Degrees have an image problem. In the struggle to control global warming, we are told that unless the Earth stays within 2 degrees Celsius of 19th-century levels, catastrophes both natural and political will arise.
The problem is that 2 degrees doesn’t sound like much. Too many people around the world, and Americans in particular, shrug as if to say, “What’s the big deal?” when they hear about this threshold. Yet scientists say even a half-degree increase in average temperature will hurt, and that the effects of warming are already widespread. We are told that warming is already killing coral reefs, pushing sea level higher, creating floods, endangering millions in heat waves, and reducing crop yields. “But really,” many say, “a half a degree — half? Really now.”
Degrees matter. We know without stepping outside there is a big difference in comfort level between a 68 and 70 Fahrenheit day. And we feel it in our bones when the weather drops from 40 to 38. What this tells us, if we think about it, is each single degree actually is a very big step. The four degrees from 86 to 90 feel like a higher order of magnitude, the difference between tolerable and too damn hot.
When we are talking about Celsius degrees, which are 1.8 times larger than the old, familiar Fahrenheit degrees, the impacts are greater. The Celsius system might be better for science, based on 100 degrees as the boiling point of water, but it’s lousy when it comes to convincing the public about the urgency of global warming. It might have been convenient to base the system on a neat 100 steps from zero (the freezing point of water), but the actual fate of the world in no small measure is now based on something invented in 1741.
Degrees need rebranding. Human nature is accustomed to size and superlatives. Dillying around explaining a 2-degree rise (Celsius) or a 3.6-degree rise (Fahrenheit) is still no way to sell a looming crisis. As the basis of a Madison Avenue pitch, it would be a non-starter. Degrees just sound small, too. Think of the phrase “by degree,” which means incrementally. And a compass, also measured in degrees, has 360 of them.
But if 38 degrees means a winter jacket is needed when leaving the house and 40 only a sweater, we know at some level that each degree is a big deal. Unfortunately, that has not translated to widespread pressure to get the United States back in the Paris Climate Accord. A different way to express and measure degrees might create a greater sense of urgency, understanding each one for how huge it actually is.