a city of six million—a city about the same size as Houston or Washington, D.C. Baghdad’s infrastructure was totaled: water, power, traffic, markets, and security fell to anarchy and local rule. The government had collapsed, walls were going up, tribal lines were being drawn, and brutal hierarchies were being savagely established. Over the next year, the city’s secular middle class would disappear, squeezed out by gangsters, profiteers, fundamentalists, and soldiers.
I was a private in the United States Army. This damaged world was my new home. If I survived.
Two and a half years later, still in the Army but safe and lazy back in Fort Sill, Oklahoma, I thought I had made it out. Then I watched on television as Hurricane Katrina hit New Orleans. This time it was the weather that inspired shock and awe, but I saw the same chaos and collapse I’d seen in Baghdad, the same failure of planning and the same tide of anarchy. The 82nd Airborne Division took over strategic points and patrolled streets now under de facto martial law. My unit was put on alert and trained for riot control operations. The grim future I’d seen in Baghdad had come home: not terrorism, not WMDs, but the machinery of civilization breaking down, unable to recuperate from shocks to its system.
That future is not going away. According to Admiral Samuel J. Locklear III, head of the US Pacific Command, global climate change is the greatest threat the United States faces, more dangerous than terrorism, Chinese hackers, and North Korean nuclear missiles.1 Upheaval from increased temperatures, rising seas, and climatic destabilization “is probably the most likely thing that is going to happen that will cripple the security environment, probably more likely than the other scenarios we all often talk about,” he said. Thomas E. Donilon said much the same thing in 2014 as National Security Advisor, arguing that the “environmental impacts of climate change present a national security challenge.”2 James Clapper, Director of National Intelligence, told the Senate in 2013 that “Extreme weather events (floods, droughts, heat waves) will increasingly disrupt food and energy markets, exacerbating state weakness, forcing human migrations, and triggering riots, civil disobedience, and vandalism.”3 President Obama’s 2010 National Security Strategy, the Pentagon’s 2014 Quadrennial Defense Review, and the Department of Homeland Security’s 2014 Quadrennial Homeland Security Review all identify climate change as a severe and imminent danger.4 More recently, the Pentagon’s 2014 Climate Change Adaptation Roadmap warned: “Rising global temperatures, changing precipitation patterns, climbing sea levels, and more extreme weather events will intensify the challenges of global instability, hunger, poverty, and conflict. They will likely lead to food and water shortages, pandemic disease, disputes over refugees and resources, and destruction by natural disasters in regions across the globe.”5
On the civilian side, the World Bank’s 2013 report, Turn Down the Heat: Climate Extremes, Regional Impacts, and the Case for Resilience, and their 2014 follow-up Confronting the New Climate Normal, offer dire prognoses for the effects of global warming, which climatologists now predict will raise global temperatures 3.6 degrees Fahrenheit above pre-industrial levels within a generation and 7.2 degrees Fahrenheit within 90 years.6 As hotter temperatures liquefy glaciers and ice sheets from Greenland to Antarctica, all that melted ice flows into the sea: Some worst-case estimates suggest we might see seven or eight feet of sea level rise as soon as 2040.7 The collapse of the West Antarctic ice sheet alone, already underway, will eventually raise sea levels by as much as twenty feet.8
As glaciers and ice sheets melt, so too will carbon and methane long frozen in seabeds and permafrost. As a greenhouse gas, methane is more than twenty times more powerful than carbon dioxide, and thousands of gigatons of the stuff lies locked under the oceans in clathrate hydrates, waiting to be released: “These solid, ice-like structures are stable only under specific conditions,” writes oceanographer John Kessler, “and are estimated to contain a quantity of methane roughly equal in magnitude to the sum of all fossil fuel reservoirs on Earth.”9 Methane-rich sinkholes have appeared in Siberia and methane bubbles have been tracked leaking from the floor of the Arctic Ocean, possibly signaling the beginning of a massive planetary “belch” capable of generating catastrophic runaway greenhouse effects.10 As geophysicist David Archer warns, “The potential for planetary devastation posed by the methane hydrate reservoir . . . seems comparable to the destructive potential from nuclear winter or from a comet or asteroid impact.”11
We’re fucked. The only questions are how soon and how badly. The Intergovernmental Panel on Climate Change’s (IPCC) 2014 report on climate impacts cautions: “Without additional mitigation efforts beyond those in place today, and even with adaptation, warming by the end of the 21st century will lead to high to very high risk of severe, widespread, and irreversible impacts globally.”12 According to the World Bank, 2.7 degrees Fahrenheit of warming now appears inevitable, even if we were to stop emitting carbon dioxide (CO2) worldwide right now.13 Projections from researchers at the University of Hawai‘i find us dealing with “historically unprecedented” climates as soon as 2047.14 Climate scientist James Hansen, formerly with NASA, has argued that we face an “apocalyptic” future—a bleak view that is seconded by researchers worldwide.15
This chorus of Cassandras predicts a radically changing global climate causing widespread upheaval, and their visions of doom are backed by an overwhelming preponderance of hard data. Global warming is not the latest version of a hoary fable of annihilation. It is not hysteria. It is a fact. And we have likely already passed the point where we could have done anything about it. From the perspective of many policy experts, climate scientists, and national security officials, the concern is not whether global warming exists or how we might prevent it, but how we are going to adapt to life in the hot, volatile world we’ve created.
There is a name for this new world: the Anthropocene. The word comes from ancient Greek. All the epochs of the most recent geological era (the Cenozoic) end in the suffix “-cene,” from kainós, meaning new. Anthropos means human. The idea behind the term “Anthropocene” is that we have entered a new epoch in Earth’s geological history, one characterized by the advent of the human species as a geological force.16 The biologist Eugene F. Stoermer and the Nobel-winning chemist Paul Crutzen advanced the term in 2000, and it has gained acceptance as evidence has grown that the changes wrought by global warming will affect not only the world’s climate and biodiversity, but its very geological structure, and not just for centuries, but for millennia.17 In the prophetic words of William Blake, written at the dawn of the carbon era more than two hundred years ago, “The generations of men run on in the tide of Time / But leave their destin’d lineaments permanent for ever and ever.”18
The International Commission on Stratigraphy, the geologists responsible for driving the “golden spikes” that demarcate different geological periods, have adopted the Anthropocene as a term deserving further consideration, “significant on the scale of Earth history,” and are discussing what level of geological time-scale it might be and at what date we might say it began.19 Is it an “epoch” like the Holocene, or merely an “age” like the Calabrian? Did it start with the beginning of the Industrial Revolution, around 1800, or during the Great Acceleration in the middle of the 20th century? With the dawn of agriculture, 12,000 years ago, or on July 16, 1945, with the first atomic bomb?20
Whenever it began, it is the world we now live in. Within a few generations we will face average temperatures 7 degrees Fahrenheit warmer than they are today, rising seas at least three to ten feet higher, and worldwide shifts in crop belts, growing seasons, and population centers. Unless we stop emitting greenhouse gases wholesale now, humans will within a couple hundred years be living in a climate the Earth hasn’t seen since the Pliocene, three million years ago, when oceans were 75 feet higher. Once the methane hydrates under the oceans and permafrost begin to melt,
