Climate Policy

[kandrathe]

Where are those numbers coming from? I can't find them on the page.

Sorry. We can go by the preferred scenario by the IPCC (scenario C), which shows (in billions of metric tons (Gton)) humans 7.0, ( 50%), nature 7.0 (50%), for a total CO2 load of 14.0, with 10.5 (75%) absorbed leaving a net 3.5.

Wouldn't biological activity (presuming plant growth?) be a net reduction in CO2, not a net increase?

You'd think that, but plants exhale CO2 in the dark, release CO2 when they burn, and when they decompose. My understanding is that with warming comes less absorption by sea water, and more decomposition. Even then, there appears to be between 1.8 GT and 2 GT of carbon missing from the atmosphere. My take on this is that the carbon cycle is really very huge, and that their are billions and billions of tons of carbon involved in the cycle. I don't think we humans really have a very good understanding of it yet, and especially how carbon gets sequestered out of the atmosphere.

On a different note: I just read an interesting article on how fish poop releases available calcium into sea water which helps sequester CO2.