Earlier this year I was watching Dennis Quaid alert the globe to a massive frozen hurricane descending from the arctic in the totally scientific film The Day after Tomorrow, when I saw a news headline that caught my eye: “A Bill Gates Venture Aims To Spray Dust Into The Atmosphere To Block The Sun. What Could Go Wrong?” And I thought exactly that (in a highly sarcastic tone): what in the world could go wrong?

Having studied this topic in college, I know how controversial it can be among scientists and the public alike. Geoengineering is defined by Oxford Languages as “The deliberate large-scale manipulation of an environmental process that affects the earth’s climate, in an attempt to counteract the effects of global warming.” I reiterate: what in the world could go wrong?

The headline refers to billionaire Bill Gates funding a Harvard University project called The Stratospheric Controlled Perturbation Experiment (“SCoPEx”). There’s a new acronym for Gen Z… IYKYK amirite? 

The project is researching a way to trigger a global cooling effect by spraying aerosol particles into the upper atmosphere that reflect sunlight away from Earth’s surface. This is a form of Solar Radiation Management (“SRM”) that mimics the effects of a natural volcanic eruption. For example, the eruption of Mt. Pinatubo in 1991 pumped 20 million tons of sulfur dioxide and ash into the stratosphere, where chemical reactions turned the gas and ash into sulfuric aerosols that circled the globe for almost 2 years and caused the global average surface temperature to decrease by 0.5C. 

This 0.5C figure is nothing to scoff at. The sixth IPCC report (“International Panel on Climate Change” – the official delegation of global climate experts) released in August states that the globe has already warmed by over 1.1C on average compared to 1850 levels – encroaching rather close to the 1.5C value that is frequently referenced as a global goal to limit the future effects of climate change.

To Gates’ credit, perhaps it is necessary to examine all of our options at this point. Geoengineering was introduced after World War II, using technology developed during the era to alter weather patterns by seeding clouds to increase their precipitation. The state of Colorado itself enacts a cloud seeding program every winter to bolster its water supply via increasing snow and thus snowmelt come summertime. However, cloud seeding is a practice that injects silver iodide into existing storm clouds to encourage condensation; not introducing a completely new environmental driver as with SRM. Fun fact – cloud seeding was discovered by Bernard Vonnegut (brother to author Kurt) along with other scientists while researching a way to control the weather, directly influencing Kurt’s famous novel, The Cat’s Cradle. 

However, the aerosols sprayed into the atmosphere during the SCoPEx experiment would eventually fall out and disperse – meaning that in order to have a sustained global cooling effect aerosol particles would need to be injected in massive amounts continuously… and indefinitely. A sudden end to this process could result in a rebound global warming rate 2 to 4 times greater than that of an unengineered climate that would wreak catastrophic havoc on sensitive ecosystems and the world.

I’ve had to bike over the same crack in the sidewalk for years. If we can’t even maintain the basic infrastructure of our roads, how can we expect to maintain a global geoengineering project?

There’s also the unintended consequences resulting from SRM. Researchers at MIT looked at the effects of solar geoengineering projected forward using climate models. They found that this human intervention would lessen the temperature gradient between the poles and equator, weakening the wind patterns that carry storm tracks in both northern and southern midlatitudes. This creates stagnant conditions favorable for drought and decreased air quality. 

According to the study, global warming itself in an unengineered climate is projected to weaken these weather patterns in the northern hemisphere at the same magnitude as with geoengineering, meaning it would be doing nothing to mitigate these consequences from climate change. Another recent study done by NOAA shows regional reductions in rainfall across the globe are also a concern, meaning countries would need to adapt to seasonal changes in precipitation that affect their livelihoods. While solar geoengineering might cool the planet in places, it would still result in an overall altered and erratic future climate.

In a world of instant gratification where we get angry if our Amazon package doesn’t arrive in 2 days, geoengineering has faced criticism as a lackadaisical solution that takes attention away from the primary solution: actually cutting our greenhouse gas emissions. 

Haven’t we interfered with our climate and the Earth enough? 

Let’s focus instead on existing solutions that mimic Earth’s natural processes to remove carbon dioxide from the atmosphere – restoring natural forests and protecting peatlands, and promoting natural regrowth of habitats that allow nature to decide what species dominate. Research shows enhancing natural ecosystems could take an extra 11 billion tons of CO2 out of the atmosphere each year. That’s a great start, not to mention expanding upon existing solar and wind energy solutions. I could devote multiple blog posts to these topics (and perhaps I will!) but I won’t attempt to tackle every single solution right now. 

We find ourselves living in a mess of our own making. Should we continue to mess with our climate as the solution?