Re: If all the ice melted...

From: Robert J. Bradbury (
Date: Mon Jul 02 2001 - 12:22:15 MDT

On Mon, 2 Jul 2001 wrote:

> I said:
> >For an optimal situation I think you actually want to increase CO2 emissions
> >right up to the point where very advanced biotech or nanotech can
> >reverse it. The more carbon you put into the atmosphere the greater
> >the "sunk cost" benefit you have during the nanotech transition.
> I don't get that. First, I doubt carbon will be the limiting material;

Aha, have you forgotten my (in?)famous Sapphire Mansion post?
It needs to be rewriten with some corrections, but the general
gist of it is still correct. The URL is:

> I anticipate it will continue to be nitrogen and phosphorus; if nanotech
> requires only a tiny portion to be 3-bond atoms they continue to
> be limiting.

On a solar-system basis, I'd agree, but on Earth we have plenty
of N2 relative to C (unless we do a lot of digging). I'd have
to do some exact mass fraction calculations but looking at the
existing pieces Eric has designed Fluorine and Sulfur could
come up as possible limiting elements as well. My earlier
post was focused on using nanomaterial primarily as structural
material, not as a more general nano-mechanical-material.
It would be useful sometime to discuss the relative fractions
of passive and active nanomaterials one might eventually

> More to the point, it's way easier to use coal and oil
> for carbon than to extract it from the atmosphere at 1%.
> Burning fossil fuel makes the carbon far less available.

The problem is that coal and oil are *owned* by someone.
You have to pay for their use. CO2 in the atmosphere is *free*
(at least for now anyway). The main point of my paper was
that we will have the energy (almost for free) to extract
the CO2 and build useful structures with the carbon in it.


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