Geoengineering describes the large-scale use of technology to manipulate the Earth system. Geoengineering strategies are currently gaining attention as possible ways to avert the undesirable consequences of climate change. One of the most plausible geoengineering ideas is known as “solar radiation management”, which proposes to offset global warming by reflecting away a portion of incoming sunlight. The easiest way to do this would be to fly a bunch of airplanes into the stratosphere to release sulfate aerosol particles. These particles would reflect away sunlight and, perhaps, could help us to avoid what would otherwise have been a climate disaster.

In a recent paper published in Ethics, Policy and Environment, on which I am a co-author, we discuss how scientific study of geoengineering is intertwined with the ethics of geoengineering. For example, if we decide that geoengineering is a fundamentally bad idea–perhaps because it could cause political turmoil or perhaps because we disagree with the idea of intentionally altering our atmosphere–then we should move on to other potential solutions to the climate problem. If we do decide that geoengineering is at least worth discussing, then we need to be careful to identify when scientific decisions are also ethical decisions. An experiment that seeks to test the effects of geoengineering over a small region will necessarily affect the local environment; whether or not such an experiment should occur is a question of ethics, not science. If geoengineering remains on the table, then these ethical issues carry as much importance as the scientific know-how. Perhaps we should therefore create an international board for the ethical, social, and legal implications of geoengineering so that our science doesn’t get too far ahead of our conscience.