Researchers at Harvard and Yale have proposed a novel and unorthodox method to combat global warming: spraying Sun dimming sulfates into the lower stratosphere.
This technique is called stratospheric aerosol injection, and the scientists proposing it have said it could cut the rate of global warming by half. Sulfate particles would be sprayed into Earth’s atmosphere at heights of as much as 12 miles. Delivery will be carried out using specially designed aircraft, balloons or naval style guns. Researchers have argued that developing a new, purpose-built tanker with substantial payload capabilities would neither be technologically difficult nor prohibitively expensive. They have estimated that the launching cost of the project would be $3.5 billion, and that it would have a running cost of $2.25 billion over a 15-year period.
Regardless, the researchers have acknowledged in their report that so far, this is a purely hypothetical exercise.
The method would also come with many risks and complexities. Coordination between multiple countries all over the globe would be required. Crop yields could be jeopardized and the sulfate content in the atmosphere could lead to droughts or other undesirable weather conditions.
For these reasons, there are many skeptics who have questioned the proposed technique. “The problem with engineering climate in this way is that it’s only a temporary Band-Aid covering a problem that will persist essentially forever, actually hundreds of thousands of years for fossil fuel carbon dioxide to finally go away naturally,” says David Archer of the Department of Geophysical Science at the University of Chicago. “It will be tempting to continue to procrastinate on cleaning up our energy system, but we’d be leaving the planet on a form of life-support. If a future generation failed to pay their climate bill they would get all of our warming all at once,” he added.
The study proposing the sun dimming technique was published in the journal Environmental Research Letters on November 23.