Carbon v. CO2


in Geek stuff, Science, The environment

Rideau Street intersection, Ottawa

When it comes to carbon pricing, there is one slightly confusing element that should be clarified. Carbon taxes are sometimes expressed as a price per tonne of carbon dioxide (CO2), and sometimes as a price per tonne of carbon. One tonne of carbon is equivalent to 3.67 tonnes of carbon dioxide. As such, a price of $10 per tonne of carbon dioxide is equivalent to a price of $36.70 per tonne of carbon.

The reason for this is basic. One mole of carbon weighs 12 grams. (A mole is a quantity of matter equivalent to 6.02 x 10^23 molecules or atoms. It is like a much bigger version of a dozen.) Each oxygen in a molecule of CO2 contributes 16 grams. As such, a mole of CO2 weighs 44 grams, while a mole of carbon weighs 12. The ratio is 3.67 to one.

{ 4 comments… read them below or add one }

Milan July 2, 2008 at 1:17 pm

Three of my photos were included in a Canada Day roundup on the The Globe and Mail website:

Trees, fog, light: Dam Mountain, North Vancouver

Pier in North Vancouver, with Burrard Inlet and downtown Vancouver behind

Bridge over the Rideau Canal, Ottawa

Larger versions of all three are on my page.

. July 8, 2008 at 11:19 am
Matt March 30, 2009 at 7:39 pm

I don’t know if you correct things after you write them, but I believe the “16” in the second to last sentence should be “12.” A small thing, but mathematically significant.

Milan March 30, 2009 at 7:42 pm


I always appreciate when people spot errors, allowing me the chance to correct them.

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