Thursday, January 18, 2007

Gaseous Mass

What weighs more: a tonne of carbon dioxide or a tonne of methane?

Transportation is a weighty matter, especially when it comes to climate change. (Oh, what a line!) We'll talk in terms of mass here though, in an effort to sound scientific. Greenhouse gases (GHG) come mostly in the form of Carbon Dioxide (CO2) and Methane (CH4). The confusing part comes from people talking about tonnes of "carbon dioxide", or tonnes of GHG, or tonnes of "carbon dioxide equivalent", or "tonnes of carbon". And that's leaving out the issue of tons and tonnes.

First off, I like all this talk about creating a market for greenhouse gas emissions. To put it simply, the idea is to put a price on the privilege of dumping greenhouse gas in the atmosphere, so people and businesses will be able to consider the cost and decide whether or not they want to release the gas. It should also help in creating a competitive market for sequestering or sinking the gas.

The going rate for dumping carbon dioxide seems to range from $5.50 per tonne up to $12. There is even talk of much higher prices, like $50 to $100. You can see that "the market" still has some work to do. The average American emits 22 to 24 tonnes of carbon dioxide "equivalent" per year, depending where you look. Canadians have similar numbers, if not worse, but Canadians are assigned the emissions of the massive oil industry in Alberta.

Looking at numbers can get complicated. I don't want to get into the chemistry, but consider the fact that the mass of a CO2 molecule is about 3 times the mass of a methane molecule. Along the same lines, the density of CO2 is also 3 times more. But methane is said to have a stronger greenhouse effect.

This is why it's best to compare using the same tools. To work out what I contribute in terms of greenhouse gas per year, I used the Canadian Government Greenhouse Gas Calculator. A word of warning: I haven't figured out what units are used for the results from this calculator, but that shouldn't matter as long as you trust the tool and you use it to compare its own results. For example, the calculator website says the average Canadian contribution is 5.5 tonnes of "greenhouse gas", quite a different number from the 23.45 tonnes of CO2 equivalent shown here. It makes me think the government version is treating a tonne of methane as 1 tonne, instead of converting it to a carbon dioxide equivalent.

Until today, I've assumed I was a global warming saint because I ride my bike to work 4 or 5 times a week. It's true that bicycle commuting makes a difference, but my other activities still leave me with significant contributions. Compare my behavior 2 years ago to what I'm doing today.

According to the Canadian Government tool, I produce 5.22 Tonnes (5223 kg) of GHG, while the average Cdn, produces 5.5, and Ontarian is 5.7 tonnes.

Apparently, 41 % is from transportation, even though I said I drive once per week to work, I said I drive about 8000 km/year. (This includes the days I drive to work, plus weekend trips to visit family and some work trips; and of course cruising down Bloor Street on Friday nights with the stereo pumping.) 2.13 tonnes are from transportation, 1.4 from heating/cooling. All my cycling effort only brings me in line with the Canadian average.

Now let's look at the impact of driving every day. If I consider myself living in the same poorly insulated small semi-detached house heated by natural gas, but add driving to work 5 times/week, I end up nearly doubling my emissions.

Bike commuting does reduce the amount of greenhouse gas I create, but not as much as I had hoped. If a greenhouse gas market (or "carbon market") came into effect, I would need to make some big improvements to home heating and insulation just to keep below the Canadian average.

Part of the reason I like working this out is because it all ties together with other aspects of reducing dependence on the oil and gas industry and everything that's tied to. Even if you're more motivated by reducing smog in the city, these numbers are important.

In the end, 5.22 tonnes of whatever doesn't mean a lot unless you compare it to something. If you go to the trouble of working out your numbers with the same calculator I used, feel free to share your numbers here.


Darren J 1/18/2007 12:27:00 a.m.


I was a 3.8 tonner. I never drive, and I live in an apartment.

Unfortunately my apartment is really crappy (drafty I mean) and I think that this may have been an underestimate. The best thing I could do for the environment would be to move.
i'm a 2.7 tonner.

I live in a detached house with 2 renters. I don't drive, nor do i use a gas powered lawn mower.
Yes, indeed. Cars, bad. Bikes, good!
I got 3.1 tonnes, over half due to heating this old house, but there's no accounting for my holiday travel. I gather that flying to Europe is like driving 10,000 km.

I wonder where or how my secondary GHG production is accounted for, such as, the heating at my workplace and in shops, or the energy that goes into manufacturing and transporting the goods I buy.
This is making my 5.2 tonnes look pretty bad.

Robb, I started to look into reel mowers (push powered) recently. I like the fact they don't ruin time spent outside with lots of noise. I saw a good web site for them that I'll dig up at some point.

Good points GMD. Shouldn't the GHG from your workplace be assigned to whoever purchases your product, if such a thing exists? I didn't think about air travel when I did this survey.

Ben, now I'm gonna worry about you getting sick. Maybe you should move. Or buy some caulking.
hey Darren,

I have one of those reel mowers too. I have a large lot, 75x185 but i am still able to finish within about an hour and a half. The hardest part of using it, is getting the yard smooth enough that it rolls along without hitting small mounds of dirt and stopping dead.

Realisitically, I'm more like a 4tonner i think. There are 4 computers in my office, 1 of which runs 24hours/day. I also have an HDTV which runs a couple hours/day. There were no sections on the questionnaire for items like this, which do draw quite a bit of hydro.
5 tonnes all thw way, baby!
Woot! 2.18 tonnes!!
I just lowered my emissions because the bills were getting too expensive (plus taking public transit and living in an apartment helped) but that's pretty good. The site said I'd make an ideal climate change embassador ^_^

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