One carbon credit represents the reduction of how much greenhouse gas?
- A.One kilogram of carbon dioxide equivalent
- B.One hundred kilograms of carbon dioxide equivalent
- C.One tonne of carbon dioxide equivalent
- D.One thousand tonnes of carbon dioxide equivalent
Show answer
Correct answer: C. One tonne of carbon dioxide equivalent
Explanation
The correct answer is C, one tonne of carbon dioxide equivalent. The tonne is the standard trading unit in every carbon market, compliance or voluntary, and it is written as 1 tCO2e. The word equivalent matters: gases other than carbon dioxide are converted into carbon dioxide terms using their global warming potential, so a much smaller quantity of methane or nitrous oxide can earn one credit. A is wrong because a kilogram is far too small to be a market unit; no registry issues credits in kilograms. B is wrong for the same reason, and a hundred kilograms is simply a tenth of the real unit, a figure offered to catch a candidate who half-remembers the tonne. D is wrong because a thousand tonnes is the scale of a whole small project's annual saving, not of a single credit; a project of that size would be issued a thousand separate credits, which is exactly how buyers are able to purchase them in small lots.