[malfist]

> concentration of carbon dioxide in seawater is more than 100 times greater than it is in air

This is straight up wrong. Unless they mean alkalinity, which is carbonate, but not dissolved CO2.

I keep both reef and freshwater aquariums. I have to inject CO2 into my freshwater aquariums to keep the plants happy, and the maximum I can go without killing off the fish is ~30ppm. Given that the PPM of CO2 in air is 4, are they trying to say saltwater has 400PPM of CO2? That would mean ocean water is 0.04% CO2. A wave would have so much foam because of how much carbonation that'd be in the water.

They're doing some funny math.

[Aperocky]

> PPM of CO2 in air is 4

This is wrong, CO2 is currently 420PPM in Earth's atmosphere.

[malfist]

Wow, how did I manage that. My numbers are all off by 100x.

So that means they're saying the ocean is 4% CO2? That would mean the ocean has more CO2 than salt (3.5% or 35 ppt)

[Aperocky]

Ocean is also about 1000x as dense as air, so it only needs 40ppm of CO2 to be 100x more concentrated as air.

[tlarkworthy]

The molecules in water are more dense than in air. They are talking about density not ratio (PPM)

[Symmetry]

"Concentration" could either mean ppm or p/m^2. When they go on to say "the volumes of material that need to be handled are much smaller" they're making it quite explicit that they mean the later.