can antacids and geoengineering help us stop global warming?

A new geoengineering experiment seeks to cool the Earth by safely emulating the aftermath of volcanic eruptions. But even if it’s successful, all it can do is buy us time.

flooding earth illustration

In the satirical world of Futurama, global warming is very real but it has been solved by the world’s “handsomest politicians.” Kind of. Every year, a spaceship drops giant ice cubes mined from Halley’s Comet into the oceans, thus cooling the planet, with the slight side effect of unchecked greenhouse gas emissions still building up in the atmosphere and requiring ever bigger ice cubes. And in a case of life imitating art, a team of scientists is considering using a fine mist of calcium carbonate, an extract from marble often used in antacids and toothpaste, and spraying it high into the stratosphere where it would deflect the sun’s rays for up to two years until another seeding would be necessary.

Now, in case you were wondering, Futurama’s solution would never work. Putting aside the basic logistics of how to make sure tons of ice survive atmospheric descent still frozen, the ice would melt far too quickly to actually cause any meaningful temperature change, rasing sea levels as it does. If the ice isn’t salty enough, it could slow, if not shut down the global oceanic conveyor by throwing off the required salinity levels to keep it going. You might recognize this as one of the worst side effects of the melting ice caps, profoundly changing weather patterns and exacerbating damaging regional storms. In other words, it would be a wildly impractical artificial disaster.

Using calcium carbonate, on the other hand, should be far more effective and practical than some other geoengineering projects intended to fight global warming, projects such as re-icing the Arctic. The idea is actually based on the aftermath of volcanic eruptions which seed the stratosphere with fine particles of sulfur dioxide that reflect the sun and can very efficiently cool the planet for years at a time. For example, the eruption of Krakatoa in 1883 lowered average summer temperatures in the Northern Hemisphere by as much as 1.2 °C and caused further abnormal dips for about five years. The 1991 Pinatubo eruption cooled the planet by 0.5 °C for more than a year. Using calcium carbonate is a less harmful way of accomplishing more or less the same thing.

can we geoengineer ourselves out of global warming?

Provided that initial tests for the effort, known as the Stratospheric Controlled Perturbation Experiment, or SCoPEx, are encouraging, the scientists behind it estimate that keeping a shroud of sun-deflecting mist capable of cooling the whole planet would take no more than $10 billion per year. It seems like it would be cheap, effective, and solve the immediate crisis caused by our pollution. But the experiment is encountering fierce political opposition for the simple reason that just like Futurama’s annual ice cube drop, it would do nothing to solve the primary problem: entire nations belching gigatons of greenhouse gasses that caused the warming in the first place.

Environmentalists and climatologists worry that SCoPEx would end up being a giant bandaid allowing us to pretend that our pollution isn’t an of control disaster severe enough to show up in the fossil record. To the credit of the researchers behind it, they certainly aren’t pitching it as the be-all and end-all of fighting global warming. Instead, they’re suggesting a way to stave off the worst case scenario known as Hothouse Earth and keep Earth from getting too hot while we clean up our act. Their critics’ objections seem to be a mix of caution and mistrust of politicians’ ability to actually do the right thing and have some long term vision when not faced with an immediate crisis.

Their caution is warranted as global cooling through fine particles in the stratosphere seem closely associated with lower crop yields. Wealthy nations which often have a surplus of food wouldn’t be severely affected or could innovate around the problem, but failing and fragile states with food insecurity could turn into basket cases and trigger another global refugee crisis while we’re still dealing with the current one, also quite possibly caused by climate change. It seems unethical to risk another civil war in a geopolitical hotspot to buy multinational conglomerates more time to transition to cleaner energy at their convenience. But then again, one can argue that uncontrolled climate change would do the same thing with punishing heat instead.

Likewise, their skepticism of politicians also makes perfect sense. They’ve proven either unwilling or incapable of doing the right thing with an actual climate crisis dangling over their heads, and for all its popularity, the Paris Agreement would’ve only limited how quickly the Earth warmed rather than halted the warming trend. Right wing populists who blame every woe in their nations on “globalists” and immigrants are refusing to participate in it while industrial Third World nations flaunt the rules, saying their developing status should grant them exemptions to keep their economies growing at the insane rates necessary to avoid recession-triggering unemployment.

Assuming that a successful geoengineering effort to cool the Earth would be seen as a ticket to avoid new regulation and making real change by the same leaders isn’t a pessimistic approach but an almost inevitable conclusion. One can almost hear the global warming denialists ignoring future ongoing efforts to artificially cool the Earth while writing a tsunami of articles and posts demanding to know what happened to all that global warming every climatologist was talking about just a few years prior, making any future-focused steps towards cleaning up the planet even more politically difficult. Considering that they’re currently arguing that our planet is actually cooling and smoke from factories isn’t toxic with a straight face, this level of dishonesty is absolutely not beneath them. Nothing is as long as their patrons’ checks clear.

we may still need a hybrid geoengineering/political approach

Unfortunately, all that said, when we consider just how little serious action has been taken on the climate front and in cleaning up our pollution, a hybrid solution may be the only way to get our act together. Our leaders already pushed us too far down a road we shouldn’t be on right now and without giving ourselves some corrective reprieve, we might still end up feeling the full brunt of climate change for decades. Willingly ignoring geoengineering solutions to buy time is the equivalent to making a suicide pact with world leaders to scare them into action, and as we discussed above, it’s not even clear if that would actually motivate them to take concrete and permanent steps in the right direction so something like SCoPEx would tell us whether we can at least buy ourselves some time to remove the political roadblocks to a cleaner planet.

And we should absolutely proceed lightly. Our atmosphere is a very complex thing and it’s not clear if recreating a benign version of volcanic cooling wouldn’t backfire. Let’s remember that volcanic winters historically caused crop failures and harmful weather anomalies, and we’d be essentially fighting fire with fire while hoping we blunted the warming just enough to minimize its ill effects. In the end, the sought after cooling could be regional instead of global and cause unforeseen problems. Likewise, a worldwide effort means certain countries may object in the strongest of terms of having their climate manipulated, creating an international PR disaster and inspiring unhinged conspiracy theorists to make it a lot worse.

Perhaps the most important thing to keep in mind is that there are no silver bullets when it comes to fighting climate change, no single solution that will revert this planet back to the range of temperatures we find comfortable. It will require coordinated efforts on multiple fronts, an educated and engaged public, and politicians who understand that borders aren’t magical barriers capable of stopping pollution, heat, and storms in the name of almighty sovereignty. Even the most successful SCoPEx tests and implementations will only help us get to the end goal of a cleaner, more sustainable, more cooperative world a little less scathed. If we want to stop global warming, we’ll still have to figure out a way to stop relying on fossil fuels as a species. There’s simply no other way to save ourselves and our world as we know it.

# science // climate change / geoengineering / global warming

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