New research confirms that the cooler temperature of the ocean surface layer enhances CO₂ absorption, with the Atlantic absorbing 7% more CO₂ annually than previously estimated.
New research reveals subtle temperature differences at the ocean surface allow more carbon dioxide (CO₂) to be absorbed.
Scientists studied the “ocean skin” – a sliver less than 2 mm deep at the ocean surface that is fractionally cooler than the rest.
Theoretical and lab work have suggested this temperature difference should increase the amount of CO₂ absorbed by the ocean – but this had never been successfully observed at sea before.
Confirming the Role of Ocean Skin Temperature
The new study – led by researchers from the University of Exeter’s Penryn Campus in Cornwall – used precision measurements to confirm that the temperature of the ocean skin does indeed aid carbon absorption.
Carried out in the Atlantic, the findings suggest this ocean absorbs about 7% more CO₂ each year than previously thought. It might sound small, but when applied across all oceans this additional carbon absorption is equivalent to one and half times the carbon captured by annual forest growth in the Amazon rainforest.
The global ocean absorbs about a quarter of humanity’s carbon emissions, slowing climate change whilst also harming the ocean, and the new findings help improve our understanding of these processes.
“Our findings provide measurements that confirm our theoretical understanding about CO₂ fluxes at the ocean surface,” said lead author Dr Daniel Ford, from the University of Exeter.
“With the COP29 climate change conference taking place next month, this work highlights the importance of the oceans, but it should also help us improve the global carbon assessments that are used to guide emission reductions.”
Contributions to the Global Carbon Budget
And the team have now included this advancement within their data submission to this year’s Global Carbon Budget assessment.
The ship observations – from two European Space Agency projects – were taken by a CO₂ flux systems that measured tiny differences in CO₂ in air swirling towards the ocean surface and away again, along with high-resolution temperature measurements.
Until now, global estimates of air-sea CO₂ fluxes typically ignore the importance of temperature differences in the near-surface layer.
Dr Ian Ashton, also from the University of Exeter, said: “This work is the culmination of many years of effort from an international team of scientists. The European Space Agency’s support for science was instrumental in putting together such a high-quality measurement campaign across an entire ocean.”
Dr Gavin Tilstone, from Plymouth Marine Laboratory (PML), said: “This discovery highlights the intricacy of the ocean’s water column structure and how it can influence CO₂ draw-down from the atmosphere. Understanding these subtle mechanisms is crucial as we continue to refine our climate models and predictions. It underscores the ocean’s vital role in regulating the planet’s carbon cycle and climate.”
Reference: “Enhanced ocean CO2 uptake due to near-surface temperature gradients” by Daniel J. Ford, Jamie D. Shutler, Javier Blanco-Sacristán, Sophie Corrigan, Thomas G. Bell, Mingxi Yang, Vassilis Kitidis, Philip D. Nightingale, Ian Brown, Werenfrid Wimmer, David K. Woolf, Tânia Casal, Craig Donlon, Gavin H. Tilstone and Ian Ashton, 25 October 2024, Nature Geoscience.
DOI: 10.1038/s41561-024-01570-7
The study’s international partners included sea temperature measurement experts from the European Space Agency and the university of Southampton.
It was funded by the European Space Agency, Horizon Europe and the Natural Environment Research Council.
The ship cruises were part of the Atlantic Meridional Transect (AMT) project led by PML.
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6 Comments
“New research confirms that the cooler temperature of the ocean surface layer enhances CO₂ absorption, with the Atlantic absorbing 7% more CO₂ annually than previously estimated.”
Another recent article [ https://scitechdaily.com/scientists-were-wrong-plants-absorb-31-more-co2-than-previously-thought/ ] claims that plants absorb 31% more CO2 than is assumed in the models.
A slightly older study came to the surprising conclusion that coastal ecosystems are an unappreciated sink for CO2. [ https://scitechdaily.com/scientists-discover-that-coastal-ecosystems-are-a-net-greenhouse-gas-sink/ ]
So where does that leave us? All the numbers have changed. ‘Experts’ have piously told us that mass balance equations ‘prove’ that the increases in CO2 are anthropogenic because that’s how the numbers work out. However, I have been suspicious for some time that those working on the Carbon Cycle don’t have sufficiently robust measurements for the CO2 flux estimates for the ocean and have worked the other way. They have derived an estimated ocean flux by rearranging the mass balance equations using measurements of anthro’ emissions and measurements of more accessible terrestrial systems. So, I question whether the mass balance equations ‘prove’ what is claimed they prove.
So is it fair to say that all the climate models that didn’t take that into account – and that’s all models – are sh!t?
My guess is “yes”.
Climate models have performed quite well Boba. There is a recent article in the Harvard Gazette titled: Exxon disputed climate findings for years. Its scientists knew better.
The Subtitle is: Research shows that company modeled and predicted global warming with ‘shocking skill and accuracy’ starting in the 1970s.
Climate models produce the correct answer.
The only thing that the early academic and Exxon models had in common was a warming trend. However, in retrospect, few were even reasonable, let along accurate. I would define “accurate” as being able to predict temperature and precipitation to at least +/-10%, and preferably to +/-1%. Even the modelers have acknowledged the problem of models running warm, which has only gotten worse in the most recent versions. That is, it is generally acknowledged that all of the Western World’s models run warm, and the latest run even warmer.
Even Jim Hansen’s (in)famous 1988 model didn’t perform as well as a simple linear extrapolation would have: https://wattsupwiththat.com/2018/06/30/analysis-of-james-hansens-1988-prediction-of-global-temperatures-for-the-last-30-years/
Climate models DO NOT produce the correct answer. Only the Russian models even come close.
Where does that take us? Simple; the science is being improved. Once upon a time phlogiston was the rage. Ideas change and develop; that is science. Be grateful.
As for the anthropogenic bit; the rapid post- 1945 increase in atmospheric CO2 and other stuff matches the increase in post-1945 world population and increased use of hydrocarbon based energy, in particular aided by the rapid post-1972 increase in the use of natural gas.
One needs more than an apparent correlation, which may be spurious, to prove cause and effect.
You seem to be convinced that the “rapid post- 1945 increase in atmospheric CO2” is responsible for the recent increase in temperature. How do you explain the flat to declining temperatures in the ’60s and ’70s that caused some to be concerned about an impending ice age return? How do you explain the poor (often negative) correlation between CO2 throughout geological time? How do you explain the lack of an impact on the seasonal CO2 levels and temperatures during the 2020 COVID shutdowns when anthro’ emissions declined as much as 14-18% in the month of April alone, and at least 10% during the October-May ramp-up phase? Neither the slope, peak, or general shape of the 2020 CO2 ramp-up phase are distinguishable from the preceding or following year.
Where is the improvement that you praise if you deny the existing paradigm might be wrong?