The climate crisis is the challenge of our time. Its effects are all around us, from coral bleaching to freak weather and mass extinctions. The clock is ticking closer to the hour where avoiding the dire consequences may no longer be feasible. While there is a need for bold political action and serious social change, scientists are also investigating technical solutions, such as carbon capture.

The most controversial branch of these solutions is known as geoengineering. The idea is that given the little time we have and the even less political will to change things, we might have to conduct global-scale alterations to our planet to stop the climate crisis – and many of these projects could have severe repercussions.

Last week, Harvard took an important step. The American university announced the formation of a committee to oversee the safety and feasibility of the geoengineering project Stratospheric Controlled Perturbation Experiment (SCoPEx). The project is backed by Bill Gates, the Hewlett Foundation, the Alfred P. Sloan Foundation, as well as university grants and donations from other groups and individual contributors.

SCoPEx would ideally test a way to cool down our planet by releasing aerosols (small particles) into the stratosphere. The aerosols would, in theory, increase our planet's albedo, thus increasing the amount of light reflected by the Earth back into space before it warms our planet.

The solution is inspired by the volcanic eruption of Mount Tambora (Indonesia) in 1815. The intense eruption released an incredible amount of volcanic ash, droplets of sulfuric acid, and water into the atmosphere, obscuring the Sun and creating a global cooling event. For exactly this reason, 1816 was known as the "year without summer".

On paper, such an approach seems to work to cool the atmosphere, at least for a short time. Studies looking at sulfur droplets suggest it only stays in the atmosphere for a few years, unlike carbon dioxide that can hang around for a century.

On top of that, there are possibly some serious consequences for species here on Earth. As reported in Nature Ecology & Evolution, this type of solar geoengineering could spell doom for many animals. It also doesn’t fix issues like the acidification of the oceans due to carbon dioxide – in fact, it might exacerbate it. The sulfur might also destroy the ozone layer.

SCoPEx, therefore, is designed to investigate the impact of releasing aerosols into the stratosphere and whether or not it is possible to create an aerosol that has little physical risks.

“I know that reducing greenhouse gas emissions and creating robust, resilient natural systems, infrastructure, and communities must remain the top priorities to address this challenge and give us our best hope for the future,” chair of the new Harvard committee Louise Bedsworth said in a statement.

“Yet, I am also aware that as the effects of climate change worsen, solar geoengineering may be looked to as a tool to mitigate these effects. I believe responsible, accessible, and transparent research is needed to understand the technical, political, and societal implications of solar geoengineering and to support informed decisions around deployment if such decisions become necessary.”

[H/T: MIT Technology Review]