As a counterpoint to the last post (emphasis mine):
…a plan to sow the oceans with iron to trigger plankton blooms, which would absorb carbon dioxide, die, and settle to the sea floor. A plan to send a trillion mirrors into orbit to deflect incoming sunlight. A plan to launch a fleet of robotic ships to whip up sea spray and whiten the clouds. A plan to mimic the planet-cooling sulfur-dioxide miasmas of explosive volcanoes, either by an artillery barrage of sulfur-dioxide aerosol rounds fired into the stratosphere or by high-altitude blimps hauling up 18-mile hoses.
None of these projects will happen, fortunately. They promise side effects, backfirings, and unintended consequences on a scale unknown in history, and we lack the financial and political wherewithal, and the international comity, to accomplish them anyway. What is disquieting is not their likelihood, but what they reveal about the persistence of belief in the technological fix. The notion that science will save us is the chimera that allows the present generation to consume all the resources it wants, as if no generations will follow. It is the sedative that allows civilization to march so steadfastly toward environmental catastrophe. It forestalls the real solution, which will be in the hard, nontechnical work of changing human behavior.
— The Danger of Cosmic Genius, Atlantic Magazine.