Mystery of the Three Scary Numbers

Inspired by “Global Warming’s Terrifying New Math,” a teacher brings the scary numbers behind climate change and climate chaos to the economics classroom.


| January/February 2014



Bill McKibben, author of "Global Warming's Terrifying New Math"

Bill McKibben, founder of 350.org and the world's most prominent climate campaigner, proposes that there are just three numbers that we need to pay attention to in order to reach some radical conclusions about the future of fossil fuels.

Photo by University of Michigan School of Natural Resources & Environment

Every now and then an article comes along that takes such a novel approach to an issue, I feel like I’m seeing something with new eyes. Such was the case when I read Bill McKibben’s 2012 Rolling Stone article, “Global Warming’s Terrifying New Math.” It made me see our climate predicament with such clarity that I knew immediately I had to figure out how to turn this article into curriculum.

The “terrifying new math” is pretty simple. McKibben, founder of 350.org and the world’s most prominent climate campaigner, proposes that there are just three numbers that we need to pay attention to in order to reach some radical conclusions about the future of fossil fuels.

The first number is 2 degrees Celsius, or about 3.6 degrees Fahrenheit. In the 2009 Copenhagen Climate Accord, 167 countries, including the United States, pledged that “deep cuts in global [greenhouse gas] emissions are required … so as to hold the increase in global temperature below 2 degrees Celsius.” The Copenhagen Accord was a timid, inadequate document. According to McKibben, even a 2 degree rise in global temperatures is fraught with danger, but it’s the only international consensus on a climate target—“the bottomest of bottom lines,” he writes. The first scary number.

The second scary number is 565 gigatons—or 565 thousand million tons. That’s humanity’s carbon “budget”—how much carbon dioxide we can pour into the atmosphere with a reasonable chance of keeping global temperatures to a 2 degrees Celsius increase. That 565 gigatons sounds like a lot until we hear that global carbon dioxide emissions rose by 31.6 gigatons in 2011, and that projections call for humanity to blast through our 565-gigaton quota in less than 16 years.

Which brings us to the final number that makes the other two numbers so frightening: 2,795 gigatons. This number represents the stored carbon in reserves held by coal, oil, and gas companies, and the countries—Kuwait, for example—that act like fossil fuel companies. McKibben notes that this number was first highlighted by the Carbon Tracker Initiative, a group of London financial analysts and environmentalists. In other words, the fossil fuel industry already has plans to exploit five times as much carbon as can be burned without exceeding the 2 degrees ceiling. Burning these fossil fuels would enter the world into a dystopia of climate science fiction—a rise in sea levels not seen in human history, species extinction, droughts, superstorms, heat waves from hell, coral kill-offs, and consequences we cannot yet imagine.

“Here’s another way of saying it: We need to leave at least 80 percent of that coal and gas and oil underground,” McKibben writes. “The problem is, extracting and burning that coal and oil and gas is already factored into the share prices of the companies involved—the value of that carbon is already counted as part of the economy.” This would be the equivalent of these companies writing off $20 trillion.