Rainforests have been labelled as the lungs of Earth because of their role in soaking up carbon dioxide and releasing oxygen into the atmosphere which are used by all plants and animals.

Despite rainforests generating around a third of Earth’s oxygen, it is our oceans that are the biggest producer of oxygen. Oceanic plankton which include drifting plants, photosynthesising bacteria and algae, absorb carbon dioxide and sunlight to produce sugars, with oxygen being released as a by-product.

Climate change will also threaten our oceans, we need to preserve them today

Oceanic plankton have been doing this for billions of years, much longer than terrestrial plants. One important species of phytoplankton alive today is the Prochlorococcus. It has been calculated that the oxygen in one of every five breaths we take is produced by the Prochlorococcus. This microscopic organism contributes to 20 per cent of the oxygen in our living ecosystem which is more than Earth’s tropical rainforests can produce.

So, perhaps oceans are the lungs of the Earth? Despite their small size, oceanic plankton have a big role in maintaining life on Earth and their importance should not be underestimated. Climate change will also threaten our oceans, we need to preserve them today.