Geo-Engineering Could Save the Planet … and in the Process Sacrifice the World

Earth is busted. Like a supercomputer whose elaborate code has developed a few bugs, the core operating systems of the planet are frayed: Ocean populations are collapsing, forests are disappearing, soils have become thin. Perhaps most worrisome, the globe's atmosphere, the ecosystem on which all other ecosystems depend, is overheating. The machinery of life appears to have malfunctioned.

Since the scale of the climate crisis became clear, the strategy for fixing this glitch has focused on remediation. To maintain the atmosphere's equilibrium, we need to reduce our emissions of greenhouse gases. Our chief goal should be to return the climate to something approximating the pre-industrial status quo.

But what if such a return isn't possible? What if the planet has gone permanently haywire? As the effects of climate change become obvious and global leaders remain unable to halt emissions, a growing number of scientists say we need to begin researching what's called "geo-engineering" -- ways to artificially reduce global temperatures and/or manipulate plants or the oceans to absorb huge amounts of CO2. Having unintentionally warmed the planet, we may have little choice but to intentionally cool it back down.

Even those most interested in geo-engineering say that the idea of deliberately deforming the planet in order to save it from ourselves is, as Stanford University's Ken Caldeira told NPR this summer, "scary." Yet if we shy away from manipulating the whole globe and continue on our present course, we could be left with a burnt Earth unlike anything ever seen. The scientists who are encouraging government-funded research into geo-engineering are driven by a powerful motive: fear. All too aware of the implications of unchecked CO2 emissions -- and worried that political systems aren't moving quickly enough to respond to changes in the planet's physical systems -- these scientists say we may have no other option than to tinker with the sky.

That some of the world's foremost climatologists are contemplating this measure of last resort reveals how desperate our predicament is. We face the prospect of leaping into a new epoch of planetary history, one in which a single species will be responsible for all other life here. Or else finding some way of accommodating ourselves to the world as we have undone it.

This places us at a moral moment involving a dangerous gamble. Do we chance toying with the entire atmosphere? Can we afford not to?

Possible geo-engineering technologies range from the whimsy of science fiction to the purely hypothetical to the unsettlingly plausible. Some are so outlandish they defy gravity. A few have undergone small-scale experimentation. At least one has the advantage of a real-world analogue. All remain on the drawing board. None are free from concerns about unintended consequences.

Geo-engineering schemes fall into two categories: attempts to absorb the CO2 in the atmosphere and efforts to manipulate the way Earth reflects sunlight, called the planet's "albedo." The first group is less controversial, because such techniques mimic natural processes. They are, however, slower, which reduces their effectiveness as a response to the kind of climate emergencies some scientists fear. Devices to re-jigger the planet's albedo can seem more worrisome, as they would create what critics have dubbed a "Frankenplanet." They are also more likely to work.

One idea for absorbing CO2 involves seeding the oceans with iron to spur plankton blooms, which inhale large amounts of carbon and then die, pulling the gas to the bottom of the sea. Another brainstorm suggests that by creating "biochar" we can arrest the amount of carbon dioxide that naturally goes into the atmosphere during plant decay. Giant kilns would take agricultural waste and dead trees and, using a process called pyrolysis, burn them without using oxygen. The resulting CO2-laden charcoal then would be buried. If that proves unfeasible, some scientists say we could genetically modify plants to absorb more of the heat-trapping gas. Or, in case that doesn't work, Professor Klaus Lackner at Columbia University proposes building "synthetic trees" that will capture CO2 and turn it into a liquid form to store underground.