concept

CLAW hypothesis

An ocean negative-feedback loop proposed in 1987, named for its authors' initials (Charlson, Lovelock, Andreae, Warren). Marine plankton, under heat and light stress, release a sulphur compound that escapes to the air and seeds cloud droplets. More plankton, more cloud-seeds, more cloud - and clouds are bright, reflecting sunlight back to space and cooling the sea surface. Warm the ocean and the plankton bloom and brew more cooling cloud; cool it and they retreat and let more sun through - life reaching up to adjust the planet's albedo, exactly as the white daisies did. Lovelock later worried about its dark twin: warm the ocean too far and the plankton collapse rather than bloom, the cooling clouds fail, and the feedback flips from stabilising to runaway.