From the University of Virginia, comes yet another incomplete press release that doesn’t give the name of the paper or the DOI:
Salt marsh carbon may play role in slowing climate warming, study shows
A warming climate and rising seas will enable salt marshes to more rapidly capture and remove carbon dioxide from the atmosphere, possibly playing a role in slowing the rate of climate change, according to a new study led by a University of Virginia environmental scientist and published in the Sept. 27 issue of the journal Nature.
Carbon dioxide is the predominant so-called “greenhouse gas” that acts as sort of an atmospheric blanket, trapping the Earth’s heat. Over time, an abundance of carbon dioxide can change the global climate, according to generally accepted scientific theory. A warmer climate melts polar ice, causing sea levels to rise.
A large portion of the carbon dioxide in the atmosphere is produced by human activities, primarily the burning of fossil fuels to energize a rapidly growing world human population.
“We predict that marshes will absorb some of that carbon dioxide, and if other coastal ecosystems – such as seagrasses and mangroves – respond similarly, there might be a little less warming,” said the study’s lead author, Matt Kirwan, a research assistant professor of environmental sciences in the College of Arts & Sciences.
Salt marshes, made up primarily of grasses, are important coastal ecosystems, helping to protect shorelines from storms and providing habitat for a diverse range of wildlife, from birds to mammals, shell- and fin-fishes and mollusks. They also build up coastal elevations by trapping sediment during floods, and produce new soil from roots and decaying organic matter.
“One of the cool things about salt marshes is that they are perhaps the best example of an ecosystem that actually depends on carbon accumulation to survive climate change: The accumulation of roots in the soil builds their elevation, keeping the plants above the water,” Kirwan said.
Salt marshes store enormous quantities of carbon, essential to plant productivity, by, in essence, breathing in the atmospheric carbon and then using it to grow, flourish and increase the height of the soil. Even as the grasses die, the carbon remains trapped in the sediment. The researchers’ model predicts that under faster sea-level rise rates, salt marshes could bury up to four times as much carbon as they do now.
“Our work indicates that the value of these ecosystems in capturing atmospheric carbon might become much more important in the future, as the climate warms,” Kirwan said.
But the study also shows that marshes can survive only moderate rates of sea level rise. If seas rise too quickly, the marshes could not increase their elevations at a rate rapid enough to stay above the rising water. And if marshes were to be overcome by fast-rising seas, they no longer could provide the carbon storage capacity that otherwise would help slow climate warming and the resulting rising water.
“At fast levels of sea level rise, no realistic amount of carbon accumulation will help them survive,” Kirwan noted.
Kirwan and his co-author, Simon Mudd, a geosciences researcher at the University of Edinburgh in Scotland, used computer models to predict salt marsh growth rates under different climate change and sea-level scenarios.
The United States Geological Survey’s Global Change Research Program supported the research.
Contact: Fariss Samarrai fls4f@virginia.edu (and tell him to make complete press releases please)
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After some searching, I found the paper and the abstract:
Response of salt-marsh carbon accumulation to climate change
Matthew L. Kirwan & Simon M. Mudd
- Nature 489, 550–553 (27 September 2012) doi:10.1038/nature11440
About half of annual marine carbon burial takes place in shallow water ecosystems where geomorphic and ecological stability is driven by interactions between the flow of water, vegetation growth and sediment transport1. Although the sensitivity of terrestrial and deep marine carbon pools to climate change has been studied for decades, there is little understanding of how coastal carbon accumulation rates will change and potentially feed back on climate2, 3. Here we develop a numerical model of salt marsh evolution, informed by recent measurements of productivity and decomposition, and demonstrate that competition between mineral sediment deposition and organic-matter accumulation determines the net impact of climate change on carbon accumulation in intertidal wetlands. We find that the direct impact of warming on soil carbon accumulation rates is more subtle than the impact of warming-driven sea level rise, although the impact of warming increases with increasing rates of sea level rise. Our simulations suggest that the net impact of climate change will be to increase carbon burial rates in the first half of the twenty-first century, but that carbon–climate feedbacks are likely to diminish over time.
“Carbon dioxide is the predominant so-called “greenhouse gas” that acts as sort of an atmospheric blanket, trapping the Earth’s heat.”
How do these people get away with publishing utter garbage like this?
Please Sir,
If warming causes sea levels to rise, doesn’t that mean more ocean area and less land area, so wouldn’t the perimeter of the smaller land area also get smaller, and wouldn’t a smaller perimeter, mean there would be less salt marshes ??
Just asking Sir; can your computator figure that out for us ?
Despite all the alarmism built into the article, I still see a Negative Feedback function in salt-water marshes. It may be an extremely minor one, but they all add up, whereas the IPCC models NEVER add up…
Scientists should include disclaimers in their papers ‘The authors are not responsible for any claptrap that the press office invents with regards to this paper, or for any ludicrous headlines that journals dream up’
Maus:
At September 26, 2012 at 3:15 pm you quote my having said,
and ask me
OK. I can justify my statement in several ways and according to several references, but I understand you to be asking for comparative natural and anthropogenic CO2 emissions data which is “acceptable to the climatology crowd” . The IPCC AR4 is the ‘Bible’ of “the climatology crowd” so I answer by citing that although it gives a slightly different value.
Please note that this reply to you is long because it explains the uncertainties which provide the different answers but concludes by providing the short answer you say you want.
The pertinent AR4 chapter is ‘7.3 The Carbon Cycle and the Climate System’ and its relevant section is ‘7.3.1.1 The Natural Carbon Cycle’ which can be read at http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch7s7-3.html
Its data is summarised in Figure Figure 7.3 which shows
And can be seen at
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/figure-7-3.html
Figure 7.3 shows total fluxes to the atmosphere by nature of 190.2 GtC/year
with 119.6 GtC/year from “vegetation, soil and detritus” and 70.6 GtC/year from “surface ocean”.
And Figure 7.3 shows total anthropogenic emissions are 8.0 GtC/year
with 6.4 GtC/year from “fossil fuels” and 1.6 GtC/year from “land use change”.
(It is rarely commented that the IPCC attributes 20% of anthropogenic CO2 emissions to “land use changes” but the IPCC does all it can to exaggerate anthropogenic effects.)
Using those emission values, nature emits 190.2 molecules of CO2 for each 6.4 molecules of CO2 emitted by human activities. This equates to nature emits 30 molecules of carbon dioxide for each molecule of carbon dioxide emitted by human activities.
Clearly, there is a discrepancy between the IPCC indication (i.e. 30) and my statement (i.e. 34). This results from the sources selected by the IPCC and the uncertainties in those estimates. The AR4 says of the values in its Figure 7.3
Clearly, IPCC science is unusual in that it cites e.g. 119.6 GtC/year for a value that is only known to +/-20% (i.e. +/- 24.0 GtC/year) and compares that to 6.4 GtC/year from “fossil fuels”.
However, I am answering your desire for information “acceptable to the climatology crowd” so I answer:
The IPCC AR4 says in Chapter ‘7.3 The Carbon Cycle and the Climate System’ that nature emits 30 molecules of carbon dioxide for each molecule of carbon dioxide emitted by human activities.
I hope this answer is clear and what you wanted.
Richard
richardscourtney says:
September 26, 2012 at 2:37 pm
Nature emits 34 molecules of carbon dioxide for each molecule of carbon dioxide emitted by all human activities.
You know, we have been discussing this already many times…
What you and many others here (“humans only emit 3% of the natural emissions”) don’t mention is that for every 34 molecules of natural CO2 emissions, the nature absorbs 34.5 molecules again within the same year. Thus 34 molecules are simply going in and out, that is throughput and doesn’t add to the total amount of CO2 in the atmosphere. It is the 1 molecule of human input and the 0.5 molecule that is extra absorbed (by oceans and vegetation), that makes the difference. Not the 34 molecules of natural emissions…
Not another model based bit of ”research”. Salt marsh can be a good mitigation for storm surge flooding but climate change?
polistra says:
September 26, 2012 at 3:42 pm
It occurs to me that we don’t actually know if the increase of CO2 in the atmosphere is OUTGASSED FROM the ocean, as it did EVERY PREVIOUS TIME it increased.
Should be possible to determine this experimentally.
According to Henry’s Law, the maximum increase of CO2 for 1°C temperature rise is 16 ppmv. As vegetation works the other way out, the average seen over ice ages (thus including large changes in vegetation/land ice cover and ocean ice/currents) is 8 ppmv/°C. As we may assume that the warming since the LIA was maximum 1°C, the total increase caused by the oceans was maximum 16 ppmv or 8 ppmv including vegetation responses. Not the 100+ ppmv we have seen since 1850 or 70+ ppmv since the measurements at the South Pole and Mauna Loa started.
There are a few places where the total CO2 (DIC) in seawater and in the atmosphere were continuously monitored, plus a lot of frequent ships surveys. These all show that the oceans are a net absorber of CO2 over the past decades, not a net source. See:
http://www.bios.edu/Labs/co2lab/research/IntDecVar_OCC.html
Calling Trenbeth to the salt marshes. Come and get your heat.
About the net quantity of CO2 absorbed by the total biosphere…
There is a relative simple method to calculate how much CO2 is released or absorbed by the total biosphere (that is plants, microbes, animals): the oxygen use. Plants capture CO2 and release at the same time oxygen in the photosynthesis process. Microbes and animals use the carbohydrates as food and use oxygen to “burn” them, that way producing CO2 and use the energy set free in that process. Thus looking at the O2 changes over time, one can calculate how much CO2 the total biosphere released or did take up. The main challenge: the necessary accuracy of the measurements of O2 in air: less than 1 ppmv in 200,000 ppmv…
Oxygen use from fossil fuel burning can be calculated from fossil fuel sales and burning efficiencies, of course with some margins of error. That shows that there was some small oxygen use from the biosphere before 1990 and an increasing oxygen production since 1990. Thus indeed, the biosphere is growing and more carbon is stored in semi-permanent reservoirs (most of the bulk growth and decay is over the seasons in leaves and small stems, only part is stored in trunks and roots and more permanent humus, peat, browncoal,…). See further:
http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf
Ferdinand Engelbeen:
Your post at September 27, 2012 at 2:19 am says in total
1.
Yes, we have debated this repeatedly.
2.
My statement that you quote is correct and you do not dispute it.
3.
Nature does NOT distinguish whether a CO2 molecule entered the atmosphere from an anthropogenic or a ‘natural’ source so it is a meaningless statement that says “34 molecules are simply going in and out, that is throughput”.
4.
There is no way to determine why nature does not sequester all the equivalent of all the CO2 emitted to the air (from both anthropogenic and ‘natural’ sources) so your assertion that “It is the 1 molecule of human input and the 0.5 molecule that is extra absorbed (by oceans and vegetation), that makes the difference” may or may not be true. I doubt it, but I cannot show you are wrong any more than you can show you are right.
Richard
Ferdinand Engelbeen:
At September 27, 2012 at 2:59 am you say
As I cite reference, link and quote in my above post at September 27, 2012 at 2:07 am, the IPCC says natural emissions total 190.2 GtC/year with an error of +/- 20%. This is an error range of +/- 38 GtC/year. And the uncertainty in the sequestration is similar.
The uncertainty of +/- 38 GtC/year in the natural emissions completely dwarfs the total anthropogenic emission of 8.0 GtC/year.
Unless, of course, you care to dispute the IPCC’s estimates of the uncertainties?
Richard
Ferdinand Engelbeen says:
September 27, 2012 at 2:59 am
The main challenge: the necessary accuracy of the measurements of O2 in air: less than 1 ppmv in 200,000 ppmv
Hi Ferdi, what is the current error range in ppm on measurement of the oxygen content of the entire atmosphere?
I think what Ferdinand is trying to say, in a rather clumsy way, is that nature reached a saturation point, and any extra will mostly accumulate.
Which is fine, I can see that. But I like the idea that nature will step in and take advantage of the surplus by ‘greening’ up and even if there is still a surplus, it has not led to any horrors that the doom sayers and models predicted
Ferdinand Engelbeen says: September 27, 2012 at 2:59 am
Found some data – plotted here comparing CO2 and O2
http://www.climateandstuff.blogspot.co.uk/2012/06/further-thoughts-on-co2-cycle.html
The rate of yearly variability in CO2 (dips in spring – peaks in winter) is too quick for plant growth and decay to explain. (how long does it take dead leaves to decay in cold).
The “suck/blow” of CO2 is happening in the arctic region as shown by the difference in min and max being higher in the polar stations – the peak to peak being almost nil in antarctica
Phyoplancton is a good candidate as it is respires in the dark (co2 out o2 in) and photosythesises in light (co2 in o2 out)
““At fast levels of sea level rise, no realistic amount of carbon accumulation will help them survive,” Kirwan noted.”
Reef-cuilding corals grow up to 20 cm a year.
http://en.wikipedia.org/wiki/Staghorn_coral
This guy says marshes are not able to do that? Extraordinary claim. But anyway – the parts that drown under his assumed meltwater pulse 1A-style “fast sea level rise” could turn into reefs… and withstand 20 cm a year of sea level rise…
Ferdinand Engelbeen says:
”for every 34 molecules of natural CO2 emissions, the nature absorbs 34.5 molecules again within the same year
Ah, the mythical source/sink balance (with a twist) raises its ugly head. Ok, let’s assume that 34:34.5 ratio is true, then it’s a good thing humans came along to release sequestered carbon or there’d be less CO2 in the atmosphere than plants require to live in something on the order of 160-200 years from the supposed pre-industrial levels. The carbon sinks would have caused a super (duper) mass extinction. LOL. Seriously though, as with all things climatological, it’s just not that simple. The ratio of emission:absorption depends upon many variables. The ocean, for example, is not one homogenous mass of water. The polar oceans are colder and therefore capable of dissolving more CO2 than the equatorial oceans. Perhaps in a CO2 induced warming world with less ice cover at the North Pole, the exposed cold water may absorb more CO2, thereby changing the ratio. Oh no, a negative feedback.
I’ll see your link to “hockey stick” style amalgamation ending circa 2003 and raise you a link to raw data ending in 2012:
http://132.239.122.17/co2qc/batches.html
Note the slightly negative trend in total CO2 since 1990. Hmmm.
EternalOptimist:
At September 27, 2012 at 4:22 am you say
It is for Ferdinand to state what he is trying to say and I make no comment on the accuracy of your interpretation. I write to comment on your point.
It is absolutely certain that nature did not reach “a saturation point, and any extra will mostly accumulate”. This is known for three reasons.
1.
If the system were saturated then CO2 equivalent to all the anthropogenic emission would stay in the air, but only an amount of CO2 equivalent to about half the anthropogenic emission stays in the air. An amount of CO2 increases in the air that is about 2% of the total annual CO2 emission (anthropogenic and natural).
2.
If the system were saturated then variations in the anthropogenic CO2 emission would relate to variations in the atmospheric CO2 content, but they don’t.
Annual anthropogenic emissions may be accounted for different 12-month periods so it is reasonable to average the data over 2 years to account for this. And errors may cause some of the anthropogenic emissions to not be accounted in the year they are emitted but to be accounted in an adjacent year, so it is reasonable to average the data over 3 years. But there is no known reason to average over more than 3 years.
The IPCC averages over 4 years because that degree of (unjustifiable) smoothing is required to obtain agreement between variations in the anthropogenic CO2 emission and variations in the atmospheric CO2 content.
3.
The observed dynamics of atmospheric CO2 sequestration show the system of the carbon cycle can easily sequester all the total CO2 emission (both natural and anthropogenic) of each year. This denies that the system is near to saturation.
At issue is why the system does not sequester all the annual emission (both anthropogenic and natural) of each year when the system dynamics indicate the system can easily sequester all of it.
Richard
Ferdinand,
Your analysis/understanding is naive. As CO2 is emitted and the CO2 concentration increases plant photosynthesis increases along with it. But there is a lag, Plants can’t consume the CO2 at the same time as it is emitted. This means that while emission is increasing, photosynthetic sequestration can’t balance it out. If CO2 emission was to increase less quickly photosysthesis would naturally come to equilibrium with Emission and the increase would stop.
Ergo, the only factor that allows CO2 to increase is that CO2 emissions are increasing, not that they are high. By increasing CO2 emission slowly enough to allow plants to come to equilibrium, we can keep burning coal without affecting CO2 levels much at all.
You suggest that Plants can’t sequester carbon, but that is pure bunkum. Here is a simple (primary school science) proof. Almost all of the oxygen in the atmosphere comes from photosynthesis converted from CO2 to Carbohydrates and Oxygen. For each oxygen molecule in the atmosphere one carbon molecule was permanently sequestered by a plant, if it was not, then the Oxygen would have been reconsumed, in the decay process, clearly much oxygen is not therefore Plants HAVE in fact sequested billions of tonnes of Carbon.
PS I also think the billions wasted on this claptrap should be spent on curing cancer and feeding the hungry – and so should you!
Bob
richardscourtney says:
September 27, 2012 at 3:23 am
The uncertainty of +/- 38 GtC/year in the natural emissions completely dwarfs the total anthropogenic emission of 8.0 GtC/year.
The error range of the natural emissions and natural uptake is not of the slightest interest (it may be 10 or 100 or 1000 GtC/year in and out, that doesn’t alter the total CO2 level in the atmosphere), as only the difference between these two is important to know for what happens in the atmosphere: an increase of CO2, a decrease or a steady state. And that difference is quite accurately known: currently about 4 GtC/year +/- 2 GtC natural variability and an error margin of +/- 1.5 GtC. Thus in average 4 GtC/year more natural sink than natural source, as the human input is about 8 GtC/year and the human output is virtually zero. That was the case for the past 50+ years, be it that the natural variability 50 years ago was about the same, but the human input a lot smaller, as was the increase in the atmosphere:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/dco2_em.jpg
Are these unvetted “press releases” proportional to the amount of taxpayer junk-grants a Uni receives (and must spend to justify them)?
And EternalOptimist, whatever Ferdinand is, I’ve never considered him clumsy….
tallbloke says:
September 27, 2012 at 3:36 am
Hi Ferdi, what is the current error range in ppm on measurement of the oxygen content of the entire atmosphere?
According to the link I sent, they reached an accuracy of 0.6-0.8 ppmv for the oxygen measurements. But of course, sampling needs to be done at places as far away from oxygen sources and sinks, that are the same places as where the current baseline CO2 stations are. Despite that, one can see the same (opposite) seasonal and year-by-year variability and the same lag in SH data as is visible in the CO2 levels.
sergeiMK says:
September 27, 2012 at 4:35 am
The “suck/blow” of CO2 is happening in the arctic region as shown by the difference in min and max being higher in the polar stations – the peak to peak being almost nil in antarctica
That the SH stations don’t show much seasonal variability does in fact prove that plankton is not the main cause: sea ice / plankton in the SH also goes up and down with the seasonal temperature swings. But both the oxygen and 13C/12C ratio changes show that anyway plants are the cause, thus land plants, as the NH has much more land than the SH.
That the NH polar stations show the largest variability is a bit misleading, because the largest seasonal variability is in the mid-latitudes, but the Ferell cells move that air polewards where it sinks again and comes back. If one compares the seasonal variability at sealevel in mid-latitudes (here the Shetland Islands, even larger swings noticed in the now abandened Schauinsland station – Southern Germany), one sees the same amplitude as in the far north:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/Fig_2.gif
Mauna Loa at 3400 m height takes more time (about a month) to follow the seasonal swings and there the swings are already more mixed in with the CO2 levels of the higher troposphere.
John West says:
September 27, 2012 at 5:21 am
then it’s a good thing humans came along to release sequestered carbon or there’d be less CO2 in the atmosphere than plants require to live in something on the order of 160-200 years from the supposed pre-industrial levels.
Please look up for the Le Châtelier Principle: for a system in dynamic equilibrium, any disturbance will give a reaction to remove that disturbance. The ice cores of any length and resolution show that there is a dynamic equilibrium in CO2 levels, only depending of the temperature. If humans (or volcanoes) add some extra CO2, that is absorbed by different processes. How fast, is a matter of how fast these processes can react on a disturbance. But the end of such a process is that the disturbance is removed until the dynamic equilibrium is reached again. That is not at zero CO2, but at the temperature dictated equilibrium…
The ratio of emission:absorption depends upon many variables.
Yes and some responses are far from linear. Therefore it is quite remarkable that CO2 levels follow temperature with such a near-linear rate (of about 8 ppmv/°C) over the past 800,000 years, except in the past 150 years…
I’ll see your link to “hockey stick” style amalgamation ending circa 2003 and raise you a link to raw data ending in 2012:
You are looking at reference batches used to calibrate on the spot measurements. These batches were taken at different places of the oceans and some were even synthetic. That doesn’t say anything about trends in the ocean waters, which must be taken over time at the same places.
chardscourtney says:
September 27, 2012 at 5:29 am
It is absolutely certain that nature did not reach “a saturation point, and any extra will mostly accumulate”. This is known for three reasons.
I do agree with point 1. be it that the 2% of all emissions in my opinion is not relevant.
2.
If the system were saturated then variations in the anthropogenic CO2 emission would relate to variations in the atmospheric CO2 content, but they don’t.
No, that would only be true if the human emissions were the only variable. But temperature variability has a large, short term effect, which overwhelms the small (in fact unmeasurable) effect of variations in human emissions.
But there is no known reason to average over more than 3 years.
There is no reason to restrict any averaging over less than 4 years. All depends of the signal to noise ratio. For sea level rise even 25 years is necessary to filter out any rise in the huge wave and tidal “noise”.
At issue is why the system does not sequester all the annual emission (both anthropogenic and natural) of each year when the system dynamics indicate the system can easily sequester all of it.
That is the main difference between our viewpoints:
In my opinion, there are different processes at work: fast processes, but with a limited capacity and slow processes with a much larger capacity. The seasonal swings are from the fast processes: the warming/cooling of the sea surface layer and the fast growth/decay of leaves mainly in the mid-latitudes. Both are limited in capacity: the oceans surface follows the CO2 levels (and temperature) very fast, but at maximum with 10% of the change in the atmosphere. Leave growth may be influenced by more CO2, but much of it decays again in fall.
The slow processes are responsible for the removal of the bulk of the excess CO2: the exchanges with the deep oceans, which have a much larger capacity, but a limited exchange rate with the atmosphere. The same for the more permanent storage of carbon in land vegetation: that takes more time. A 100% increase in CO2 of the atmosphere causes an average 50% increase in growth in the best circumstances, which are seldom met in nature. The current 30% increase in the atmosphere caused maybe 2% more permanent storage (1.5 GtC / 60 GtC exchange rate) per year in the biosphere.