"I'm not a scientist." No doubt you've heard that from one or another politician as -- of all things -- a rationale for dismissing science. Of course, what this means is that if some particular scientific finding runs counter to their policies, the most expedient way to close down questioning on the topic is to pretend they're just too modest to discuss a subject in which they lack academic expertise. As if even to attempt to understand it might be a gesture of disrespect for its practitioners.
It seems to me I hear this sort of thing most often from someone who wants to think climate science or evolutionary biology are in dispute (of course, you also have the conspiracy theorists, the anti-vaccine sorts, the Bigfoot chasers -- in descending order of political clout). Now, I took a little biology in high school, and I've read a couple of books on it, and although I'm not an expert, I feel like I have a layman's grasp of natural selection, and to some extent genetics. But I never took a course in climate science, and to own the truth, I've never read an actual textbook on the subject. It seems logical to me that certain gasses would trap heat more than others, and that if we released a lot of them it might affect the climate, but then again, many a naive blunder started out looking very logical.
So I happened to be in New York a few days ago and found myself at the offices of the Environmental Defense Fund (an organization I regard very highly, and recommend you visit at https://www.edf.org), where I met an actual climate scientist. PhD and everything. And while it might not have been the equivalent of taking a course, it was helpful to hear a few details fleshed out and ask a few questions. I didn't take notes (which I now regret), but here, for what they're worth, are a few things I took away from the conversation:
- The differences between greenhouse gasses can be complex but meaningful. It's not just a question, for example, of how much heat one of them might trap, but also of how long it stays in the atmosphere. Carbon dioxide, say, isn't the most potent thermal insulator among them, but it stays in the atmosphere a long, long time. Black carbon from cooking stoves, however (which is how a lot of the world makes dinner), falls out of the atmosphere in about a week, but it contributes quite significantly to the greenhouse effect while it's there, and of course it's constantly being renewed. A lot of climate change is baked in, as it were, but a lot -- theoretically, half -- we can still stop.
- It might be ambitious meeting the two degrees goal. Not impossible, but difficult. I personally take heart in the recent example California has set in water conservation. If we can't stop at quite two degrees we can keep it close, and the feeling seemed to be it wouldn't necessarily be a nightmare scenario.
- Unless of course we hit the tipping point at which the methane pockets trapped in the permafrost or the seafloor get released. Then apparently it's yikes time. And we don't really have a clue what that point might be.
Another thing I was somewhat surprised to hear was that the Paris accords, whatever comes of them (and the vibe was hopeful), will be voluntary among the signatories. Nothing binding. Apparently if it were binding, our Congress would simply overturn it. Don't ask me what's wrong with them. I'm not a scientist.