David Archer - University of Chicago

successful, would curtail emissions by about 6% below 1990 levels, while carbon cycle
models show that eventual cuts of order 50% would be required to truly stabilize the CO 2
concentration of the atmosphere.
Carbon emissions could be lessened quite a bit by conservation and efficiency.
Sources of carbon-free energy such as windmills and solar energy exist and are rapidly
being scaled up. A forecast of the amount of energy civilization will require in the
coming century suggests that large, new sources of energy may be required in the future.
Nuclear energy is essentially carbon-free but it would take a new nuclear power plant of
current design built every other day for the next 100 years to keep up with forecast
energy demand. New ideas include solar cells on the moon, beaming energy back to
Earth as microwave radiation, or high-altitude windmills, mounted on kites tethered in
the jet stream.
With our growing technological and intellectual prowess, as well as our exploding
population, we are slowly taking over the job of managing the biosphere. May we do it
wisely!
Chapter 1 12/18/05 6