Normally such carbon drawdown would simply get recycled back into the air, as bacteria or animals consumed the plant material and breathed the carbon out. But with the right conditions, masses of Azolla could have sunk quickly to the ocean bottom and been buried before decomposing, constituting a one-way transfer of carbon from the atmosphere into the earth. As its blanket of carbon dioxide thinned, Earth rediscovered the joys of glaciers and ice caps.
