Wednesday, July 2, 2014

Climate Misconception #1: Climate change is a pollution problem

Again, before I begin, a word about the ground rules.  There are two that apply to the treatment of misperceptions.  The first is that I am not going to name names or try to document who said what.  My purpose is not to criticize anyone else but simply generate a little clarity.  Second, as with the whirlwind tour of climate science, I’m not interested in precision or scholarly heft.  The question I want to pose is simply, how should we think about this problem?  That sets a lower bar on how detailed I need to be.

The first misconception is in some ways the deepest and most interesting of all of them.  When we think of environmental problems, we think of pollution.  The mental framework we invoke is that there is some specific environmental resource—the air, the water, the soil, our own bodies—that is being harmed by an overload of substances that have polluted it.  Air pollution is caused by chemicals going up smokestacks or out of tailpipes.  Water pollution can be traced to industrial discharges, agricultural runoff and other sources.  People watched with morbid curiosity as the radioactive emissions from Fukushima first contaminated parts of Japan, then spilled into its coastal waters and now (in much lighter concentrations) disperse through air and ocean currents.  Pollution is about harmful substances moving from point A (where they were confined or under control) to point B (the resource that is damaged by them).  For every instance of pollution there is an identifiable polluter, the individual, business or government that is responsible for causing this substance to go where it shouldn’t.

The pollution template has become so familiar that we apply it to new forms of environmental harm without giving it a second thought.  Loud people or machinery cause noise pollution; urban lighting causes light pollution.  Ignorant or dishonest thought pollutes our communications and very consciousness.  Pollution began as an act, developed into a metaphor and now structures how we think about wide swaths of modern life, wherever something we value is at risk of being destroyed or degraded.

It’s entirely natural that we would come to think about climate change as a pollution problem—natural but wrong.  The difference is the carbon cycle.  Here’s an example: suppose you cut down a tree and burn it.  In doing this, you’ve instigated a flow of carbon from biomass to atmosphere, and the atmosphere is where carbon operates as a greenhouse gas.  That makes you a carbon polluter, right?  Well, not exactly.  If a new tree grows to replace the one you cut down, it will cause a reverse carbon flux from the atmosphere back to the biota (living organisms).  The flows will be different in quantity and timing, but it’s simply wrong to isolate a single action within the carbon cycle, like cutting down a tree, from the complete operation of the cycle itself.  The pollution model, with its simple assumption that the impact of an act can be determined from a one-time transportation of a pollutant from location A to location B, doesn’t apply.

This also means that the people whose actions move carbon into the atmosphere are not necessarily “polluters”.  We’ll see this later when we look at electric cars.  The fact that carbon goes out my tailpipe but not yours doesn’t mean that I am a carbon polluter when I drive and you’re not.  As you can imagine, this misunderstanding plays havoc with the industry that calls itself carbon accounting.  I’ll go after that one later in the series.

As the earlier discussion of carbon and earth history should make clear, there is an action that is directly responsible for exacerbating climate change: bringing previously sequestered carbon out of the earth.  When that happens, the carbon reenters the global carbon cycle and will lead to an increase, sooner or later, in greenhouse gases.  Of course, the likely entry channel will be combustion, but if you make road paving material out of it or simply allow it to spill somewhere, the carbon will find a path.

Now if you’re so inclined, you can make loopholes, qualifications and intricate verbal distinctions that allow you to squeeze carbon into a pollution framework.  I’m not saying you can’t.  But invoking the pollution template in this context is an invitation to sloppy thinking.  The problem is not, how do we keep carbon out of the atmosphere, but how do we keep carbon down in the ground and out of the carbon cycle altogether?

If you’re hungry for specifics, stay tuned: several forthcoming misconceptions flow naturally from the initial mistake of thinking about climate change as a pollution problem.

Addendum: The cartoon version of the argument

Saying that the buildup of greenhouse gases in the atmosphere should not be thought of as a pollution problem rubs a lot of people the wrong way.  Isn’t this statement just crazy?  To make the point as clear as possible, let’s look at it in pictures.

Version A: Cow farts according to the pollution model
In this version, Bessie emits a cloud of methane (CH4) which rises into the atmosphere.  Bessie is a polluter.  End of story.

Version B: Cow farts according to the carbon cycle model
Bessie is still sending methane onward and upward.  However, the carbon content of Bessie’s fart was derived from corn feed, and this situates it in the carbon cycle.  CO2 was withdrawn from the atmosphere, where it was temporarily fixed in corn plants as CH2O (approximately).  Carbon in this form was shoveled into Bessie’s trough.

Now, truth be told, Bessie is still a problem: her farts (and burps) effectively convert a less damaging greenhouse gas, CO2, into a more powerful one, CH4.  Her net effect, however, is less than this, because one has to take account of her entire place in the carbon cycle.  This net effect would be close to zero if we could light a match near Bessie’s butt and flare off her discharge, which would convert the methane back to good old CO2.  Of course, the rest of the corn-Bessie carbon cycle is complex, with questions related to land use alternatives, energy inputs into farming and corn processing, and so on.  But the point is that the entire carbon cycle has to be considered when passing judgment on Bessie, not just her direct emissions into the atmosphere, as the pollution model would have it.  If you think the whole world understands this, try googling “cow farts global warming”.

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11 comments: said...

Oh dear, Peter, I have been mostly impressed and supportive despite some minor quibbling on the last one of this series. I am all for heightening awareness of biogeochemical cycles and all that, having pushed that sort of thing myself for, well, decades.

But this particular post seems seriously out of whack. All pollutants that are important in organic chemistry, which means get into the bio part of those bgc cycles, have bgc cycles, and will have some sink. Often what is going on is precisely the same as what you describe with carbon: humans injecting more of the pollutant from its sinks into the cycles with this greater amount being a "pollutant" when it gets emitted from some human economic activity into various parts of the environment, just as happens with carbon.

The obvious example is sulfur, the deadliest of all air pollutants, which largely enters the atmosphere as SO2 from burning of coal. This is pretty much identical to what goes on with carbon. Humans are digging up this coal where this "excess" sulfur has been stored for however long and is now being injected into the sulfur cycle. When it enters the air (along with CO2) from pipes coming out of coal-burning industrial facilities it is entering the bgc in pretty much exactly the same way that the extra carbon we are also digging up out of the ground and injecting into its bgc is.

Do you really wish to say that SO2 emissions from coal burning facilities is not "pollution"?

Peter Dorman said...

These posts paint with a broad brush, Barkley, and of course a lot of detail gets swept aside. My answer to your question is that it is a matter of degree.

Yes, lots of substances have their cycles, not only carbon. Yes, SO2 is in the atmosphere only temporarily, from a long run perspective.

But it's a matter of degree, isn't it? It's about the relationship between sinks and fluxes, as well as the time-datedness of effects. If you don't actually emit the sulfur as SO2 it will take a very long time for it to make its way to the atmosphere. And the reverse flux, fixation of atmospheric sulfur, is a whole lot slower too.

Meanwhile, sulfur's negative effects are mainly on human health, so they are time-dated in a way that GHG's aren't.

In the end, pollution is a metaphor. It isn't 100% true even in all the contexts it works pretty well in, but there is little practical significance to the imprecision. In climate change the practical significance is huge. said...

Well, Peter, I do not want to go on about this, but I really do not see why you even bothered to argue that CO2 emissions are not "a pollutant," when pretty much all public discussion of this considers such emissions to be so, particularly when it gets down to it, your only difference between C and S and N and other such is time horizons involved. I have never ever heard of anybody previously arguing that the time horizon of a pollutant has anything to do with whether or not it should be called a "pollutant" or not, and I do not see what point you are making in this post at all.

Unknown said...

"[H]ow should we think about this problem?"

Not in economic terms for sure. Climate change means that the world's food supply will shrink greatly as the oceans become less productive and current farmland experiences temperature and precipitation changes that reduce output.

Simply stated, climate change will reduce the capacity of the Earth to support human life.

Climate change is an existential threat and any and all resources need to be marshaled to reduce the loss of human life. said...


Agreed. And how does deciding not to call CO2 emissions "pollution" help us achieve avoiding the bad outcome? People identify "pollution" as something they do not like and would like to reduce, which is what we would like to do with CO2. What should we call it instead that will move this forward?

John Quick said...

A science curriculum project I did some work for defined "pollution" as putting more of a substance into a system than the system could deal with. (Not those exact words, but that was the gist.)

Under that definition, atmospheric carbon dioxide is indeed a pollutant.

Peter Dorman said...

If you define pollution in a way that incorporates the carbon cycle and doesn't fixate on the immediate relationship between the "polluter" and the resource (like the atmosphere) being polluted, no problem! But most of the world has a pretty narrow, specific conception of what pollution means, and it conforms to the first cartoon in the post. If it makes you happy, I could change the name of this misconception to "climate change is a problem that can be understood by examining solely the direct relationship between an entity that emits a pollutant and a resource that suffers pollution". said...


I do not think you are helping yourself with this. Sure, technically speaking cow farts are pollution, and humans have even added to this by putting more Bessies out there. And, heck, Ronald Reagan once famously said that trees cause pollution, although on the matter of carbon, they help reduce it.

But, really, that most people will think it is silly to talk about cow farts as pollution, even though we may think of them as such, this is not going to convince most people that they should not call car farts (not to mention coal-fired industrial facilty farts) pollution.

Again, lots of things people call pollution without question involve people intervening in bgc cycles and putting more from the sinks into the cycle, with P and N examples.

Peter Dorman said...

Barkley, there is a huge literature, academic as well as mass media and internet ravings, on the subject of cow farts and climate change. Seriously, take my advice, google these search terms, and read for a while. The cartoon may be cutesy but the topic isn't. Meanwhile, if you have another phrase to sum up the misconception I'm targeting, please offer. My goal is to promote clear thinking, not (only) piss people off.

I'll get to car farts a little later in this series.

Sandwichman said...

"Burnham does not recognize the dialectic, but the dialectic recognizes Burnham, that is, extends its sway over him."

I will resist the temptation to paraphrase Trotsky. However, I do want to raise the issue that perhaps pollution is a dialectical concept in the sense that Georgescu-Roegen specifies in "The Entropy Law and the Economic Process" (see pp. 45-47)... "a dialectical concept -- in my sense -- does not overlap with its opposite throughout the entire range of denotations."

Stuart said...

Just a comment from a non-expert: this post to me to argue only that burning carbon fuels is not the originating act of pollution; it is the path carbon takes to get to the atmosphere, but the real act of pollution is extracting the carbon from deep sequestration in the first place. Setting the time issue aside, we could believe that global warming is a threat and still accept the thesis of the post: but to combat carbon pollution we would not (for example) tax the people who use it, we would tax the people who extract it from the ground in the first place, since they are the original source of increased quantities of carbon in the "carbon cycle".

But even if it's true that carbon will find a path, it's not true that all paths are equal. We can slow the progress of carbon into the atmosphere by discouraging the quickest paths, and those are the usual suspects: cars, factories, power plants. And by reducing the demand for carbon-burning cars, and carbon-powered factories and power plants, we reduce the demand that induces the original extraction of carbon from the ground. So there's still room for a carbon use tax, too.