On 9 Jan, 19:56, Tom Gardner wrote:
Could not any excess CO2 be removed by
planting more trees (or at least not chopping down the forests we
already have) anyway?

Oh, come on, don't be intellectually lazy. At least think it through.
(1) takes a long time to lock up carbon in a tree
(2) trees are carbon-neutral - think what happens after they die

Precisely. Trees are Carbon Neutral and not all the CO2 gets locked up
as wood - some of it is used for making leaves which are shed and rot
down. When a tree has reached full maturity, it can be chopped down
and the wood used as a building material, which locks up carbon for
further period of time. All the unwanted branches and offcuts can be
burnt as a fuel. This is what humans always did before coal, oil and
natural gas became available, and what we will probably have to go
back to doing after they run out. The important thing is to plant
another tree that will continue to remove CO2 from the atmosphere,
which is what we have failed to do on a consistant basis for the last
few hundred years.

Trees and all other plants also breathe out Oxygen, which we do rather
need for our own metabolic purposes. QED.

Derek Copeland