I was watching some people argue on TV about global warming, and I was struck at how rhetorically incompetent a lot of scientists are. I suppose that shouldn’t come as a surprise: scientists are trained in science, not rhetoric. In politics, “rhetoric” is a polite word for “bullshit”, which is what you normally hire a trained bullshit expert for.
Of course, you know what a bullshit expert is. You see them on TV all the time. Political pundits, paid consultants, lobbyists, politicians, lawyers, Madison Avenue advertising men, and a host of other bullshit experts dominate the way we think about the world, right down to your average used-car salesman. What’s more, they’re very, very good at it.
In the political arena, scientists are simply outgunned. The anti-global warming guy threw out a bunch of vague claims about temperature going up and down in certain parts of the world, the pro global warming person replied by making equally vague claims about how scientists look at long-term trends rather than short ones. Unfortunately, to a casual observer, both sides appear to be making equally valid points, and in a sense they are, because neither one is really backed up with anything. The problem is that the supporting data is much too complicated to explain in 30 seconds on a TV show, so the scientist expects that you will actually investigate further on your own. After all, that’s how scientists behave when they see competing claims in science journals. But that is not what the public does: the public responds to such an exchange by assuming that both sides are equally unreasonable.
I find this situation unbelievably frustrating. Almost 100% of the debate about global warming focuses on temperature trends, and it’s easy to confuse people about temperature trends. After all, temperatures go up here, they go down there, it doesn’t seem to add up to anything convincing, right? Scientists have done an absolutely lousy job of explaining why they’re so confident in the warming trend. Part of it is because science is complicated and hard to explain to people, and part of it is the fact that they’re just not that good at this marketing stuff.
I’m no marketing expert either, but let me see if I can give it a crack. There are three things you need to understand about global warming:
- Temperature is a sign of warming or cooling, but it is not actually the same thing as warming or cooling. It is very superficial, in the same way that the Dow Jones industrial average is a rather superficial indicator of the economy. It is also much more volatile than the underlying warming or cooling trends, again just like the Dow Jones. Heating and cooling are actually a function of energy, not temperature.
- To understand the difference between energy and temperature in a climate, consider the analogy of energy and weight in your body. If you’re taking in more calories than you burn every day, then you’ll gain weight. Does this mean you’ll necessarily gain weight tomorrow? No, your weight might fluctuate due to other factors. You might be heavier tomorrow, but you might be lighter. You’ll get some confusing data if you check your weight every 10 minutes, but if you’re eating the same diet you ate years ago but your physical activity level has plummeted, then you know what will happen.
- So how do scientists know that the Earth is getting fat on energy? Simple: they’ve conducted experiments on CO2 which prove that increased CO2 levels in the upper atmosphere will block some of the infrared radiation emitted by the Earth. In other words, the Earth isn’t shedding as many calories every day as it used to. It’s like an athlete who’s become a couch potato. He may not eat precisely the same thing every day, so his weight might fluctuate from day to day, but over the long term, you know he’ll gain weight. Similarly, there might be fluctuations in non CO2-related environmental factors, but given the fact that CO2 reduces the amount of calories we shed every day, the conclusion is inescapable: high CO2 levels will make the Earth warmer than it would otherwise have been. Even if we hit a cooling period, it would have been more of a cooling period if there were less CO2 in the atmosphere, and when we switch back to a warming period, the CO2 will make it worse than it would otherwise have been.
Of course, I don’t really expect global warming deniers to give the matter any serious thought, but if you’re one of those fence-sitters who doesn’t understand why scientists are totally unfazed by confusing temperature data or the existence of alternate warming/cooling mechanisms, maybe that will help. Yes, the Earth does have a lot of warming and cooling mechanisms, but the increased CO2 level means that we’re not shedding as many calories every day as we otherwise would, so whatever happens with those other mechanisms, the CO2 will make it warmer than it would otherwise have been.