Dear friends,
Greetings from Davos, Switzerland! Many business and government leaders are gathered here again for the annual World Economic Forum to discuss tech, climate, geopolitics, and economic growth. While the vast majority of my conversations have been on AI business implementations and governance, I have also been speaking about our latest AI climate simulator and about geoengineering. After speaking about geoengineering onstage at multiple events to a total of several hundred people, I’ve been pleasantly surprised by almost uniformly positive reactions. You can play with our simulator here.
Here’s why I think we should seriously consider geoengineering: The world urgently needs to reduce carbon emissions, but it hasn’t happened fast enough. Given recent emission trends, without geoengineering, there’s no longer any plausible path to keeping global warming to the 1.5 degrees Celsius goal set by the Paris agreement. Under reasonable assumptions, we are on a path to 2.5 degrees of warming or worse. We might be in for additional abrupt changes if we hit certain tipping points.
If you tilt a four-legged chair by a few degrees, it will fall back onto its four legs. But if you tip it far enough — beyond its “tipping point” — it will fall over with a crash. Climate tipping points are like that, where parts of our planet, warmed sufficiently, might reach a point where the planet reorganizes abruptly in a way that is impossible to reverse. Examples include a possible melting of the Arctic permafrost, which would release additional methane (a potent greenhouse gas), or a collapse of ocean currents that move warm water northward from the tropics (the Atlantic Meridional Overturning Circulation).
Keeping warming low will significantly lower the risk of hitting a tipping point. This is why the OECD’s report states, “the existence of climate system tipping points means it is vital to limit the global temperature increase to 1.5 degrees C, with no or very limited overshoot.”
The good news is that geoengineering keeps the 1.5 degree goal alive. Spraying reflective particles into the atmosphere — an idea called Stratospheric Aerosol Injection (SAI) — to reflect 1% of sunlight back into space would get us around 1 degree Celsius of cooling.
Now, there are risks to doing this. For example, just as global warming has had uneven regional effects, the global cooling impact will also be uneven. But on average, a planet with 1.5 degrees of warming would be much more livable than one with 2.5 degrees (or more). Further, after collaborating extensively with climate scientists on AI climate models and examining the output of multiple such models, I believe the risks associated with cooling down our planet will be much lower than the risks of runaway climate change.
I hope we can build a global governance structure to decide collectively whether, and if so to what extent and how, to implement geoengineering. For example, we might start with small scale experiments (aiming for <<0.1 degrees of cooling) that are easy to stop/reverse at any time. Further, there is much work to be done to solve difficult engineering challenges, such as how to build and operate a fleet of aircraft to efficiently lift and spray reflective particles at the small particle sizes needed.
Even as I have numerous conversations about AI business and governance here at the World Economic Forum, I am glad that AI climate modeling is helpful for addressing global warming. If you are interested in learning more about geoengineering, I encourage you to play with our simulator at planetparasol.ai.
I am grateful to my collaborators on the simulator work: Jeremy Irvin, Jake Dexheimer, Dakota Gruener, Charlotte DeWald, Daniele Visioni, Duncan Watson-Parris, Douglas MacMartin, Joshua Elliott, Juerg Luterbacher, and Kion Yaghoobzadeh.
Keep learning!
Andrew