From: Gordon Mohr (email@example.com)
Date: Mon Aug 21 2000 - 11:18:57 PDT
Steve Dossick writes:
> Anyone have any idea how long it would take for our lovely Mother Nature
> to fix her planet even if we piggy humans turned off all the
> pollution/greenhouse gases? I'm thinking this problem is bigger than
> the presidency....
Why wait for Mother Nature?
I see a green house and I want it painted white.
# Before upending society to battle global warming, why not try something
# easier, like better reflecting the sun's heat?
# On My Mind
# By Tim W. Ferguson
# RUSSELL SEITZ
# ASSOCIATE, OLIN INSTITUTE FOR STRATEGIC STUDIES
# Al Gore's answer to global warming is raising fossil fuel taxes. This
# may be as irrelevant as it is expensive and intrusive. For the
# greenhouse effect is not driven by fossil fuel burning, but by the
# power of the sun. Which is why, when a greenhouse gets too steamy, you
# whitewash it. This simple, passive solar cooling works so well,
# regardless of size, that it even applies to that largest of
# greenhouses, the Earth itself.
# The real problem is Earth's low albedo--it reflects only a small
# fraction of the sun's energy because most of its surface is dark
# compared to a snowfield or a coat of white paint. Such white surfaces
# reflect three times as much as bare rock or desert soil, and up to ten
# times as much as deep water or black asphalt paving.
# It is easy to calculate how much it would take to counter the retention
# of heat by greenhouse gases in the atmosphere. A large amount of
# radiant energy streams in from the sun; a small quantity of the same is
# trapped by carbon dioxide. The trapping effect comes to 1.62 watts per
# square meter of the planet's surface, of which some 300 to 400
# milliwatts is due to past fossil fuel burning. That 350 milliwatts is
# still only a thousandth of the incoming solar energy. Which is why
# enhancing the reflectivity of a corresponding fraction of the earth's
# surface to the brightness of a snowfield would reverse the cumulative
# environmental impact of the industrial revolution. A thousandth of the
# earth's surface comes to 200,000 square miles. Let's do a little
# more--250,000 square miles--to allow for the fact that a white surface
# on the ground is not a perfect mirror into outer space.
# Split 6 billion ways, brightening up 250,000 square miles is not such a
# formidable task: It comes to about 1,000 square feet apiece. Apart from
# that one-time obligation, we'd have to continue with a small annual
# dose of brightening to counteract the new damage from today's fossil
# fuel burning. This annual obligation would be on the order of a few
# percent of the one-time cost.
# There is plenty of space to install this cheap and passive insurance
# against climatic bracket creep: Even at a rate of 5,000 square miles a
# year, it would take centuries to exhaust the supply of treeless
# badlands. Compared to the draconian economics of global carbon
# taxation, whitewashing might be something of a bargain.
# The greatest benefits would arise from whitening or brightening dark
# unvegetated landscapes in sunny climates, in effect providing "snow"
# that would not disappear from rocky uplands with the coming of summer.
# The bright surface need not be artificial--introducing and propagating
# any of many species of bright-leafed vegetation, natural or genetically
# engineered, can have the same effect.
# Or we could lighten up the hundreds of thousands of square miles of
# roofs and roadways that already exist, starting with those expanses of
# asphalt that already contribute to cities being warmer than the
# countryside. Titanium dioxide is the best pigment for producing this
# "White House Effect": enduring, utterly nontoxic and dirt cheap--one
# penny's worth will cover a square foot nicely. China clay, or kaolin,
# is less efficient as a reflector, but an order of magnitude cheaper.
# Applying a paint film of either can suffice to raise the reflectiveness
# of most natural surfaces from 25% or less to 75% or more, at a
# materials cost on the order of around $250,000 per square mile.
# America's annual per capita share of such a global solution would cost
# as much as a couple of gallons of gas.
# Once you understand that the sun power entering our atmosphere is
# nearly 100,000 times the power of the whole human energy economy, you
# can comprehend how, at one and the same time, carbon taxation would be
# both a fiscal enormity and an environmental irrelevance. After two
# generations of solar-cell R&D it still costs $3 million a megawatt to
# convert sunlight into electrical power. But $300 worth of aluminum foil
# will reflect a megawatt of solar energy back into space.
# It will grieve the green and frugal alike to learn that some things are
# cheaper than energy conservation. Just saying no to the passive solar
# heating of the Earth is one of them.
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