Carbon Cycle

[AbruptSLR]

Laurent,

Thank you for this link (in Reply #149). 

I sincerely hope that this initiative works before global temperature increases (and associated drought-flood cycles, wildfires, over-population, and stimulation of CO2 emissions from the soil due activation of microbes in the soil) over-stress the world's plants.

Best,
ASLR

[AbruptSLR]

Getting back to the figures that I posted in my Reply #147, showing that RCP 2.6 & 4.5, are highly dependent on the use of bioenergy and carbon capture storage (BECCS), I would like to note that when we acknowledge that BECCS is a possible negative feedback (if carefully managed by mankind as cited in Reply #149); it is important that we also acknowledge that most feedback mechanisms are skewed significantly towards the positive side of the spectrum; and currently due to ESLD (erring of the side of least drama) none of the RCP scenarios include the fat-tailed PDF (probability density function) positive feedback probability associated with possible CO2 emissions from carbon currently in the soil due to increasing world temperatures.  The attached image shows how big this impact could be for SRES AB1 (comparable to RCP 8.5), and this does not include the possibility of enhanced methane emissions say from permafrost and hydrate degradation.

[ritter]

Per the linked reference (& two associated attached images), both RCP 2.6 & 4.5, are highly dependent on the use of bioenergy and carbon capture storage (BECCS), which is highly uncertain technology for reducing CO2 in the atmosphere.

These projections do not include CO2 and methane release from melting permafrost either.

[ccgwebmaster]

Per the linked reference (& two associated attached images), both RCP 2.6 & 4.5, are highly dependent on the use of bioenergy and carbon capture storage (BECCS), which is highly uncertain technology for reducing CO2 in the atmosphere.

These projections do not include CO2 and methane release from melting permafrost either.

Or from a dying burning Amazon, or various other biosphere changes in other parts of the world?

Or, most likely, from the warming contribution of shifting ice albedo in an Arctic not forecast to vanish for far longer than reality hints at?

[AbruptSLR]

As it appears that most commenters posting here feel that the RCP (Representative Concentration Pathways) scenarios do not adequately capture the upper end of risks of positive feedback mechanisms.  I provide the following link (and associated selected images) from an August 2013 Skeptical Science guide explaining how these scenarios were developed.

http://www.skepticalscience.com/docs/RCP_Guide.pdf

The first attached image shows that RCP 8.5 was developed to match the 90th percentile of published literature available before 2007, and thus ignores any ECS or economic information developed after that time.

The second attached image (with both world population and GDP data) shows that RCP 8.5 assumes that world population would be about 10 Billion people by 2050; which is the current median (not the 90% CL) projection for that date.

The third attached image shows the assumed primary energy sources for the RCP scenarios indicating that we are currently following a mix closely matching that assumed for RCP 8.5.

As creating new scenarios using our latest information would probably give alarming results, it would seem possible that the IPCC will stop developing such scenario and may not even publish an Assessment Report 6 (so as to avoid excess drama).

[AbruptSLR]

According to the linked reference the level of bioenergy with carbon capture and storage (BECCS) required in order to achieve RCP2.6 both relies on optimistic assumptions for technology developments and/or puts the world's food supply at risk.  Thus it does not seem advisable to assume that BECCS will allow the world to remain below the 2 degree C temperature target.

Etsushi Kato, Yoshiki Yamagata, (2014), "BECCS capability of dedicated bioenergy crops under a future land-use scenario targeting net negative carbon emissions", Earth's Future, DOI: 10.1002/2014EF000249

http://onlinelibrary.wiley.com/enhanced/doi/10.1002/2014EF000249/

Abstract: "Bioenergy with Carbon Capture and Storage (BECCS) is a key component of mitigation strategies in future socioeconomic scenarios that aim to keep mean global temperature rise below 2°C above preindustrial, which would require net negative carbon emissions in the end of the 21st century. Because of the additional need for land, developing sustainable low-carbon scenarios requires careful consideration of the land-use implications of deploying large scale BECCS. We evaluated the feasibility of the large-scale BECCS in RCP2.6, which is a scenario with net negative emissions aiming to keep the 2°C temperature target, with a top-down analysis of required yields and a bottom-up evaluation of BECCS potential using a process-based global crop model. Land-use change carbon emissions related to the land expansion were examined using a global terrestrial biogeochemical cycle model. Our analysis reveals that first-generation bioenergy crops would not meet the required BECCS of the RCP2.6 scenario even with a high-fertilizer and irrigation application. Using second-generation bioenergy crops can marginally fulfill the required BECCS only if a technology of full post-process combustion CO2 capture is deployed with a high-fertilizer application in the crop production. If such an assumed technological improvement does not occur in the future, more than doubling the area for bioenergy production for BECCS around 2050 assumed in RCP2.6 would be required; however, such scenarios implicitly induce large-scale land-use changes that would cancel half of the assumed CO2 sequestration by BECCS. Otherwise, a conflict of land use with food production is inevitable."

[Grunt]

OSU part of major grant to study Southern Ocean carbon cycle
09/09/2014
CORVALLIS, Ore. – A new six-year, $21 million initiative funded by the National Science Foundation will explore the role of carbon and heat exchanges in the vast Southern Ocean – and their potential impacts on climate change.

The Southern Ocean Carbon and Climate Observations and Modeling program will be headquartered at Princeton University, and include researchers at several institutions, including Oregon State University. It is funded by NSF’s Division of Polar Programs, with additional support from the National Oceanic and Atmospheric Administration and NASA.

The Southern Ocean acts as a carbon “sink” by absorbing as much as half of the human-derived carbon in the atmosphere and much of the planet’s excess heat. Yet little is known of this huge body of water that accounts for 30 percent of the world’s ocean area.

Under this new program known by the acronym SOCCOM, Princeton and 10 partner institutions will create a physical and biogeochemical portrait of the ocean using hundreds of robotic floats deployed around Antarctica. The floats, which will be deployed over the next five years, will collect seawater profiles using sophisticated sensors to measure pH, oxygen and nitrate levels, temperature and salinity – from the ocean surface to a depth of 1,000 meters, according to Laurie Juranek, an Oregon State University oceanographer and project scientist.

“This will be the first combined large-scale observational and modeling program of the entire Southern Ocean,” said Juranek, who is in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “It is a very important region, but difficult to access – hence the use of robotic floats to collect data. However, not everything that we need to know can be measured by sensors, so we’ll need to get creative.”

Juranek's role in this project is to develop relationships between the measured variables and those that can't be measured directly by a sensor but are needed for understanding Southern Ocean carbon dioxide exchanges. These relationships can be applied to the float data as well as to high-resolution models. To do this work she is partnering with colleagues at NOAA's Pacific Marine Environmental Laboratory.

In addition to its role in absorbing carbon and heat, the Southern Ocean delivers nutrients to lower-latitude surface waters that are critical to ocean ecosystems around the world, said program director Jorge Sarmiento, Princeton's George J. Magee Professor of Geoscience and Geological Engineering and director of the Program in Atmospheric and Oceanic Sciences. And as levels of carbon dioxide increase in the atmosphere, models suggest that the impacts of ocean acidification are projected to be most severe in the Southern Ocean, he added.

"The scarcity of observations in the Southern Ocean and inadequacy of earlier models, combined with its importance to the Earth's carbon and climate systems, means there is tremendous potential for groundbreaking research in this region," Sarmiento said.
Resources:
http://oregonstate.edu/ua/ncs/archives/2014/sep/osu-part-major-grant-student-southern-ocean-carbon-cycle
http://www.scienceclarified.com/Ca-Ch/Carbon-Cycle.html
http://news.bbc.co.uk/2/shared/spl/hi/sci_nat/04/climate_change/html/carbon.stm

[Bruce Steele]

Grunt, I posted a link for the 21 million study on the "Selected Forcing " page. Abrupt SLR has a lot of good southern hemisphere info there. The carbon cycle work in the new study will be very interesting.  Welcome to the Forum.

 
Re: Selected Forcing Factor for Abrupt SLR from the Collapse of the WAIS
« Reply #302 on: September 12, 2014, 06:34:21 PM »
A  co-ordinated 21 million dollar study to deploy a large field of Argo floats has been funded and although the link below doesn't specify the deep dive abilities of the new Argo floats I am sure they will be deployed. We may get a much better picture of the current state of the Southern Oceans  carbon cycle with the new pH sensors that are also part of this study. What is going on with Antarctic Bottom Water formation? A clearer picture is soon to arrive .

   https://scripps.ucsd.edu/news/southern-oceans-role-climate-regulation-ocean-health-goal-21-million-federal-grant
 Logged

[Laurent]

Should we upgrade photosynthesis and grow supercrops?
http://www.newscientist.com/article/mg22429892.900-should-we-upgrade-photosynthesis-and-grow-supercrops.html?cmpid=RSS|NSNS|2012-GLOBAL|environment#.VDKqHVFJzlc

[Bruce Steele]

http://www.cbd.int/doc/publications/cbd-ts-75-en.pdf

U.N. Report on acidification. If I might suggest pages 78-81 re. Ocean carbon cycle and potential effects on climate.  Some of these are better constrained than others but > 10 years ago we weren't much worried about any of them. Well I suppose a few people were, the fact that warm water holds less Co2 than cold water isn't news but the effects of  ballasting of organic matter by calcium carbonate? Still not news but maybe should be.

[AbruptSLR]

Further to Bruce's post about ocean acidification, the following link reports on New Zealand's efforts to directly measure the local ocean acidification under areas of Southern Ocean sea ice:

http://www.scoop.co.nz/stories/SC1410/S00023/niwa-scientists-working-under-the-ice-in-antarctica.htm

[Laurent]

Waterloo discovery: Tiny ocean organisms are big B12 producers
https://uwaterloo.ca/stories/waterloo-discovery-tiny-ocean-organisms-are-big-b12-0

Andrew Doxey and Josh Neufeld, professors in Waterloo’s Department of Biology, point out that the discovery has implications for climate change because the availability of vitamin B12 may control how much or how little biological productivity by phytoplankton takes place in the oceans. Phytoplankton remove carbon dioxide from the atmosphere much like plants and trees.

[Laurent]

Climate change: Models 'underplay plant CO2 absorption
http://www.bbc.com/news/science-environment-29601644

[Pmt111500]

Climate change: Models 'underplay plant CO2 absorption
http://www.bbc.com/news/science-environment-29601644

The relevant Abstract here:
http://www.pnas.org/content/early/2014/10/10/1418075111 (can't find the whole article)

shorter and likely too simplified abstract:
CO2 getting into leaves diffuses far and wide in the cavities in leaves, this drops the amounts near photosynthetic centers, chloroplasts, more than previously estimated. Thus the 16% discrepancy between (some or nearly all) carbon cycle models and reality may have been  explained. CFE (carbon fertilization effect) has been included into models also previously, but results presented in this study are indicating these equations should be modified to better represent CFE in nature (previously most CFE calculations and models have been obtained from the studies conducted in greenhouses). At least looking at C3-plants (is it about a 1/2 of planets plantlife?). I think they're stating CFE in models should represent a larger proportion of carboxylation part of NPP than previously. This of course won't effect the other attributes in calculating NPP such as water amounts and nutrient scarcity/excess.

Sort of good news if the rise in ghg's stops someday, likely makes the recovery phase of this spike we're living through shorter, or so I gather. Other conclusions might be there too.

[Pmt111500]

Waterloo discovery: Tiny ocean organisms are big B12 producers
https://uwaterloo.ca/stories/waterloo-discovery-tiny-ocean-organisms-are-big-b12-0

Andrew Doxey and Josh Neufeld, professors in Waterloo’s Department of Biology, point out that the discovery has implications for climate change because the availability of vitamin B12 may control how much or how little biological productivity by phytoplankton takes place in the oceans. Phytoplankton remove carbon dioxide from the atmosphere much like plants and trees.

Nice that this source has been identified. Pretty amazing, life. Those Archaea and bacteria are pretty clever. I wonder how many chemists there are in the world who could produce this one starting from the elements. It's of course been known that the algae get this from somewhere, but I doubt geoengineer-types will throw this in ocean to increase algal withdrawal of CO2, it's pretty expensive stuff. To those who think that's just a vitamin sold in pills and bottles the chemical formula might be more illustrative of the complexity of this essential nutrient:

[morganism]

don't know how i missed this methanogen paper, i was following microbial nanowires pretty closely

someone just imaged some living ones, and found that they were extending psuedopods, not building chemical bridges, and physically handing off electrons.

They do this by enlisting geobacter

http://phys.org/news/2013-11-microbiologists-reveal-unexpected-properties-methane-producing.html#inlRlv

this may be very important in the arctic ponds studies done earlier, and referenced further up as

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0078204

[morganism]

and it looks like sequestering isn't going to work that well. It doesn't convert to limestone very quickly

http://arstechnica.com/science/2014/10/natural-underground-co2-reservoir-reveals-clues-about-storage


would prob be more efficient to just pull it out of the atmo, and feed it to microbes.

[Bruce Steele]

Back on May 1 Laurent posted a link to an article about current Pteropod shell dissolution along the West Coast of North America. The NOAA cruise that documented this problem was revisiting the same transects that an earlier cruise ( 2008 ) had documented undersaturated water conditions.The same transects that earlier showed
surface to bottom undersaturation were revisited to again test dissolved Co2 and aragonite saturation levels and also to test the fitness of Pteropod populations. In the graph linked below those areas with
greater degrees of  undersaturation also correspond to increased shell dissolution of sampled Pteropods.

  http://rspb.royalsocietypublishing.org/content/suppl/2014/04/28/rspb.2014.0123.DC1/rspb20140123supp2.docx

[Bruce Steele]

Here are some links to the two NOAA cruises mentioned above. The graph i linked was from the Proceeds of the Royal Society Paper.

http://www.noaanews.noaa.gov/stories2014/20140430_oceanacidification.html

http://www.pmel.noaa.gov/co2/story/Research+along+the+West+Coast

[Bruce Steele]

Here is a new potential positive feedback resulting from extra Co2 enhancing bacterial efficiencies near the ocean /atmospheric surface. This one is new to science and as such not well studied but effects may change composition of organic particles in aerosolized surface water.

11.11.2014
The oceans’ sensitive skin
Ocean acidification affects climate-relevant functions at the sea-surface microlayer

November 11, 2014/Kiel. Ocean acidification might alter climate-relevant functions of the oceans’ uppermost layer, according to a study by a group of marine scientists published in the “Journal of Geophysical Research: Oceans”. In an experiment led by GEOMAR Helmholtz Centre for Ocean Research Kiel, the researchers observed a close coupling between biological processes in the seawater and the chemistry of the sea surface microlayer. Also, they noted a growing number of specialised bacterial and algal cells in this microenvironment. These changes might influence interactions between the ocean and the atmosphere such as the air-sea gas exchange and the emission of sea-spray aerosols that can scatter solar radiation or contribute to the formation of clouds.

Like a skin, the sea-surface microlayer separates the ocean from the atmosphere. The exchange of gases and the emission of sea-spray aerosols – two functions that are crucial for climate – take place in this boundary film. A mesocosm experiment by scientists from GEOMAR Helmholtz Centre for Ocean Research Kiel, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research Bremerhaven (AWI) and the Institute for Baltic Sea Research Warnemünde (IOW) reveals for the first time how ocean change might affect the special physical, chemical and biological characteristics of the ocean’s uppermost boundary. The results are published in the “Journal of Geophysical Research: Oceans”. First author is Dr. Luisa Galgani who conducted the study as part of her PhD at GEOMAR and AWI.

“Experiments have shown how ocean acidification, a change in the ocean chemistry due to the uptake of man-made carbon dioxide, influences the growth and efficiency of marine bacteria as well as the sinking of carbon-rich particles”, Dr. Luisa Galgani resumes. “We know that organic material and microorganisms accumulating in the sea-surface microlayer are similar to those found in the water column below. So we expected that ocean acidification-driven changes in ocean biogeochemistry in the water column can also be reflected in the microlayer. It is important to understand changes in this microenvironment, because it might have consequences for air-sea interactions that are relevant for our climate.”

To investigate consequences of ocean acidification on marine systems, future ocean scenarios have been simulated with the KOSMOS mesocosms (KOSMOS: Kiel Off-Shore Mesocosms for future Ocean Simulations) at Raunefjord, Norway. These nine large floating structures, each of which isolates 75.000 litres of seawater, were brought to different carbon dioxide (CO2) levels as to be expected for upcoming decades and centuries. For one month, the surface of six mesocosms was sampled daily with a glass plate.

Analyses of the samples verified that organic compounds in the sea-surface microlayer reflected the temporal development of phytoplankton growth in the water column. Also, at higher CO2 levels, the concentrations of bacterioneuston, marine bacteria inhabiting the surface, increased. More acidic conditions promoted changes in the dynamics of organic matter. Especially proteinaceous marine gels became smaller but more abundant probably because they served as a nutritional substrate in the sea-surface microlayer, where higher abundances of microorganisms were more efficient in degrading the organic material accumulated during a phytoplankton bloom.

“From previous studies we know that the activity of marine bacteria is stimulated at high CO2”, Dr. Galgani explains. “Based on our observations in the sea-surface microlayer, we think that this could be very important as it may imply a positive feedback on atmospheric CO2 from oceanic sources, that is, from microbial metabolism at the air-sea interface.”

Additionally, stimulated bacterial degradation might heavily affect the organic composition of nascent sea-spray particles, upon which relies the ability of marine aerosols to interact with the climate system. In the era of climate change, the contribution of marine aerosols is still poorly understood. “There is a long way ahead before we can determine how the ocean provides raw material for clouds formation”, Prof. Dr. Anja Engel, head of the research group Microbial Biogeochemistry at GEOMAR, states. “However, we think that our study provided an additional piece of the puzzle and we are directing our research in investigating more the structure and the dynamics of the air-sea interface to better estimate ocean-atmosphere interactions in a high CO2 world.”

http://www.geomar.de/index.php?id=4&no_cache=1&tx_ttnews%5Btt_news%5D=2158&tx_ttnews%5BbackPid%5D=185&L=1

[Bruce Steele]

Woods Hole has set and maintained data profilers that record temperature and salinity profiles of the water column in the Arctic Ocean. These ITP buoys ( ice tethered profilers ) show in real time the various water masses, stacked somewhat like a layer cake , all across the Arctic.
 This year buoy 84 is sending pCo2 ( Co2 dissolved in the water ) readings as well. I will look further to see if more buoys have pCo2 monitors on them but this is a nice addition to the water column profiles established for several years already.

   http://www.whoi.edu/page.do?pid=139036

[johnm33]

I guess this is the best place for this interesting vid. http://www.space.com/27798-u-s-and-china-co2-litters-earth-s-atmosphere-one-year-timelapse.html   [about 3 min]

[wili]

And I guess this is the best place for this:

Vast amounts of methane appear to be leaking undetected from Australia's biggest coal seam gas field, according to world-first research that undercuts claims by the gas industry.

Testing inside the Tara gas field, near Condamine on Queensland's Western Downs, found some greenhouse gas levels over three times higher than nearby districts, according to the study by researchers at Southern Cross University.

The study has potential national consequences because last week's energy white paper forecast a massive expansion of Australian coal seam gas drilling, and called for environmental objections to be removed to make large-scale gas extraction easier

Methane, carbon dioxide and other gases appear to be leaking up through the soil and bubbling up through rivers at an astonishing rate, the researchers said.

"The concentrations here are higher than any measured in gas fields anywhere else that I can think of, including in Russia," said Damien Maher, a biochemist who helped conduct the tests. "The extent of these enriched concentrations is significant."

http://www.smh.com.au/environment/climate-change/methane-leaking-from-coal-seam-gas-field-testing-shows-20121114-29c9m.html#ixzz3JWnwJbsm

[LRC1962]

Not sure about scientific veracity as I can not seem to find any literature to back it up, but did come across this in a documentary that seems to indicate that if you have high airborne concentration of nitrogen that falls onto trees an interesting event  occurs. The tree starts giving off more CO2 then it is taking in. portion that deals with it starts at 30:52 min. If information is right then this is a feed back loop not talked about much, if wrong then I would like to be educated.

[Bruce Steele]

LRC, i was under the impression that rising atmospheric nitrogen and Co2 levels have increased the terrestrial component of the carbon cycle. As both atmospheric nitrogen and Co2 have been going up over the last ~ 200 years the relative composition of atmospheric 50% terrestrial 25% and oceans25% portions
of the anthropogenic carbon sink have remained fairly constant. The only way for that to be true is if each component part increases the amount of carbon it uptakes as the amount we release increases.
 Here is a paper that shows increasing nitrogen and Co2 are synergistic not antagonistic on plant growth and as a result carbon uptake. There are other factors like temperature and moisture than can affect the ability of the terrestrial sink to hold on to that carbon ( sink it ) faster that respiration or decomposition releases it and climate heating may reach some point that fire , drought or microbial decomposition disrupts the current % balances of the terrestrial sink or stratification and acidification negatively  effects  the ocean sink but so far these sinks have kept pace. If either of these two sinks is compromised then the atmospheric percentage will as a consequence increase so it is something to understand as we stress the system but so far the carbon cycle has suffered our abuses.

    This link doesn't describe the nitrogen component but does show increased growth in earths biome for various reasons.
http://earthobservatory.nasa.gov/Features/GlobalGarden/

   

[Laurent]

Microbes discovered by deepest marine drill analysed
http://www.bbc.com/news/science-environment-30489814

[wili]

http://blog.ucsusa.org/global-warming-fact-co2-emissions-since-1988-764

More than Half of All Industrial CO2 Pollution Has Been Emitted Since 1988

By the end of this year, more than half of all industrial emissions of carbon dioxide since the dawn of the Industrial Revolution will have been released since 1988 — the year it became widely known that these emissions are warming the climate.

I recently learned this startling fact from my colleague Richard Heede at the Climate Accountability Institute. Heede drew upon historic estimates of annual global carbon emissions from fossil fuel burning and cement manufacturing by the U.S. Department of Energy’s Carbon Dioxide Information Analysis Center (CDIAC) and the 2014 annual update on the global carbon budget and trends published by the Global Carbon Project (GCP), an international scientific research consortium studying the global carbon cycle.

The GCP estimates that in 2014, we will release a record 37 gigatons (GT) of carbon dioxide to the atmosphere from burning coal, oil, and natural gas, and manufacturing cement. That’s a 2.5 percent increase over emissions in 2013, itself a record year. This brings the total industrial carbon dioxide emissions since 1751 to an estimated 1480 Gt by the end of this year. And, remarkably, more than half of these emissions, 743 Gt, or 50.2 percent, have released just since 1988.

[Bruce Steele]

"The ultimate storage capacity of the ocean critically depends on the total amount of carbon emitted. Burning of 5000GtC of potentially available fossil fuel reserves would lead to a higher long-term Co2 level in the atmosphere and a reduced fractional ocean uptake capacity in comparison to, e.g. burning only 1000GtC 
( Archer 2005 ) . The impact on societies and life even after 100,000 years 
depends, thus, on our behavior concerning usage of fossil fuel reserves today." 

It has taken me ten years of reading to get a decent grip on this subject. In the below linked ( open access) paper is a very good synopsis of the ocean carbon cycle with some insights to the terrestrial carbon cycle included. 66 pages but well worth the effort.

http://www.earth-syst-dynam-discuss.net/5/1607/2014/esdd-5-1607-2014.pdf

[Bruce Steele]

Wili, When  I started my education on acidification in 2004 we were burning about 27 GtCo2 annually and like your link says we are now emitting around 37GtCo2. Nothing I have read on the policy and solutions page of this blog has changed that trend. Nothing in the dreamland certain people reside in can resolve this burning issue. The numbers in chart you linked+ land use change emissions are and will continue to scrub out various lifeforms on this planet.  If we continue, and all signs are we will, the downsides of our optimism , it's all good ,and full steam ahead f/f driven civilization are extinctions extending some 100,000 years into the future. The irony is we will have done it to maintain our creature comforts and expectations of unlimited growth. What a legacy ours. 

[wili]

Thanks, Bruce. It is a huge and subtle factor.

As I understand it, if we stopped all further CO2 emissions today, the oceans would continue to absorb CO2 because we have been raising atmospheric concentrations so fast, the oceans have not 'caught up' to an equilibrium level yet.

But then the oceans would release more CO2 whenever atmospheric levels started to drop, extending the effective atmospheric 'staying time' of CO2 in the atmosphere.

And of course, as we warm the oceans, it becomes harder for them to absorb as much CO2.

I still don't have a clear sense of whether we could at some point warm the oceans so much that they start shedding CO2. Basically, I wonder what level of heating overcomes what level of atmospheric concentrations. I'm sure there are some basic physics equations that would solve that. I'll look over your linked source to see if I can get some insights.

ETA: I found this bit from p. 14 particularly notable:

Burning of 5000 Gt C of potentially available fossil fuel reserves would lead to a higher long-term CO2 level in the atmosphere and a reduced fractional ocean uptake capacity in comparison to, e.g. burning only 1000 Gt C (Archer, 2005).

The impact on societies and life even after 100 000 years depends, thus, on our behaviour concerning usage of fossil fuel reserves today. This fact as well has to be taken into account for greenhouse gas emission reduction strategies.

[AbruptSLR]

Past 2100, I think that our biggest concern may be methane emissions from hydrates and the permafrost as discussed in the linked article; which reported on the findings from cores that indicated two carbon pulses during the PETM, with the first one smaller than the second; which raises the possibility the with strong forcing, positive feedback mechanisms (possibly from methane hydrates) may be stronger than previously thought.  As we pump all of this heat into the oceans it will eventually contribute to decomposition of marine methane hydrates:

http://www.nbcnews.com/science/environment/earths-future-ancient-warming-gives-ominous-peek-climate-change-n268721

Quote: "Intriguingly, Bowen and his colleagues determined that there were actually two releases of carbon into the atmosphere, one before the PETM and one shortly after it started.
And that may be a sign of scary things to come.
"One possible explanation is that the first, the smaller one, caused some climate change that triggered a second one," Bowen said. "So it's possible that the current pulse we are adding to the atmosphere may trigger unanticipated feedbacks that might lead to warming that could last hundreds of thousands of years."
That first release of carbon could have been the result of volcanism, Bowen says. And that might have caused the oceans to warm, which could have led to the melting of methane that lies in frozen deposits on the sea floor. And that could have accounted for the second pulse.
"We don't need a ton of warming for that to happen," Bowen said. "That's a little scary.""

http://www.nature.com/articles/ngeo2316.epdf?referrer_access_token=8qL2xHzOIEYqtOXeHGWNHNRgN0jAjWel9jnR3ZoTv0MFms2cyCBGVzLm4qXkc0yPPRqtmlhoybdEeLtzJY_dafXV2xa9tGePtpL1D8YTJOU%3D

[Bruce Steele]

The oceans are the ultimate sink for almost all anthropogenic carbon emissions. Although physical forces are responsible for the equalization of gas pressures across the oceanic/ atmosphere interface
( sea surface ) biological processes are largely responsible for transferring the carbon to depth . Although most carbon is recycled it is almost exclusively biologically produced shell that is responsible for very long term sequestration of carbon. So anything that cuts the oceans ability to sequester carbon changes the ability of the planet to put carbon away for very long 100,000 to millions of years time scales. Physical processes of rain dissolving both terrestrial carbonates and silicates can restore the pH balance of the oceans and thus it's ability to sequester carbon but this process takes ~ 100,000
years. 
 There are many interacting processes both biological and physical driving the carbon cycle. So by our release of Co2 we have forced a temperature spike in our atmosphere and oceans as well as a rapid shift in ocean pH. The heating will magnify further releases of terrestrial carbon and with enough heat force terrestrial sinks into sources.  Those releases will further both heating and acidification. Methane from both terrestrial and ocean sources will contribute to atmospheric heating and as Co2 is a breakdown product of methane reduction so too will methane contribute to acidification.
 Two big things then begin to compromise the oceans carbon cycle . Heating causes increased stratification. Very cold salty water is required for bottom water formation and ventilization. As the surface waters warm and as the arctic and antarctic ice begins to melt it both freshens and warms the areas responsible for bottom water formation, i.e. Less mixing and stratification. Downwelling drives both oxygen and nutrients to depth and upwelling brings back the nutrients to surface waters so stratification chokes off biological productivity and part of the carbon sink. Acidification is the second part that also interrupts part of the oceans ability to sink carbon.
 The net result of all this is that at the very same time the system becomes overtaxed with 
Co2 the earth processes to remove it long term begin to fail. This is why there is such a long tail on the effects of our carbon emissions and nobody can really tell you at what point we have crossed the rubicon. Once the sinks become sources we have locked  the earth system into finding a new stable state 

[Laurent]

Where does the fat go when you lose it? (Hint: The fat fairy is not involved.)
http://www.washingtonpost.com/news/to-your-health/wp/2014/12/16/where-does-the-fat-go-when-you-lose-it-hint-the-fat-fairy-is-not-involved/

[Bruce Steele]

There are three lifeforms that predominate the shell builders in the open ocean. Coccoliths, forams, and diatoms. Anything that challenges the productivity of these lifeforms disrupts potentially the strength of the oceanic carbon pump. The study below looked at the effects of increased Co2 on diatoms in the Bering Sea.

 From the conclusion ,     The present study showed that an increase in Co2 levels could have negative impacts on diatom biomass in the Bering Sea, especially under Fe-limited conditions. Because diatoms play pivotal roles in carbon sequestration and food webs in the Bering Sea( Springer et al 1996 Takchashi 2002 ) our results indicate that ocean acidification might alter the biogeochemical processes and ecological dynamics in the study area.

http://www.biogeosciences-discuss.net/11/18105/2014/bgd-11-18105-2014.pdf

[werther]

I had a look at methane after my regular check of the Keeling Curve. Although the scale difference makes it hard to assess the similarity of both curves, it is clear both trend upward and accelerate through the last two years.

There’s no 'burp' yet. My guess is that the most important origin of the recent acceleration is to be found in the oceans. Their recent warming promotes the activity of bio-degrading microbes. There’s more than enough degradable biomass at hand. Human produced waste, sediment contamined with dung and fertilizers, oil spills, dying sea-life.

Second, the transition to use of natural gas (FI through fracking) and upscaled open coal mining in FI China and India could be a source.

I’d suggest the thawing and oxidization of permafrost biomass contributes, but is not yet the most important accelerator.
While that might be reassuring for now, it is ominous that even without passing the threshold for largescale permafrost thaw and hydrate release there’s no sign that human efforts to reduce GHG emissions have any success.

[Laurent]

Researchers identify missing component in marine carbon, sulfur cycles
http://phys.org/news/2015-01-component-marine-carbon-sulfur.html

[Laurent]

Melting Glaciers Pose a Carbon Menace
http://www.livescience.com/49510-melting-glaciers-release-carbon.html

[jai mitchell]

2C of warming is equal to 700 Gigatonnes* of Carbon Anthropogenic emissions:

http://www.pik-potsdam.de/~victor/recent/friedlingstein_etal_C4MIP_2005

see figure 2a


*note: the 700 GT of Carbon emissions value is equivalent to 300 GT of Carbon from the earth since 55% of all human emissions are removed by the earth.  The carbon cycle emissions represent a net reduction in the earth's carbon removal ability.

-also note:  emissions from frozen soils not modeled below.

[Bruce Steele]

Current methods of measuring temperature and salinity to determine acidity are restricted to in situ instruments and measurements taken from research vessels. This approach limits the sampling to small areas of the ocean, as research vessels are very expensive to run and operate.

The new techniques use satellite mounted thermal cameras to measure ocean temperature while microwave sensors measure the salinity. Together these measurements can be used to assess ocean acidification more quickly and over much larger areas than has been possible before.

Dr Peter Land from Plymouth Marine Laboratory who is lead author of the paper said: "In recent years, great advances have been made in the global provision of satellite and in situ data. It is now time to evaluate how to make the most of these new data sources to help us monitor ocean acidification, and to establish where satellite data can make the best contribution."

A number of existing satellites can be used for the task; these include the European Space Agency's Soil Moisture and Ocean Salinity (SMOS) sensor that was launched in 2009 and NASA's Aquarius satellite that was launched in 2011.

http://www.eurekalert.org/pub_releases/2015-02/uoe-sir021315.php

[Laurent]

Solving carbon mysteries of the deep ocean
http://newsoffice.mit.edu/2015/solving-carbon-mysteries-deep-ocean-0217

[AbruptSLR]

The following link leads to a video showing a comparison of direct atmospheric CO2 measurements vs direct measurement of radiative forcing, and they track very closely with seasonal and long-term trends:

[Pmt111500]

The following link leads to a video showing a comparison of direct atmospheric CO2 measurements vs direct measurement of radiative forcing, and they track very closely with seasonal and long-term trends:

they're claiming that's the first measurement from the ground (I guess without help from the satellites), though likely this has been done occasionally before, just not through a whole year.
the things scientists must do, for some idjots who believe the properties of gases change when gases are outside the lab.

[KeithAnt]

I suppose this study might be termed a denier's nightmare, the measurement of the energy balance in situ:

 http://phys.org/news/2015-02-carbon-dioxide-greenhouse-effect.html?utm_source=nwletter&utm_medium=email&utm_content=ctgr-item&utm_campaign=daily-nwletter

[AbruptSLR]

The linked reference (with a free access pdf) discusses 850 to 2100 CE calibration of carbon cycle dynamics & climate change:

Lehner, F., Joos, F., Raible, C. C., Mignot, J., Born, A., Keller, K. M., and Stocker, T. F.: Climate and carbon cycle dynamics in a CESM simulation from 850–2100 CE, Earth Syst. Dynam. Discuss., 6, 351-406, doi:10.5194/esdd-6-351-2015, 2015.

http://www.earth-syst-dynam-discuss.net/6/351/2015/esdd-6-351-2015.pdf

Abstract: " Abstract. Under the protocols of the Paleoclimate and Coupled Modelling Intercomparison Projects a number of simulations were produced that provide a range of potential climate evolutions from the last millennium to the end of the current century. Here, we present the first simulation with the Community Earth System Model (CESM), which includes an interactive carbon cycle, that continuously covers the last millennium, the historical period, and the twenty-first century. Besides state-of-the-art forcing reconstructions, we apply a modified reconstruction of total solar irradiance to shed light on the issue of forcing uncertainty in the context of the last millennium. Nevertheless, we find that structural uncertainties between different models can still dominate over forcing uncertainty for quantities such as hemispheric temperatures or the land and ocean carbon cycle response. Comparing with other model simulations we find forced decadal-scale variability to occur mainly after volcanic eruptions, while during other periods internal variability masks potentially forced signals and calls for larger ensembles in paleoclimate modeling studies. At the same time, we fail to attribute millennial temperature trends to orbital forcing, as has been suggested recently. The climate-carbon cycle sensitivity in CESM during the last millennium is estimated to be about 1.3 ppm °C−1. However, the dependence of this sensitivity on the exact time period and scale illustrates the prevailing challenge of deriving robust constrains on this quantity from paleoclimate proxies. In particular, the response of the land carbon cycle to volcanic forcing shows fundamental differences between different models. In CESM the tropical land dictates the response to volcanoes with a distinct behavior for large and moderate eruptions. Under anthropogenic emissions, global land and ocean carbon uptake rates emerge from the envelope of interannual natural variability as simulated for the last millennium by about year 1947 and 1877, respectively."

[Laurent]

Keystone plankton 'go slow' as ocean acidity rises
http://www.theecologist.org/News/news_round_up/2775311/keystone_plankton_go_slow_as_ocean_acidity_rises.html

[Bruce Steele]

Laurent, Thanks for the link to the variable light / diatom study. ASLR and I put some comments in over on the consequences page about the same paper. The issue of geo-engineering also came up so
as usual the same conversation could be posted on a number of different threads. How the carbon cycle interacts with light intensity is about as fundamental as it gets so I would expect similar experiments on different plankton species will be something we see in the future. The whole notion that moderating light intensity via geo-engineering might be temporarily beneficial to an important part of the carbon sink is something to contemplate. Spooky on so many levels.   

[Laurent]

Sorry, I did see your post later on.
Here is something that may be involved in carbon cycle ?

These Ultra-Small Bacteria May Be The Tiniest Life Forms On Earth
http://www.huffingtonpost.com/2015/03/02/smallest-life-on-earth-bacteria_n_6783382.html?utm_hp_ref=green&ir=Green

[Laurent]

 Hungry insects may halve forest carbon sink capacity

http://www.newscientist.com/article/dn27064-hungry-insects-may-halve-forest-carbon-sink-capacity.html?cmpid=RSS|NSNS|2012-GLOBAL|environment#.VPTB5c13_z8

[Bruce Steele]

Decreased calcification in the Southern Ocean over the satellite record
Published 3 March 2015    Science Leave a Comment
Tags: Antarctic, calcification, chemistry, field
Widespread ocean acidification is occurring as the ocean absorbs anthropogenic carbon dioxide from the atmosphere, threatening marine ecosystems, particularly the calcifying plankton that provide the base of the marine food chain and play a key role within the global carbon cycle. We use satellite estimates of particulate inorganic carbon (PIC), surface chlorophyll, and sea surface temperature to provide a first estimate of changing calcification rates throughout the Southern Ocean. From 1998 to 2014 we observe a 4% basin-wide reduction in summer calcification, with ~9% reductions in large regions (~1×106 km2) of the Pacific and Indian sectors. Southern Ocean trends are spatially heterogeneous and primarily driven by changes in PIC concentration (suspended calcite), which has declined by ~24% in these regions. The observed decline in Southern Ocean calcification and PIC is suggestive of large-scale changes in the carbon cycle and provides insight into organism vulnerability in a changing environment.


Freeman N. M. & Lovenduski N. S., in press. Decreased calcification in the Southern Ocean over the satellite record. Geophysical Research Letters. Article (subscription required).

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[Laurent]

May be that other bacterias are important for carbon and nitrogen cycles.
http://www.eurekalert.org/pub_releases/2015-03/uomc-mmh030215.php

Microbes can breathe oxygen like you and I, but when it goes away, they can breathe other things, such as nitrogen," she said. Understanding how these reactions work in low oxygen zones is important. As the ocean warms up, those zones may expand.