Geologists who don't deny human-caused climate change: my experience

I’m still thinking about perceptions of how geologists think about climate change. But this time I’m not going to try to explain it. This time I’m going to tell a story.

Before I get started, let me get one thing straight. I’m not going to go through the arguments for anthropogenic global warming, because 1) I’m not a climate scientist, and 2) other people have done it. I’m going to talk about how I came to be convinced. Hold on, because it’s far more convoluted than simply reading a paper and realizing that the conclusions were sound. In fact, I’m going to go way back.

I had been fascinated by glaciers since childhood - I grew up in Maine, and my favorite place, Mount Katahdin, was eroded into cirques and arretes that made it a far more spectacular mountain than one might expect from its elevation (5267 feet). Plus my yard was full of random rocks – so random that I was skeptical about stratigraphy when I first heard of it – and from an early age, I learned to blame the glaciers for making the lawn somewhat dangerous to mow.

My childhood was in the 70’s. I don’t know if I saw that infamous Newsweek cover about global cooling – I was eight years old at the time – but I remember a rather vivid nightmare about running away from an advancing glacier. (Just in case a climate denialist wanders in here and is impressed by my youthful prescience, I was also worried that the Loch Ness Monster’s cousin lived in the shallow, algae-slimed lake in town. I mean, I was eight. I wasn’t reading the scientific literature at the time or anything.)

And then, in the mid 80’s, I went to college in Minnesota. So when I first heard scientific discussions of climate change, it was in the context of understanding the ice ages of the past million years. We talked about glacial landforms in my geomorphology class, but we didn't talk much about what drives climate change. When we did, it was mostly a bit of arm-waving about Milankovitch cycles and about not really knowing what caused climate to change.

I first heard of the greenhouse effect in a student presentation in my Advanced Environmental Geology class in 1988. I don’t remember most of the presentations, but that one struck me as something weird, almost out of the realm of science fiction, but also worth paying attention to.

I started grad school at Stanford in 1989. At the time, Stanford was strong in the solid earth sciences, but had little expertise in surface processes, oceanography, or climate. (There were a couple of hydrogeologists, a micropaleontologist, and an organic geochemist on the faculty, and one grad student was working on marine records of El Nino events. And that was pretty much it.) But the new Dean proposed a program in Earth Systems Science, and there was a seminar series to start it off. I don’t remember most of what was discussed in the talks, but I think that that’s where I began to get the sense that global warming was something that I might have to worry about in my lifetime.

A few years later, after I had started my first job, I heard a convincing talk by Stephen Schneider, as part of a big symposium at a small liberal arts college. I heard Schneider speak again in 1998, I think, while I was on sabbatical (back at Stanford for a few months). And in the meantime, I read science fiction, especially the Mars books by Kim Stanley Robinson*. (If you haven’t read them, one of the plot points involves collapse of an ice sheet in Antarctica, and political chaos that results from rising sea levels in an overpopulated world.) I also spent the mid-to-late 90’s in a small department with a physical oceanographer and a marine geologist whose research included studies of Arctic Ocean currents and young ocean sediments off the Antarctic Peninsula. They were the only people I knew working on climate-related work, and the possibility of anthropogenic climate change was something that they discussed as an underlying principle, not as a fringe idea.

So throughout the 90’s, I viewed global warming as a problem for the distant future, supported by science, but something that might affect my kids. Maybe. When the Kyoto negotiations happened in the late 90’s, I had spent ten years hearing the same big picture from scientists: more carbon dioxide increases temperature; we are increasing carbon dioxide in the atmosphere; we’re going to cause climate to change.

In the early 2000’s, I was shocked to see the future already beginning to arrive, not science fiction any more, but real events. The Larson B ice shelf collapse in 2002 was especially disturbing. There were some other studies that came out at the same time that I can’t remember, but for a while, it seemed as though every week brought a new press release about yet another indication that climate change was already happening. AGU’s statement on climate change came out around the same time, I think. And I was teaching Earth Systems Science myself, so I felt obligated to try to understand climate, even if I had not been formally trained in it. And the papers that I’ve seen since 2002 haven’t shown any sign that the scientific understanding is changing. The science seems to have matured, to arguments over details of why glaciers behave in certain ways, and how various regions respond, and how sensitive is climate to carbon dioxide. But the basic concerns that drive the research don’t seem to have changed since I first heard about the greenhouse effect in the 80’s.

And in the meantime, the Northwest Passage opened.

I don’t study climate myself. I’ve specialized in rocks from the middle of the crust: old, hot, and deep. As far as research goes, I have nothing to add to the discussion. But geology is a related field, and in undergrad institutions, geology departments are the places where climate science is taught, if it is taught at all. And that means that, when climate scientists visit and speak, I pay more attention than I might to a talk by a geneticist or a string theorist.

Until there were signs that we might do something about carbon dioxide, I didn’t hear about people who were skeptical about anthropogenic climate change. And when I encountered them, I had already been convinced by fifteen years of talks by people who were trying to explain their research. I haven’t heard anything from the skeptics that makes me distrust Schneider or my oceanographer colleagues.

And I don’t have nightmares about glacial advance any more. (Now the Loch Ness Monster, on the other hand...)

*I know that being influenced by fiction isn't a good scientific argument. But that doesn't mean that fiction makes no impression on people.