Recently in Environment Category

Look if John Boehner wants to believe that global warming isn't happening or isn't bad or whatever, then fine. But can we at least be spared this kind of stupidity:

STEPHANOPOULOS: So what is the responsible way? That's my question. What is the Republican plan to deal with carbon emissions, which every major scientific organization has said is contributing to climate change?

BOEHNER: George, the idea that carbon dioxide is a carcinogen that is harmful to our environment is almost comical. Every time we exhale, we exhale carbon dioxide. Every cow in the world, you know, when they do what they do, you've got more carbon dioxide. And so I think it's clear...

OK, so this is, as Wolfgang Pauli is supposed to have said "not even wrong". First, nobody is claiming that CO2 is a carcinogen. The reason people want to reduce CO2 emissions isn't that they give you cancer, it's that CO2 causes global warming. So, the fact that you exhale it hardly leads to the conclusion that it's somehow a great idea to radically increase the CO2 content of the atmosphere.

Even if the reason to restrict CO2 was that it was bad for humans instead of the environment (like, say mercury) this wouldn't follow. Have you noticed that you're inhaling CO2? It's a waste product from aerobic respiration (look up the Krebs Cycle). Boehner's argument is like suggesting that feces isn't bad for you because you emit it regularly, as do cows, etc., but I'm assuming he'd like to minimize his feces consumption.

Interestingly, while CO2 is a waste product, it's not actually toxic. You wouldn't want to breathe an all CO2 atmosphere, but CO2 is what stimulates the breathing reflex. Oxygen, on the other hand, is fairly toxic once you get too far above the normal partial pressures in the atmosphere.

Julian Sanchez's post about the difficulty of evaluating technical arguments has been circulating fairly widely. In the middle is a somewhat strained analogy to cryptography:

Sometimes, of course, the arguments are such that the specialists can develop and summarize them to the point that an intelligent layman can evaluate them. But often--and I feel pretty sure here--that's just not the case. Give me a topic I know fairly intimately, and I can often make a convincing case for absolute horseshit. Convincing, at any rate, to an ordinary educated person with only passing acquaintance with the topic. A specialist would surely see through it, but in an argument between us, the lay observer wouldn't necessarily be able to tell which of us really had the better case on the basis of the arguments alone--at least not without putting in the time to become something of a specialist himself. Actually, I have a possible advantage here as a peddler of horseshit: I need only worry about what sounds plausible. If my opponent is trying to explain what's true, he may be constrained to introduce concepts that take a while to explain and are hard to follow, trying the patience (and perhaps wounding the ego) of the audience.

Come to think of it, there's a certain class of rhetoric I'm going to call the "one way hash" argument. Most modern cryptographic systems in wide use are based on a certain mathematical asymmetry: You can multiply a couple of large prime numbers much (much, much, much, much) more quickly than you can factor the product back into primes. A one-way hash is a kind of "fingerprint" for messages based on the same mathematical idea: It's really easy to run the algorithm in one direction, but much harder and more time consuming to undo. Certain bad arguments work the same way--skim online debates between biologists and earnest ID afficionados armed with talking points if you want a few examples: The talking point on one side is just complex enough that it's both intelligible--even somewhat intuitive--to the layman and sounds as though it might qualify as some kind of insight. (If it seems too obvious, perhaps paradoxically, we'll tend to assume everyone on the other side thought of it themselves and had some good reason to reject it.) The rebuttal, by contrast, may require explaining a whole series of preliminary concepts before it's really possible to explain why the talking point is wrong. So the setup is "snappy, intuitively appealing argument without obvious problems" vs. "rebuttal I probably don't have time to read, let alone analyze closely."

Unfortunately, Sanchez has the cryptography pretty much wrong. He's confused two totally separate cryptographic concepts: public key cryptography, and one-way hashes. Some PKC (but not all) involves multiplying large prime numbers. Hash functions (with the exception of VSH, which is impractically slow and not in wide use), don't involve prime numbers at all. Neither does symmetric encryption, which is what you actually use to encrypt data (PKC is used primarily for key exchange and authentication/signature). Now, it's true that prime multiplication is indeed a one-way function (or at least we hope it is) and hash functions are intended to be as well, but other than that, there's not much of a connection.¹ That said, however, I've seen this post referenced several places, and with the exception of Paul Hoffman, who pointed it out to me, few seem to have noticed, that, well, it's horseshit. I suppose this is an argument in favor of Sanchez's thesis.

^1.Hash functions are actually one-way in an important sense that prime number multiplication is not: any given integer only has one unique factorization, whereas there are many messages that hash to a single value, so it's always possible with enough computational effort to reconstruct the original primes. However, given a hash value and no other information, it's not possible to determine which of the possible input messages was fed in.

One of Slate's odder sections is the "Green Lantern", where they take on some simple question like "should I buy a natural or artificial Christmas Tree" and try to analyze it from an environmental perspective. The most recent article asks whether you should throw away your leftovers or flush them down the garbage disposal. Unfortunately, the articles tend to be pretty useless: sometimes they have a real answer but often they thrash around for a while giving you the pros and cons of each option and conclude that maybe you should do A and maybe you should do B:

The research is unambiguous about one point, though: Under normal circumstances, you should always compost if you can. Otherwise, go ahead and use your garbage disposal if the following conditions are met: First, make sure that your community isn't running low on water. (To check your local status, click here.) Don't put anything that is greasy or fatty in the disposal. And find out whether your local water-treatment plant captures methane to produce energy. If it doesn't--and your local landfill does--you may be better off tossing those mashed potatoes in the trash.

Or maybe not... Here's another example:

If these ideas don't excite you, the Lantern recommends putting the new cash toward insulating your family's home. Of course, whether this makes sense depends on your local climate and whether you buy or rent. (Likewise, the current state of your home will determine just how much insulation your $100 will buy.) For the rest of you, it might be wisest to replace any antiquated, energy-inefficient appliances you might have--along the lines spelled out here. (Let's put aside the complicated question of carbon offsets, which will be addressed in a future column. Suffice to say that they wouldn't be the Lantern's first choice.)

I'm not saying I can do any better; rather I think this is reflective of a systemic problem with this kind of overall cost/benefit analysis. While it's possible to measure the power consumption, carbon emissions, etc. of any particular microactivity, it's pretty hard to do an overall cost/benefit analysis of whether you should do A or B when each of them consists of a whole bunch of individual activities, all of which require their own analyses. The economist type answer is to levy Pigouvian taxes on each individual component (e.g., carbon taxes) and then let the market sort things out. I don't know if that would work any better, though, but I don't see people being able to do this kind of analysis for each individual purchasing decision either.

For some reason, Slate continues to let Gregg Easterbrook write about science. This time, the topic is Thomas Friedman's new "Hot, Flat, and Crowded". I'm not really interested in engaging with most of the piece, which is pretty much the party line [yes global warming is happening but it's not clear it will be that bad; other problems (poverty, clean drinking water, etc.) are much worse; Thomas Friedman is a hypocrite who lives in a big house; the government will screw things up if we let them regulate; industry is innovative!], but the following is just confused:

Friedman concludes Hot, Flat, and Crowded by proclaiming greenhouse damage could cause humanity to be "just one more endangered species." Better to consult history on this topic. Greenhouse gases are an air-pollution problem. Smog and acid rain, the two previous serious air-pollution problems, once were viewed as emergency threats. Then federal standards were imposed, and inventions and new business models were devised; now smog and acid rain are way down in the United States and declining in much of the rest of the world. And no international treaty governs smog or acid rain! Nations have adopted smog and acid-rain curbs because it is in their self-interest to do so. The same dynamic will take hold for climate change, not long after the United States finally imposes greenhouse-gas rules. Unquestionably the future is flat and crowded. Hot? Maybe not.

I suppose one could argue that GHGs are an air pollution problem, but precisely what distinguishes GHG emissions from other air pollution problems is that the effects aren't localized. In the case of both acid rain and smog (especially smog), the effects are felt near the emissions source so although there are the usual public good/incentive problems, regional authorities can restrict pollutant outputs in their areas and thus control the effects of the pollution. The Beijing olympics provide a good example of this: the air quality in Beijing is bad because of loose emissions controls, but that doesn't mean the air quality in Bali is bad, let alone the air quality in Lake Tahoe. Moreover, when the Chinese decided to improve Beijing air quality for the Olympics, they were able to do so (at least to some extent) without having to consult with every other country on Earth.

By contrast, the effects of GHG emissions are felt globally regardless of the source, so this is a pure public good (well, public bad) issue, with all the attendant collective action problems. We don't have much incentive to control our emissions here in California if people elsewhere aren't going to. Moreover, it seems unlikely that global warming will have equally negative effects on everyone, so the incentives may be even more misaligned (if, for instance, low-emitters are likely to suffer worse effects).

Even more annoyingly, if Easterbrook actually wanted to pick an apropos example, rather than just being glib, there is one readily at hand: chlorofluorocarbon (CFC) emissions. CFCs were widely used as refrigerants and aerosol propellants, but it was discovered in the 1970s that when released into the atmosphere they caused ozone breakdown. Like GHGs, the effects of CFC emission don't occur near the source (in fact, CFCs are the likely cause of the Antarctic "ozone hole"). The good news is that CFC emissions are way down and it looks like the ozone depletion may be starting to slow. How did this happen? An international treaty, The Montreal Protocol, was negotiated (Wikipedia says it took effect in 1989) [BTW, check out the Wikipedia article for the 1980s-era industry denials that anything was wrong.] dramatically restricting the use and emissions of CFCs. Funny that Easterbrook chose to talk about smog and acid rain instead.