“There are three kinds of lies: lies, damned lies, and statistics.” Although this quote was popularized by Mark Twain early in the 20th Century, here in the 21st Century, amidst the war of words over global warming, the saying perhaps should be updated to: “There are three kinds of lies: lies, damned lies, and computer models.”
This is the third article in my Microsoft Hohm™ Blog series on critical thinking, or “how do we know what we think we know,” specifically in regards to climate change. In my last article, I briefly discussed some non-controversial elements of climate science such as the carbon cycle. I promised to address the controversial stuff—namely, the question of whether human greenhouse gas (GHG) emissions are causing global warming—in this article.
To address this controversy, we must answer two related questions: (1) Is climate change occurring, and (2) if so, to what extent are humans responsible?
Those who deny that climate change is occurring like to point out problems with computer programs used to predict future global temperatures under various emissions scenarios. Regardless of how well computer models match historic climate records, detractors (rightfully) claim that future warming is purely theoretical and cannot be “proven.” Indeed, if we can’t predict the weather accurately a few days in advance, how can we hope to predict the climate of planet earth with any degree of certainty 50 or 100 years in the future?
Well, as a computer programmer it pains me to say this, but throw out every computer model argument for global warming. The question of whether or not global warming is happening now does not depend upon any theoretical modeling of the future. Even our best modern supercomputer models of the effects of doubling atmospheric carbon dioxide (CO2) are tracking eerily close to tedious, crude pen-and-paper calculations first proposed by Swedish chemist Svante Arrhenius over a century ago!
So, all computer models aside, how do we know the planet is warming now? We rely, of course, primarily on temperature observations from individuals and weather stations. We have fairly accurate temperature records going back hundreds of years, but we have other historic records going back thousands of years that can provide valuable insight regarding general climate trends. More importantly for really long-term historic climate records, we have tree ring studies, ice core samples, and even records written in stone. All of these records agree: our planet is warming.
Of course, any student of ancient history will tell you that our planet has undergone many cycles of warming and cooling in the past. There are many natural reasons for these cycles, which bring us to the question of whether or not humans are responsible for our current warming trend.
As noted in my last article, CO2 and other GHGs are linked explicitly to the greenhouse effect, and humans have been releasing increasing amounts of GHGs, mostly by burning fossil fuels since the Industrial Revolution. This, then, is the critical question: Are the GHGs released by humans primarily responsible for our planet’s current fever? The simple answer is, yes. Here’s how we know:
- Humans release CO2 and other GHGs—a lot of them. In fact, every year humans release 100 times the amount of CO2 released from all the planet’s volcanoes. We know this, among other ways, due to the fact that CO2 released by burning fossil fuels has a unique chemical signature. In other words, the “global warming CSI team” has found clear forensic evidence that humans are guilty of the climate crimes for which we have been charged!
- Although much of the CO2 released by burning fossil fuels stays in the atmosphere and contributes to warming the planet, one reason that we have not experienced more warming to-date is due to the fact that the world’s oceans have been absorbing large amounts of our CO2, which in turn is causing them to become dangerously acidic.
- When the oceans become saturated with CO2, then even more of it will stay in the air, and warming will increase. The rate of increase will accelerate as methane (another GHG) currently locked under permafrost and under oceans escapes back into the atmosphere when polar ice melts and seas warm. Methane is 25 times more potent than CO2 at warming the planet, and its widespread release from ancient stores is one of many such scary “feedback loops” that could cause our planet to get much hotter much faster.
Understanding these concepts does not require a PhD in climate science, but it does require a basic understanding of science. This brings me to my Microsoft Hohm Book of the Week: Unscientific America: How Scientific Illiteracy Threatens our Future by journalist/author Chris Mooney and scientist Sheril Kirshenbaum. In a review of the book, a blogger at RealClimate.org (“Climate science from climate scientists”) states: “What I found most refreshing about the book is that it not only isolates the history behind, and source of, the problem in question—the pervasiveness and dangerousness of scientific illiteracy in modern society–but it offers viable solutions. This book is a must read for anybody who cares about science, and the growing disconnect between the scientific and popular cultures.”
To recap: The bad news is that humans are responsible for our currently-observed global warming. The good news is that, since we’re responsible, we can change our ways. We’re not doomed to unstoppable global warming due to sunspot cycles or subtle, long-term changes in our planet’s alignment and orbit around the sun. But we must act fast and utilize tools like Microsoft Hohm to make planet-saving—as well as money-saving—changes. More on that in my next article!
Blog post from - Kyle G. Crider He has a B.S. degree in Environmental Studies from the University of Alabama and a Master of Public Administration degree in Urban Planning & Policy Analysis from UAB, where he’s currently in the Interdisciplinary Engineering Ph.D. program.