A Harvard physicist recently proposed an interesting way to cool the earth — brighten the sea. Russell Seitz wants to pump bursts of tiny bubbles into the ocean. Seitz reasons that because bubbles increase water’s reflectivity, injecting tons of extra bubbles into the sea will lower water temperatures and help cool the planet. It may sound totally crazy, but Seitz says he has research to back up the idea.
The ocean’s natural bubbles already brighten water, producing an effect known as undershine. But because the bubbles aren’t plentiful compared to the amount of water on the planet, they contribute less than one-tenth of one percent of the Earth’s reflectivity (or albedo). Seitz says producing bursts of microbubbles that are about 1/500th of a millimeter in diameter essentially creates a mirror effect in water. Using computer models, the scientist found that microbubbles double water’s reflectivity even at a very low concentration of one part per million. He says the bubbles could cool the planet by up to three degrees Celsius and help conserve water by preventing evaporation in rivers and lakes.
To produce the bubbles, boats would need to use devices that mix water with compressed air. However, Seitz admits that generating microbubbles on a large scale might be difficult. A bubble’s lifespan depends on the amount of organic matter and nanoparticles in the water, so the strategy might not be successful in areas of ocean that are especially clean.
The idea is certainly interesting, but it does bring up some questions: Namely, what effect would all these extra bubbles have on sea life like fish, plankton, mammals and corals?