As the COP18 in Doha cranks along into its second week, onlookers follow the proceedings and ponder how the results of continued negotiation will affect them. Frustrated environmental activists bemoan the slow progress made by the UNFCCC over the past two decades and call for more ambitious action, industry groups look out for any changes in emissions reduction targets or country stances that will affect their bottom line, and journalists search for stories amid a mass of bureaucratic wrangling. But as heads-of-state, negotiators, and observers come and go from air-conditioned plenary rooms and corporate hotels, the earth continues to cycle carbon, heedless of the political quagmire that has plagued climate negotiation since the UNFCCC was drawn up in 1992.
Oceans absorb carbon dioxide at an ever slowing rate as they acidify and near saturation. As this natural buffer weakens, more of the carbon we release goes straight to the atmosphere. The Thermohaline circulation, a giant ocean conveyor belt that drives the world’s major currents, continues to supply Europe with warmth from the tropical Gulf Stream before it cools off the coast ofGreenlandand sinks into abyssal depths—at least for now. Land plants and armies of phytoplankton sequester carbon during their lifetime. After they die, microorganisms respire that carbon back into the air. Massive ice sheets continue to melt, exposing long-buried terrain that absorbs the suns radiation more readily than reflective glaciers. These and many other processes are what control how fast our global thermometer spikes; they are inexorable and inherently non-political.
PHOTO: Aitcho Island, Antarctica. These Gentoo penguins couldn’t make it to Doha for COP18, but they will continue to move their nesting grounds south along the Antarctic Peninsula as temperatures rise.
Environmentalist, author and 350.org founder Bill McKibben has summed up this idea by stating that the climate problem is no longer a political one but a simple matter of physics. The argument goes that we’ve run out of space to put all the carbon we generate and we only have a little leeway before things may spiral out of control. Ignoring the politics of climate change entirely would be foolish; whichever way you slice it, creating aDurban platform that all countries will sign on to will require massive political compromise. However, McKibben’s sentiment is dead on: we are altering the very composition of the atmosphere at a geologically unprecedented rate and will face massive consequences at a global scale unless we take dramatic action. The complex machinery of climate doesn’t operate on commitment periods or negotiation deadlines. It doesn’t wait for anything.
If we suspend disbelief for a moment and think of climate change from a purely physical perspective, the climate math is fairly straightforward: in order to maintain warming below 2 deg C above pre-industrial levels, a target implicitly agreed upon by most UNFCCC parties, we need to burn less than 565 more gigatons of carbon, accomplishable by reducing global emissions by about 5% annually until 2050.
Admittedly, some of the physics of climate change are poorly understood. For example, scientists are not much closer to understanding how clouds affect climate than they were fifteen years ago—clouds’ white color reflects radiation, their water vapor acts as a potent greenhouse gas, and their prevalence may increase and decrease at different altitudes in a warmer climate. Furthermore, while scientists have succeeded in calculating how much climate change increases the odds of extreme weather events, they are still far from being able to use climate models to prove whether a specific extreme event can be blamed on a warming world.
However, we can derive wisdom from some general guiding principles from the field of paleoclimatology, the field of science devoted to uncovering the history of earth’s climate long before there were thermometers to measure temperature. What are the key insights we glean from the record of ancient climates? Let’s review some general findings that paleoclimatologists have elicited from climate proxies:
- The climate cocoon: all of human history is a subset of an uncharacteristically mild and relatively stable period in climate history. This climate cocoon, a conspicuously long interglacial period, is all we’ve ever known. With carbon dioxide levels higher than they’ve been in over 800,000 and increasing at a rate the earth has likely never seen we’re setting the stage for a violent emergence from our cocoon.
- It wasn’t always like this… the earth’s climate is highly variable. Paleoclimatology gives us the bounds within which climate has oscillated from almost complete glaciation with sea level hundreds of meter lower than today to much warmer periods. Understanding these boundary conditions helps contextualize where we might be heading by the end of the century.
- Change can be abrupt: Abrupt climate changes with large temperature shifts have occurred in the recent past, recent in both the geologic and anthropogenic senses. By combining archeological and environmental history we see that some of these changes led to the collapse of civilizations, as in ancient Mesopotamia and Central America.
- Feedbacks rule climate: Relatively small shifts in orbital parameters, greenhouse gas concentrations, and the composition of the biosphere seem to be amplified by natural feedbacks that can bring about dramatic change.
Despite the importance of these findings, the Paleoclimatologists who study the history of abrupt climate change are understandably reticent to politicize their work. They are neither paid nor trained to communicate complicated scientific concepts to the public. Conversely, negotiators in Dohaaren’t reading the latest issue of Science while they ride the shuttle to the conference center, nor should they have to.
We grow weary of apocalyptic climate hysteria. Pessimists claim that understanding the ancient climate record is just another way to scare ourselves into inaction with tales of catastrophic climate change powerful enough to turn the earth into a frozen ball of ice or a steaming hellhole. But to allow ourselves to be overwhelmed by the power and fickleness of our climate system is to admit defeat. If we have the power to change the very makeup of our atmosphere, it must be within our grasp to avoid dangerous warming if we act quickly and decisively. COP18 must at minimum establish a clear roadmap for how theDurbanplatform will be drawn up before 2015, and ideally do much more. Acknowledging lessons from the ancient climate record is a step in the right direction, an admission of the awesome power of abrupt climate change.
 Peterson, Thomas “Explaining Extreme Events of 2011 from a Climate Perspective.” American Meteorological Society. 2012.
 Alley, R. B. “Abrupt Climate Change.” Science. 2005.