by Alex Epstein
A huge source of confusion in our public discussion is the separation of people (including scientists) into “climate change believers” and “climate change deniers”—the latter a not-so-subtle comparison to Holocaust deniers. “Deniers” are ridiculed for denying the existence of the greenhouse effect, an effect by which certain molecules, including CO2, take infrared light waves that the Earth reflects back toward space and then reflect them back toward the Earth, creating a warming effect. But this is a straw man. Every “climate change denier” I know of recognizes the existence of the greenhouse effect, and many if not most think man has had some noticeable impact on climate. What they deny is that there is evidence of a catastrophic impact from CO2’s warming effect. That is, they are expressing a different opinion about how fossil fuels affect climate—particularly about the nature and magnitude of their impact.
Once I was clear on how unclear the questions we were asking were, I could ask better questions and get better answers. And once I got clearer on how to use experts as advisers, not authorities, and how to always keep in mind the big picture, I had a much better chance of getting the right answers to the right questions.
Here’s how I put the right questions now, from a human standard of value.
The first is: How does fossil fuel use affect climate livability? When we burn fossil fuels, what are all the climate-related risks and all the benefits that result?
Given that our standard is human life—we want the climate we live in to be as livable as possible—there are two types of impacts we need to study and weigh. The first is the impact of CO2 on climate itself. CO2 affects climate in at least two ways: as a greenhouse gas with a warming impact, but also as plant food with a fertilizing impact (plants are a major part of the climate system as well as a benefit of a livable climate). I’ll refer to these as the greenhouse effect and the fertilizer effect. The second impact of CO2, which is rarely mentioned, is the tendency of cheap, plentiful, reliable energy from fossil fuels to amplify our ability to adapt to climate—to maximize the benefits we get from good weather and ample rainfall and minimize the risks from heat waves, cold snaps, and droughts. I’ll refer to this as the energy effect.
Discussion of climate change often assumes that any man-made climate change is large if not catastrophic and that our ability to adapt is not all that important. This is unacceptable. It is prejudicial to assume that anything is big or small, positive or negative, before we see the evidence. We have to actually investigate the facts. It might be that the greenhouse effect leads to a tiny, beneficial amount of warming or that having or not having fossil fuels to build sturdy infrastructure is the difference between two hundred and two hundred thousand people dying in a hurricane.
Granted, acquiring evidence is often hard because of so many conflicting reports, which is why it’s so important to get experts to explain what they know and what they don’t know clearly and precisely.
The bottom line: For the three major climate impacts of fossil fuels—the greenhouse, fertilizer, and energy effects—we want to know how they work and how they affect us, all the while asking, “How do we know?”
CLIMATE LIVABILITY 101
To understand how each climate-related effect of fossil fuels works, we need to be clear on what exactly we’re talking about when we talk about climate and climate livability. And a good place to begin is with the atmosphere.
The atmosphere is the mixture of gases around the Earth (held by its gravitational field) that makes life possible with oxygen (that humans breathe), carbon dioxide (that plants breathe), nitrogen (that plants eat), et cetera. It is a fascinating, fluid system that causes the heat of the sun and the water of the oceans and the plant life on the Earth’s surface to lead to all kinds of local weather conditions around the globe.
Weather refers to present, near-term atmospheric conditions, especially temperatures and precipitation. At any given time on Earth, there exists a huge range of colder and warmer climates with different weather patterns that have different benefits and risks for human life. Climate is the longer-term (usually measured in thirty-year increments) weather trends in a given region: how hot and cold it gets, how much precipitation there is, what kind of storms pop up, et cetera. The global climate system is the sum of atmospheric conditions around the globe over time.
Talk about “the climate” tends to misrepresent how climate works. It makes climate seem like something uniform and unchanging rather than one part of a diverse, ever-changing system.
Climate change is a change in the general weather patterns on a local level. Global climate change, often equated with climate change per se or man-made climate change, is change in the overall climate system and its diverse subclimates. There are many factors that affect local and global climate, including changes in the sun’s intensity, and changes in plant life that alter the concentration of different elements of the atmosphere and thereby change, for example, the amount of water vapor in the air. Locally, human activity can have major impacts. In Phoenix, for example, temperatures in the center of the city are up to 10 degrees Fahrenheit higher than in the rural areas.2
How can climate and climate change affect us? One crucial truth is that climate is naturally volatile and dangerous. Absent a modern, developed civilization, any climate will frequently overwhelm human beings with climate-related risks—extreme heat, extreme cold, storms, floods—or underwhelm human beings with climate-related benefits (insufficient rainfall, insufficient warmth). Primitive peoples prayed so fervently to climate gods because they were almost totally at the mercy of the naturally volatile, dangerous climate system.
In any era, it’s easy to think that volatile, dangerous weather is unique to our era and must prove some dramatic climate change, whether natural or man-made. Every year, the news is full of headlines about dramatic, often tragic climate-related events—headlines like these:
“20,000 Killed by Earthquake: Toll Is Growing, Bodies Float Down Ganges to the Sea”3
“100 Are Injured, Property Damage Exceeds $1,000,000: Tornado Strikes Three States, Bitter Cold in North Area”4
“Death’s Toll Mounts to 60 in U.S. Storms”5
“1,500 Japanese Die in Hakodate Fire; 200,000 Homeless: Largest City North of Tokyo Is in Ruins and Mayor Says It Is ‘a Living Hell’”6
“Where Tidal Wave Ruined Norway Fishing Towns”7
“Antarctic Heat Wave: Explorers Puzzled but Pleased”8
“7 Lives Lost as Tropical Storm Whips Louisiana: Hurricane Moves Far Inland Before Blowing Out Its Wrath in Squalls”9
“Widely Separated Regions of the Globe Feel Heavy Quake”10
“Earth Growing Warmer: What Swiss Glaciers Reveal”11
“Death, Suffering over Wide Area in China Drouth [Drought]”12
“Toll of Flood at High Figure: Over 100 Bodies Recovered and 500 Persons Missing in Southern Poland”13
“Cuban Malaria Increases: Thousands Become Ill in Usual Seasonal Spread of Disease”14
“Mid-West Hopes for Relief from Heat; 602 Killed”15
“Famine Faces 5,000,000 in Drouth [Drought] Area”16
“Rumanians Are Alarmed by Epidemic of Cholera”17
While these headlines read like they’re straight out of today’s news, they are actually from 1934—before significant CO2 emissions began. Climate is always volatile, climate is always dangerous.
Or take the issue of sea levels. We are taught to think of sea level rises as an evil inflicted on nature by human CO2 emissions. We will explore today’s sea level trends, and the role of fossil fuels in them, later in this chapter, but it is almost universally conceded that any sea level rise today is tiny compared with the enormous, rapid sea level rises that have occurred over the last ten thousand years.
Thus, climate change, extreme weather, volatility, and danger are all inherent in climate whether or not we affect it with CO2 e
missions.
Thus, when we think about how fossil fuel use impacts climate livability, we are not asking: Are we taking a stable, safe climate and making it dangerous? But: Are we making our volatile, dangerous climate safer or more dangerous?
We’ll start with the potential source of risk: the greenhouse effect.
THE GREENHOUSE FEAR
The greenhouse effect is the centerpiece of the prediction of catastrophic climate change. There are basically three parts to the prediction. (1) Man-made greenhouse gases emitted by fossil fuel combustion will cause dramatic warming of the global climate system. (2) Dramatic global warming will cause a dramatic, harmful change in the global climate system. (3) Those changes will overwhelm human beings’ capacity for adaptation, rendering the planet far less livable.
Those are the steps that lead numerous scientists, environmental leaders, and political leaders to make statements like that of James Hansen, probably the world’s most politically prominent climate scientist: “CEOs of fossil energy companies know what they are doing [by emitting CO2] and are aware of long-term consequences of continued business as usual. In my opinion, these CEOs should be tried for high crimes against humanity and nature.”18
If any element of the greenhouse fear turns out to be false—if CO2 emissions don’t cause dramatic warming, if dramatic warming doesn’t cause harmful climate change, or if human beings can adapt well, then CO2 emissions are not catastrophic.
In investigating whether they are or not, we’ll start with the foundation: the amount of warming caused by the greenhouse effect from adding more CO2 to the atmosphere.
WHAT EXACTLY IS THE GREENHOUSE EFFECT?
The greenhouse effect is a warming effect that certain molecules, including water and carbon dioxide, have when they are in the atmosphere. When infrared radiation from the sun reflects off the planet and heads toward space, these molecules, called infrared absorbers, reflect some of it back, causing heat.19 The impact of these gases in the atmosphere is analogized, in its warming impact, to the glass in a greenhouse that helps keep plants warm.
Thanks to the greenhouse effect, the surface of Earth is many degrees warmer than it would otherwise be. Many scientists say that without it, the planet would be some 33 degrees Celsius (59 degrees Fahrenheit) colder—an ultra–Ice Age.20
When fossil fuels—hydrocarbons—are burned, or oxidized, the hydrogen becomes H2O and the carbon becomes CO2.
It’s worth noting that every part of this process has climate impacts. The H2O introduces new water vapor into the climate system and the burning of fossil fuels adds heat to the system—but both of these impacts are too small to make a noticeable difference. Much more significant, the human activities powered by fossil fuels are perfectly capable of affecting local climates. In cities, the bricks, pavement, and buildings impede the flow of ventilating winds, raising temperatures, especially nighttime lows, making heat waves more frequent. This man-made local warming is often far greater than the global warming trend over the last 150 years, which is .8 degree Celsius (1.44 degrees Fahrenheit), a quantity that cannot be perceived without instruments).21
Now let’s look at CO2. It’s a greenhouse gas that exists in trace quantities in the atmosphere—just under .03 percent (270 parts per million, or ppm) before the industrial revolution, a level that we have increased to .04 percent (396 ppm).22
How do we know about the greenhouse effect of CO2? The best way: it can be studied in a laboratory. The temperature difference between a box with a glass ceiling and normal atmospheric gas concentrations and one with additional CO2 is measured when sunlight shines into it.
As with any effect, a crucial question is: What is its magnitude—including, at what rate does additional CO2 change the effect? Some phenomena are linear, which would mean that every molecule of CO2 you add to the system will add a unit of heat the same size as the last one. In some phenomena, the effect is constantly increasing or accelerating; in this case, every molecule of CO2 you add to the system would be more potent than the last (this is the sense that we get from most popular treatments of the greenhouse effect). Then there are diminishing or decelerating phenomena—every molecule of CO2 you add to the system would be less potent than the last.
Anyone discussing this issue should know what kind of function the greenhouse effect follows. While I’ve met thousands of students who think the greenhouse effect of CO2 is a mortal threat, I can’t think of ten who could tell me what kind of effect it is. Even “experts” often don’t know, particularly those of us who focus on the human-impact side of things. One internationally renowned scholar I spoke to recently was telling me about how disastrous the greenhouse effect was, and I asked her what kind of function it was. She didn’t know. What I told her didn’t give her pause, but I think it should have.
As the following illustration shows, the greenhouse effect of CO2 is an extreme diminishing effect—a logarithmically decreasing effect.23 This is how the function looks when measured in a laboratory.
Notice that we are just before 400 ppm (which means CO2 is .04 percent of the atmosphere), where the effect really starts tapering off; the warming effect of each new molecule is not much.
This means that the initial parts per million of CO2 do the vast majority of the warming of our atmosphere. The image below shows how, all things being equal, the heating effect of each additional increment of CO2 is smaller and smaller.
Figure 4.1: The Decelerating, Logarithmic Greenhouse Effect
Source: Myhre et al. (1998)
So why do we have the idea that the greenhouse effect means rapid global warming? Because the proven greenhouse effect is falsely equated with the related but speculative theory that the greenhouse effect of CO2 is dramatically amplified by other effects in the atmosphere, leading to rapid warming instead of the otherwise expected decelerating warming.
Some predictions of dramatic global warming (and ultimately catastrophic climate change) posit that the greenhouse effect of CO2 in the atmosphere will greatly amplify water vapor creation in the atmosphere, which could cause much more warming than CO2 acting alone would. This kind of reinforcing interaction is called a positive feedback loop.
What is the evidence for these predictions compared to the greenhouse effect?
To listen to most cultural discussion, predictions of dramatic global warming and associated catastrophic climate change are absolutely certain.
Secretary of State John Kerry said “absolutely certain” in a landmark speech discouraging the people of Indonesia from using fossil fuels, after they have experienced a major increase in prosperity due to increasing use of fossil fuels:
The science of climate change is leaping out at us like a scene from a 3D movie. It’s warning us; it’s compelling us to act. And let there be no doubt in anybody’s mind that the science is absolutely certain. It’s something that we understand with absolute assurance of the veracity of that science. . . . Well, 97 percent of climate scientists have confirmed that climate change is happening and that human activity is responsible. These scientists agree on the causes of these changes and they agree on the potential effects . . . they agree that, if we continue to go down the same path that we are going down today, the world as we know it will change—and it will change dramatically for the worse.24
We’ll get back to the 97 percent number in a minute, but if you press any climate scientist for an explanation, he will explain (or admit) to you that there is nothing resembling absolute certainty about these large positive feedback loops and the predictions associated with them. This is called the problem of determining climate sensitivity; how much warming, in practice, in the full complexity of the atmosphere, does x amount of CO2 cause? How strong a driver of climate is CO2?
Those who speculate that CO2 is a major driver of climate have, to their credit, made predictions based on computer models that reflect their view of how the climate works. But fatally, t
hose models have failed to make accurate predictions—not just a little, but completely.
While everyone acknowledges that the climate is too complex to predict perfectly, the idea behind catastrophic climate change is that CO2 is an overwhelming driver of the global climate system and thus that its warming impact is predictable over time—in the same way that knowing the climate factors where I live, in Southern California, allows you to predict that it will be mostly dry, even though you can’t predict exactly when it will rain.
Climate scientists who believe CO2 is such a powerful driver feel confident in making models—simplifications—of the global climate system that predict its future based on CO2 emissions.
Just about every prediction or prescription you hear about the issue of climate change is based on models. If a politician talks about “the social cost of carbon,” that’s based on model predictions. If an economist talks about “pricing fossil fuels’ negative externalities,” that’s based on model predictions. If we hear dire forecasts of drought going forward, that’s based on model predictions. Which means if the models fall, they are invalid. Therefore we need to ask the experts advising us an obvious and essential question: How good are the models at predicting warming or the changes in climate that are supposed to follow from warming?
One pitfall in asking this question is that we have to make sure we have evidence of models predicting climate in advance. Why do I say “in advance”? Because part of climate models involve “hindcasting” or “postdicting”—that is, coming up with a computer program that “predicts,” after the fact, what happened. There are reasons to do this—namely, it’s important to see if your model could have accounted for the past. But a model is not valid until it makes real, forward predictions. It’s a truism in any field of math that if you are allowed enough complexity, you can engage in “curve fitting” for any pattern of data with an elaborate equation or program that will “postdict” exactly what happened in the past—but in no way does that mean it will predict the future. (Many investors lose money doing this sort of thing.)