The idea of ”geoengineering” as a response to the dangers of climate change involves putting particles, perhaps sulfur, into the atmosphere to counteract the effects of carbon and other warming gases. The idea is controversial. One side emphasizes the dangers of tinkering with the climate. In fact, the 2013 film Snowpiercer and Follow-up TV Show Imagine a future where geoengineering to offset global warming goes too far and leads to an ice age. On the other hand, if you believe that the dangers of climate change are immediate and enormous and that efforts to reduce carbon emissions on a global scale are insufficient, then the logic of that position forces you to consider alternatives you might not otherwise favor, from geoengineering to a renaissance in nuclear energy. (For previous posts on geoengineering over the past decade, see here , here , here , and here .)
But likewise Increase Emissions of sulfur into the atmosphere would be a form of geoengineering to curb the risks of climate change. Diminish Sulfur emissions into the atmosphere would be a form of geoengineering that increases the risks of climate change. In 2020, the International Maritime Organization agreed to reduce sulphur emissions from ships. The goal was to reduce existing air pollutants related to sulphur in port cities, and from that perspective, the policy was a huge success. But from a climate change perspective, the policy may have made the problem worse. Syris Valentine tells the story in an easy-to-read way, linking it to basic science research.“When Shipping Cut Its Sulfur Emissions, It Became an Accidental Experiment in Geoengineering” subtitled “How Cleaning Up Shipping Could Cut Pollution and Warm the Planet” (grainJuly 18, 2024).
Marine sulphur emissions have been reduced by 80%. Studies conducted before the program was adopted estimated that this reduction could save at least 500,000 lives over the next five years, mainly in port cities around the world, which account for the majority of these emissions.
On the other hand, several studies have suggested that the reduction in sulfur in the atmosphere could alter cloud patterns and double the amount of global warming over the next decade. For those who want more details on the evidence, here it is. A prominent study published in Atmospheric Chemistry and PhysicsIn another study, Communication Earth and Environment. As you might expect, the research results in this area are not entirely consistent. Here are some: Pre-print, awaiting review, Studies have found smaller effects.
A group of seven researchers are concerned enough about this issue to publish it. An open letter to be published in the journal Oxford Open Climate Change, The International Maritime Organization has been asked to change its rules to allow ships to continue to emit more sulphur when they are on the high seas, away from populated areas. The idea is to keep sulphur in the air to offset the warming effects of carbon emissions while reducing sulphur emissions near port cities, which would provide immediate health benefits.
The practical conflict here is real, as is the difficulty of thinking about geoengineering. If you favor an immediate, do-everything-now, all-hands-on-deck approach to tackling the dangers of climate change, then it makes sense to continue with the forms of geoengineering that have existed before, namely, ships emitting sulphur while they are away from land. If you oppose this form of geoengineering, even though the practice of ships emitting sulphur into the atmosphere has existed for decades, then you are willing to accept that the need to reduce atmospheric carbon levels must be balanced against other environmental concerns.
