By Dianne Dumanoski, Author and Environmental Journalist
(This article appears in the July, 2011 issue of The ACUPCC Implementer)
Even for scientists, the challenge of global warming can be mind-boggling and complex, but the bottom line is both simple and clear. The change is already under way and hitting harder and faster than expected. And what is ultimately at stake is the human way of life we call civilization.
Despite two decades of research and debate, the notion persists that climate disruption is primarily an environmental hazard — a dangerous misconception that continues to be widely perpetuated by those who urge action on climate change to “save the planet.” This plea, repeated even by Nobel laureates and editorial writers in the New York Times, belies the true nature of the danger. Based on what scientists now know about our planet’s eventful history, it is a safe bet that Earth itself will survive fossil fuels and industrial civilization just as it has endured previous calamities —asteroid hits, a catastrophic oxygen pollution crisis, and even the deep freeze of “snowball Earth”.
The urgent question, therefore, is not whether the Earth can survive a different climate, but rather what the changes ahead may mean to human societies. Media coverage of global warming and Al Gore’s film An Inconvenient Truth have highlighted the physical hazards of extreme weather, melting ice sheets, rising seas, and the eventual loss of low-lying areas and coastal cities. But climate disruption poses other grave hazards as well, which may send our societies and the global economy reeling into chaos long before our coastal cities are lost to rising seas. Whatever else is in jeopardy, this is first and foremost a crisis for humans and our current civilization.
If the world’s economy continues on its current trajectory of exponential growth driven by fossil fuels, today’s college students will live in a perilous time that one study on climate change and national security described as The Age of Consequences. They will almost certainly witness a dramatic and dangerous jump in global temperatures in their lifetime; see the demise of coral reefs and other marine life as excess carbon dioxide makes the world’s oceans increasingly acidic; endure severe climate disruption; and possibly even confront outright catastrophe from abrupt shifts in the Earth’s climate system.
The litany of looming threats includes the end of agriculture in some regions because of permanent drought, shrinking food supplies and famine, waves of environmental refugees, and on the heels of these woes — political instability and failed states. In the decades ahead, climate change will threaten the peace and stability of the planet and rank at the top of the list of national security concerns.
It will also increasingly dominate the public health agenda as higher temperatures and climate extremes increase the burden of infectious diseases and globalization increases the likelihood of pandemic. Moreover, at a time when societies will have to channel a significant part of their wealth toward substantial and continuous adaptation, climate instability may foster volatility in the economic system and destabilizing boom and bust cycles.,  As the former World Bank chief economist Sir Nicholas Stern warned in his widely read report “The Economics of Climate Change,” the cost of inaction will be higher in the long run than the cost of phasing out fossil fuels.
The current scientific understanding of climate change is extremely confident in some respects and at the same time deeply uncertain in others. There is overwhelming agreement among most climate scientists that greenhouse gases released by human activity have caused “‘most’ of the ‘unequivocal’ warming of the Earth’s average global temperature over the second half of the 20th century” and that temperatures will continue to rise as excess greenhouse gases accumulate in the atmosphere. The claim by conservative skeptics that the fundamental science of global warming is “uncertain” has no basis., 
The uncertainty lies rather in our ability to forecast the consequences of the change already underway. Scientists cannot predict exactly how climate systems will behave if carbon dioxide levels climb to three or four times what they were at the start of the Industrial Revolution. If the human enterprise continues on the current trajectory, this will easily happen by the end of the century. The consequences will hinge in large part on climate sensitivity, on how the Earth responds as human activity pushes the balance of gases in its atmosphere way beyond the normal range. While climate skeptics accuse those urging action to combat global warming of being “climate alarmists”, there is abundant evidence that we are not as alarmed as we should be. Again and again, scientific studies have documented that real-world change has been happening far faster than the model-based forecasts. This is an unsettling prospect, indeed. Given the range of uncertainty and the speed of change to date, the future could be anything from seriously disrupted to utterly catastrophic.
It may sound melodramatic to say that the fate of civilization hangs in the balance. But this is, in fact, a sober, inescapable conclusion when one examines the nature of the relatively recent social development we call “civilization” and the long view of the Earth’s climate history recorded in the ice cores scientists have been retrieving from the ice sheets on Greenland and Antarctica.
The civilized way of life, which started taking hold some 6,000 years ago, is a specific kind of human culture — one based on the domestication of plants and animals and on permanent human settlements. And despite the dramatic technological development since then, the whole flashy, high tech human enterprise of the 21st century still rests on this ancient foundation, the food technology developed in the late Stone Age during farming revolutions in several parts of the world. This “new” way of obtaining food has allowed large complex societies to develop — societies with cities, governments, armies, social classes, and a variety of specialized professions — doctors, priests, goldsmiths, potters, musicians, and writers. And eventually a global society with astonishing technology and the internet. Civilization may experience a post-industrial era, but it will never have a “post-agricultural” phase.
Our civilized way of life, which is impossible without agriculture, depends on a stable climate.
Modern humans emerged some 200,000 years ago and through most of our species’ existence we lived as nomadic hunters and gatherers following where the shifting food supply led us. Farming and civilization came very late in our career.
The deep ice, which records the long history of conditions on Earth over the past 800,000 years, tells us many things, but three facts about our situation stand out.
The first is this: the exceptional overall stability of the climate over the past 12,000 years made settled life and farming possible for the first time in the history of our species. For the past million years, the Earth has swung between ice ages and warmer interglacials, but moments on Earth with a climate as warm and benign as ours today have been few, fleeting, and very far between. Through most of the human past, our ancestors had to cope with a chaotic climate marked by extreme variability, a climate that could not support agriculture. The world as we know it — with agriculture, civilization, and dense human numbers — has only been possible because of a rare interlude of climatic grace. A long summer. This is because the Earth’s orbit changes shape over time and plays a role in climate cycles. We live at a truly extraordinary time in the Earth’s volatile history.
Second, the ice record shows that current human activity is pushing the Earth system, which sustains life as we know it, way beyond the normal range recorded in the ice cores and doing so at an alarming speed. Without interference, this long summer might have lasted another 10,000 to 20,000 years — given the Earth’s current orbit. Now, however, this exceptional moment on Earth is drawing to a close. We know from the ice core record that carbon dioxide levels today are far higher than any time in the past 800,000 years. What lies ahead is radical uncertainty.
Third, the notion that global warming is going to proceed like a smooth escalator, carrying northern climes into an era of balmy winters, is common and persistent, but counting on an escalator-like change in climate is sheer folly and may put us in even greater danger. On the contrary, the Earth’s climate history writ in the ice cores contains evidence of swift, intense, revolutionary change in less than a century or even within a single decade.
One such leap occurred 14,700 years ago, when the Ice Age ended within a remarkable three years. The state-of-the-art climate models do no capture the magnitude nor the abruptness of these climate leaps.
The most mind-boggling insight from the ice cores is that rapid climate change is normal; it is not a freak event or an exception, it is the rule. When the Earth system changes, this is how it behaves. The faster the warming and the higher temperatures rise, the greater the chance that change will arrive in abrupt shifts and surprises — shocks that could lead to the collapse of social and economic systems.
For most of the human past, the climatic conditions our ancestors encountered often varied more from decade to decade than they have during the past twelve thousand years. A return to past patterns of extreme variability would be devastating to agriculture and make farming impossible. And if farming becomes impossible, it will mean the end of the settled, civilized way of life we’ve enjoyed during the long summer.
The question is no longer will we save the Earth, but rather will we act to preserve conditions necessary for civilization as we know it.