Cloud brightening is a climate control approach that uses the spraying a fine mist of sea water into clouds to make them ‘whiter’, so that clouds reflect more sunlight back into space. The effect could lead to a reduction in surface water temperatures by around half a degree Celsius.
An article in Digital Journal reviewed research, from NUI Galway’s Centre for Climate & Air Pollution Studies, that dismissed the cloud brightening is because of increased levels of sulfate in the atmosphere.
The research presented the view that sea salt entering the atmosphere through vertical updrafts negate the cloud brightening effect. To support the model, scientists collected and analyzed data from a vessel sent to Antarctica. This expedition provided a sufficiently large clean air to allow results to be compared to measurements made in more polluted areas.
Commenting on the research, SilverLining Executive Director Kelly Wanser tells Digital Journal: “Marine cloud brightening relies on natural processes to cool the atmosphere by adding optimally-sized salt particles to clouds that are most likely to deliver a brightening effect.”
The technology needs to be targeted to the right location, Wanser says. “Because of this, it is not proposed for areas with high existing aerosol concentrations—whether from sea-salt, organic sources, or man-made emissions—like the Antarctic region that is the focus of the study.”
She adds further: “As the study points out, new aerosols would compete with existing ones, reducing any brightening effect. The study includes some interesting findings, but it is not suitable for drawing conclusions about the viability of marine cloud brightening as a broader climate intervention technique.”
SilverLining, a non-profit, focuses on driving research on strategies to ensure safe pathways for climate within a decade, including cloud brightening technologies.