Giving Compass' Take:

• Michael Keller explains how the ocean acts as a CO2 sink, taking in as much as 34 gigatonnes of human-made carbon from the atmosphere between 1994 and 2007.

• How can this information inform the work of climate and environmental funders? 

• Learn how carbon in the ocean leads to ocean acidification. 

Researchers have determined how much human-made CO2 emissions the ocean took up between 1994 and 2007.

Not all of the CO2 that the combustion of fossil fuels generates remains in the atmosphere and contributes to global warming. The ocean and the ecosystems on land take up considerable quantities of these human-made CO2 emissions from the atmosphere.

The ocean takes up CO2 in two steps: first, the CO2 dissolves in the surface water. Afterwards, the ocean’s overturning circulation distributes it: ocean currents and mixing processes transport the dissolved CO2 from the surface deep into the ocean’s interior, where it accumulates over time.

This overturning circulation is the driving force behind the oceanic sink for CO2. The size of this sink is very important for the atmospheric CO2 levels: without this sink, the concentration of CO2 in our atmosphere and the extent of anthropogenic climate change would be considerably higher. Determining what share of the human-made CO2 the oceans absorb has long been a priority for climate researchers.

As reported in Science, the researchers found that the ocean took up as much as 34 gigatonnes (billions of metric tons) of human-made carbon from the atmosphere between 1994 and 2007. This figure corresponds to 31 percent of all anthropogenic CO2 emitted during that time.

Read the full article about the ocean as a CO2 sink by Michael Keller at Futurity.