Cigarettes and CO2
February 28, 2011 2:01 PM   Subscribe

How much CO2 emissions result from cigarette smoking? Could aggregate cigarette smoking worldwide be considered to have an effect on global warming?
posted by beisny to Grab Bag (12 answers total)
I don't have any numbers at all, but it's a very good bet that the carbon footprint of the tobacco industry itself (farms, manufacturing, offices, marketing, shipping, etc.) absolutely dwarfs the impact of actually burning the things.
posted by theodolite at 2:11 PM on February 28, 2011

I believe not, as cigarettes are carbon neutral as they are recently grown and you are just releasing the CO2 that they recently took to grow.

Fossil fuels are the problem.
posted by Frasermoo at 2:11 PM on February 28, 2011 [1 favorite]

The carbon that is combusted in the act of smoking is carbon neutral but unlike biomass use for energy you are not using the sunlight captured in photosynthesis for any generating purpose so any energy emissions used in the production and supply chain will count (unlesss they are from renewables).

On the other hand, since tobacco is an appetite inhibitor you would have to take into account any savings in food production and supply against the energy used for tobacco growth.
posted by biffa at 2:27 PM on February 28, 2011

Best answer: I did some very rough calculations.

A US Class A cigarette is defined by 1000 cigarettes having 3 pounds of tobacco or less.
If we assume that 1000 cigarettes = 3 pounds of pure carbon (it's not), we can work out that 3 pounds of carbon, reacted completely to CO2 (it doesn't), would result in 11 pounds CO2. This is because Carbon has an atomic weight of 12.066, Oxygen at 15.99, the ratio works out to where it's roughly 44(12+16+16) pounds CO2 per 12 pounds carbon, or 3.67:1. Anyhow, I said this was rough.

In the world, 5.5 trillion cigarettes are smoked per year (per wikipedia). This means 5.5 billion * 1000 cigarettes, or 60.5 billion pounds of CO2, again, assuming all of a cigarette is pure carbon. 60.5 billion pounds is 30.25 million standard tons, or 27.4 million metric tons.

The annual estimate to the global CO2 production is 27 billion metric tons (no clue how accurate that is), which would mean cigarettes account for 0.1%.

The caveat: I overestimated everywhere along the way in how much CO2 cigarettes produce. A cigarette is obviously not pure carbon, it has hydrogen, oxygen, nitrogen, phosphorus, etc. Conversely, I did not calculate in the effects on CO2 from manufacturing, shipping, advertising, etc., nor did I subract the amount of CO2 from growing.

tl;dr: Burning of one year's worth of cigarettes would result in 27 million metric tons, or 0.1% of all global CO2 emitted, if cigarettes are made purely of carbon, burn completely to CO2, and the growing, farming, manufacturing, shipping and lighting of cigarettes were 100% ignored.
posted by Mister Fabulous at 2:31 PM on February 28, 2011 [1 favorite]

Yup, I charmed in to say that they're carbon neutral. If you didn't harvest the plant and let it decay in the field it would offgas exactly as much carbon as it had absorbed during its growth cycle. It's the same for letting a tree rot on the ground versus burning it for heat.

The environmental component comes from the farming, harvesting, and preparation---there might actually be a significant number there, although I suspect it's less globally than, say, Wal-Mart's logistics.
posted by TomMelee at 3:10 PM on February 28, 2011

Frasermoo is correct. Like any plant tobacco is getting its carbon from extracting CO2 from the air so the amount of CO2 produced by smoking is irrelevant to the topic of global warming. The agricultural issue isn't irrelevant because tobacco production is resource intensive and arguably it's a pure waste since the product is unnecessary and harmful. In perspective though about a hundred times more wheat is grown in the world than tobacco: other agriculture dwarfs tobacco and overall fossil fuel use dwarfs the impact of agriculture.
posted by nanojath at 3:19 PM on February 28, 2011

I have measured the air in smoking rooms, and carbon MONoxide (CO) is produced in far higher amounts than is CO2.
posted by Danf at 3:27 PM on February 28, 2011

For what it's worth according to this CO2 is less than 10% of the composition of tobacco smoke (maybe NSFW Erowid cannabis and tobacco smoke comparison page). While I still think Mister Fabulous' analysis is essentially irrelevant from the perspective of global warming impact you may want to take that into consideration, as the "made purely of carbon, burn completely to CO2" assumption is probably introducing an order of magnitude of estimation error.
posted by nanojath at 3:34 PM on February 28, 2011

While I still think Mister Fabulous' analysis is essentially irrelevant from the perspective of global warming impact you may want to take that into consideration, as the "made purely of carbon, burn completely to CO2" assumption is probably introducing an order of magnitude of estimation error.

I figured there was at least an order of magnitude of error. My point was that if you cranked every stat up to the highest amount possible with extreme overestimates, you will still wind up with all of the tobacco smoked in the world still not having any significant effect on global warming.

Everyone here is correct. The CO2 produced by smoking is irrelevant.
posted by Mister Fabulous at 4:05 PM on February 28, 2011

Could aggregate cigarette smoking worldwide be considered to have an effect on global warming?

No. Cigarettes are not a fossil fuel.

The fossil fuels used to support tobacco and pulpwood farming and cigarette manufacture and distribution would certainly contribute somewhat.
posted by flabdablet at 5:21 PM on February 28, 2011

There is a methodology called economic input-output life cycle assessment (EIOLCA) that can be used to explore questions like this. It's good for figuring out large scale emissions if you are okay using somewhat coarse economic sectors, and you don't mind data that's ten years old. According to the free tool available at the previous link, the "Tobacco product manufacturing" sector produced 348 tons of CO2e per million dollars of economic activity, of which 100 tons is due to farming, 80 tons due to energy, 20 tons to due self-purchases within the sector, etc -- using 2002 data from the US model. (search for tobacco, and set the output to GHG, and you'll see; it's quite easy to use.)

Within this tool I can't figure out how to find the absolute size of the sector to convert this to a raw number, but I think it is based on the US economic census, which says the sector accounts for about $38.5 billion annually.

Total emissions in the sector are thus approx. 348 * 38,500 = 13.4 million tons CO2e annually.

According to this inventory prepared by the EPA, total net US GHG emissions (sources minus sinks) were about 6200 Tg CO2 in 2002 (I interpolated between 2000 and 2005), or 6200 million tons (Mt). Thus 13.4 million tons is 13.4/6200 = 0.2% of the US's total emissions, in 2002.

It's a modest number, not negligible. Compare with, let's say, snack food manufacturing: 652 t/$M; $17B; total 11Mt, slightly smaller. Or breakfast cereal manufacturing: 952 t/$M; $9.1B; total 8.6Mt; the little guys add up. What about Walmart? We don't have that level of data, but the retail trade sector does 265 t/$M, and the general merchandise subsector is $445B -- I think this is Walmart and competitors -- which gives a total of 117Mt.

Combustion of biomass including tobacco is often considered to be carbon neutral, though this ignores non-CO2 GHG emissions like CH4, NO2, etc, which can add up, depending on the combustion process; it's only carbon neutral if combustion is perfectly efficient. I would need to be convinced that the total impact is negligible, Mr. Fabulous, since the stuff you neglected is the stuff you need to crank up, not the CO2. However, intuitively I agree with your conclusion. It's kind of amusing if you try to find an answer to this question because tobacco smoke is one of the most heavily studied pollutants in history, yet no-one has attempted the relatively simple global warming potential calculation (as far as I can tell in a few minutes of looking). The reason for this is that tobacco smoke is a direct source of negative health effects which are much more prominent and important than any possible indirect effects from climate change, so there is really no good reason to approach it from the latter angle.
posted by PercussivePaul at 7:14 PM on February 28, 2011 [1 favorite]

One "environmental" effect of cigarettes not addressed by CO2 emissions is their particulate and reactive gas (formaldehyde, etc.) emissions, i.e. their health effects.

You probably aren't a smoker, but the mass of soot that comes out of a cigarette is more than that coming out of an average car driving along the highway.*

To be specific, by "soot" I mean the particulate matter generated by cigarette combustion. Such soot has significant climate effects globally, but cigarette sources would affect human health rather than climate.

*I can't find my source for the "average car" data, but here's a comparison to diesel engines.
posted by mostly-sp3 at 1:33 PM on March 1, 2011

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