Environment

Study suggests the ocean is soaking up twice as much CO2 as we thought

Study suggests the ocean is so...
New research suggests we may have been underestimating the role the ocean plays in soaking up CO2 from the atmosphere
New research suggests we may have been underestimating the role the ocean plays in soaking up CO2 from the atmosphere
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New research suggests we may have been underestimating the role the ocean plays in soaking up CO2 from the atmosphere
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New research suggests we may have been underestimating the role the ocean plays in soaking up CO2 from the atmosphere
Marine chemist Ken Buesseler on a research expedition in 2018
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Marine chemist Ken Buesseler on a research expedition in 2018

The world’s oceans play an important role in regulating the amount of carbon dioxide in the atmosphere by absorbing billions of metric tons of it each year. A new study suggests we may have been greatly underestimating the effectiveness of this vast carbon sink, with new modeling from scientists at Woods Hole Oceanographic Institution (WHOI) finding that the ocean’s “biological pump” is actually capturing twice as much CO2 as previously thought.

Just like forests, oceans act as a carbon sink by absorbing the gas through organisms that use it for photosynthesis. The phytoplankton that inhabit the seas engage in this process by using sunlight and carbon to produce food and energy.

The microscopic organisms then either die or are gobbled up by zooplankton, both of which will pull them deeper into the ocean and take their stores of carbon along for the ride. There they can become buried in sediment or eaten up by larger marine creatures. Overall, the oceans are thought to absorb around a third of the carbon dioxide emitted through human activity in this way.

But the WHOI scientists believe this “biological pump” may be pulling in a lot more carbon than we give it credit for. The team arrived at this conclusion by rethinking the way we calculate what is known as the euphotic zone, which is the section of upper ocean layer that sunlight is able to penetrate.

“If you look at the same data in a new way, you get a very different view of the ocean’s role in processing carbon, hence its role in regulating climate,” says WHOI geochemist Ken Buesseler.

Marine chemist Ken Buesseler on a research expedition in 2018
Marine chemist Ken Buesseler on a research expedition in 2018

Instead of relying on measurements taken at fixed depths, the scientists instead used data gathered from chlorophyll sensors, which reveal the presence of the phytoplankton and therefore the true edges of the euphotic zone. Following this analysis, the team concluded that the depths of this boundary vary around the world, and taking this into account the ocean absorbs around twice as much carbon each year than we had thought.

The team says if widely applied, this new understanding of the biological carbon pump can offer a clearer picture of how carbon emissions are impacting the climate, and how global policies can be implemented to mitigate its effects.

“Using the new metrics, we will be able to refine the models to not just tell us how the ocean looks today, but how it will look in the future,” Buesseler says. “Is the amount of carbon sinking in the ocean going up or down? That number affects the climate of the world we live in.”

The video below provides a summary of the research, while the paper was published in the journal Proceedings of the National Academy of Sciences.

The ocean's carbon pump works better than we thought!

Source: Woods Hole Oceanographic Institution

15 comments
vince
If the carbon sink is twice what we thought we might have a little more time before global warming turns catastrophic heh?
guzmanchinky
That's good news, but how long can our ocean keep it up? We need to get off fossil fuels for most applications asap, both for the environment and because electric cars are fast... :)
Rumata
They told only the half of the truth. It is true, that the oceans produce the 2/3 of the oxigen on the Earth. However, it is also true, that the CO2-level in the atmosphere is determined by temperature-dependent balance between of gaseous CO2-level in the atmosphere and solved CO2-level in oceans. At the moment this balance means that there is 50 times more solved CO2 in the oceans, than the amount of the gaseous CO2 in the atmosphere. Hence, the 98% of the 5ppm/year CO2-emission of the mankind is immediately soaked up by the oceans, and only 2% (0,1ppm/year) is left in the atmosphere, which is unmeasureably low. That's the reason, that the yearly amount of CO2-emission of mankind has no measureable effect on the yearly increase of atmospheric CO2-level. Even if we would burn all known fossil fuel reserve on the Earth, we could increase the CO2-level of the oceans and the atmosphere only by 11%, which is neglible. We should understand, that for short (<1000 year) terms, the atmospheric CO2-level is determined only by temperature-dependent balance between the solved CO2-level in the oceans and the gaseous CO2-level in the atmosphere. Fossil carbon burning and photosynthesis can have measureable effect on theatmospheric CO2-level only on long (>>1000 year) terms. And as the CO2-emission of the mankind has no measureable effect on atmospheric CO2-level, the CO2 emission of mankind cannot have any measureable effect on global average temperature. That's the ugly naked truth.
Worzel
The Oceans do not absorb ''carbon'' they absorb CO2 where carbon is locked to oxygen. No sensible person would refer to the oceans as ''hydrogen lakes,'' because that would be considered as somewhat foolish, as the hydrogen is locked to oxygen, in the form of water. However, the amount of anthropogenic CO2 in the atmosphere that is absorbed by the oceans is trivial, in comparison to the CO2 emitted by the estimated one million volcanoes, that erupt continuously along the various oceanic ridges. Its about the equal of a burp in a thunderstorm! So, gladly, there's no likelihood of the plant life of the world being wiped out from lack of CO2 in the immediate future.
PhilipKFreeman
I think the oceans can produce a lot more oxygen with the right stimulus .
paul314
We owe the oceans a lot of thanks, but this also means that disturbances to marine carbon cycles could have even more of an impact on climate than we think. If humans screw things up so that phytoplankton production (or consumption) drops, or downwelling ocean currents are reduced, we're in even more trouble than we thought we were.
Cryptonoetic
I find it incredible that this has been missed for half a century. So, is the science settled for real now? THE SCIENCE IS NEVER SETTLED!
Greg Mooney
I guess this means we are not going to die in 12 years. What will the doom-sayers turn to next? Never mind.
KennyReed
When these climate change discussions ramped up this topic was almost ignored and what data out there was limited and widely varied in quantities and time frames. It is good to see a good dose of reason and attention going to one of our natural healing mechanisms, the oceans. Only with precise data can we understand and solve our problems. Thanks for the article.
Douglas Rogers
The variability in the water band is the elephant in the room that is never talked about. 95% of the greenhouse effect on the Earth is due to water vapor and the variability in this exceeds the total effect of CO2 and methane.