What if we could engineer the ocean to absorb more carbon dioxide? What if we could cool the planet, not with emissions cuts alone, but by enhancing the ocean’s natural carbon cycle?

From ocean alkalinity enhancement and iron fertilization to artificial upwelling, ocean geoengineering ideas are growing louder in scientific circles—and raising serious questions in ethical and policy debates.

Today, we’ll unpack the science, explore the risks, and ask: Is this humanity’s Plan B—or a Pandora’s box?