Ours is a culture with sharply conflicting stories about science. On the one hand, there is the notion that science can do anything, and on the other there is the archetype of the mad scientist, the Dr. Frankenstein or Dr. Strangelove, who through his overreaching wreaks havoc on the world.

Geoengineering, which has come to mean addressing the climate-change crisis with a single, massive, planetary techno-fix, has landed, for the most part, in the mad-scientist category, and with good reason. Over the last decades, we've gotten object lesson after object lesson in the perils of "unintended consequences" as projects small and large have gone awry. There's DDT, the deadly pesticide that was supposed to a boon for agriculture. There are chlorofluorocarbons, or CFCs, which were initially celebrated as a multi-use industrial convenience but turned out to deplete the ozone layer. And beyond these one-off examples there's our runaway industrial culture, a global if not quite scientific experiment, which has put the entire planet at risk.

The geoengineering concepts that are being bruited about are stamped with the stuff of genius—and hubris, too. There are three general approaches. First, pull carbon dioxide out of the air, possibly by fertilizing the oceans with iron. Second, create a sunshade, for instance by pumping sulfur dioxide into the atmosphere. Third, cool the planet in other ways. For instance, an inventor named Ron Acer recently filed a patent application for a scheme to spray massive amounts of salt water into the air over windy and arid areas in the northern hemisphere, thereby reducing global temperatures.

These are grand schemes indeed. But are they too grand? Let's put our cultural assumptions aside for a moment and ask a straightforward question: has the time come to put our Dr. Strangelove biases aside and take geoengineering seriously?

The argument against geoengineering can be summed up in the two powerful words cited above: unintended consequences. The celebrated engineer and systems thinker Amory Lovins put it best: "The biggest cause of problems is solutions."

There are basically three arguments in favor of geoengineering.

Cost. It has been estimated that seeding the atmosphere with sulfur dioxide would cost $25-$50 billion a year. Ron Acer has placed the price of his global air-conditioning system at a few billion dollars. These numbers are miniscule compared to more usual climate-change strategies.

Feasibility. Standard approaches to climate change require widespread buy-in and massively decentralized engagement. This makes them difficult to carry out. Because geoengineering solutions can be undertaken on a top-down, command-and-control basis, they can be more readily implemented.

Desperation. The reality of climate change is turning out to be worse than expected. It's now projected that the Arctic could be ice-free by 2013, decades sooner than projected. Meanwhile emissions are rising faster than the worst-case scenario projected as recently as 2007 by the Intergovernmental Panel on Climate Change.

This suggests that any set of approaches short of geoengineering could be a cataclysmic example of us fiddling while the planet burns.

Believe me, I don't want to be thinking this way. But I can't help but wonder: in a world on the brink, the mad-scientist approach may be our last and best hope.