Thinking through carbon sequestration

I've been trying to figure out what to say to my classes about carbon sequestration. As Brian mentioned in a comment, if we're going to lock carbon dioxide in rocks (well, artifically*), geologists are going to need to be involved.

I ought to be able to think through the problem from first principles. Carbon dioxide is part of all sorts of natural systems, after all. When it dissolves in water, it makes the weak acid that is responsible for much of the natural weathering of silicate minerals. It's released by metamorphic reactions, and the relative amounts of carbon dioxide and water in metamorphic fluids is important in determining which minerals are stable. It's one of several gasses that dissolve in magmas, and is important in its own ultra-weird magmas: carbonatites, which erupt molten baking soda in the East African Rift (and which concentrate rare earth elements in old deposits). At low temperatures, carbon dioxide, carbonic acid, bicarbonate, and carbonate ions make a fascinating buffer system. (I don't think I explained that one very well, the one time I taught environmental geochemistry. But it's still a fascinating system.)

And that's just the chemistry. There are also questions about fluid flow through rocks and fractures, and about possible rock fracture associated with high fluid pressures. It's hard to know exactly where to start, especially because the info sources that I've read don't try to explain things from first principles.

So how, exactly, is this carbon sequestration supposed to work, and how does it relate to all the various CO2 factoids that I've accumulated over time?

The answer depends on the rock and fluid involved, it seems. A number of possible environments have been proposed, and the issues are somewhat different for each one.

1) Use waste CO2 to enhance recovery of oil and gas. I was vaguely aware that carbon dioxide was used to help recover more oil from old oil fields (mostly because CO2 is produced near Durango - it's actually a commercially produced commodity). I didn't know much about how it works, though - was it used to increase the fluid pressure in the rock, and force the oil out, or did the CO2 dissolve in the oil and change its properties? It turns out that both happen. Yes, the carbon dioxide changes the fluid pressure. But it also dissolves in the oil and makes it flow more easily, which makes it possible to recover more of the oil.

This is already being done - in fact, carbon dioxide is produced commercially to be used in oil fields. So it makes sense to capture waste CO2 and use it instead. (Perhaps this should be considered CO2 recycling rather than sequestration, however - I assume that CO2 dissolved in the oil comes back to the surface with the oil. Not that there's anything wrong with recycling - make less waste, use if for useful purposes instead. But it doesn't take the CO2 away forever.)

2) Pump the CO2 into coal. The methane that adsorbs onto the surfaces of coal has become a commercially important source of natural gas (especially in the San Juan Basin, just south of Durango). Traditionally, the methane is released by pumping water out of the coal. But carbon dioxide also adsorbs onto the surfaces of coal. Maybe CO2 could be used to enhance coal-bed methane production, too.

This technique is being tried in my backyard. If it works, it's got a lot of potential, because coal-bed methane and coal-burning power plants (as a source of carbon dioxide) can be very near one another. (In fact, there are currently two coal-fired power plants near Farmington, New Mexico.) I don't know much about the surface chemistry of coal, so I don't have a good sense of what factors could make this work or not.

3) Pump the CO2 into deep, salty formation water. This is the target of the experiment that Lee Allison described today. I'm not entirely certain of the characteristics of the ideal "saline formation" sequestration project. I think the idea is that a) the salty water is isolated from useable groundwater, probably by some kind of low-permeability cap (like a classic oil reservoir would have); and b) the salty water would make a good chemical buffer for the carbonic acid. I'm not sure of the chemistry of the buffering - this is where I wish that I remembered the complications that happen in the systems of carbonic acid, bicarbonate, and carbonate when there's something in the system other than calcite and carbon dioxide. (I'm guessing that the high concentration of dissolved solids helps buffer the system, since the focus isn't entirely on limestones.) I'm also not sure how the dissolution of carbon dioxide in water affects the potential for problems with increased pore fluid pressure. (Increasing the amount of fluid in rock can make rock break. If you want to get oil out of the rock, this is a good thing; if you want to keep carbon dioxide from escaping, I'm guessing that it would be bad. Unless you can make the reservoir rock more permeable without breaking the less permeable cap?)

And this doesn't include ideas about using carbon dioxide to speed the weathering of silicates. (I think that's partly what's going on with the suggestions to sequester carbon dioxide in basalt, for instance.)

So I'm not sure how to discuss the issue in intro classes. I think I need more information. I would like to tell them about the ideas that have been proposed, however - particularly because some are happening in our own backyard.

*Carbon is naturally locked in rocks like coal, oil shale, and limestones. We let it out when we burn oil, coal, or natural gas, or when we make cement. But natural processes don't remove carbon as fast as we burn it for energy. So if we want to use fossil carbon for energy, and we don't want to deal with the consequences of putting all that carbon dioxide in the atmosphere, we've got to do something to speed up the process.

Climate change and intro geology textbooks

A few days ago, I got the semi-annual phone call from my textbook rep. What am I teaching next semester, do I need any new books, how do I like my current textbook (Exploring Earth), etc, etc, etc. And then she told me that the book was being revised, and did I have any comments for the authors.

"Yes," I said. "I like the book overall, but I've got one criticism..."

It's in the section discussing global warming. The discussion is good, except... well, except for the waffling.

Here's the intro to the climate change spread of pages. (Bold type is added by me for emphasis. Italics are original in the book - they are the way that new terms are introduced.)

Most data indicate that some global warming is occurring. Many scientists propose that human activities, including the burning of fossil fuels and the clearing of forests, contribute greenhouse gases to the atmosphere. Astronomical factors, such as Earth's orbit around the Sun and an increase in sunspot activity, can also contribute to warming. Other factors may lead to global cooling, such as ash from large volcanic eruptions and an increase in certain aerosols in the atmosphere.

Here's an excerpt from discussion of ice cores:

Many scientists infer that these increases in greenhouse gases are partly responsible for the recent increase in temperature, but there remains debate about this controversial topic.

And here's the discussion of climate modeling:

The simultaneous rises of anthropogenic (human-caused) CO2 and temperature may be related. Climatologists use computer models to account for the effects of the various factors that might cause warming. Some model results are consistent with observations of past climates, so may be reliable. Some models suggest that anthropogenic greenhouse gas emissions are a contributor to warming in the last century. The relative roles of different factors over the last 100 years, as predicted by these models, are shown by this bar graph.

The facts (and the supporting graphs and discussions of the factors that control atmospheric temperature) agree with my understanding of the science. But the statements are all qualified in ways that leave room for people to argue that we don't really understand the problem. "Many." "Some." And then there are the references to sunspots and the Earth's orbit, which are certainly discussed in the literature, but which may not deserve a spot in the large font at the beginning of the section. And there are the references to debate, and the subtle implications that there could be problems with modeling. (Models "may be reliable." And then again...)

So I told my textbook rep about my complaints about the wording. She was surprised at my particular complaints...

...because she's been getting the opposite complaint. That the statements about climate change are too strong.

She asked if I would be willing to review chapters for the revised edition. I said yes - but that climate change is not my area of expertise. (The youngest rocks I've worked on are around 100 million years old. The shallowest rocks I've worked on were metamorphosed at depths of around 10 km. Young surface processes? Very important, but not my expertise.)

So if you are a climate scientist, and are willing to review climate science for an introductory physical geology textbook, McGraw-Hill needs you. Please, somebody, make sure that introductory geology books reflect the best evidence that's out there.

(Why do I care? Well, I don't like misleading students. And anthropogenic climate change is an important topic beyond the political and economic issues that it raises. The ideas of climate scientists drive research in other areas of geology - see Dave Petley's post today about the possible effects of global warming on landslides as just one example. Waffling about climate change seems like... well, it reminds me of waffling about plate tectonics in 1987. There were plenty of skeptics about plate tectonics in the 80's, but students were poorly served by the textbooks that portrayed plate tectonics as some wacko idea. And, yes, there were books in the 80's that did just that - my undergrad sedimentology book, for instance. I still feel cheated by that book.

I don't want to cheat my own students by teaching them outdated or misleading science.)

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.

Geologists and denial of human-caused climate change

There's an interesting post at Real Climate about a session on climate change at the International Geological Congress. Apparently, the session included quite a few speakers who are skeptical about human-caused climate change, which led Rasmus Benestad (the Real Climate contributer who wrote the article) to ask:

What is going on? Is there a higher proportion of geologists that have a completely different view on climate change, or was this a biased representation of the community?

To be honest, I don't know. I do know geologists who are skeptical about human-caused climate change. Most of them are retired petroleum geologists. (That may be due to sampling bias, however; Durango is one of those places where geologists go to retire, and the Four Corners Geological Society is affiliated with AAPG, so I drink with retired petroleum geologists about once a month.) But last fall, I also saw a talk by a petroleum geologist who tried to explain why he was convinced that humans are affecting climate, and saw a number of industry geologists thinking about what he said.

Here's an edited version of what I said in a comment on Real Climate. I'm curious what other people think. Why are many geologists resistant to the idea of human-caused climate change?

I’m a solid-earth geologist (structural geology, metamorphic petrology), and I agree with Steve Milesworthy. [Milesworthy observed that the arguments of skeptical geologists tend to be, essentially: 1) there have been natural warm spells in the past, so the current climate change is also natural; 2) life has survived climate change in the past; and 3) climate science is just modeling and can't be trusted.] But I think there's more too it than that.

The fundamental assumption of geology is uniformitarianism: the present is the key to the past. We’ve recently been trying to convince the world that we’re relevant to humans because the past can also say something about the future: earthquake hazards, volcanic hazards, flood hazards - geology can give a longer-term perspective than history, and tell us that, for instance, a 5000-year-old volcano is potentially dangerous.

Geologists can get misled by uniformitarianism, though. The past helps us understand the future, but only if the same physical and chemical processes are operating. It’s hard for geologists to accept that humans are more than temporary, surface-scratching creatures - that we can affect the underlying physical and chemical processes that drive the geology that we study. And it’s hard to trust ideas that come out of physical and chemical models when they aren’t confirmed by something that we see in rocks. (Geologists will often dredge up the example of Lord Kelvin’s attempt to determine the age of the Earth from heat flow calculations - Kelvin was very wrong, because his model was incomplete, not because models are inherently useless.) And geologists have known for a long time that climate changes, so if it was natural in the past, there’s no reason to blame humans…

…except that there are good reasons to blame humans, and climate scientists have built a convincing case based on many different lines of evidence. (Geologists should respect that; it’s essentially the same way that solid earth geoscientists build big ideas.) You can’t test whether humans cause climate change by looking at a time when humans weren’t around… it’s like proving that magma doesn’t cause metamorphism by looking at metamorphic rocks that were heated by other processes. Geologists should get that, because we think that way, too.

And most geologists who have been in grad school since the late 80’s do accept and respect climate research. If we’re in the same departments, or have climate researchers coming to department seminars, then we hear and understand the arguments. But people who work in government agencies that separate geology from climate, or who work in oil & gas or mining, or who work in academic departments that are strictly solid earth - well, those people aren’t directly exposed to the current thinking of climate researchers. And they are perfectly capable of thinking about climate like geologists did in the 70’s. (Milankovitch, Milankovitch, Milankovitch.)

So geologists should accept climate change, but there are lots reasons why some don’t. The reasons are bad, but they exist.

Resources, environment, and teaching intro geoscience in the 21st century

The Teaching Intro Geoscience workshop ended with small-group discussions about what's different about teaching intro geo courses in the 21st century. The discussion was spurred by the workshop's tag - the On the Cutting Edge series features lots of workshops on "Teaching X in the 21st Century" (where X has equaled petrology, structural geology, hydrology, sedimentary geology, geophysics, geomorphology, and intro geoscience), but we weren't talking as much about what's new as about how to teach effectively, period.

The summary of the discussion hasn't been uploaded yet, and I don't remember it well enough to summarize it. (As a friend likes to say, "I've slept since then.") But I want to talk about something that I was thinking about, but didn't say (because I was talking too much already).

The geosciences are central to understanding and dealing with big problems that humans are dealing with right now. We've said this in the past, but suddenly the geosciences are on the front page of newspapers (even when there hasn't been an earthquake, a volcanic eruption, or a flood) and are central to election issues. High prices for gasoline and natural gas, and the proposed solutions (wind, sun, nuclear, geothermal, new drilling offshore, oil shale, gas from shale, coal gasification, coal-bed methane), and the potential environmental costs of the various solutions (global warming, nuclear waste disposal, impacts from mining everything from coal to the components of solar panels, oil spills, groundwater contamination) - geoscientists contribute to understanding all of these things. For as long as I've been in geology, we've been talking about this stuff, but during the last fifteen years, few of these issues have grabbed students' attention. But the world is different - different again, for those of us shaped by the economy of the 1970's, but different for the first time for the majority of intro students.

The misconceptions we've got to deal with are overwhelming. I've recently realized that many people don't realize that methane (the greenhouse gas released by burping cows, among many other sources) is the scientific name for natural gas (the stuff that heats their home, and the fuel that T. Boone Pickens wants to use to replace gasoline in cars). And that natural gas is different from oil (and the various things that come from crude oil, such as gasoline and diesel fuel and #2 fuel oil and plastics and asphalt), but that propane can be produced from both natural gas and crude oil. And that coal gasification and coal-bed methane are different things. And that the sun's light hits Earth at different angles in the summer and winter (and that the sun is not closer in the Northern Hemisphere summer), and if you want to design effective home solar panels, you should think about that. And that the direction the wind blows depends on many things, and isn't the same all the time. And... and... and...

I don't handle resource geology very well. I'm one of those people who has taught it at the end of the semester, crammed into one discussion, and it hasn't usually gone well. (Not even when I start it by making students brainstorm a list of all the resources that they use when driving to the mountains to go skiing.) Part of the problem is my background: I grew up in the 70's as one of the "damn Yankees freez[ing] in the dark" and got into geology in the 80's because I liked water, and I became a hard-rock geologist in the early 90's, when the only resource geologists getting jobs were hydrologists. But maybe my background could also be a strength now. I've never worked for oil or mining (and was briefly an environmental geochemist), but I know plenty of people who do. (That's one side effect of being the past president of an AAPG-affiliated society.) I've taken oil money (Arco funded my graduate advisor, and Chevron, Shell, and Mobil had all endowed funds that supported graduate students), but am familiar with the overwhelming evidence for human-caused climate change. (I read the literature, I've been a member of AGU, I know climate researchers and trust their competence as scientists.) I don't think that demonizing either environmentalists or oil/gas/mining companies gets us anywhere close to solving the tough problems we've got to deal with.

So I'm thinking about what to do. I'm teaching Earth Systems Science, which gives me both opportunities and constraints. I can't simply structure an entire intro course around resource problems (though that could make a good topical intro course), but I can fit resources into the theme of big geochemical cycles. (Too bad I don't really structure my course using an earth systems approach - my one attempt left students saying "Earth is a complex system and we can't understand it," which was not the response I had hoped for.) Maybe I can use resource issues as case studies for discussions of all sorts. Maybe I should find a way to talk about organic stuff (like petroleum and coal) in my minerals section - they aren't minerals (because they're organic), but they are important chemical components of rocks. I could talk about what makes oil, coal, and natural gas in my discussion of sedimentary rocks. I could figure out some way to talk about fracture mechanics (and why cracks are important for both water and natural gas, and why they are potentially dangerous in places like the Crandall Canyon mine collapse) when I'm talking about earthquakes and structural geology. I already talk about climate change, but I could work in some kind of final brainstorming session that ties everything together. (Was that vague? I swear, before I do anything in class my instructions will be more specific.)

What would you do? What misconceptions have you encountered about resources? How would you deal with them - especially when it comes to misconceptions that are entrenched in political beliefs, from the Right or the Left?

I can almost see the CO2 from here...

Earlier this month, Purdue University released some very cool visualizations of the movement of carbon dioxide in the US. (Callan and Mel blogged about it.)

This week, they've released a list of the top twenty counties for CO2 production in the US.

And the top ones are...

1. Harris, Texas (Houston) - 18.625 million tons carbon/year
2. Los Angeles, California (LA) - 18.595
3. Cook, Illinois (Chicago) - 13.209
4. Cuyahoga, Ohio (Cleveland) — 11.144
5. Wayne, Michigan (Detroit) — 8.270
6. San Juan, New Mexico (Farmington) — 8.245

One of these things is not like the others... Farmington has fewer than 45,000 residents. It does, however, have two coal-fired power plants, with another proposed.

It's absolutely stunning to see Farmington on the list with three of the four largest cities in the country, and with major industrial cities of the midwest.

Teaching: thinking globally, observing locally

Yesterday morning, the National Weather Service issued a blizzard warning for my local mountains. It was the perfect set-up for a winter storm: a storm off the coast of Baja California, a jet stream that looped way down to Baja, and then up across central Arizona and straight for our mountains. I was on my next-to-last day discussing weather in my intro class, and it made for a perfect discussion. We could talk about winds, about low and high pressure, about the role of the mountains in controlling the weather in Durango and Denver.

The students were attentive and engaged, in the way that’s only possible when the professor is discussing the possibility of a powder day with a class full of skiers.

And then it fizzled.

It’s been raining. Raining hard. The temperature has stayed in the mid-30’s (F), even through last night. If it had been just a few degrees colder, there would be more than a foot of snow on the ground. But even though it has cooled a bit this afternoon, and there are now some big, fluffy flakes in the air, the snow isn’t sticking. I can see where the snow line probably is: there’s a layer of low clouds around 8000 feet, and that’s where the NWS is currently predicting the snow accumulation stops.

I only live at the edge of the mountains, and the ski area reportedly has two feet of fresh snow, and expects at least another foot. So the students won’t be disappointed.

But the lack of snow down here is important. Snow stays on the ground for months, and a lot of the water soaks into the ground. Rain runs off. And the cold and the snow help the pinyons and the Ponderosas fight off the bark beetles that have been killing the trees and making the summer fire hazards that much worse.

One storm doesn’t mean much. But changes in the snow level are one of the predictions of climate scientists like Jonathan Overpeck (who spoke here a couple years ago). And on Monday I’m talking about climate. So: do I use this storm as an example?

In some ways, that would be a very dangerous thing to do. Many people confuse climate with weather, and assume that if a winter is snowy, or a summer is cool, or a hurricane season is less active than expected, then global warming has turned out to be wrong. But weather and climate are not the same thing: weather is local and short-term; climate is regional or global, and deals with longer-term trends.

On the other hand, global climate can seem distant and irrelevant. Even with CNN and the internet and Google Earth exercises, it’s easier to care about things in one’s own backyard. One of the successes of An Inconvenient Truth, in my opinion, was the way it took a global scientific issue and made it personal, made it worth caring about.

So. Should I use the local weather as an example, and risk students walking out of class convinced that a single storm is what confirms or denies the existence of global warming? Or should I stick with discussing evidence that has been peer-reviewed by specialists, and remember that I’m professionally a structural geologist, not a meteorologist, and I am probably missing some crucial explanation for why this storm appears to be fizzling out, at least at my elevation?

(As I write, of course, the snow has begun to stick. Maybe we’ll get something out of this one after all.)

Links: drought in Turkey & SE US, Tambora, visualizing climate change

Some links to things I've been reading (and thinking about for classes):

RealClimate has a guest post from Figen Mekik about climate change and drought in the Mediterranean. It's a great combination of a personal perspective (Mekik is originally from Turkey) and explanation of the processes involved. In particular, Mekik explains the North Atlantic Oscillation, which I've always found confusing... but which is kind of an Atlantic version of El Nino, and which can have an important impact on weather in Europe, North Africa, and North America.

John Fleck has been watching the drought in Georgia and blogging about what the historical record shows. Is the problem with climate, or with population growth, in this case? (The definition of drought, after all, depends on how much water a given area needs.)

For anyone who, like me, needs a good source of images for climate change lectures: the global warming art site. I recognize the graphs from the peer-reviewed literature (and the wiki pages associated with them have all the references). And it's really nice to have access to the graphics in color, and in an easy format for importing. (Thanks to Michael Tobis and John Fleck for the links.)

And, finally, remembering "the year without a summer" and the eruption of Tambora. I heard the story on NPR this morning while I was driving in. In 1816, people starved in Europe, and New England had snow in the middle of the summer... all because of the eruption of a volcano on the other side of the world. Tambora's eruption was bigger than Krakatoa's (which also had a cooling effect later in the century). (Thermochronic had a great post about Tambora, as well, and connected it to the writing of Frankenstein and with landscape paintings.)

Teaching with An Inconvenient Truth

I'm showing An Inconvenient Truth in class the week after next, while I'm away at the Geological Society of America meeting. I'm going to leave the class with questions to answer while I'm away. But... what should I ask?

I've used climate change to discuss the intersections between science and public policy before. I used to show What's up with the Weather?, a NOVA/Frontline documentary made after the Kyoto Accord was signed, but before the 2000 election. By 2004, it felt really dated, in part because of the four years of the Bush administration, and in part because study after study after study had come out showing that climate is changing now. So when An Inconvenient Truth came out on DVD last fall, I bought it and immediately showed it in class.

But I think I need a different approach to the discussion for the two videos. What's up with the Weather explained the science behind the greenhouse effect (and did a very nice job, I thought - there was a particularly good demonstration of the absorption of infrared radiation by CO2), but it also gave a fair amount of time to climate skeptics, and to people who had a variety of different views about what we should do, if anything. So I asked students to watch for the answers to a number of factual questions (such as what the greenhouse effect is, and what kinds of climate proxies can be used to infer past climate conditions, and what sorts of positive and negative feedback mechanisms can affect global temperature changes), and then I spent the discussion time talking about how to interpret media discussions of science. (We brainstormed lists of facts vs testable hypotheses vs opinions - I wanted them to leave the discussion ready to critically evaluate what they are told.)

That approach won't work for An Inconvenient Truth. In many ways, the movie is a piece of rhetoric... but it's rhetoric based on pretty solid science. (There's been a lot discussion lately about the UK court finding nine errors in the movie, and fortunately there are also some good discussions that evaluated the science behind nine points. Deltoid summarizes the response of a number of different climate scientists; RealClimate's summary is here.) And at the same time, it isn't hard to find critiques of the movie - try the Wall Street Journal's editorial page, for instance.

So I want students to think critically about everything that they hear and read. But, on the other hand, I don't want to encourage students to parrot the climate denialists - I want them to think about the science, about what's happened with CO2 and about the different sorts of effects that it can have.

So... any ideas about what I should do, or what kinds of questions I should ask? Should I ask about specific key points, to reinforce them? (I would love to send the students to the peer-reviewed literature to have them see what the experts really say. Unfortunately, our library is very limited - if it's not in Nature or Science, the students will have trouble finding it - and I think the students need somebody to translate scientific language for them. And if I send them to the web in search of more info, how will I make sure they are looking at reliable sources, and not climate-denial blogs? I don't want them to get in the habit of evaluating on-line sources by choosing ones that agree with their preconceived notions.)

(I do have another idea. I'm considering giving a pre-test and a post-test, same questions, and seeing if An Inconvenient Truth leaves the students with an improved understanding of climate change. One reason: I showed the movie to a math-phobic friend, and she said that she had never understood graphs before watching the gimmick with Al Gore on the lift. And that made me wonder if Gore explained the science more clearly than scientists had... which is the real reason why I show the movie in class.)

IPCC and the Peace prize - historic moment for scientists?

Congratulations to the IPCC (and to Al Gore, as well) for being award the Nobel Peace prize.

And I've got a question. Is this the first time that a group of scientists has been awarded the Peace prize for communicating their results to the world? (Linus Pauling won in 1962 - but that was for activism against nuclear testing (according to Wikipedia). He won the prize in Chemistry for his science.)

I don't think Doctors without Borders quite count as scientists - and there again, they use their scientific expertise specifically to help people.

Are there any other scientists or science-related groups that I've missed?

(Edit: I did miss one: an agricultural scientist who won the Peace prize in 1970.)

More on the climate denial junk mail

Real Climate is putting together a Wiki debunking the "review article" included with the climate denial petition. If you've got expertise in any of the fields that have been messed up in the article, head over there and add your info to their project. (It's not my field, though I know enough to recognize misinformation.)

And if you've got colleagues who wonder what's going on with the petition, send them over there as well. Apparently geologists, biologists, engineers, and computer scientists at least were all targeted with this mail.

(Thanks, Brian, for pointing me to the link. But I'm curious - did the faculty in your department get this as well? Or did they avoid big-name research universities, and target those of us at small public colleges, community colleges, etc - people who have PhDs, but who have fairly small libraries and get a lot of papers via interlibrary loan, pdfs on author web sites, and so forth?)

Climate denial junk mail

Have other geoscientists out there been getting this junk mail?

I checked my work mailbox a few minutes ago, and along with advertisements for custom lab manuals and scanning electron microscopes, I got something rather odd: what appeared to be a reprint of a journal article debunking anthropogenic global warming, a photocopy of a 2000 op-ed article from the Wall Street Journal, and a request to send a petition postcard to a group called "GWPP."

I'm not going to sign it. But I'm curious how they got my address, and whether they're targeting all geologists.

I was also curious about the journal - "Journal of American Physicians and Surgeons." What is a medical journal doing publishing about climate change - even a review article about climate change?

It turns out that it isn't even a respected medical journal - it's known amongst medical bloggers for a lack of real peer review and a general anti-vaccine stance. And the authors of the article are running the petition drive, which is funded by "private non-tax deductible donations by interested individuals."

I'm embarrassed for the 19,000 scientists who have signed the petition. And I'm embarrassed that anyone thought I would be likely to sign it.

Misleading headline of the day: groundwater and climate change

From ScienceDaily and the US Department of Agriculture: ”Climate Change Likely To Help With Groundwater Recharge”.



Image source: http://www.usgcrp.gov/usgcrp/images/ocp2003/WaterCycle-optimized.jpg
I get my water from a well that runs dry every so often. And I’ve heard Jonathan Overpeck talk about how global warming may affect the southwestern US - in particular, how it may affect our pattern of snowfall and snowmelt, and therefore exacerbate our current drought. So I was particularly curious about where, and under what circumstances, increased CO2 would lead to increased groundwater recharge. (The groundwater situation depends, after all, on many things. What’s the nature of the aquifer – is it shallow or deep, spatially restricted or regional? What kind of rocks is it in, and how and where do they connect with the surface? What’s the land use, the vegetation, the rainfall, the snow pack?)

So I checked out the actual paper. It is focused on modeling the effects of increased rainfall on two areas in Australia with different seasonal rainfall patterns. The study’s particular contribution was modeling the effects of plant growth on recharge – previous studies had left out the effects of transpiration.

Probably the most important point left out of the press release had to do with the assumptions: in these two areas, global climate models predict rainfall to increase (14% in one area, and 37% in the other). The study therefore shows that increased evaporation and transpiration shouldn’t use up the increased rainfall, and some of the water should go into the groundwater. And that’s an important result, and the study demonstrates an approach that could be used for other scenarios.

But as the authors themselves say in their conclusion:

The direction and magnitude of the change in local recharge depended on the combination of climate scenarios, vegetation, and soil properties. It is not possible to make generic conclusions about climate change impacts based on this limited sample of climatic zones in Australia.

(Their words; my emphasis.)

Contrast the conclusion of the press release from ScienceDaily:

In both locations, changes caused to soil, precipitation and plant transpiration by simulated climates with twice the existing CO2 led to significant changes to the rate of groundwater recharge. Water recharged from 34 percent slower to 119 percent faster in the Mediterranean climate, and from 74 to 500 percent faster for the subtropical climate.

While the opportunity for decreased recharge rates exists, the general trend is towards increase. Future research will investigate whether those changes would benefit or harm those ecosystems.

The press release never mentions that the simulation included an increase in rainfall... which is probably the single most important factor in increasing groundwater recharge.

And the headline. That headline. “Climate Change Likely to Help With Groundwater Recharge.” The headline does exactly what the authors of the study warn against doing: it makes generic conclusions from a limited study of particular places.

Well. I don't live in Australia, and climate models predict less rainfall for my corner of the world. So regardless of the headline, I'm not going to count on my well recovering any time soon.

AAPG recants on climate change... a little

I was at a dinner meeting/talk with a lot of oil & gas geologists (and geophysicsists) last night, and I learned that the American Association of Petroleum Geologists has revised its position statement on climate change.

For some background: as recently as mid-summer, the AAPG had an official position statement that emphasized the role of natural processes in controlling climate, both in the geologic past and in the present. It specifically mentioned things like solar forcing mechanisms (which have been disproven as mechanisms for recent climate change). It talked about needing more research (which is all well and good, but, well... there has been a lot of research already, and it's pretty darn conclusive).

In short, the old statement made geologists look bad - it made it look as though we didn't respect the work of climate scientists (who, in many cases, work in the same academic departments with geologists). And I think it made geologists look like bad scientists, period.

Well, apparently enough AAPG members complained about the statement, and it's been revised. It is still pretty conservative, talking about the need for more research. But it does include statements like:

"- AAPG supports reducing emissions from fossil fuel use as a worthy goal." (However, the statement is weakened by implying that this requires an economic tradeoff.)

"- AAPG supports the pursuit of economically viable technology to sequester carbon dioxide emissions and emissions of other gases in a continuing effort to improve our environment and enhance energy recovery."

"- AAPG supports measures to conserve energy, which has the affect of both reducing emissions and preserving energy supplies for the future."

The opening paragraph makes some pretty weak statements:

"Although the AAPG membership is divided on the degree of influence that anthropogenic CO2 has on recent and potential global temperature increases, the AAPG believes that expansion of scientific climate research into the basic controls on climate is important."

The climate change skeptics are still there... but AAPG is changing. Slowly.

[Side note: I'm not a member of AAPG; I'm more interested in rocks that are too hot for oil.]

sceptics after a scientific revolution: global warming and plate tectonics

I wish I could remember where I read this criticism of An Inconvenient Truth, but I don't, so I'll have to paraphrase it.

[Edit: yorrike commented with the reference I was thinking of: Geek Counterpoint, at http://geekcounterpoint.net/files/GC060U.html, said:

00:06:40
Metaphor -- fit of South American & African coastlines, difficulties that plate tectonics / "continental drift" had in being accepted.

Comment: This is a really lousy choice of metaphor. The theory of "continental drift" had a tough fight being accepted because it took decades to find data that explained how it worked. Once the data was available, though, the scientific community came around very quickly.

The rest of the post will read weird now, but I'll leave it as it is.]

Near the beginning of the movie, Al Gore tells a story about an old science teacher he once had. According to the story, someone asked the teacher about the similarities of the coastlines of South America and Africa, and asked whether they could ever have fit together. The teacher said no.

The story was told as a lesson that scientists can change their minds. It's also used as a parallel to discussions of anthropogenic global warming, to suggest that a scientific revolution has already occurred. (Science historian Naomi Oreskes, who has studied both the development of plate tectonics and the debate over global warming, has made that point. There are links to her work at the end of the Stranger Fruit post.)

Anyway, I chuckled at the plate tectonics reference in An Inconvenient Truth, and found it pretty appropriate. But I read a comment recently that took issue with it.

The argument went that plate tectonics was accepted quickly, after the data to support the theory built up. There are still skeptics about global warming. So the parallel must be inappropriate.

But, well... I think that geologists have been telling the story of the development of plate tectonics a bit too well. Now, I'm too young to have been at that pivotal AGU meeting where the pieces are said to have fallen into place. But I'm not too young to have encountered skeptics, even decades after the theory was accepted. One of them retired from my current institution less than a decade ago; recent alums still want answers to his questions.

And he wasn't alone - in fact, some very prominent geoscientists, people whose data and ideas contributed to the development of plate tectonics, remained skeptical until their deaths.

I can't find anything online that says this, but none other than Maurice "Doc" Ewing, founder of the Lamont Geological Observatory, supposedly remained skeptical about plate tectonics until his death in 1974. And that's despite being responsible for the amazing exploration of the ocean floor that was responsible for the revolution. (I'm pretty sure that this story comes up at some point in Naomi Oreskes' book Plate Tectonics; if it doesn't, I've heard it repeated by Lamont alums.) That's right. Plate tectonics was developed using data collected by Doc Ewing's researchers, but Ewing himself never accepted it.

S. Warren Carey was a much more obvious skeptic. He worked on the problem of mid-ocean ridges soon after they were recognized, and he argued that they were the result of spreading of the ocean floor. That was an amazing contribution to the science, and he was awarded a GSA Structure/Tectonics Career Contribution Award in 2000 for that and other work. But he never believed that subduction occurred - he argued that the earth was expanding, and that subduction zones were actually zones of extension. (There are some pretty pesky focal mechanisms to explain, and there's the problem of how that magma gets to the surface.) He wrote about "diapiric krikogenesis" as an alternative explanation for arcs, as late as the 1980's.

Those two examples were people who did ground-breaking work in the field. I'm pretty sure there are others. The pioneers of plate tectonics are retiring now, and the skeptics are passing away, and the stories that we tell introductory students begin to seem like ancient history. So much like ancient history that students (and members of the general public) can't imagine a debate ever occurring. And now students and others look at things like the AAPG statement on climate change and think that it means that the science is not settled - that settled science means that there are no disagreements, no mutterings about this or that hole in the theory. But the continued existence of skeptics doesn't mean that. It just means that it's hard to change the minds of people who were taught the old stuff. That the continents are fixed. That the climate has always changed and therefore all climate change is natural.

On the morning of Halloween, GSA is having a symposium on the causes of global warming. The issue seems to have been settled at AGU for years. It will interesting to see whether the GSA symposium feels like settled science (and a discussion of policy alternatives), or whether the debate at GSA continues.

book rec: Storm World by Chris Mooney

As students walked into my Earth Systems Science class on the first day of fall semester, 2005, they saw a satellite image I had just grabbed from NOAA’s website: Hurricane Katrina, aimed straight at New Orleans. It seemed like the perfect image to illustrate the relevance of studying Earth. But I’m a solid-earth geoscientist; I’ve never taken a class in Oceanography or Climatology or Meteorology. And when the science about hurricanes and global warming became big news, I wasn’t very well prepared to answer students’ questions about what scientists really think. Since then, I’ve read news reports, NOAA’s web page, articles in Science, Real Climate... and I’ve had trouble figuring out how all the pieces fit together.

Storm World, the new book by Chris Mooney, gives me the context I needed. It starts by tracing the history of ideas about hurricanes through the 19th and 20th centuries. One of Mooney’s central points is the difference in methodology and models, from the very beginning, between scientists who started with physically based models and scientists who started with observations. It’s a familiar pattern to this field geologist, who has heard Ernest Rutherford’s comments about physics vs. stamp-collecting in many different guises. But in the history of hurricane science, it’s clear that both approaches can provide insights, and both can miss the mark. For instance, in the 19th century, two key aspects of hurricanes were recognized by the two different groups: physics led to theorizing about the release of heat as clouds form, and observations led to descriptions of a hurricane’s circling winds. (It took recognition of the Coriolis effect to show that the two models could work together.) Although it is possible to follow the two approaches into the 21st century, the researchers interact, sometimes by attacking one another, and sometimes by picking up an idea from the other group and transforming it. (For instance, observations showed that hurricanes derive their power from warm ocean water – which leads to the big question addressed first by theoreticians: what happens if we warm the atmosphere and oceans?)

The book continues by tracing the debate over what effect (if any) global warming will have (or has already had) on hurricane strength. It covers the science, the personalities, and the media attention in 2005. All the while, it manages to be simultaneously even-handed and engaging. I don’t know why it works – the history and the science are both complicated, and the cast of characters is immense. And yet the story is woven together so neatly that I never felt the need for a time line or a chart showing the academic genealogy of the major players.

And now I have answers to a lot of my questions. What exactly is the Atlantic Multidecadal Oscillation, and why don't I understand the explanation on NOAA's website? (Answer: it's an alternate way of explaining recent warm temperatures in the tropical Atlantic, one that doesn't rely on global warming. It isn't clear whether there really is a cycle, or whether temperature changes from the 70's (cooler) to the 00's (warmer) are the result of natural processes or anthropogenic global warming.) Why does NOAA's website contradict articles in Science? (Answer: partly because there's argument over the articles, but also partly because of decisions by political appointees.) The history and politics of the science are fascinating, and have influenced the way in which the science is described to the general public. These are things I need to know - as a teacher, I also have the opportunity to frame discussions in particular ways, just as science journalists do. I haven't yet decided how I will change my discussion of climate in class, but I'm thinking that it may need a bit of an overhaul.

It is refreshing to read such an engaging account of science in action. I would recommend it to anyone who is interested in the history of science, in climate and weather, or in the interactions of science, the media, and public policy. And for anyone who, like me, teaches about weather and climate in the context of introductory science courses, the book is an absolute must-read.