It was recently reported that the EU, in the face of continuing economic hardship, may contemplate scaling back its rules on carbon emissions. Here in the United States climate change remains a political football, as established science is denied by politicians and every effort is made to obfuscate the facts and create the illusion of uncertainty where, in reality, none exists. As many of us endured the recent “polar vortex” that dropped temperatures across much of the country to Arctic levels (and stranded castaways at the Annual Meeting hotel), we were treated to the spectacle of pundits and other climate-change deniers scoffing at the notion of “global warming,” since it was cold outside. Indeed.
Climate change is almost fiendishly fashioned as a problem that humanity cannot deal with politically. It is long-term, incremental, and global. Human politics are short-term, fast-paced, and parochial. The effects of climate change manifest themselves not in a single, attention-grabbing event but lurk in a pattern of increasingly bizarre and extreme weather conditions. A hurricane Katrina might ravage Louisiania or a Sandy New Jersey, or a mega-tornado cut a swathe of devastation two-and-a-half miles across in Oklahoma, or Colorado might go from record droughts and seasons of fire to biblical-level floods in the space of a few weeks, but none of these individual occurrences can be definitively pinned on climate change. They monopolize the TV news cycles as dramatic, stand-alone events, but the longterm patterns underlying them are far less arresting.
And so we sat inert for decades as scientists were warning us about the coming problems and predicting what see around us today: temperature extremes get more extreme, each successive year tops the list of the hottest on record, hurricanes are stronger, tornadoes more massive, and the ice caps melt at an accelerated rate. But, for the sake of short-term economic benefit, even the EU is willing to contemplate relinquishing its leadership role on climate change and reverse itself on carbon emissions. The long-term nature of climate change is insidious. It is very difficult for human beings to plan for action beyond their natural lifespans. For creatures with a life expectancy of 70-80 years, a gradual process that might only make itself felt dramatically 40 or 50 years after our deaths does not strike us as urgent. This is especially so if it means we have to give up something now to benefit people then-.
Add to this witches’ brew of external circumstance and our perceptual limitations the localized and short-term nature of our political structures, and we concoct the perfect storm of inertia. For effective action to take place, nation-states at different levels of economic development have to agree on a single course of action (which they manifestly cannot), and politicians focused not even on their natural lifespans but on the next election cycle have to embrace contemporary hardship for future benefits. And not just that, but benefits that will not be felt by them or any of their constituents, who will all be dead when they come to fruition.
The picture, then, looks grim. Why all the pessimism, you might ask? Because we students of the ancient world have vivid models to work from. We know what it looks like when an advanced society collapses, and we have a prime suspect in such disasters – mass population movements. The Great Bronze Age Collapse of ca. 1200-1100 BCE saw the end of the Middle Assyrian Empire, the end of the Hittites and the Mycenaeans, and Egypt put under pressure by the mysterious “Peoples of the Sea.” The migration of Celts in the third century BCE, the threat of the Cimbri and Teutones to Rome in the second, the Hunnic invasion of the Roman Empire and the subsequent collapse of the west in the fifth century CE, the sharp contraction of the Byzantine Empire in the seventh century CE, the movement of Slavs into the Balkans, the later devastation of classic Arabic lands by the Mongols, even the collapse of the Maya – in every instance, it has been large movements of peoples that wreaked the havoc.
So what sets whole populations on the move? Over this matter, there is much debate but it seems increasingly clear that environmental conditions have often played a key role. The Cimbri are said to have begun their migration due to flooding in their Danish homelands (Strabo 7.2.1, who is skeptical, since not all Cimbri migrated). Almost half a century ago Rhys Carpenter argued that climate change ultimately stood behind the Great Bronze Age Collapse, when a shift in the trade winds precipitated by changes in the polar ice-cap created a drought that caused famine and induced peasants to rise up against their Mycenaean overlords, for instance, or put whole populations on the move, such as the “Peoples of Sea” (likely a multi-ethnic confederation of desperadoes). Even if not all past migrations have been triggered by climate change or environmental factors, it remains historically established that mass migrations are the single greatest threat to human civilizations.
These insights offer unsettling prospects for us today. It is sobering to contemplate that the inhabitants of fourteenth-century BCE Hattusa, gazing out from their formidable walled city in central Anatolia on a Hittite realm that stretched thousands of miles in every direction, thought that this was the way the world was, the natural order of things. People in the fifth century CE could hardly imagine a world without Rome, which had provided the daily framework of life for over twenty generations and, at its height, presided over the lives of perhaps sixty million souls. Today the ruins of both cultures attract tourists.
What we take for granted as “the way the world is” proves to be a very fragile structure. If entire worlds – of the Hittites, Mycenaeans, Romans – could by overwhelmed by population movements involving several hundred thousand people, what is going to happen when millions go on the move as their homelands are rendered uninhabitable by droughts and floods? How will nation states react to the appearance of hordes of desperate people on their borders? The threat of climate change is not death by drowning or dehydration. The threat of climate change is us.