Could salt help soothe our climate woes? Senior scientist Robert Nelson of the Planetary Science Institute seems to think so. At a recent Lunar and Planetary Science Conference in Texas, Nelson suggested that sprinkling salt above clouds could hold off sunlight and cool our planet, according to Science Magazine. But as with many geoengineering ideas, this one isn’t without controversy.
Finely powdered salt injected into the upper troposphere might help humanity stave off some of the impacts of climate change, according to Nelson. His suggestion isn’t too far off those of other scientists who want to introduce microscopic particles into the stratosphere to reflect sunshine into space, imitating the impact of volcanic eruptions that have served to temporarily cool Earth. But his might be more benign than others, Science Magazine said. The senior scientist tossed out alumina or sulfur dioxide: the first could lead to chronic disease, embedding in our lungs if we inhaled it; the second could lead to acid rain or erode the ozone layer.
Instead, he turned to salt: it’s more reflective than alumina, according to Science Magazine, and harmless for people. Nelson also thinks if salt were crushed into tiny particles in the correct shape and diffused randomly, the mineral wouldn’t block infrared heat the Earth releases.
Volcanologist Matthew Watson of the University of Bristol is one scientist who has called out potential problems with Nelson’s approach. He led an ultimately canceled geoengineering experiment, in which his team considered injecting salt in the stratosphere. But the substance contains a lot of chlorine, which he said could help destroy ozone. With limited amounts of water in the stratosphere, and salt so attracted to it, even a small amount could impact the formation of wispy clouds; we have know idea what consequences this would trigger.
Nelson might be able to address issues by injecting salt into the upper troposphere instead of the stratosphere — at least, that’s what he hopes. But he said we should still work to curb carbon emissions, saying, “This would be a palliative, not a [long-term] solution.”
Via Science Magazine