Hands off my thermostat!

Global warming, global cooling

At a basic level, the challenge of climate change is to determine who will control the earth's thermostat. Before the industrial revolution, the thermostat was set by processes beyond the control of humans. Once humans began injecting large amounts of carbon dioxide into the atmosphere, they gained increasing control over the thermostat, nudging it slowly upward. The increase has accelerated, causing worried climate experts to plead that it be limited to 1.5 degrees Celsius. They fret that it will go higher, to as much as 3 or 4 degrees above preindustrial levels.

Implicit in their concerns and their calls is the idea that the pre-industrial setting of the thermostat was optimal. This idea is not without evidence. Humans and our civilizations evolved in a climate at that setting. Yet one doesn’t have to be a curmudgeon to question whether the received climate was indeed best for the human race. There are plenty of things about preindustrial conditions that we have happily changed. We no longer accept infant mortality of fifty percent. We no longer are satisfied with life expectancies of thirty-five years. We no longer live with famines as a matter of course.

Until now, human influence on the climate has pushed the thermostat in one direction only. We know how to make the thermostat go up. But technologies are being tested to remove carbon dioxide from the atmosphere, potentially pushing the thermostat back down. So far it remains several times more expensive to pull a ton of carbon dioxide out of the atmosphere than a ton sells for on carbon markets. The cost curve of carbon sequestration slopes downward, though, as most technical cost curves do. It's not unlikely that in a generation or two, humans will have the ability to lower the earth's thermostat setting.

At that point, the debate over climate will take a new twist. What really is the optimal setting? Is it what the setting was in 1800? In 1000? People living in different parts of the world will have different answers. By 2050, large parts of the Middle East and the Indian subcontinent might be uninhabitable during the hot season. Presumably people who live there will want to cool things down. Canadians might have become accustomed to milder winters and longer summers and not want to give them up.

How will these decisions be made? At present, decisions about the thermostat are made by individuals, corporations and governments, and are often made by default. The legitimacy, such as it is, of this system is the legitimacy of preexistence. It's what we inherited. Many climate reformers consider it unsatisfactory and would love to change it. But because it’s the status quo, it’s wrapped in values—especially the value of national sovereignty—that render it resistant to change. In 2003, American military forces invaded Iraq to compel a change in that country’s arms policy. Congress and the American people went along. So far, no one is talking about invading other countries to compel a change in climate policy. 

But once we achieve the ability to lower the thermostat, we will be beyond the realm of a received status quo. We’ll have to work something out. Old brownstones in New York, built as single residences but later subdivided into flats, often have central heating. At some point in the autumn the residents decide to fire up the boiler. From then till spring, everyone lives with the same thermostat setting. This leads to the curious circumstance where on bitterly cold days, certain residents will have their windows open; it’s the only way they can adjust the temperature if their flats grow too warm.

Unlike the brownstones, the earth doesn’t have windows to open. But like the brownstones, where upper floors are often warmer than lower ones, any thermostat adjustment will have different effects on people in different regions. Some people and countries might settle for 1.5 degrees higher than historic norms. Others will demand a rollback all the way to 0. Still others, conceivably, may call for a setting below 1800’s. 

Debates over climate are fraught right now; they will become more contentious as our control of climate grows. Ask anyone who’s lived in one of those brownstones.