This is a rewritten version of a piece I wrote in college–it is a fictional representation of mt attempt to play “devil’s advocate” with what I knew about climate change at the time. The character of Skeptico is entirely fictional. The information in the piece came largely from the book, Global Warming: The Complete Briefing, by John Houghton, from Cambridge University Press. It’s an excellent book, but it was written in 1997, so if you read it, remember the case for climate change being real has grown even stronger in the past seventeen years.
I remember posting this piece here, but cannot find it in the archive, so I’m posting it again.
Let us say that I sit down on the edge of the dock next to my friend, the climate skeptic, whom we will call Skeptico. The tide is up, so I can swish my bare feet in the water, as my companion is already doing. We admire the view in silence together for a few minutes before either of us speaks.
“I don’t get why you environmentalists have to be so negative,” he says. “Look at this! It’s beautiful. If you had your way, no one would ever see this, no one would fish here, no one would get to enjoy this…all these things take fossil fuels. I don’t think we should consider getting rid of all the modern conveniences that let so many people enjoy the environment in the first place.”
“Is that a rhetorical statement or a real question?” I ask. “Do you want to talk about why I do the things I do?”
“Yeah, I do, actually.”
“Ok,” I begin, “you mentioned fossil fuels. It sounds as though you don’t think their use should be limited. That implies that you don’t think global warming is a problem. Is that true?”
“Yes, that’s true. I don’t think we should give up things we want and need and worked hard to get just because of some unproven theory.”
“Why do you call it an unproven theory?”
“Well, that’s what it is, right? It’s just a theory, it’s not fact.” Skeptico seems almost angry, saying this, and fidgets a bit. I think for a minute.
“Sounds like you’re saying that theories are ideas that are not yet proven, that when it is proven, it graduates to fact-hood.”
“Ok, that’s not what a theory is, not the way scientists use the term, anyway. Theories are attempts to organize and explain the things you know so you can make educated guesses about the things you don’t know. Like if I know why the water is warm today I can get a good idea whether the water will be warm tomorrow. Makes sense so far?”
“Yeah, I know what a theory is,” replied Skeptico, irritably, “but theories do change. They say one thing this year, another thing the next. You can’t tell me that a theory is the same thing as a fact.”
“No, I’m saying a theory is a completely different thing than a fact. You’re right, theories do change, and sometimes they are abandoned altogether and replaced. But that doesn’t mean that theories are just guesses; theories are the ideas with which we make guesses. The more consistently right the guesses are, the more reliable the theory is. When high tide was yesterday is a fact. We can use a theory about tides to predict when high tide will be today—and that’s reliable enough that you’ll plan your day around it so you can go fishing. I’ve seen you do it.”
“You know it like a poet,” Skeptico replies, but seems slightly embarrassed and lapses into thought for a moment before speaking again. “Oh, so when they say ‘theoretically, such and such is true,’ they’re guessing, but the guess isn’t a theory–it’s theoretical because a theory generated it?” My friend seems pleased by this insight, but frowns again a moment later. “But why is global warming a reliable theory? I don’t see the sea level rising.”
“You don’t? This island was wider ten years ago,” I point out.
“That’s erosion from storms. That’s different.”
“I’m not so sure about that,” I respond, “but in any case, global warming isn’t a theory, it’s data. The greenhouse effect is a theory.”
“That’s just rhetorical,” Skeptico protests. “It’s not my fault if I don’t use exactly the right terms. You know what I mean!”
“No, it isn’t rhetorical. Global warming isn’t a theory because ‘global warming’ just means the globe is getting warmer—which it is. It’s been measured. That’s data, not an explanation of data. The theories are about why the globe is warming and what is going to happen next.”
“Ok, well, either way, how do we know the theory is reliable?”
“Because it’s the same set of theories they use to predict the weather.”
“The weather! Weather predictions are completely unreliable!” Skeptico scoffs.
“Really?” I challenge. “It’s not exact, but in the last few years they’ve gotten pretty good. I’ve seen you decide not to go out on the water when they’re predicting thunderstorms. Weekly outlooks are usually right, and they can predict the track of hurricanes within a few hundred miles a week ahead of time.”
“Ok, that’s a few days. That’s different than the decades you’re talking about with climate change.”
“There are longer-term predictions as well, like for El Niño-related events. It all depends on what kind of simulation the computers run. But there is a lot of overlap in both theory and data for climate vs. weather. And the weather reports are accurate enough to act on, so the climate predictions should be, too.”
“Ok, that makes some sense. But I’m still not going to just take some weatherman’s word for it.”
“Nor should you,” I say. “Listen, at their most basic, these theories are pretty simple. The idea is that several of the gases modern human activity produces trap heat. As the atmospheric concentration of these gases rise, so does the global temperature, creating all sorts of problems. That’s the idea on the table here. Where do you see weaknesses?”
“How do we know the planet as a whole is getting warmer? Couldn’t it just be some kind of sampling error? Or some kind of natural cycle?”
“They compile measurements from all over the planet and take an average. They can also chemically analyze the air bubbles in glaciers to see what temperature the air was when the snow originally fell—that’s not enough to get a global average from, but it does go back many thousands of years, and ice cores can be taken at many locations all over the planet and compared. According to that record, the warming over the recent few decades is not normal.”
“How do we know these gasses trap heat? Has that been proven?”
“Basically, yes, it has. For example, was identified as a greenhouse gas back in the eighteen hundreds. I can look up the names of the people who made the discovery if you like, when we get back to the computer lab. The Earth doesn’t actually receive enough sunlight to account for the planet being as warm as it is, unless something in the atmosphere were trapping heat. When CO2 was first identified as a greenhouse gas, they calculated out what would happen if carbon dioxide concentrations increased, and they came very close to predicting the actual warming we’ve experienced. Wouldn’t it be strange if their theories were wrong but something else heated up the planet exactly as if they were right?”
“Ok, but what if carbon dioxide levels aren’t rising? Is that possible?”
“If carbon dioxide levels aren’t rising, where else is all the carbon dioxide released by modern industry going?”
“Yeah. Anyway, changing carbon dioxide levels have been measured, too. I suppose—theoretically—that data could be wrong, but there’s so much data involved from so many different sources that would have to be an awfully big foul-up or a ridiculously vast conspiracy. If we’re going to go there, we might as well say nothing is reliable ever, which is not particularly realistic.”
“Ok, but we’ve been talking about a simple version of these theories, right? It’s not really simple. I’ve read articles about these things, how increased cloud cover could block a lot of sunlight, or how melting ice in the North Atlantic could change ocean currents and cause another ice age…even if in the simple version the Earth would continue to warm, how do we know what will happen in real life where things aren’t simple?”
“Well, most of that detail, is accounted for in those computer programs. That’s why climate predictions require so much computer power to calculate. Yes, it’s possible some undiscovered something will fix the problem or buy us more time, but it’s equally possible that some surprise will make things much worse. There have been a couple of nasty surprises already, like Antarctic and Greenland ice melting much faster than expected.”
“I heard about that, but I don’t really know who to believe. You don’t even think scientists are always right–you take vitamins with no established daily value, you’d rather take unproven herbal things than medicine….”
Ooh, touché! I chuckle a bit before speaking.
“I question mainstream science; I don’t reject it wholesale. I question everything, as do you, which is why we get along. Look, if modern science was completely out to lunch, modern technology wouldn’t work as well as it does, and it clearly does work. One aspect of science is an extended community of people who share data and check each others’ conclusions. Sure, sometimes they still make mistakes, but the system works well enough that we’ve created the modern world. So, when the top scientists of almost every country in the world say an issue is important, I pay attention.”
The tide has ebbed while we talked; I can’t reach the water with my feet now. The swallows that darted over the water after insects by day have been replaced by bats as night comes on. We watch the bay turn pink and silvery under the reflected light of the fading sunset and then Skeptico speaks again.
“Ok, so we know the temperature is rising because it’s been measured. We know the atmospheric concentration of greenhouse gases is rising because that’s been measured, and anyway, where else are the gases we produce going besides the sky? We know they are greenhouse gases because they have been studied by chemists whose predictions proved reliable, and we know rising temperatures are going to cause problems because weather forecasters say so and they’re usually at least partly right. We know all this isn’t the product of some wild-haired maverick because many well-respected scientists agree with it, and we can’t just assume that all of them are crazy together because if they weren’t right most of the time modern technology wouldn’t work. That’s an answer for everything…but I still don’t know. I don’t know if I trust mainstream science.”
“Look, I’m not saying to trust them. I’m saying think about what is most likely. Do you really want to bet the future of life on Earth that thousands of the most intelligent and well-educated people on the planet are all wrong at the same time in the same way? And that their “mistake” actually conforms to common sense in most respects? I mean, you read the news. Does it look like the weather has been normal for the past decade or so?”
“Do you want to bet the economy that they’re right?”
“Who said the economy is really on the line here? Isn’t using less petroleum and wasting less energy a good idea anyway?”
“That’s another conversation.”
“Yes, probably for another time. I’m getting bit up. But think about it. When you do arithmetic, how do you check your answers? You do the problem again, right? Maybe you even do it two different ways. If you get the same answer, that means you’re right, right? If your only remaining argument against anthropogenic climate change is to suggest that thousands of scientists all made the same mistake over and over again for decades on end, that really doesn’t sound too convincing.”
“No, I suppose not. I still want to think about this, though.
“Good. Thinking things through is good,” I say.
Skeptico gets up, stretches a bit, and fumbles for shoes. Neither of us thought to bring a flashlight, although the moon is almost full and should make additional light unnecessary. I fish a bottle of bug spray out of my pack, explaining that I plan to stay out a bit longer. Before going, Skeptico turns to me and thanks me for our conversation.
“I didn’t think you’d actually talk to me about this stuff, but you really took my questions seriously.”
“And neither of us died!” I laugh. “Good night!”
“Good night. See you tomorrow.” And my friend walks off.