Humboldt squid

Megan McArdle is a libertarian who is basically sane, so she is not a global warming denier or anything. However, comments like this strike me as missing the point:

What's at stake is the degree of warming associated with our carbon dioxide emissions. In particular, to what extent the earth's many complex and not necessarily well understood feedback systems may mitigate (or exacerbate) temperature increases. I've long been skeptical of the more catastrophic scenarios, because all this carbon used to be in the atmosphere, which probably defines a ceiling on how bad it will get--a ceiling well below "WE'RE ALL GOING TO DIEEEEEEEE!!!"

I think she's narrowing in too much on the temperature aspect here. While it's true that earth has "many complex and not necessarily well understood feedback systems" that determine what the average global temperature will be, what is really relevant here is that the biological environment is made up of even more complex and even less understood systems, and we simply can't predict what all of the consequences will be for these systems if and when the global temperature shoots up. To invoke some Rumsfeldese, there are known unknowns and then there are unknown unknowns. It is the unknown unknowns that really make global warming such a serious threat--the stuff that no one could have predicted.

Personally, when I envision ecological disruption from climate change, it's something along the lines of the Humboldt Squid takeover of the North Pacific. The story here is that since 1960 the numbers of this kind of squid has exploded, altering the ecosystem so that fisheries for "anchovies, sardines, hake and rockfish"--all species that the squid feed on--are threatened. They theorize that nitrogen-rich farming runoff is causing a favorable environment for the squid, but the region in which they dominate continues to expand, and nobody knows why:

In the KQED-TV story, Gilly says that the OML [oxygen minimum layer] may be growing -- getting thicker and coming closer to the surface. And where the OML grows, the squid follow.

Nobody knows why the OML is growing, though. Does it have something to do with climate change? Is it related to agriculture? It would be handy to know.

This is the kind of thing we should be envisioning, I think, when we talk about the dangers of global warming--stuff like, oh shit, now squid are taking over the ocean. Of course, in this particular case the success of the squid isn't really too disruptive (besides endangering some fisheries, the article doesn't seem to be too worried about any of it), but the point is that this is the type of system that's being affected, and these are the types of consequences we can expect to encounter as global temperatures rise.

Carbon footprint

I decided to "calculate my carbon footprint". The result: I emitted 9.44, or about 10 tons of CO2 over the past year. The US average is 20.4; the industrial average is 11; and the worldwide average is 4 (I imagine that the non-industrial average must be something far below 4).

I have no idea how accurate this site is--indeed, some things tipped me off that it might not be the most accurate tool in the world (the obsession with local food, for example). But assuming it's giving somewhat meaningful results, you can still get a ballpark idea of what the big sources of CO2 are.

Of course, the big differentiator for me was the fact that I don't have a car and that I can bike to work--all of which is a function of living in a dense city. If I were living in LA with my own car, I imagine my mark would be up near 20. Moreover, air travel takes a pretty hefty toll--of my 10 tons/yr, 3 of those are from air travel (which goes to show that the gains from getting a fuel-efficient vehicle can be cancelled out by a jetsetting lifestyle).

Anyway, if anyone knows of a better CO2 footprint calculator, let me know.

Some actual capitalism for a change

Good to see that the EPA will start to require major industries to track and report their CO2 emissions. The important thing to remember is that assessing costs to those who emit greenhouse gases is completely in line with the tenets of capitalism, since emitting greenhouse gases imposes a cost on everyone that is not properly priced in the market (the costs--which are mostly deferred until the ecological shit really hits the fan--end up being socialized as governments bear the burden of cleaning up after the effects of global warming).

Carbon taxes correct a market failure--and you can't tax carbon if you don't know how much is being emitted.

George Will smackdown

George Will's latest article contains some specious empirical claims about global warming, and the internet has responded with force.

More data

Nothing gets by you guys! Patrick--who remains curiously astute after knocking back a few--rightly gets to the heart of the matter, which is the comparative greenhouse gas intensity of different kinds of foods. Luckily, the study (pdf) underlying the Ezra Klein post has a chart that captures precisely this information:
(You may need to click the image to read it without squinting.)

Now, I'm not any kind of trained statistics person but I'm pretty sure that by "normalization by X" they mean the greenhouse gas (GHG) output expressed as a rate of "CO2-equivalent emitted per X". So for example, the second dataset means that red meat results in about twice the amount of GHG per dollar as chicken/fish/eggs--i.e., $5 worth of red meat has the same footprint as $10 worth of chicken/fish/eggs.

I imagine the measure we ought to be most interested in is the GHG per kCal figure (third dataset), since we are trying to figure out how to lessen the GHG impact of our diets regardless of cost and, er, food weight. Viewed this way, cows are definitely the biggest culprit: red meat looks to be about 2.5 times more GHG-intensive per kCal than chicken/fish/eggs, and dairy is slightly worse than chicken/fish/eggs as well. So the biggest gains, it seems, can be had by replacing most of our red meat with white meat or vegetables, and replacing dairy with...not dairy.

(Note: some greenhouse gases affect the climate more than others--hence the generic unit of measurement "CO2e", or CO2-equivalent.)

Anyway, in case all that wasn't very clear, here's the abstract to give you the main idea:

Despite significant recent public concern and media attention
to the environmental impacts of food, few studies in the
United States have systematically compared the life-cycle
greenhouse gas (GHG) emissions associated with food production
against long-distance distribution, aka “food-miles.” We find
that although food is transported long distances in general (1640
km delivery and 6760 km life-cycle supply chain on average)
the GHG emissions associated with food are dominated by the
production phase, contributing 83% of the average U.S.
household’s 8.1 t CO2e/yr footprint for food consumption.
Transportation as a whole represents only 11% of life-cycle
GHG emissions, and final delivery from producer to retail
contributes only 4%. Different food groups exhibit a large range
in GHG-intensity; on average, red meat is around 150% more GHG-
intensive than chicken or fish. Thus, we suggest that dietary
shift can be a more effective means of lowering an average
household’s food-related climate footprint than “buying local.”
Shifting less than one day per week’s worth of calories
from red meat and dairy products to chicken, fish, eggs, or a
vegetable-based diet achieves more GHG reduction than buying
all locally sourced food.