Landscape in a box: How climate can set valley spacing

Credit: Joshua Roering

I haven’t done this very often, but I couldn’t resist a short post on a recent study that connects with the title of this blog.

In many areas where water slices into the surface as it searches for sea level, the landscape is defined by hills creased with sharp stream valleys. There may be broad hills separated by a relatively sparse network of valleys, or valleys and gullies may invade almost everywhere, leaving only narrow bits of high ground. Apart from things like rock/sediment type, geomorphologists have surmised that the difference between those two extremes is a pair of competing forces: 1) the evenly distributed downhill motion of hillslope sediment and 2) the focused erosion of flowing streams in the valleys. If hillslope erosion is stronger, broad hills win out. But if river erosion is dominant, a dense network of valleys will carve up those hills.

That idea is a difficult one to test. If you sit yourself down to watch a landscape change, you’re going to be disappointed. Researchers have used computer simulations to explore this relationship, but that’s not the same as seeing it in the geologic flesh. Kristin Sweeney and Joshua Roering at the University of Oregon, and the University of Minnesota’s Christopher Ellis, took a different tack, building a sandbox model to play with the phenomenon in miniature.

The challenge in building physical models is to get all the forces to scale down, and it’s impossible to pull that off in this case. Although they used very fine-grained silica, the particles are still going to be too big, and the raindrops too large, etc. But even if it isn’t a planet-in-a-box, the model served well as a useful stand-in. Water was dropped onto the sediment in one of two ways: through very fine misters and needle-point droplets. The droplets hit the miniaturized surface like huge raindrops, moving sediment on impact. This takes the place of a number of processes that move sediment downslope, like freeze-thaw “creep”, burrowing animals, tree root wedging, and landslides.  The gentle mist, on the other hand, collected and rolled into gullies to flow downhill. Two sides of the box dropped gradually, creating an ever-lower outlet for sediment-laden water. This is like the tectonic uplift that maintains a steep gradient and makes for rapid streamflow.

During their experiments, “precipitation” alternated between the mist and the droplets for 10 to 15 hours. The researchers varied the proportion of each experiment that water was descending as a mist and as droplets. More mist gives you more valley erosion, while more droplets gives you more diffuse hillslope erosion. A laser scanner frequently mapped the surface of the model sediment to track the progress of landscape erosion.

In experiments where valley erosion was stronger, the result looked like this:

In the experiments where hillslope erosion dominated, however, the result looked like this:

That backs up the theory explaining valley spacing as a competition between stream and hillslope erosion. Not only does that mean that climate controls this striking characteristic of landscapes, but changes in climate and vegetation should lead to an interesting evolution of that landscape. As the researchers write, “Robust linkages between transport processes and topography, as discussed here, are an important component of interpreting planetary surfaces as well as decoding paleolandscapes and sedimentary deposits.” And that’s how a sandbox can tell you about other worlds, and the past of this one.

Science. DOI:10.1126/science.aab0017

Ruminating on a Kentucky farmer

(Sorry about the pastoral pun. I hope you can stomach it. *ahem*)

Dan Kahan, whose research into how the public comes to form opinions on scientific issues reveals the huge importance of our cultural identity and network, has been doing a lot of thinking about a couple enigmatic archetypes: the “Pakistani Doctor” and the “Kentucky Farmer”. (I won’t try to give the entire backstory here, but you can find it via this post.) The Pakistani Doctor, encountered through interviews by researcher Salman Hameed, professes to find evolution important and true in the context of medicine, but rejects human evolution as antithetical to his/her Muslim faith. The Kentucky Farmer, on the other hand, accepts that the climate is changing and alters his farming accordingly, even as he rejects the scientific conclusion that humans are responsible for climate change.

So are these people holding contradictory notions inside their head? How are we to understand their thinking? Dan’s point, as spelled out in the post linked above, boils down to this: these people see no contradiction, and they tell us that the difference between the “evolution” they believe and the “evolution” they disbelieve is context. It’s the cultural relevance. We may be tempted to say, “Yes, but the context is irrelevant— the thing is either true or it is not,” but perhaps we only say that because we successfully pretend that we don’t do the exact same thing. So, in Dan’s view, evolution as it applies to medicine is literally a different concept than evolution as it relates to religious beliefs, and that’s all we need to know to resolve this apparent contradiction. Again, read Dan’s post to flesh this out (and in case I’m poorly representing his argument).

Now, I largely find this insightful and interesting, but a bit of it has continued to stick in my craw, which I promised Dan I would elaborate. I’m going to focus on the Kentucky Farmer. I agree that we should take this farmer at his word when he (implicitly) says that “climate change” with respect to his farm is simply different than “climate change” as it relates to the liberal/conservative point of contention. However, I think stopping there over-reduces what’s going on. The two ideas (of “climate change”), arrived at through the cultural network, come as packets with specific factual baggage. The ideas can differ in content as well as cultural relevance— and if you sit down with the Kentucky Farmer for a beer, I contend it’s highly likely he can tell you all about it. Dan has, of course, thought of this, but seems to have framed it more as a competing hypothesis that comes with rejection of what you might call the “cultural context hypothesis”. I want to push back on that, and argue that this point cannot be left out if you want to fully understand what’s going on.

I’ll rely on my personal experience with the Wisconsin farmer, as I think I’m justified in believing these attitudes to be broadly shared. The Wisconsin farmer has also noticed the unusual weather of recent years, and attests that the current climate differs from the one his father worked with. So yes, you’d better believe he’s willing to adjust his practices. And no, he’s not willing to pin this change on human activities— he finds that hard to believe, so who really knows? And besides, he knows the weather is an unpredictable beast prone to mood swings. Things go up, and things go down, and that’s just how it works. It’s been warmer and drier lately, and someday it will probably be cooler and wetter again. Everything goes in cycles, you know? He’s happy to plan for next summer based on the last ten, because what else can you do?

The “climate change” he rejects isn’t just the liberal variety (context), it’s also different (content).  That climate change is the result of SUVs, coal power plants, and is supposedly going to get warmer and warmer and warmer until there’s some kind of doomsday, according to Al Gore. Here’s the key: ask him what he thinks the climate will be like in 60 years. Does he need to make changes to his farm to ensure his kids’ success? I can almost guarantee he’ll say, “Oh, who knows, maybe warmer, maybe cooler. I wouldn’t get too carried away.” If he truly accepted the reality of climate change as it relates to agriculture, he wouldn’t hesitate to bank on further warming, but that’s not what the “climate change” he accepts means to him. (Might he deny that “global warming” is a synonymous label for his “climate change”?) These things are factually distinct.

This will exhibit itself in his policy preferences. He may support policy that helps farmers adapt to (cyclical, unpredictable) climate change. He will not support policy that actually addresses the cause and mitigates it, because he doesn’t believe in that kind of climate change.

So while I think it’s really useful to consider the fact that we can think differently about a concept if it occurs in multiple contexts, I think we have to wrestle with the fact that in some cases these concepts will be sculpted into distinct things— either by our own reasoning or via our cultural network. Dan has written that it can be almost condescending to decree that the Kentucky Farmer is contradicting himself, and to demand a solution to his foolish paradox. However, I think it can also be condescending to stop him when he gives us one reason why he doesn’t feel he’s contradicting himself— he may not be done explaining things he has put a lot of thought into. I don’t think what I’ve outlined above superficially “explains away the paradox”, as Dan put it, any more than the “cultural context hypothesis” does so. It’s just digging far enough into the details to be sure we understand what the Kentucky Farmer is telling us.

I don’t think we can really celebrate the Kentucky Farmer’s willingness to accept “climate change” as it relates to his normal, everyday business, because he’s not accepting the same facts we’re concerned about. We may find it illustrative to discover how his “climate change” has been sculpted to become culturally palatable, though. Why is he willing to accept those facts/beliefs? We can come up with plenty of plausible reasons. (Perhaps human/divine control of nature, perhaps opposition to regulations on markets or government control, etc.)

However, we shoudn’t expect that he will necessarily be amenable to our version of “climate change”, given the right context. Context may not be the only thing that allowed his “climate change” to pass through the cultural filter.

General Climate Discussion (2)

Update: please head over to the new Discussions page!

Once more: McPherson’s methane catastrophe

For better or worse, I want to briefly  return to Guy McPherson’s claims of human extinction within 20 years via a climate catastrophe. Guy is aware of my criticism of his argument, but has declined to consider the problems I pointed out (instead choosing to accuse me of being paid to disagree with him, which would be news to my bank account). Because I’ve seen him reduce his climate claims to the same two keys a few times now, I thought it might actually be worth singling them out for detailed inspection (even though both are mentioned in my previous post, which was a little overwhelming). I’ll try to keep this simple, but the desire to be thorough can make that a challenge…

(Runaway) Train to Siberia

The first claim is that there is an incontrovertible, rapidly accelerating release of methane from the Arctic. (Example here.) McPherson ascribes this to a destabilization of methane hydrates (also called clathrates) in the sediment beneath the Arctic seafloor. Ostensibly, this is based on the research of a team including Natalia Shakhova that has been studying methane release along the East Siberian Arctic Shelf, but McPherson’s claims about that research come from posts on the “Arctic News” blog. This blog, run by a retired petroleum geologist named Malcolm Light and someone writing under the name of Sam Carana, posts a great deal of strange and unscientific claims about earthquakes and methane in the Arctic.

Specifically, McPherson points to a post there interpreting the Shakhova et al. research as indicating an exponentially-growing release of methane from the East Siberian Arctic Shelf. Apart from the fact that two data points can’t  tell you there’s an exponential trend (rather than, say, a straight line), this also makes the mistake of assuming that there are actually two data points! What really happened is that the Shakhova group tried to estimate the total annual emission of methane from the East Siberian Arctic Shelf after observing some plumes above focused release points. (It’s not yet known if these releases have increased recently— the submerged permafrost has been thawing for thousands of years, since sea level rose coming out of the last ice age.) A couple years later, they published a new estimate based on expanded observations. This was a revision of their earlier estimate, now that they had more data in hand. Sam Carana treated these two estimates as independent numbers representing a time series— asserting that the emission of methane had more than doubled in just a few years. From there, Carana extrapolated to predict that emissions would increase about 1,000 times over by 2040. As a result, he/she predicts a cartoonish increase in the global average temperature of 11 C by 2040. (Actual climate models, on the other hand, project a temperature increase of around 4 C by 2100 if we fail to reduce greenhouse gas emissions— and that’s a deeply troubling scenario.)

Actual measurements of methane in the atmosphere don’t show any such sudden, accelerating spike, and climate scientists don’t believe anything like this “clathrate gun” scenario is underway. The Arctic News Blog obsesses over some satellite measurements of methane in the Arctic, believing that they support the claim of runaway methane emissions. (A researcher who worked on validating that satellite dataset confirmed to me that the raw data the blog is using hasn’t been through any quality control algorithm, and that the instrument hasn’t been validated for some of the kinds of conclusions Carana wants to draw.) By showing that some recent measurements of methane in the Arctic are above the global trend, they believe they are demonstrating a sudden increase. This is misguided, because the Arctic is always above the global average. That’s why we calculate averages. If you measure CO₂ in the smokestack of a coal-burning power plant and find that it’s much higher than the global average from last week, you can’t conclude that is CO₂ suddenly spiking globally. That sort of apples-to-plastic-oranges comparison is meaningless.

So when McPherson claims that “the clathrate gun has fired“, he does so without any evidence whatsoever. Rather, he relies on elementary mistakes made by a blogger who doesn’t appear to understand the science. Not data. And not published research. Not only do climate scientists not think that such a thing is underway, most don’t think it’s likely to be a worry this century.

Do the D-O

The second claim is that Paul Beckwith, a PhD student at the University of Ottawa, predicts 5 – 16 C of global warming within a decade— or, in a softer version, that Beckwith believes such a warming event could occur within a decade in the near future. McPherson continues to make this claim, despite the fact that it has repeatedly been shown to him to be inaccurate. To be fair, Beckwith has stated the second version of this— that such a thing could happen. However, Beckwith also appears to be confused. (I tried several times to get this straightened out with Beckwith, but haven’t had any luck.)

Beckwith has been referring to climatic swings called Dansgaard-Oeschger events identified in Greenland ice cores that occurred every 1,000-2,000 years during glacial periods (“ice ages”). During the abrupt warming phase of these events, the cores record 5-17 C warming in as little as a decade. Following that jump, temperatures gradually dropped over the following centuries. Dramatic as they are, they are not swings in global average temperature, but swings in local Greenland temperature. (This is what ice cores record.) Dansgaard-Oeschger events are terrifically interesting, and there has been a lot of research focused on understanding them. While there are still competing hypotheses for their cause, it’s generally agreed that they involve changes in the large-scale circulation of the Atlantic Ocean— what’s called the Atlantic Meridional Overturning Circulation (AMOC). In the North Atlantic, cooled, salty surface water from the south mixes downward and returns southward at depth. This movement has a large impact on temperatures around the North Atlantic, and the downward mixing that drives the circulation is relatively sensitive, meaning that it can be slowed or jammed up. One way to do that is by increasing the input of freshwater from melting glacial ice, decreasing the density of surface water.

It’s possible that messing with the AMOC could shrink the extent of sea ice off Greenland’s eastern coast, which would help explain the rapid and large temperature shift recorded in the ice cores there. Regardless, the shift would have been largest in Greenland, smaller around the rest of the North Atlantic, with only knock-on effects (mainly in precipitation) beyond that. (That said, CO2 did slowly rise about 10 ppm before some D-O warming events and drop after— a product of ocean circulation change— and methane did increase a couple hundred ppb over a few centuries around them— probably due to wetlands.) The point is that they are not instances of global warming, they are regional events. Noting that Greenland rapidly warmed 5-16 C over one or a few decades in the past does not imply that the entire globe could do the same thing today. In order to change the average global temperature so significantly, you have to alter the planetary balance of incoming and outgoing energy in a big way. That didn’t happen during the Dansgaard-Oeschger warming events. Given that these events seem to entail changes to the Atlantic Meridional Overturning Circulation, they’re really not analogous to the greenhouse-gas-induced global warming we’re currently experiencing. They’re certainly not analogous to the methane hydrate catastrophe scenario that McPherson is preaching. Beyond that, there’s likely a good reason they only occurred during glacial periods and aren’t likely to occur now. The latest IPCC report, for example, judges a sudden shutdown of the AMOC this century “very unlikely“.

So…

McPherson seems to think that these two points are his strongest, but there’s really nothing there to support his eschatalogical message of imminent human extinction— and those who aren’t sure what to make of his dire claims should take that into consideration. If we listen to climate scientists, instead, we find more than enough justification for immediate action on climate change without resorting to sci-fi-like exaggeration. And action would be a lot more productive than sitting around waiting for an extinction that isn’t going to show up on the date circled on your calendar.

The tragedy of “environment” as a political word

In cultural battles, as most of us can attest, things get emotional. Small things can set people off. Complex issues get simplified down to bite-size kernels that mainly serve to separate Us from Them. There are trigger words, pregnant with meaning— often pregnant with twins. Which meaning is the is evil, mustachioed one depends on who you ask. Sometimes the triggers are invented for the battle, but other times innocent, important words get pulled into the fray. And that can be a tragedy.

One such tragedy besets the word “environment”, and confusion about the definition hasn’t helped. The environment, of course, is everything on this planet we call Earth. It’s everything around us. It’s the air we breathe in town and the air we breathe in the country. It’s the water that comes out of our taps; it’s the waters we photograph on vacation. It’s the squirrels on our birdfeeder and it’s the predators we listen to David Attenborough describe on TV. But to many, it’s just something “out there”. National parks. National forests. Antarctica. The Amazon.

Taken that way, “save the environment” gets parsed as “help some trees somewhere at the expense of people”. Those naive tree-huggers, ya know? That framing underlies a great many environmental debates, whether that’s the restoration of wolf populations or the maintenance of water flows to sustain fish populations.

And that’s the railroad switch that sends even the word “environment” down different tracks. It’s hard to find someone who doesn’t appreciate the beauty of wild places. It’s even harder to find someone who doesn’t want healthy surroundings. And yet, it’s now nearly a cultural fact that “environment” is a word for far left-wing liberals. Being a conservative— or maybe even a moderate— means disregarding this “environmental agenda” for far too many people. Get too close to something “environmental” and you could lose your cultural credibility. That makes it even harder to get people to see that the environment is not separate from the world in which they live, and that, in fact, their life and prosperity depends entirely upon it.

We can’t have serious discussions about how to protect the things we all enjoy and depend on because our words straddle cultural lines in the sand. That toxicity even prevents us from using other words to connect on common ground, because we are quick to retreat to the same old, tedious, fighting. It’s ignorant science-deniers vs. ignorant bleeding-heart hippies. Land punches. Score points. You already know there’s no talking with these people.

“Environmentalist” shouldn’t be a contentious description any more than “pro-children” or “anti-house-fire”— and we shouldn’t really need any of them. Unfortunately, groups like ConservAmerica still have their work cut out for them, as do we all.

General Climate Discussion (1)

Update: Please head over to the new Discussions page!

Due to the incredible (and continuing) response in the comments on my post about Guy McPherson, I’m creating a fresh thread for general discussions or questions about climate here. Any comments specific to the Guy McPherson post can continue there.

Understanding strike and dip on geologic maps

In order to understand geology, we need to think about the rocks below our feet in three dimensions. Those spatial relationships— what’s on top of what, how rocks are faulted or folded— give us all kinds of interesting information. While maps are useful in all kinds of ways, they’re a little lacking in the 3-D department. So when we’ve measured the orientation of a rock layer, we need a way to represent that on a map. Here’s a basic primer on how that’s done.

The geological lingo for this is “strike and dip”. The words may be confusing at first, but it’s really quite simple. Let’s start with some nice, horizontal sedimentary rocks. Pretend the top of this block is the surface of the Earth. Picture a kangaroo hopping across it, if that helps or entertains you.

Let’s picture a single layer of that rock and tilt it downward to the right. The tilt of that layer is what we call “dip”. We describe this layer as dipping to the right, because that’s the direction it’s tilted downwards toward. We measure the dip as the angle between the layer and horizontal.

Now, let’s try to imagine looking at that same tilted layer from directly above it. Again, it’s dipping downward to the right. Draw a horizontal line across that layer— that’s what we call the “strike”. (Don’t worry about why we use that word.) In this example, the strike is north-south. That means this layer is dipping to the east.

Here’s a block made of tilted layers instead of horizontal ones. The top of the block is still the surface of the Earth, but I’ve sliced out a piece of the block to help us visualize this better. Imagine you’re looking at a cliff.

When you look at the side of the block, you can see the dip. When you look at the top of the block (the surface), you can see the strike. Click the image below to explore a real outcrop of sandstone and siltstone from the Oregon coast that looks a lot like this. Be sure to zoom in and get a closer look.

Here’s an annotated image of that outcrop, just to make sure you can see the strike and dip. You can click on this image to see more photos from this spot. If you click this link, you can check out  the area with Google Earth.

Geologists carefully measure the strike and dip on an outcrop like that using a tool called a Brunton compass, pictured below.

Wikimedia Commons

Once you’ve made the measurements, you can display them on a geologic map— which was our goal at the start of this post. Strike is easy enough, since it’s a compass direction. If we measured the rock striking north-south, we would draw a short, vertical line on the map in the location of our measurement (assuming up is north). If the rock was dipping 45 degrees to the east, we would add a tick mark at the midpoint of  our strike line, pointing east. Think of the tick mark as an arrow pointing in the direction a ball would roll if you could set it on that rock layer. Just below that we would write the measured dip: “45”. It would look something like the example below. The different colors on the map represent the different rock layers exposed at the surface, just like looking at one of the block diagrams from above. Without the strike and dip symbol, we would have no idea if those layers were dipping to the west, to the east, or were vertical. But by adding this simple symbol, we can understand something about the 3-D orientation of the rocks.

Hat tip to Lockwood DeWitt for giving me the idea for this post.

How Guy McPherson gets it wrong

Recently, a few Ars Technica commenters have been posting references to the work of Guy McPherson on climate articles. McPherson is a retired professor of ecology at the University of Arizona, and he runs a blog called Nature Bats Last. In recent years, he has turned his energies to dire warnings of impending climate catastrophe. Those warnings go far beyond what you’ll find anywhere else: McPherson believes humans will go extinct in as little as two decades.

Now, lots of people run blogs that make wild claims, so why am I spending time on this one? McPherson claims to simply be passing along scientific data to the public— data that most scientists are unwilling to talk about and governments are trying to keep secret. As a result, his followers (I mean to use that term more in the Twitter sense than a religious one) seem confident that they have the weight of science behind them. It takes careful examination of McPherson’s references, and a familiarity with the present state of climate science, to uncover that his claims aren’t scientific at all. I also get the feeling that his internet following might not be insignificant (as noted by climate scientist Michael Tobis) and could be growing, yet I couldn’t find any direct challenges with a web search. This makes one.

Bizarro denial

First, I want to go over general problems with McPherson’s claims and talk about what climate science is really telling us. For those wanting specifics, I’ll post a list of point-by-point corrections of McPherson’s main “Climate Change Summary and Update” post in the third section.

In many ways, McPherson is a photo-negative of the self-proclaimed “climate skeptics” who reject the conclusions of climate science. He may be advocating the opposite conclusion, but he argues his case in the same way. The skeptics often quote snippets of science that, on full examination, doesn’t actually support their claims, and this is McPherson’s modus operandi. The skeptics dismiss science they don’t like by saying that climate researchers lie to keep the grant money coming; McPherson dismisses inconvenient science by claiming that scientists are downplaying risks because they’re too cowardly to speak the truth and flout our corporate overlords. Both malign the IPCC as “political” and therefore not objective. And both will cite nearly any claim that supports their views, regardless of source— putting evidence-free opinions on par with scientific research. (In one example I can’t help but highlight, McPherson cites a survivalist blog warning that Earth’s atmosphere is running out of oxygen.)

McPherson bills himself as a scientist simply passing along the science (even as he dismisses climate scientists and their work), but he cites nearly as many blog posts and newspaper columns as published studies. When he does cite a study, it’s often clear that he hasn’t taken the time to actually read it, depending instead on a news story about it. He frequently gets the information from the study completely wrong, which is a difficult thing for most readers to check given that most papers are behind paywalls (not to mention that scientific papers aren’t easy to understand).

McPherson leans heavily on claims from people associated with the “Arctic News” blog about a catastrophic, runaway release of methane that supposedly is already underway in the Arctic. Unfortunately (or, rather, fortunately), the data don’t match their assertions. The latest IPCC and NAS assessment reports, in fact, deemed such a release “very unlikely” this century. One reason for that is that the Arctic has been this warm or warmer a couple times in the last 200,000 years, yet that methane stayed in the ground. Another reason is that scientists actually bother to study and model the processes involved. One thing McPherson and others like to point to is the recent work by Natalia Shakhova’s group observing bubbling plumes of methane coming up from the seafloor on the Siberian Shelf. Since we’ve only been sampling these plumes for a few years, we have no idea whether that release of methane is increasing or if these are long-term features. Similar plumes off Svalbard, for example, appear to be thousands of years old. (More to put this methane in context here.)

That’s exactly the kind of detail and  nuance that’s absent from McPherson’s claims. Instead, he’s content to link to YouTube videos or blog posts (some ludicrously unscientific— see below) and run with the idea that catastrophic warming is guaranteed as a result. He just latches onto anything that sounds scary. McPherson is especially fast and loose with timeframes. He likes to point to the magnitude of past climate changes (which took thousands of years or more) as proof that we are about to undergo similar changes in the next couple decades. That’s quite clearly a fallacious argument, but McPherson never concerns himself with the details. All the casual reader learns it that there was a huge change in the past analogous to the present that shows just how screwed we really are.

And that’s McPherson’s thing— despair. We’re absolutely doomed, he tells us, and there’s nothing we can do about it. Everything is lost. He derides any sort of optimism or action as “hopium”. He notes in one recent post that “With an eye to improving my ‘bedside manner’ when I deliver presentations, I’ve recently become a certified grief-recovery counselor.” With such an extraordinary view, you would expect him to make the scientific case for extinction very clearly. But he does not. His argument fundamentally reduces to “positive feedbacks exist, ergo extinction”. That is, he lists examples of positive feedbacks (things that amplify change, like the added sunlight absorption of ocean water that has lost its sea ice cover) for a while, intending to overwhelm you with the number of processes that could add to global warming. And that’s it. There are no numbers explaining how big an effect each could have, no analysis of likely warming impacts, nothing. The fact is that climate scientists know about all these processes. But instead of throwing their hands up and saying “Oh, shit”, they actually do science.

Again, specific examples of these things are given in the last section of this post. If you take a look at some of his mistakes and demonstrably false claims, you’ll have a hard time thinking of him as a credible source of information.

[Update 3-13-14: Michael Tobis has covered some of the points I skipped over—namely, McPherson’s discussion of feedbacks— in a new post.]

Just the facts

So let’s briefly lay out the central claims of McPherson’s position, and review what the science really says. I think those are 1) positive feedbacks imply runaway global warming, 2) we will experience at least 3 to 4 degrees C warming in the next couple decades, and 3) on a 4C warmer planet, humans are dead.

Numero uno. While the concept of a positive feedback (a little change triggers an addition that makes the change bigger, triggering another addition that…) sounds like snowballing without end, that’s not actually the case here. These positive climate feedbacks (and there are negative feedbacks, by the way) amplify warming, but only to a certain extent. After all, these same processes were in play when the Earth warmed out of the last glaciation (over the last ~18,000 years), which obviously didn’t scorch the planet. Without any of these feedbacks, the glacial/interglacial differences would be much smaller, but they do not cause runaway warming.

There is such a thing as a runaway greenhouse effect– just ask the planet Venus. However, a recent study looking at what it would take to trigger such an event on Earth ballparked the requirements at around 75 times the amount of CO2 currently in the atmosphere, 5.5 times the methane, and some other greenhouse gases. The “business-as-usual” scenario in the latest IPCC report, where we do nothing to curtail greenhouse gas emissions, ends the century at about 2.3 times today’s CO2 and 2 times the methane. We have a lot of things to worry about, but a runaway greenhouse isn’t one of them. (McPherson, by the way, cites this same paper as if it shows that we’re about to trigger a runaway greenhouse.)

So what are we facing if Arctic methane releases increase? Climate scientist David Archer shows some back-of-the-envelope math here. If the release increased by a factor of 100 and lasted for a century, it would be the equivalent of increasing today’s CO2 by 25-90%. Bad? Yes. Extinction? No.

Nummer zwei. The latest IPCC report projects roughly 0.3 to 0.7C of warming by 2035. (The exact numbers are a little complicated, but I explained it here.) Farther into the future, the different emissions scenarios diverge. The “business-as-usual” scenario results in about 2.6 to 4.8C warming by 2100. Rosier scenarios involving moderate efforts to stabilize greenhouse gases yield warming of about 1.1 to 3.1C by 2100. There are precisely zero scientific studies projecting several degrees of warming by 2035, as McPherson predicts. (In fact, he cites one blogger’s childish prediction of a whopping 20C increase by 2050.)

Numéro trois. So what are the impacts of 4C warming? Here’s a handy summary of the many impacts described in the 2007 IPCC report (this section of the newest report isn’t out yet). They include increased droughts, more extreme rainfall, rising sea levels, serious problems for many ocean organisms, real problems for many terrestrial species, lowered agricultural yields… It’s not pretty, and we very much want to avoid it, but it’s not human extinction.

If you think the IPCC reports are lying about the state of the science, feel free to do a Google Scholar search for “climate change projections” in published studies.

[Note 4-7-14: A comment from Paul Beckwith has revealed that I incorrectly attributed some statements and materials to the Arctic Methane Emergency Group, either due to Guy McPherson’s attribution or misunderstandings of my own. I considered preserving these statements for transparency, but don’t want to make the post too hard to read, so I will simply make the appropriate edits. I am grateful to Paul for bringing it to my attention.]

Errata

Okay. These corrections and notes apply to this post on McPherson’s blog, which I took to be the most complete explication of his views available for fact-checking. The point of this tedious list is to back up the points I raised above and illustrate the untrustworthy and unscientific nature of McPherson’s claims.

As his post appears to be updated over time, I’ll note that I accessed it on 2-13-2014. I’ll just go top to bottom.

–Guy McPherson (I’ll abbreviate as “GM”) cites the Brysse et al “side of least drama” paper to support his claim that climate scientists are simply unwilling to speak out about the imminent and existential threat of climate change. The paper absolutely does state that “scientists are biased not toward alarmism but rather the reverse: toward cautious estimates”. However, it’s more than a stretch to extend this to the idea that civilization is collapsing and we’re going extinct but climate scientists are saying everything is fine.

–GM writes, “Ever late to the party, the Intergovernmental Panel on Climate Change (IPCC) admits global warming is irreversible without geoengineering in a report released 27 September 2013.” This can only be seen as a new “admission” if you know nothing about the carbon cycle. Warming is irreversible because CO2 remains in the atmosphere for centuries to millennia— this has always been known. Irreversible does not mean unstoppable, however, as GM seems to be implying. Reducing emissions stabilizes greenhouse gas concentrations, limiting warming. In order to lower temperatures, CO2 will have to be removed from the atmosphere— geoengineering. Old news.

–Now we get to “On a planet 4 C hotter than baseline, all we can prepare for is human extinction.” The reference for this pretty important statement? An opinion piece in the Guardian.

–GM references the paper I mentioned above about a runaway greenhouse effect on Earth being easier to trigger than previously thought. Of course, we saw that it requires far, far more warming than any realistic scenario of anthropogenic climate change— a point that is explicitly made in that paper.

–GM notes the discovery of a recent greenhouse gas (perfluorotributylamine) that is 7,100 more potent than CO2, molecule-for-molecule. This seems to be included only for the scary number. How much of it is in the atmosphere? At about 0.18 parts per trillion (in Toronto), it’s completely irrelevant to questions about the climate change we’re currently undergoing.

–GM cites a Geological Society of London release about climate sensitivity— the amount of warming we get from a given increase in CO2. GM describes it by saying that “Earth’s climate could be twice as sensitive  to atmospheric carbon as previously believed.” But that’s not what the release says. The climate sensitivity values that are usually discussed (around 3C for a doubling of CO2) are specific measures over specific timeframes, developed to create a standardized comparison between models. The release describes an analysis of longer-term change, as the climate system comes into equilibrium over millennia. It’s that long-term change that the release says could be double the shorter-term sensitivity . If we’re discussing what we’re facing over the next few decades, that is completely irrelevant.

–Here’s where the Arctic methane stuff gets hot and heavy, as one person is quoted as saying, “The world is probably at the start of a runaway Greenhouse Event which will end most human life on Earth before 2040.” There’s simply no evidence for this. You won’t find any published studies to support it. GM goes a step further, citing an “analysis” on the “Arctic News” blog, predicting a 20C warming by 2050. What is this prediction based on? Curves drawn on a chart. If you fit the right polynomial (a dangerous activity) to the Arctic temperature data that shows roughly 2C warming from 1980 to 2010, you can get it to skyrocket to 20C by 2050. (Well, actually you can’t quite, so a steeper line is simply drawn on.) No climate model. No physics. Just a line. This isn’t science. This is the kind of thing that lazy climate “skeptics” do (the smarter ones won’t).

–GM includes a graph from the same “Arctic News” blog showing methane data. First, it claims that methane is 1,000 times more potent than CO2 (it isn’t) and thus responsible for the vast majority of global warming (it isn’t). Beyond that, it plots a single measurement of atmospheric methane from a single spot in the Arctic (>2,600 parts per billion) on a chart of global average atmospheric methane (currently about 1,800 ppb).  This sudden “increase” is assumed to represent a catastrophic release. Unfortunately, this is simply ignorant. Methane concentration varies quite a bit around the world— highest in the Arctic, lowest in the Antarctic. Absolutely no effort was made to create an apples-to-apples comparison like, at the very least, calculating an average concentration for the Arctic for that week.

–GM reports that the US Navy “predicts an ice-free Arctic by summer 2016”. What does the linked post actually say? The lower bound of the predicted decline in a sea ice model run by Navy researchers was 2016. The researcher calls this “an aggressive interpretation”. What was the central date in the projection? Or the upper bound? We aren’t told. How does this sea ice model compare to others? GM isn’t interested in helping us find out. I would guess this means he hasn’t looked.

–GM quotes climate scientist Jason Box from a newspaper story, saying, “In 2012 Greenland crossed a threshold where for the first time we saw complete surface melting at the highest elevations in what we used to call the dry snow zone.” He uses this to support his contention that the climate system reached a tipping point— a threshold to runaway change—  in 2007. But what Box was actually talking about was a freak event several days long in which melting conditions existed across the entire ice sheet. This was viewed as a weather event, not a significant climate event.

–In a note dismissing biofuels, GM describes them as “the nonsensical notion that industrial civilization can be used to overcome a predicament created by industrial civilization”. This is obviously an axiomatic assertion that makes you worry about GM’s objectivity.

–GM provides a timeline of climate “predictions”, ostensibly showing that they have become more and more alarming over the past few years. (We’ll leave aside, for the moment, that he doesn’t seem to understand the difference between projections— predictions contingent on scenarios of future emissions— and actual predictions.) An updated version of this list can be found here. [Update: I’ve been told that version is actually not the most recent.] The list is flat-out wrong. I dug up the actual numbers on several of them for an Ars commenter. GM claims the IPCC predict 1C of warming by 2100 in their 2007 report. It actually projected roughly 1.8 to 4C, depending on the emissions scenario. These numbers were equivalent to the projections from the previous report in 2001. Next, GM claims the Hadley Centre predicted 2C by 2100 in 2008. The document he links to provides no projections of global temperature of any kind. At the other end of the list, GM claims that the International Energy Agency predicted 3.5C warming by 2035 in 2013. The link goes to a poorly re-written press story from 2010. What did the IEA really say? Their 2010 report described a scenario in which the trajectory of growing emissions by 2035 was such that we would eventually hit 3.5C warming before greenhouse gases were stabilized. [Update: GM had already removed the IEA “prediction” from his post.] So does this list show climate projections becoming rapidly more dire? That’s a big, fat no.

–GM writes, “These assessments fail to account for significant self-reinforcing feedback loops (i.e., positive feedbacks, the term that implies the opposite of its meaning). The IPCC’s vaunted Fifth Assessment will continue the trend as it, too, ignores important feedbacks.” It’s not true that these assessments ignore positive feedbacks. It is true that not all processes are included in climate models, which continue to be developed. The link GM provides is to a story relates to the fact that the generation of models used for the latest IPCC report do not simulate thawing permafrost. For reference, one model that does simulate this process now projects that it would add an additional 0.1 to 0.7C warming by 2100 due to a release of CO2 that would raise the global concentration by 40 to 100 ppm. My guess is that those numbers aren’t scary enough for GM to want to mention them. (To be fair, that’s probably a conservative estimate, but it’s nowhere near the kind of thing GM is talking about.)

–GM cites a paper showing that Earth may have lost its moderate climate to a runaway greenhouse if it were more than 1% closer to the Sun (though it also notes that their analysis doesn’t account for clouds, which might broaden the range). He believes this supports a claim that “A minor change in Earth’s atmosphere removes human habitat. Unfortunately, we’ve invoked major changes.” How does one square this with warmer climates in Earth’s history, none of which triggered that runaway greenhouse? The Cretaceous period, notably, was far warmer than the present day. It wasn’t until an asteroid impact wreaked havoc on the climate system that a mass extinction took place. GM’s definitions of “minor change” and “major change” are fuzzy.

–GM brings up a temperature record from Concord, Massachusetts, in a very interesting parallel to climate “skeptics”. Individual records that show cooling over some period are often cited as proof that all this global warming stuff is hooey. Or the accuracy of a particular record is called into question in some way, as if climate science is a house of cards that can be brought down by the exposure of a single flaw. In this case, GM claims that while the instrumental temperature record indicates about 1C warming there since 1840, an analysis of the flowering dates from Henry David Thoreau’s journals indicates a warming of 2.4C. First off, it’s interesting to note GM implying that instrumental records are woefully inaccurate, when it’s this very information that helped climate science work out the anthropogenic nature of climate change. Second, if GM had bothered to read the paper, he would have discovered that the 2.4C number comes from the local instrumental record, not the flowering dates. The instrumental record was used to study how the flowering dates changed with temperature. I have no idea where he got the 1C number from.

–GM claims that the Next Generation Science Standards (for public schools) “buries the relationship between combustion of fossil fuels and planetary warming”. “The misadventures of the corporate government continue”, he complains. In a post about evolution and climate change in those science standards by the National Center for Science Education, they quote from the standards: “Human activities, such as the release of greenhouse gases from burning fossil fuels, are major factors in the current rise in Earth’s mean surface temperature (global warming).” Why did GM make this up?

–GM cites a briefing from the UN talks in Copenhagen saying that the past shows sea level should be 23 meters higher at today’s CO2 concentration. What does this briefing, from a Jamaican reef biochemist, note about this? “IPCC projections are based on modes for a time period of 20, 50, or 100 years, when the response of the climate system to increased CO2 takes thousands of years, so models miss more than 90% of the long term response…” Again, we’re up against timeframe details. GM equates long-term equilibrium changes with short term, decadal ones. Here’s a study looking at the same thing: they estimate the long term sea level rise at today’s CO2 at 9-31 meters, noting that would take 500 to 2,500 years. The reason for this is that these studies are based on estimating past sea levels and CO2 concentrations (which is complicated). These records are necessarily at long term equilibrium, because that’s what the geologic record preserves for us that far back in time.

–I don’t think I need to comment on this claim: “In other words, near-term extinction of humans was already guaranteed, to the knowledge of Obama and his administration  (i.e., the Central Intelligence Agency, which runs the United States and controls presidential power). Even before the dire feedbacks were reported by the scientific community, the administration abandoned climate change as a significant issue because it knew we were done as early as 2009. Rather than shoulder the unenviable task of truth-teller, Obama did as his imperial higher-ups demanded: He lied about collapse, and he lied about climate change. And he still does.”

–“Arctic News” returns, along with a YouTube video, to claim that “Arctic methane release and rapid global temperature rise are interlinked — including a temperature rise up to about 1 C per year over a decade,according to data from ice cores“. The “analysis” is someone looking at data from a Greenland ice core, deciding that methane looks more important than CO2 (physics need not apply), and noting the abrupt warming at the end of the Younger Dryas, an interesting period about 12,000 years ago and is thought to have been brought about by a disruption of ocean circulation. (Questions remain.) First, temperatures calculated from Greenland ice cores are local temperatures, not the global average, and the change during the remarkable event was less elsewhere. Second, the methane increase in the ice cores they point to as the cause of the warming is from about 450 to 750 ppb— a difference of 300 ppb. Remember that the global average today is about 1,800 ppb. Methane has increased about 150 ppb since 1985. Has that had a similar effect to what they’re proposing? The first link in GM’s statement contains this ludicrous extrapolation: “The atmospheric temperature increase in Australia this year (0.22C) indicates that in 10 years it will exceed 2.2C and in 30 to 40 years, 6.6C to 8.8C.” I’m not sure you can get more unscientific than that. Australia, by the way, has warmed about 1C since 1950.

–For the sake of my sanity, I’m going to skip over the list of positive feedbacks. Suffice to say, some of them are just more “Arctic News” claims and several others are mis-reported. Others are fine. [Michael Tobis took a look at this list in this post.]

–GM finally comes right out and says “the scientists writing official reports on climate change are lying”.

–GM writes “And never mind that warming in the interior of large continents in the northern hemisphere has outstripped model predictions in racing to 6-7 C already, according to a paper that tallies temperature rise in China’s interior in the 15 May 2013 issue of the Proceedings of the National Academy of Sciences.” What does that study really say? “Here, we show central China is a region that experienced a much larger temperature change since the Last Glacial Maximum than typically simulated by climate models… We find a summertime temperature change of 6–7 °C that is reproduced by climate model simulations presented here.” The Last Glacial Maximum, remember, is the peak of the last “ice age” around 20,000 years ago. Why is GM pretending that parts of China have experienced 6-7C of anthropogenic warming, and that this shows projections of future warming to be too conservative?

–GM writes “Through late March 2013, global oceans have risen approximately ten millimeters per year during the last two years. This rate of rise is over three times the rate of sea level rise during the time of satellite-based observations from 1993 to the present.” Sounds like it’s accelerating rapidly, doesn’t it? Even his link is to a post showing why this is not a sign of acceleration. The tremendous La Nina of 2011 dumped tons of rain on Australia and the Amazon, adding so much water to continental storage that sea level fell over 5 mm. As that water drained back to the oceans, sea level rise increased. You can see the most up-to-date data here. This is cherry picking. This is what climate “skeptics” do.

–GM writes “On a particularly dire note for humanity, climate change causes early death of five million people peach year.” This links to a story about an NGO report. The summary from the actual report states, “This report estimates that climate change causes 400,000 deaths on average each year today, mainly due to hunger and communicable diseases that affect above all children in developing countries. Our present carbon-intensive energy system and related activities cause an estimated 4.5 million deaths each year linked to air pollution, hazardous occupations and cancer.”

–GM writes, “The Guardian‘s headline from 13 November 2013 announces, ‘Global warming since 1997 more than twice as fast as previously estimated, new study shows.'” Sounds like global warming is accelerating beyond scientist’s projections! The story refers to a study (which I covered here) showing that one particular global temperature dataset (there are several) was underestimating recent temperatures, primarily due to a lack of measurements in the Arctic. That bias (by which I mean measurement bias, not bias in the political sense) made the recent slowdown in atmospheric warming (related to some action in the Pacific) seem a little larger than it really was. Other datasets had less of this bias. Accounting for this still leaves the last decade of atmospheric warming slower than the previous one. (Again, this is natural variability— warming of the ocean hasn’t slowed.)

–GM writes, “Global loss of sea ice matches the trend in the Arctic. It’s down, down, and down some more, with the five lowest values on record all happening in the last seven years (through 2012).” This may seem like a nit-pick, but this is a pointless statement. The global sea ice trend depends on two places- Antarctica and the Arctic. In Antarctica, there’s been a slight increase recently, while the Arctic has seen a large decrease. Therefore, the reason that global sea ice is down is that Arctic sea ice is down.

–GM writes, “[T]he 13 September 2013 issue of Science contains another surprise for mainstream scientists : The Pine Island Glacier is melting from below as a result of warming seawater.” It’s well known (and bloody obvious) that warming seawater melts marine-terminating glaciers. Calling this “another surprise for mainstream scientists” is just a mindless pot-shot.

–GM writes, “The climate situation is much worse than I’ve led you to believe, and is accelerating far more rapidly than accounted for by models.” The link goes to a YouTube video from David Wasdell of the “Apollo-Gaia Project” telling a parable. He’s not a scientist, but his videos are used as evidence several other times, as well.

–GM cites a Peter Wadhams prediction of ice-free Arctic summers by 2015 or 2016 (more than once, I think). Apart from Wieslaw Maslowski, you won’t find other sea ice researchers making such a dire prediction. As you can see, it would take a truly incredible change in the next couple years for this prediction to come true.

–Back to the pointless pejoratives, we get “In a turn surprising only to mainstream climate scientists, Greenland ice is melting rapidly.” First, this link just refers to the freak surface melting weather from July 2012 I mentioned above. Second, the rate that Greenland ice is melting is no surprise to climate scientists, who have been the ones documenting it year in and year out. GM uses the phrase “mainstream climate scientists” like Sarah Palin says “lamestream media”.

–Here’s a hum-dinger I mentioned way up above. “As one little-discussed example, atmospheric oxygen levels are dropping to levels considered dangerous for humans, particularly in cities.” Yes, that link goes to a survivalist blog. No, we’re not going to suffocate because burning fossil fuels is using up all the oxygen in the atmosphere. It’s true that fossil fuel combustion has sightly lowered the concentration— this is one way we know humans are responsible for rising CO2— but it’s not even remotely close to a significant decrease. Between 1990 and 2005, the proportion of oxygen in the atmosphere decreased about 0.02%.

–GM writes, “An increasing number of scientists agree that warming of 4 to 6 C causes a dead planet. And, they go on to say, we’ll be there by 2060.” The link goes to a blog post by writer David Spratt, who was used as a reference before. Spratt gets the 4-6C comment from a reference to warming in 2100. He invents the “as early as 2060” himself. The “dead planet” part of the statement refers to this World Bank release about the dangerous impacts of 4C warming. Spratt describes this as ending “the world as we know it”, which GM flips into “a dead planet”. You won’t find any such description from World Bank.

–GM cites a video of a PhD student talking about the possibility of 6C warming in a decade and uses this graph to support it, presumably because the spike at the end looks scary. Apart from the fact that the graph doesn’t actually come from the paper he cites, but rather data from two papers (one of which he cites) combined with a business-as-usual projection for the next century (which he does not explain), the scary spike at the end is just the same ~3C warming by 2100 IPCC projection he was discounting earlier. To tidy up the math here, 3C/90yrs =/= 6C/10yrs.

–The end of the post claims that the Pentagon is surveilling us online in case finding out that we’re going extinct turns us into ecoterrorists. Just sayin’…

–Lastly a quote from another post of GM’s, which he explains why he thinks the collapse of human civilization can’t get here quickly enough. “Yet, seemingly contrary to these simple, easy-to-reach conclusions, I work toward collapse. Largely unafflicted by the arrogance of humanism, I work on behalf of non-human species. Industrial civilization is destroying every aspect of the living planet, and I know virtually nobody who wants to stop the runaway train. Yes, collapse will kill us. But our deaths are guaranteed regardless, unless I missed a memo.”

Update: I’ve discovered some interesting comments on GM’s post. A poster named Eric took issue with some of GM’s claims, and pointed out a few of the same errors I’ve outlined above (like reports not saying what GM claims they say). To make sure his criticism came across correctly, Eric noted, “I’m not saying climate change is a non issue- In fact I happen to think that it is humanities BIGGEST issue. However hyperbole and exaggerated threats serve no purpose but too slow down the response and make people lose hope. I appreciate your time and I hope I have contributed to the discussion in a meaningful way.”

After another poster asked if GM was going to respond, he wrote, “I will not take time to deal with Eric the denier. No amount of evidence will convince deniers of anything, so I’ll not waste my time. If you’re interested in evidence, there’s plenty in this post to support all I’ve written and said.” This appears to be a representative exchange.

Observational vs historical science

Update: For another take on this, check out this great article by John Timmer.

In last night’s debate between Bill Nye and Kentucky’s Creation Museum founder Ken Ham, Ham focused on a favorite argument of his. Ham thinks all of science can be neatly divided into two types: observational (or experimental) science, and historical science. In his view, observational science is sound, because it can be tested in a laboratory. Historical science, however, is just a belief about the past that cannot be tested, and so is not really science. Now that’s an atrocious misrepresentation of the way that, say, geology, is actually done, but it’s a tremendously useful claim for Young Earth Creationists like Ham.

It allows them to shrug off virtually any piece of scientific evidence that disagrees with their religious contentions about the history of the Universe and life on planet Earth. The first bit is obvious. By positioning any science that deals with the past as merely conjecture, they need not deal with evidence at all. “Well, you have your beliefs and I have mine,” they can say. Suddenly, the accumulated knowledge of centuries of scientists has been put on equal footing with a literal and dogmatic reading of the Bible. The second bit is even more pernicious. If evidence of physical or biological processes in the modern day (fitting under Ham’s umbrella of “observational”, and therefore trustworthy, science) causes problems for the Young Earth Creationist viewpoint, it is simply claimed that the observed process must have been different in the past– which, of course, is not a claim that can be tested with evidence because it is “historical”. During the debate, Ham stated that treating physical processes as if they functioned similarly in the past is just an assumption. (His contention that the very laws of physics twiddled around capriciously in just the right way to make each of his outrageous claims work out, however? An acceptable assumption, to him.) In this way, every scientific weapon that could possibly do damage to the claims of Young Earth Creationists is blunted and turned away.

Let’s put the past behind us

But how is this so-called “historical science” really done? Are we merely forming beliefs about the past that cannot be tested? The answer is an emphatic, resounding, “NO!!” In the debate, Bill Nye used an example that many in the audience could relate to: the TV show CSI. We all have an intuitive feel for the fact that forensic evidence at a crime scene can tell us about who was there and what happened. Let me try a simpler analogy.

Imagine that we’re examining ancient tablets on which Arabic numerals (1, 2, 3…) were once drawn with pricks of black pigment akin to a tattoo. As the tablet has been worn, chipped, and even broken over time, many of the dark points are gone. How, then, can we determine which numeral was drawn? Well, whether or not you realize it, we have 10 working hypotheses for each digit. That is, it could be 0-9. Each numeral has its unique shape. Now, we carefully map the position of the remaining points and see this.

We can rule out some of our hypotheses– some numerals. The numeral 3, for example, is not consistent with these points.

That was a test. The data points, these literal points of pigment, eliminate some of the hypotheses. Which hypotheses remain? Well, it could be a 1, obviously. It could also be part of a 4, or even a 7 drawn straight up and down, or possibly even a 9 without a curve at the bottom. However, that means there are 6 numerals we know it cannot be. Now, perhaps we study enough of the numerals in this archaeological find to learn that 7s were always drawn diagonally and 9s with curves. And let’s go a step further, and say that the iron in the pigment suffused into the surrounding material such than an MRI can show us if a point was once near a surface that has since eroded. That MRI shows no signs of the rest of a numeral 4.

Now, we will have our caveats and perhaps, in this silly example, we will not be 100% confident in our conclusion, but we will be able to say that the available evidence is only consistent (or at least most consistent) with a numeral 1. Because we are thinking scientifically, we will always be open to future evidence challenging this conclusion. If a new kind of analysis somehow finds points tracing out the rest of a 4, we will immediately revise our conclusion to state that the available evidence is most consistent with a numeral 4. Were we there to see the numeral drawn? No. Do we have a complete copy of it? No. Is our conclusion merely an assumption untested by evidence? Absolutely not.

Ken Ham misrepresents the scientific study of Earth or cosmic history because he has to in order to defend his beliefs, which are completely inconsistent with the available evidence.

Elementary, my dear Watson

In science, we must always be careful to make a distinction between an observation and an interpretation. Observations are inarguable. They are measurements. A telescope measured a given intensity of light at x wavelength. A mass spectrometer measured a given ratio of isotope A to isotope B in a mineral sample. Interpretations provide meaning to observations. According to this calculation, that isotope ratio corresponds to an age of x.x million years. If research causes some detail of that equation to change slightly, our calculated age will, too. That wouldn’t, however, change the measured isotope ratio.

When thinking scientifically, observations must always be in control of interpretations. Or as Jacob Bronowski put it, “This is the scientist’s moral: that there is no distinction between ends and means.” Your conclusion is only good to the extent that you carefully followed the scientific method.

For Ken Ham and other Young Earth Creationists, however, things are much different. As Ham freely admitted several times during his debate with Bill Nye, his starting point is that his literal reading of the Bible is an unerringly accurate representation of the world. He starts with an interpretation about the world– that a global flood ravaged the Earth and must account for the details of life history and the Earth’s surface, for example– and constructs a force-field of Biblical inerrancy around it. Any observation that is inconsistent with the interpretation is explicitly rejected. It bounces right off. Observations don’t tell Ken Ham that his interpretation is wrong. Ken Ham’s interpretation tells him that the observations are wrong.

So, in fact, even the “observational science” that Ken Ham lauds as trustworthy is antithetical to the thing he calls “creation science”.

Two-channel communication and the sci comm broadcast

The following thoughts are hopefully instructively wrong.

The idea that science communication inherently occurs via two channels— meaning and content– strikes me as one of the most useful ways of thinking about it. The content entails the information, be it news of a fresh study or an explanation of some concept, and the meaning is determined by how that information strikes the receiver. If a climate skeptic and a climate advocate read the same article, they receive the same information but radically different meanings. If you have a homogeneous audience, you can attempt to control what you transmit on the meaning channel. For a mixed audience, however, your options are limited to trying to avoid inflaming a few known, hazardous meanings.

To twist this model around a bit, I can imagine the goals of science communication fitting into different channels, as well. In the spirit of one-upmanship, I prefer three channels. The first is the information channel, where the goal is simply to inform those with a desire for that information. Here, the “deficit model” can actually be quite a decent fit, just as self-motivated students can learn a lot from a very dry course that would be considered pedagogically poor. There are tons of science-hungry, curious people out there that love to learn about their topics of choice. There’s certainly plenty of space for you to do a better or worse job of engaging readers, but they’ll basically be content if you can communicate clearly. (I’ve blabbed on before about “preaching to the choir“.)

The second channel is the persuasive one. Here it will be more important to have a specific audience, as you’re attempting to win them over from a position of mild or strong opposition. They could be people skeptical of anthropogenic climate change, resistant to evolutionary science, or fearful of genetically modified food. The deficit model will be about as useful here as a kayak in the desert, considering the fine array of psychological weaponry we all have for fending off information inconsistent with our beliefs and cultural identity. This is usually the arena where we’re crapping on the deficit model. The public opinion needle on [insert topic here] is remarkably resistant to the dissemination of information, so this information-based science writing thing isn’t working. I hope I’m wrong about this, but what if that’s a bit like complaining about the number of square pegs that made it through round holes? I think most people writing about science do so with the hope that it can make a difference on contentious and important issues, but that may be be asking for miracles.

The third channel doesn’t reach out to the curious or to the opposed, but to the non-curious. The apathetic.  We’re trying to shift people into the curious camp, where they are reachable with other types of science communication that can get to deeper places. You run MythBusters marathons on channel 3 and see if you can get people to tune in to NOVA on channel 1 more often. (Going back to the content/meaning model of communication, this is an attempt to change the general meaning on science content from “not meant for me– boring” to “something I can dig”.)

Can we really work on more than one channel at once? We spend a lot of time talking about communication problems in “traditional” (for lack of a suitable term) science writing– how to reduce polarization and minimize the potential for readers to tune us out. There are certainly ways to be more effective, but overall, it seems pretty damn hard, and I’m starting to wonder. Many solutions for improving communication on channel 2 aren’t compatible with traditional science writing, because the solutions are to do other things– two-way conversations, appeals to cultural frames, pulls over pushes. Great, let’s do those things, but what about improving the science writing, too? Does the paucity of results there mean we haven’t looked hard enough (it’s not like there’s a lack of enthusiasm…) or does it mean you simply can’t do that much to make a screwdriver into a better hammer?

At the very least, maybe we need to be more specific when we talk about improving science communication. (Improve it on which channel?) And maybe the answer to the question “How can traditional science writing help with contentious topics?” is an unhappy one– do no harm and inform the receptive curious. If that’s the case, a lot less energy needs to be spent on making channel 1 work do channel 2’s job.

If there are ways to, as Peter Broks put it, become co-creators of meaning in the traditional avenue of newsy science writing, then that’s what we need to talk about. The conversation seems to often lack the specificity needed to be useful to that avenue, which leads to frustration and wheel-spinning because science news isn’t formal education isn’t informal education isn’t guerrilla outreach.

Like a lazy high school student on Yahoo! Answers with math homework, I just want to know how to get this part right.