Microsoft founder Bill Gates recently invested in a drastic approach to lowering the surface temperature of the earth, solar geoengineering. Along with other individuals and 14 companies, he helps to fund the Stratospheric Controlled Perturbation Experiment (SCoPEx) at Harvard University. The study has raised a total of $16,225,000 as of August 2019.

What is solar geoengineering?

Solar geoengineering relies on the idea that all of the heat on the earth is from the sun. Certain gasses in the atmosphere keep the heat near the planet. Gasses like carbon dioxide, in this sense, act as insulators, keeping the heat close to the earth instead of letting it escape. gasses like carbon dioxide trapping solar heat in the earth’s atmosphere too well creates the climate change trend.

From this background, two paths of dealing with climate change can be discerned. One is to reduce carbon emissions. This would decrease the amount of it that is in the atmosphere trapping solar heat. The other is to change the amount of solar heat that the earth and the surrounding atmosphere absorb initially. This is the path that solar geoengineering pursues.

To decrease the amount of solar heat that the earth absorbs, a plane would release small particles into the stratosphere, about 50 km above the earth’s surface. These particles will reflect a portion of the sunlight, theoretically creating cooler surface temperatures. However, while many researchers have run simulations, this has never been tried in the actual atmosphere. They have not yet determined the most beneficial article to use, either.

The SCoPEx Project

Later next month, the group anticipates running its first real-world experiment. While computer simulations can be highly accurate, the environment is extremely complex. Thus, running small-scale tests is an essential step before deploying this strategy on a scale that could impact worldwide temperature.

This will involve, per the research website, using a “high-altitude balloon to lift an instrument package approximately 20 km into the atmosphere.” The machine will then release approximately 2kg of naturally occurring chemicals like calcium carbonate and sulfates into the air. The release of these chemicals will create a “perturbed air mass” approximately one kilometer long and 100 meters across. This will allow for measurement of this theoretical idea in a real-world setting. Researchers will outfit the balloon with equipment to measure “aerosol density, atmospheric chemistry, and light scattering.” After particles are released, researchers will use these pieces of equipment to measure the effectiveness of this tactic.

Ethical Issues

Such a large amount of particles would have to be dispensed that they would spread to cover the entire atmosphere. Thus, this strategy would affect all countries and people on earth. All nations would have to consent in order for this strategy to be used fairly. If the particles were released into the atmosphere without the consent of all countries, it could create tension between nations, or even incite war.

Additionally, many condemn this idea as a lazy approach to dealing with climate change, because it does not address the ultimate cause of the crisis: pollution. Thus, solar geoengineering would have to be used continuously, constantly releasing more and more particles to reflect sunlight, if carbon emissions are not curbed. If carbon emissions continue at their current rates, geoengineering couldn’t be stopped without temperatures rising several degrees as soon as there weren’t particles in the atmosphere anymore.