In 2010, the chairman of the House Committee on Science and Technology recommended more research into geoengineering; the British government has begun to spend public money in the field.

Bill Gates has funneled millions of dollars into geoengineering research. And he has invested in a company, Intellectual Ventures, that is developing at least two geoengineering tools: the “StratoShield,” a 19-mile-long hose suspended by helium balloons that would spew sun-blocking sulfur dioxide particles into the sky and a tool that can supposedly blunt the force of hurricanes.

THE appeal is easy to understand. Geoengineering offers the tantalizing promise of a climate change fix that would allow us to continue our resource-exhausting way of life, indefinitely. And then there is the fear. Every week seems to bring more terrifying climate news, from reports of ice sheets melting ahead of schedule to oceans acidifying far faster than expected. At the same time, climate change has fallen so far off the political agenda that it wasn’t mentioned once during any of the three debates between the presidential candidates. Is it any wonder that many are pinning their hopes on a break-the-glass-in-case-of-emergency option that scientists have been cooking up in their labs?

But with rogue geoengineers on the loose, it is a good time to pause and ask, collectively, whether we want to go down the geoengineering road. Because the truth is that geoengineering is itself a rogue proposition. By definition, technologies that tamper with ocean and atmospheric chemistry affect everyone. Yet it is impossible to get anything like unanimous consent for these interventions. Nor could any such consent possibly be informed since we don’t — and can’t — know the full risks involved until these planet-altering technologies are actually deployed.

While the United Nations’ climate negotiations proceed from the premise that countries must agree to a joint response to an inherently communal problem, geoengineering raises a very different prospect. For well under a billion dollars, a “coalition of the willing,” a single country or even a wealthy individual could decide to take the climate into its own hands. Jim Thomas of the ETC Group, an environmental watchdog group, puts the problem like this: “Geoengineering says, ‘we’ll just do it, and you’ll live with the effects.’ ”

The scariest thing about this proposition is that models suggest that many of the people who could well be most harmed by these technologies are already disproportionately vulnerable to the impacts of climate change. Imagine this: North America decides to send sulfur into the stratosphere to reduce the intensity of the sun, in the hopes of saving its corn crops — despite the real possibility of triggering droughts in Asia and Africa. In short, geoengineering would give us (or some of us) the power to exile huge swaths of humanity to sacrifice zones with a virtual flip of the switch.

The geopolitical ramifications are chilling. Climate change is already making it hard to know whether events previously understood as “acts of God” (a freak heat wave in March or a Frankenstorm on Halloween) still belong in that category. But if we start tinkering with the earth’s thermostat — deliberately turning our oceans murky green to soak up carbon and bleaching the skies hazy white to deflect the sun — we take our influence to a new level. A drought in India will come to be seen — accurately or not — as a result of a conscious decision by engineers on the other side of the planet. What was once bad luck could come to be seen as a malevolent plot or an imperialist attack.