Plankton - The planet's largest CO2 storage 'store'

According to a study just published on February 14 by the Organization for the Advancement of Space and Earth Sciences (AGU), based in Washington, USA, the sea is the Earth's largest "storage" of CO2. , but not land or plants. This research is a project of the International Ocean Discovery Program (IODP).

Plankton in sea water.

The scientists studied plankton's ability to permanently store CO2 in the oceans around Zealandia - a continent with 94% of its area under the sea, the remaining 6% including the islands of New Zealand and New Zealand. Caledonia. They found that the amount of CO2 stored was equivalent to the amount of CO2 released into the environment in the area. In prehistoric times, the percentage of CO2 stored was even higher - demonstrating the possibility

"Plankton species are the planet's largest CO2 stores," the study claims.

To get there, the team drilled into the bottom of Zealandia to survey how the continent formed, and analyze environmental changes recorded in its sediments.

The two scientists involved in the study were analyzing seawater samples collected from the oceans around Zealandia.

"Sucking" CO2 to the bottom of the ocean

Most of the organic carbon released from the carcasses of animals, plants, and algae is "eaten" by bacteria in both the ocean and the forest land. In the sea, plankton make up the vast majority. When they die and sink, the CO2 absorbed by their bodies will be stored in the deep sea.

Besides, their carcasses when falling to the sea floor will help form chalk and limestone, with the main ingredient being calcium carbonate (CaCO3). These two rocks have a huge capacity to store CO2.

Research shows that the rate of formation of chalk and limestone from plankton remains is 20 tons/km2/year. Zealandia's area is about 6 million square kilometers, meaning 120 million tons of chalk and limestone are formed each year, and 53 million tons of CO2 are stored. This is equivalent to, or even more, the CO2 emissions from fossil fuel combustion in the region today (CO2 emissions in New Zealand and surrounding islands are 45 million tons per year, or 0.12 percent. % of total global CO2 emissions).

Two scientists involved in the study were discussing sediment samples collected at the sampling table.

Scientists predict that the formation of chalk and limestone from plankton remains will likely increase in the future.

"As the oceans warm, more CaCO3 will be formed, although ocean acidification will certainly occur," said Professor Rupert Sutherland from Victoria University of Wellington (New Zealand), one of the scientists. study participants, said.