Page 261 - James Rodger Fleming - Fixing the sky

increase in the amount or brightness of marine stratocumulus clouds in the lower
atmosphere might provide significant offsets to global warming. one possible
mechanism would be through adding cloud condensation nuclei from emissions
of sulfur dioxide; several hundred coal-fired power plants might do the job.
In 1989 James Early, a scientist at Lawrence Livermore National Laboratory,
revisited the issue of space mirrors and linked space manufacturing fantasies
with environmental issues in his wild speculations on the construction of a
solar shield “to offset the greenhouse effect.” His back-of-the-envelope calcu-
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lations indicated that a massive shield some 1,250 miles in diameter would be
needed to reduce incoming sunlight by 2 percent. He estimated that an ultra-
thin shield, possibly manufactured from lunar materials using nano-fabrication
techniques, might cost “from one to ten trillion dollars.” Launched from the
Moon by an unspecified “mass driver,” the shield would reach a “semi-stable”
orbit at the L point 1 million miles from the Earth along a direct line toward
1
the Sun, where it would perch “like a barely balanced cart atop a steep hill, a
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hair’s-width away from falling down one side or the other.” Here it would be
subjected to the solar wind, harsh radiation, cosmic rays, and the buildup of
electrostatic forces. It would have to remain functional for “several centuries,”
which would entail repair missions. It would also require an active position-
ing system to keep it from falling back to the Earth or into the Sun. In other
words, it was not feasible. Early did not indicate what a guidance system might
look like for a 5-million-square-mile sheet of material possibly thinner than
kitchen plastic wrap, with a mass close to 1 billion kilograms (2.2 billion pounds
in Earth gravity). He alluded to the enormous scale and costs of this project
and its “major undefined systems,” while disingenuously declaring it to be a sim-
pler project, “much smaller in size and scale,” than controlling the temperatures
on other planets of the solar system. By this “logic,” even controlling the tem-
perature of the entire solar system would be “simple” compared with galactic-
scale engineering!

national academy, 1992

The publication of the National Academy of Sciences report Policy Implications
of Greenhouse Warming: Mitigation, Adaptation, and the Science Base (1992) is
well within the memory of the current generation of climate engineers. The mas-
sive report, whose synthesis panel was chaired by Daniel J. Evans, former gover-
nor and U.S. senator from Washington State, examined what was known about
greenhouse gases and their climatic effects and then presented geoengineering

244 | tHe Climate enGineerS