It's only specious in your eyes, and it's surely no argument. It's a
fact. Burning fossil fuels releases new CO2 into the air, adding to
concentrations, burning biofuels releases co2 removed in the previous
growing season, not adding to concentrations. That's all there is to it.


Except that it's not true. When you release CO2 into the air,
it doesn't matter where it CAME from. it only matters where
it would have gone if you hadn't burned it.

So the open question is whether growing corn for fuel
REMOVES more carbon from the air than would have been
removed had you not grown corn for fuel.

If you burn one ton of carbon in the form of dead dinosaurs,
that puts one ton of carbon in the air, if you burn one
ton of carbon in the form of corn-oil, that ALSO puts one
tone of carbon in the air. If you grow a ton-s worth
of carbon-bearing corn, and then burn it. The net effect
on the atmosphere is zero. If you grow one ton's worth
of carbon bearing corn and DON'T burn it, the net effect
is minus one ton. How much carbon is in the
parts of the corn that you don't burn? How much
carbon is in whatever would be growing there if you
weren't growing fuel-corn?