Carbon emissions are drawn deep into the Southern Ocean by plunging currents, scientists have found, challenging the idea that carbon is locked away from the atmosphere by being absorbed across vast areas of ocean.
The team of scientists from the British Antarctic Survey and CSIRO found carbon makes its way into the sea through funnels created by a combination of winds, currents and massive whirlpools which carry warm and cold water around the ocean.
This carbon capture process occurs in well-defined regions in the Southern Ocean, which the researchers have mapped.
The findings are published today in Nature Geoscience.
“The Southern Ocean is a large window by which the atmosphere connects to the interior of the ocean below,“ said lead author Dr Jean-Baptiste Sallée from the British Antarctic Survey.
“Until now we didn’t know exactly the physical processes of how carbon ends up being stored deep in the ocean,” he said.
The team explored the workings of the ocean with the help of small robotic probes, known as Argo floats, which dive to depths of two kilometres. The researchers also analysed temperature, salinity and pressure data.
Study co-author Dr Richard Matear from CSIRO’s Marine and Atmospheric Research division said the investigators focused on how carbon was transferred from the surface layer into the ocean interior because “the process sets how much carbon the ocean can take up,” he said.
“The ocean plays a really important role in the uptake of our anthropogenic carbon emissions. About a quarter of our CO2 emissions end up in the ocean and the Southern Ocean accounts for almost half (40%) of that number.”
The map of carbon capture in the Southern Ocean will be used to model climate change projections and help assess potential methods to increase the ocean’s carbon capture.
Carlos Duarte, Director of the University of Western Australia’s Oceans Institute, said the Southern Ocean was known as a carbon sink, but until now “the suite of processes responsible for this sink was poorly understood”.
Professor Duarte said the findings would give researchers a better grasp of the role the Southern Ocean played in the uptake of CO2 by the ocean. “The new estimate will not alter the global estimate, which is independently constrained, but gives a quantitative understanding of the processes involved,” he said.
“Researchers will now be able to explore possible changes in this role as ocean dynamics change – not just from climate change, but from other impacts such as changes in atmospheric circulation over the Southern Ocean, driven by the depletion of the ozone layer over Antarctica.”
Derek Bolton
Retired s/w engineer
Referring to it as "capture" could be a bit misleading. Yes, it gets it out of the atmosphere, and by transporting it to depth avoids near-term acidification of surface layers. But if nearly all the CO2 drawn down this way remains as dissolved CO2 it only delays the problem.
Gerald Wilhite
logged in via Facebook
Delay is good, especially when you are dealing with complex things that are not well understood by everybody. According to the June 2012 data from Hadley Centre of the UK Met Office and the Climatic Research Unit (CRU) of the University of East Anglia, we haven't experienced any global warming since 1997. Check it out. Here's the link to a interesting graph showing temps versus CO2:
http://thegwpf.org/the-climate-record/6272-massive-human-co2-emissions-still-unable-to-reverse-natures-global-cooling-over-last-15-years.html
Derek Bolton
Retired s/w engineer
Yes, delay is good, but it's important to understand that that's all it is. It doesn't make the problem go away.
David Boxall
logged in via Facebook
Gerald Wilhite: "Here's the link to a interesting graph ...". And the link is to:
The Global Warming Policy Foundation (GWPF), a United Kingdom group opposing action to mitigate climate change. In other words, a climate science denial site.
Gary Murphy
Independent Thinker
Here's a link to recent increases in oceanic heat content (esp. 0-2000m).
http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/
David Arthur
n/a
gwpf? You mean Nigel Lawson's "Global Warming Policy Foundation", the subject of the 21 October 2011 Guardian article "Lord Lawson's Global Warming Policy Foundation is spreading errors" (http://www.guardian.co.uk/environment/2011/oct/21/lord-lawson-global-warming-errors).
"The former chancellor is an avowed climate sceptic – and the 'facts' he repeats are demonstrably inaccurate".
Bruce Moon
Bystander!
Derek
If you want to question the word 'capture', try looking at this vid of the extreme southern ocean...
http://www.youtube.com/watch_popup?v=T4FIS1FnOQg
Cheers
Derek Bolton
Retired s/w engineer
Great video, but I don't get the relevance to my comment. You'll need to be less subtle.
Gil Hardwick
Anthropologist
Let's not worry too much about wording for the moment, what is really very important here is new knowledge on the processes at work.
That's what matter right now, else we have no way to plan effectively or put in place amelioratory preocedures.
Failing that we will remain forever helplessly subject to the hysterics constantly whinging and complaining - the 'ethicists' with their perpetual bitching and moaning - worse than anything else we are ever likely to experience.
I'd sooner see the planet die that have to put up with much more of it.
David Boxall
logged in via Facebook
Gil Hardwick: "I'd sooner see the planet die...". Be careful what you wish for, you just might get it.
David Arthur
n/a
Gil's had his quarter century of academic publishing success; perhaps he is not overly concerned for the planet subsequent to his departure. (Change what you can, accept what you can't, and know the difference; Gil's mind, for one, is not to be changed (:-)) ).
Michael Brown
Professional, academic, company director
I always find it interesting that climate reserachers are able to analyse and project global warming down to fractions of a degree, but then they regularly put out new studies saying things like "until now the suite of processes responsible for this sink was poorly understood”. It would be useful if they would list right now all the critical processes that are poorly understood.
That may explain the recent divergence between atmospheric CO2 and temperature trends, the lack of change in Antarctic sea ice, the very low global tropical storm activity, the flat ocean temperatures, the slowing of sea level rise, and all the other real world findings which are contradicting so many of their predictions. Perhaps they really don't know enough about the underlying processess to make any accurate projections at all. And when will they move on from "projections" to "forecasts" and "predictions"?
Gary Murphy
Independent Thinker
Flat ocean temperatures? Check out the recent 0-2000m oceanic heat content increases.
http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/
Here's the sea level rising: http://sealevel.colorado.edu/
Antarctic Temperatures
http://en.wikipedia.org/wiki/File:Antarctic_Temperature_Trend_1981-2007.jpg
from http://en.wikipedia.org/wiki/Climate_of_Antarctica
David Arthur
n/a
"recent divergence between atmospheric CO2 and temperature trends"
1. 1998 was an El Nino year, 2011 was a La Nina year
2. 1998 was before large-scale Chinese emissions of sulfate aerosols, 2011 was later on.
3. 1998 was before large-scale polar ice melting, 2011 was later on.
"lack of change in Antarctic sea ice"
Read moreto the extent that it isn't changing, Antarctic sea ice is being maintained by acceleration of ice off terrestrial Antarctica. After some decades of ice accumulation on terrestrial…
Lincoln Fung
Economist
If ocean can absorb CO2 in that way, then instead of the current research on much more costly CO2 capturing and storing underground technologies, perhaps studies should be undertaken to explore how make the CO2 (from power generations or large concentrations of some other CO2 producing processes) pass through water to be captured and and stored in water to be either put into the ocean or used in irrigation.
Would that be a feasible project or idea to deal with CO2 emissions?
Derek Bolton
Retired s/w engineer
Lincoln, thank you for neatly illustrating the point in my first post on this article. Having the oceans 'capture' the CO2 as dissolved CO2 (as opposed to depositing organically captured CO2 in sediments) is not a solution to the problem. It merely delays the effects of the problem at the earth's surface (and correspondingly extends the time it will take to restore normal conditions if and when we eliminate CO2 emissions). At the same time it might accelerate impacts on life in the deeper ocean.
David Arthur
n/a
A fair question, Lincoln, except that capturing CO2 in water causes the water to become more acidic.
Before the usual horde of drongoes point out that the oceans are slightly alkaline and therefore can't become more acidic, perhaps it should be explained that the terms "more acidic" and "less alkaline" mean, in water-CO2 systems, EXACTLY THE SAME THING.
There's a useful explanation of water-carbonate chemistry at http://research.nmsu.edu/molbio/bioinfo/tutorials/env-engr/carbonate/carbonate.html
David Arthur
n/a
Could Prof Duarte and Dr Matear comment on the suggestion (eg Lovelock and Rapley letter published in Nature 2007) that large vertical pipes with one-way valves be deployed in tropical oceans to transport nutrient-rich deep water back up to the surface, with the intention of enhancing primary productivity?
One objection to this may be that deep water is CO2-rich, and bringing it back to the surface may cause CO2 transfer back to the atmosphere; I'd suggest that carbon fixing by primary productivity has the additional benefit of increasing biomass, for which carbon ultimately would be drawn down from the atmosphere.
Dean Ashby
Company Owner at Ezestore Storage Sydney
Yes Derek Bolton, I agree both “capture” and “storage” can be quite misleading as it doesn’t really make the problem go away. The fact of the matter is that manufacturing is on the rise around the world and so more greenhouse gases are released, and that is happening here in Australia. The best way is of course to reduce greenhouse emissions in the first place by reducing all our consumer needs. However, that being said, I suppose carbon capture and storage is the best solution right now as we speak.
Mark S
Self Storage Franchisee at Archive Storage
With such info, researchers are able to see the depth of the carbon storage deep under the ocean. That will give them the opportunity to search for means and methods to pump more carbon under the ocean to tackle our plunging carbon emissions rate. However, intense research needs to be completed to ensure the sustainability of the process and derive with the conclusion whether or not the underground carbon storage will last for a long period of time.