Diatoms are tiny one-celled algae, too small to see with the naked eye. These minuscule organisms are masters of capturing carbon dioxide from the environment, and so productive and prolific that they fix up to 20% of the Earth’s CO2. According to a recent research paper, they are one of the world’s most powerful resources for removing CO2 from the atmosphere, absorbing an estimated 10-20bn tonnes every year, equal to the amount of carbon captured annually by all of the world’s rainforests. And as an added bonus, they also give off oxygen as a byproduct of photosynthesis.
Diatoms float in surface waters of oceans where they use sunlight to turn carbon dioxide into compounds used for their growth and development. They are particularly efficient at concentrating the CO2 captured inside their cell, which helps to explain how they fix so much carbon.
When the diatoms die, they sink to the ocean floor and become sediment, in effect locking the carbon away. Alternatively, the diatoms are eaten by other sea creatures such as whales, and the carbon ends up in the animals’ droppings that also fall to the ocean floor and become buried.
