The scariest thing about geo-engineering, as it happens, is also the thing that makes it such a game-changer in the global-warming debate: it’s incredibly cheap. Many scientists, in fact, prefer not to mention just how cheap it is. Nearly everyone I spoke to agreed that the worst-case scenario would be the rise of what David Victor, a Stanford law professor, calls a “Greenfinger”—a rich madman, as obsessed with the environment as James Bond’s nemesis Auric Goldfinger was with gold. There are now 38 people in the world with $10 billion or more in private assets, according to the latest Forbes list; theoretically, one of these people could reverse climate change all alone. “I don’t think we really want to empower the Richard Bransons of the world to try solutions like this,” says Jay Michaelson, an environmental-law expert, who predicted many of these debates 10 years ago.
Even if Richard Branson behaves, a single rogue nation could have the resources to change the climate. Most of Bangladesh’s population lives in low-elevation coastal zones that would wash away if sea levels rose. For a fraction of its GDP, Bangladesh could refreeze the ice caps using sulfur aerosols (though, in a typical trade-off, this might affect its monsoons). If refreezing them would save the lives of millions of Bangladeshis, who could blame their government for acting? Such a scenario is unlikely; most countries would hesitate to violate international law and become a pariah. But it illustrates the political and regulatory complications that large-scale climate-changing schemes would trigger.