Yesterday's New York Times brings us How to Cool a Planet (Maybe), by William J. Broad, Jun 27, 2006 — explaining the whats and whys or a resergence in looking for engineering solutions to global warming threats.
In the past few decades, a handful of scientists have come up with big, futuristic ways to fight global warming: Build sunshades in orbit to cool the planet. Tinker with clouds to make them reflect more sunlight back into space. Trick oceans into soaking up more heat-trapping greenhouse gases.
Their proposals were relegated to the fringes of climate science. Few journals would publish them. Few government agencies would pay for feasibility studies. Environmentalists and mainstream scientists said the focus should be on reducing greenhouse gases and preventing global warming in the first place.
But now, in a major reversal, some of the world's most prominent scientists say the proposals deserve a serious look because of growing concerns about global warming.
Worried about a potential planetary crisis, these leaders are calling on governments and scientific groups to study exotic ways to reduce global warming, seeing them as possible fallback positions if the planet eventually needs a dose of emergency cooling. …
Many scientists still deride geoengineering as an irresponsible dream with more risks and potential bad side effects than benefits; they call its extreme remedies a good reason to redouble efforts at reducing heat-trapping gases like carbon dioxide. And skeptics of human-induced global warming dismiss geoengineering as a costly effort to battle a mirage.
Even so, many analysts say the prominence of its new advocates is giving the field greater visibility and credibility and adding to the likelihood that global leaders may one day consider taking such emergency steps. …
[In an earlier era] critics of geoengineering argued that it made more sense to avoid global warming than to gamble on risky fixes. They called for reducing energy use, developing alternative sources of power and curbing greenhouse gases.
But international efforts like the Kyoto Protocol — which the United States never ratified, and which China and India as members of the developing world never had to obey, freeing the current and projected leaders in greenhouse gas emissions from its restrictions — have so far failed to diminish the threat. Scientists estimate that the earth's surface temperature this century may rise as much as 10 degrees Fahrenheit.
Geoengineering's advocates say humankind is already vastly altering the global environment and simply needs to do so more intelligently. …
"Climatic engineering, such as presented here, is the only option available to rapidly reduce temperature rises" if international efforts fail to curb greenhouse gases, Dr. Crutzen [Nobel laureate from the Max Planck Institute] wrote.
"So far," he added, "there is little reason to be optimistic."