Solar Geoengineering—What Could Possibly Go Wrong?

Commentary

The United States is now investigating how to inject chemicals into the atmosphere in order to block out the sun.

The idea is to use a “stratospheric aerosol injection” to essentially mimic the effects of the aftermath of a volcanic eruption, where the sun is blocked out for a prolonged period of time. The goal here is, however, to somehow reduce greenhouse gases.

What could possibly go wrong?

The research, which was done by the Office of Science and Technology Policy on a congressional mandate, created a plan for “solar and other rapid climate interventions.”

Besides injecting chemicals into the atmosphere, it also looked into “marine cloud brightening,” which makes clouds less reflective, as a way to allow more sunlight to reach the earth’s surface.

Mexico in January banned these types of experiments.

A company called “Make Sunsets” had begun experiments on solar geoengineering in Baja California, in December 2022. It launched weather balloons that were releasing sulfur particles into the stratosphere.

It was a small experiment that used less than 10 grams of sulfur dioxide. But Mexico wasn’t having any of that. The country banned future programs on solar geoengineering. An official statement from its Ministry of Environment and National Resources notes that since 2010, under the U.N. Convention on Biological Diversity, there is a moratorium against the use of geoengineering.

It states: “Solar geoengineering practices seek to counteract the effects of climate change, through the emission of gases into the atmosphere such as sulfur dioxide, aluminum sulfate, among others. This process induces the sun’s rays to be reflected back into space, thus avoiding the increase in temperature in a specific geographical area.”

Yet it adds something important. Apparently, the harm of programs like this is known.

According to the Mexican government, “there are enough studies that show that there would be negative and unequal impacts associated with the release of these aerosols, which cause meteorological imbalances such as winds and torrential rains, as well as droughts in tropical areas; in addition to generating impacts on the thinning of the planet’s ozone layer.”

Interest in the concept started after a volcanic eruption in 1991 in the Philippines. Mount Pinatubo blasted 20 million metric tons of sulfur aerosols into the atmosphere. This sparked interest among climate change enthusiasts because the natural disaster caused a cooling in global temperatures that lasted for two years.

But risks or not, and regardless of studies already showing the harm such programs would have, there are people set on moving forward.

Billionaire Bill Gates made headlines in 2019 when he was funding a new program to replicate the effects of a massive volcanic eruption.

Interestingly, the program he was backing falls under the “stratospheric aerosol injection” concept that the White House is now saying it’ll look into. According to CNBC, under the Gates program, “Thousands of planes would fly at high altitudes, spraying millions of tons of particles around the planet to create a massive chemical cloud that would cool the surface.”

Of course, programs such as this predate that. In 2018, the journal Environmental Research Letters had a study from a pair of researchers at Harvard and Yale that proposed the idea of “stratospheric aerosol injection.” It notes a body of research on the concept, mainly from 10 to 20 years ago, but also notes there was a proposal as well from the National Academies of Science in 1992.

LiveScience noted in 2018 that a program to “Spray Cheap Chemicals in the Air to Slow Climate Change” would be surprisingly cheap. It would cost about $3.5 billion over the course of about 15 years. Once it’s ready to go, it would cost another $2.25 billion each year.

It notes that if the solar dimming chemicals were sprayed in the stratosphere, the effect would last for a year to 18 months.