I guess I’m confused on the definition of a “tonne” of CO2. Am I to believe that if that cube was completely full of CO2 that volume of CO2 would weigh 1000kg?

Nevermind, just looked it up. It’s actually a measure of volume, just 1000 cubic meters, which makes perfect sense.

Edit: it was actually the first one, although a “tonne” as a measure of volume does exist.

I guess I’m confused on the definition of a “tonne” of CO2. Am I to believe that if that cube was completely full of CO2 that volume of CO2 would weigh 1000kg?

Nevermind, just looked it up. It’s actually a measure of volume, just 1000 cubic meters, which makes perfect sense.

Edit: it was actually the first one, although a “tonne” as a measure of volume does exist.

You had it right the first time, 1 tonne (1000 kg) of CO2 at standard temperature and pressure would have a volume equivalent to that cube.

Confirmed with this MIT page: https://climate.mit.edu/ask-mit/how-much-ton-carbon-dioxide

Gas doesn’t seem heavy until you handle gas canisters full and empty.

I mean, those are much higher than 1 atmosphere though.

Sure. Don’t often store more than 7,000 L STP and that’s a 2m cube.