Marine Cloud Brightening

Facts for Prelims

Marine Cloud Brightening

Context: The concept of marine cloud brightening is gaining prominence recently as a tactic for addressing extreme ocean heat and as a way to reduce coral bleaching and safeguard marine ecosystems.

About:
• The concept of cloud brightening traces back to British cloud physicist John Latham, who proposed this idea in 1990 as a means to control global warming by altering the Earth's energy balance.
• Latham's calculations suggested that brightening clouds over vulnerable ocean regions could counteract the warming caused by a doubling of pre- industrial atmospheric carbon dioxide.

Mechanism:
• In clean maritime air, clouds primarily form from sulfates and sea salt crystals, which are relatively scarce, leading to larger droplets with lower light reflection.
• Marine cloud brightening (MCB) seeks to boost marine cloud reflectivity (albedo), making clouds whiter and brighter.
• It involves using water cannons or specialized vessels to release fine sea water droplets into the atmosphere.
• As these droplets evaporate, they leave behind salt particles, serving as cloud condensation nuclei that foster the formation of denser, brighter clouds.