UNIVERSITY OF EXETER
The world’s oceans soak up more carbon than most scientific models suggest, according to new research.
Previous estimates of the movement of carbon (known as “flux”) between the atmosphere and oceans have not accounted for temperature differences at the water’s surface and a few metres below.
The new study, led by the University of Exeter, includes this – and finds significantly higher net flux of carbon into the oceans.
It calculates CO2 fluxes from 1992 to 2018, finding up to twice as much net flux in certain times and locations, compared to uncorrected models.
“Half of the carbon dioxide we emit doesn’t stay in the atmosphere but is taken up by the oceans and land vegetation ‘sinks’,” said Professor Andrew Watson, of Exeter’s Global Systems Institute.
“Researchers have assembled a large database of near-surface carbon dioxide measurements – the “Surface Ocean Carbon Atlas” (http://www.socat.info) – that can be used to calculate the flux of CO2 from the atmosphere into the ocean.
“Previous studies that have done this have, however, ignored small temperature differences between the surface of the ocean and the depth of a few metres where the measurements are made.
“Those differences are important because carbon dioxide solubility depends very strongly on temperature.
“We used satellite data to correct for these temperature differences, and when we do that it makes a big difference – we get a substantially larger flux going into the ocean.
“The difference in ocean uptake we calculate amounts to about 10 per cent of global fossil fuel emissions.”
Dr Jamie Shutler, of the Centre for Geography and Environmental Science on Exeter’s Penryn Campus in Cornwall, added: “Our revised estimate agrees much better than previously with an independent method of calculating how much carbon dioxide is being taken up by the ocean.
“That method makes use of a global ocean survey by research ships over decades, to calculate how the inventory of carbon in the ocean has increased.
“These two ‘big data’ estimates of the ocean sink for CO2 now agree pretty well, which gives us added confidence in them.”
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The authors of the paper include scientists from Herriot-Watt University, the University of the Highlands and Islands, and from the Max Planck Institute in Germany .
Funders of the study included the Royal Society, the Natural Environment Research Council and the European Space Agency.
The paper, published in Nature Communications, is entitled: “Revised estimates of ocean-atmosphere CO2 flux are consistent with ocean carbon inventory.”
HT/Latitude and Yooper
It is so comforting to see another bit of ‘Settled’ Science veering sharply off the rails and falling into disuse.
Models, wrong again?
How did the ocean part of the carbon cycle work during the Mesozoic (250-65 million years ago) with 1000-2000 ppm CO2? The biosphere was in vibrant health on land and sea. Where was the carbon apocalypse? How were the carbon “sinks” not “overwhelmed”?
I guess a Brontosaurus was a carbon sink.
All these carbon cycle stories are short-sighted, fantastical and inconsistent with the evidence of palaeo-history.
And no – the “dim sun” lower past insolation won’t play a role as recently as the Mesozoic.
Charles,
This paper is Watson et al 2020.
As the post here notes, it is indicating that Ocean Carbon uptake is widely underestimated because of a realisation that temperature variations impact the oceans ability to absorb atmospheric CO2.
The next issue is how this paper relates to Friedlingstein et al 2019, “ Global Carbon Budget 2019”.
That paper is the successor to the Le Quere et al papers on the Global Carbon Budget from 2008 to 2018.
Friedlingstein et al 2019 already noted “ (3) an apparent underestimation of the CO2 variability by ocean models outside the tropics”.
Watson et al 2020 must reopen the entire issue of the Carbon Budget, surely.
And the reaction by climate scientists to date…….?
Here’s the paper:
https://www.nature.com/articles/s41467-020-18203-3.pdf
Jim Steele,
Thanks again for further reducing my ignorance about pH and CO2 in the ocean. Appears that my error was confusing modeled with observed results.
copy
The claim pH fell by 0.1 for 200 years is the result of models that do not consider the biological impacts and simply model the effect of higher atmospheric concentrations assuming an equilibrium develops.