How NOAA and Bad Modeling Invented an “Ocean Acidification” Icon: Part 2 – Bad Models

Guest essay by Jim Steele

Director emeritus Sierra Nevada Field Campus, San Francisco State University and author of Landscapes & Cycles: An Environmentalist’s Journey to Climate Skepticism

Are the Oceans’ Upper Layers Really Acidifying?

As detailed in Part 1, NOAA’s Bednarsek, incorrectly attributed the dissolution of sea butterfly shells to anthropogenic CO2 although the evidence clearly showed the natural upwelling of deeper low pH waters were to blame. Based on models employed by NOAA’s Feely and Sabine, Bednarsek claimed the upper ocean layers are becoming more acidic and less hospitable to sea butterflies relative to pre-industrial times. However detecting the location and the depth at which anthropogenic CO2 now resides is a very, very difficult task. Because the ocean contains a large reservoir of inorganic carbon, 50 times greater than the atmospheric reservoir, the anthropogenic contribution is relatively small. Furthermore anthropogenic carbon comprises less that 2% of the combined CO2 entering and leaving the ocean surface each year. Thus there is a very small signal to noise ratio prohibiting accurate detection of anthropogenic CO2. Despite admittedly large uncertainties, modelers boldly attempt to infer which layers of the ocean are acidifying.

(To clarifying terminology, an organic carbon molecule is a molecule that is joined to one or more other carbons, such as carbohydrates and hydrocarbons. CO2 with a lone carbon is considered inorganic, and when dissolved can take 3 forms (or “species”) collectively referred to as Dissolved Inorganic Carbon (henceforth DIC): 1) Carbonic acid (H2CO3), 2) Bicarbonate ion (HCO3) after losing one H+ 3) Carbonate ion (CO3-2) after losing a second H+ )

However model results are based on three very dubious assumptions:

1) Models assume surface layers absorb anthropogenic CO2 by reaching equilibrium with atmospheric concentrations. With minor adjustments, models simply calculate how much dissolved inorganic carbon (DIC) will be added to the ocean based on increased atmospheric CO2 since pre-industrial times.

2) Models assume CO2 will diffuse into the upper ocean layers and be transported throughout the ocean in a similar fashion to tracers, like CFCs. Because CFCs accumulate disproportionately near the surface, models assume DIC does as well.

3) Models assume biosphere is in a steady state. Thus they do not take into account increased primary production and the rapid export of carbon to depth.

Although there is no doubt anthropogenic CO2 is taken up by the oceans, assertions that ocean surface layers are acidifying are the results of faulty model assumptions.

What Equilibrium?

CO2 equilibrium is rarely achieved between ocean and atmosphere. Ocean surface pH and thus calcium carbonate saturation levels are determined by the efficiency of the biological pump. In other words, when, where, and how much CO2 enters the ocean surface, requires surface CO2 concentrations to be lower than atmospheric concentrations. That difference depends on how much CO2 is fixed into organic carbon by photosynthesis and subsequently exported it to depth, or how much CO2 is upwelling. Photosynthesis indiscriminately draws down all CO2 molecules that have invaded surface waters either via upwelling from depth or by diffusion from the atmosphere. Despite opposing effects of mixing and diffusion, the biological pump maintains a strong vertical gradient of high surface water pH and low DIC, with decreasing pH and increasing DIC at greater depths. In regions where strong upwelling of DIC from the deeper ocean overwhelms the ability of photosynthesizing organisms to sequester carbon, surface pH drops and CO2 is outgassed to the atmosphere. Several models estimate that without the biological pump, atmospheric CO2 would increase by 200 to 300 ppm above current levels.

The efficiency of the biological pump determines to what depths anthropogenic carbon will be transported. However NOAA’s Sabine does not model the effects of the biological pump, oddly stating “although ocean biology plays an integral role in the natural distribution of carbon in the ocean, there is no conclusive evidence that the ocean uptake and storage of anthropogenic carbon, thus far, involve anything other than a chemical and physical response to rising atmospheric CO2.”

Does Sabine truly believe the undeniable biological pump discriminates between anthropogenic and natural carbon? Or does he believe that there have been no changes in primary production and carbon export? As primary production increases, so does the carbon export to depth. Annual primary production in the Arctic has increased by 30% since 1998. We can infer primary production increased in the Sargasso Sea based on a 61% increase in mesoplankton between 1994 and 2006. North Atlantic coccolithophores have increased by 37% between 1990 and 2012. And primary production and carbon export in the Peru Current has dramatically increased since the end of the Little Ice Age. The increasing trend in primary production and accompanying carbon export is potent evidence supporting an alternative hypothesis that the biological pump has sequestered increased invasions of anthropogenic CO2.

An examination of seasonal changes in surface CO2 concentration, illustrates how the biological pump determines when and how much CO2 enters the ocean, and how much DIC accumulates near the surface. As exemplified by the graph below from 2008 buoy data off the coast of Newport, Oregon (Evans 2011), each spring photosynthesis lowers ocean surface CO2 to 200 ppm, far below current atmospheric concentrations and much lower than what would be expected from equilibrium with a pre-industrial atmosphere. Spring surface waters are supersaturated, and any downwelling or mixing of these supersaturated waters cannot acidify upwelled water or subsurface layers. Furthermore the springtime draw down conclusively removes any anthropogenic CO2 residing in sunlit waters. Furthermore experiments show CO2 is often a limiting nutrient and added atmospheric CO2 stimulates photosynthesis. Microcosm experiments found that when atmospheric CO2 was increased, the plankton community consumed 39% more DIC.


Upwelling season begins in summer extending through fall. As illustrated above, upwelling events rapidly raise surface concentrations of CO2, reaching 1000 ppm. Physics dictates there can be no net diffusion from the atmosphere into the ocean when the oceanic concentration is higher than atmospheric, and thus there are virtually no anthropogenic additions during upwelling season. Here any lowering of surface pH or calcium carbonate saturation must be due to upwelling.

Finally during the winter, (not illustrated) surface waters exhibited a steady CO2 concentration of 340 ppm. Although photosynthesis is reduced, and winter mixing brings more subsurface carbon and nutrients to the surface, the surface remains below equilibrium with the atmosphere. Although surface concentrations are low enough to permit the invasion of atmospheric CO2, the biological pump continues to export that carbon to depth so that surface layers remain supersaturated all winter.

Diffusion of CO2 into the ocean is a slow process. It is believed that it requires about 1 year for the oceans to equilibrate with an atmospheric disturbance. But as spring arrives, increasing sunlight again enhances photosynthesis, so whatever anthropogenic CO2 that may have invaded the surface over the course of the year, is once again fully sequestered and pumped to depth, lowering surface CO2 concentrations to 200 ppm. Bednarsek’s claim that anthropogenic CO2 is acidifying the upwelled water along the Oregon California Coast is once again not supported.

Tracers Do Not Correctly Simulate Transport of Anthropogenic Carbon


Tracers like chlorofluorocarbons (CFCs) are synthetic gases that are biologically inert. They were introduced to the world during the 1920s primarily as a refrigerant. Climate scientists have assumed the physical transport and accumulation of CFCs and increasing anthropogenic carbon will be similar. Below in Figure 1, the red area just south of Greenland designates an area that has accumulated the most CFCs. This local concentration happens when high salinity Atlantic waters cool and carry surface water and its dissolved gasses downward to the abyss forming North Atlantic Deep Water. It is estimated that this downwelling has exported 18% of all CFCs below 1000 meters; implying dissolved anthropogenic carbon has been similarly exported and sequestered. However elsewhere CFCs accumulate disproportionally in upper surface layers, so models assume dissolved anthropogenic CO2 is likewise accumulating nearer the surface.


Both CFCs and CO2 are gases, and their solubility is similarly modulated by temperature. Warm waters of the tropics absorb the least amount of CFCs and CO2, as illustrated by the dark blue regions in Figure 1 from Willey 2004. Thus equatorial waters feeding the California Undercurrent that upwell along the west coast have likewise absorbed the least amounts of anthropogenic carbon, if any. (The extremely low level of CO2 diffusion into the tropical ocean plus the super saturation of tropical waters, casts great misgivings on any claim that coral reefs have been significantly affected by anthropogenic acidification.)

However, unlike inert CFCs, any CO2 entering sunlit waters is quickly converted to heavy organic matter by photosynthesis. Although dissolved CFCs and dissolved carbon are passively transported in the same manner, particulate organic carbon (alive or dead) behaves very differently. Particulate carbon rapidly sinks, removing carbon from the surface to depth in ways CFC tracers fail to simulate. Examination of the literature suggests “various methods and measurements have produced estimates of sinking velocities for organic particles that span a huge range of 5 to 2700 meters per day, but that commonly lie between tens to a few hundred of meters per day”. Low estimates are biased by suspended particles that are averaged with sinking particles. Faster sinking rates are observed for pteropod shells, foraminifera, diatoms, coccolithophorids, zooplankton carapaces and feces aggregations, etc that are all capable of sinking 500 to 1000 meters per day. These sinking rates are much too rapid to allow respired CO2 from their decomposition to acidify either the source waters of upwelling such as along the Oregon and California coast, or the surface waters

Earlier experiments had suggested single cells sank very slowly at rates of only 1 meter per day and thus grossly underestimated carbon export. However single-cell organisms will aggregate into clusters that increase their sinking rates. Recent studies revealed the “ubiquitous presence of healthy photosynthetic cells, dominated by diatoms, down to 4,000 m.” Based on the length of time healthy photosynthesizing cells remain viable in the dark, sinking rates are calculated to vary from 124 to 732 meters per day, consistent with a highly efficient biological pump. Although NOAA’s scientists have expressed concern that global warming will reduce the efficiency of the biological pump by shifting the constituents of phytoplankton communities to small, slow-sinking bacteria, new research determined that bacteria also aggregate into clusters with rapid sinking rates ranging from 440 to 660 meter per day.

Sequestration of carbon depends on sinking velocities and how rapidly organic matter is decomposed. Sequestration varies in part due to variations in the phytoplankton communities. Depths of 1000 meter are considered to sequester carbon relatively permanently, as waters at those depths do not recycle to the surface for 1000 years. Weber 2016 suggests 25% of the particulate organic matter sinks to 1000 meter depths in high latitudes while only 5% reaches those depths at low latitudes. But long-term sequestration does not require sinking to 1000 meter depths. Long-term sequestration requires sinking below the pycnocline, a region where the density changes rapidly. Dense waters are not easily raised above the pycnocline, so vertical transport of nutrients and carbon is inhibited creating long-term sequestration. Because the pycnocline varies across the globe, so do sequestration depths.

Below on the left is a map (a) from Weber 2016, estimating to what depths particles must sink in order to be sequestered for 100 years. Throughout most of the Pacific particles need only sink to depths ranging from 200 to 500 meters. In contrast the golden regions around the Gulf Stream, New Zealand and southern Africa must sink to 900 meters.

The map on the right (b), estimates what proportion of organic matter leaving the sunlit waters will be sequestered. The gold in the Indian Ocean estimates 80% will reach the 100-year sequestration depth, while 60% will reach sequestration depths along the Oregon California Coast. Again casting doubt on Bednarsek’s claims of more recently acidified upwelled waters acidifying sea butterfly shells. Elsewhere in map “b”, 20% or less of the exported carbon reaches sequestration depths.


The combination of sinking velocities and sequestration depths suggests significant proportions of primary production will be sequestered in a matter of days to weeks. This is consistent with the maintenance of the vertical DIC and pH gradients detected throughout our oceans. However it conflicts with claims by NOAA’s scientists.

Biased by CFC observations Sabine wrote, “Because anthropogenic CO2 invades the ocean by gas exchange across the air-sea interface, the highest concentrations of anthropogenic CO2 are found in near-surface waters. Away from deep water formation regions, the time scales for mixing of near-surface waters downward into the deep ocean can be centuries, and as of the mid-1990s, the anthropogenic CO2 concentration in most of the deep ocean remained below the detection limit for the delta C* technique.”

That NOAA scientists fail to incorporate the fact that particulate carbon can be sequestered to harmless depths in a matter of days to weeks instead of “centuries” appears to be the cause of their catastrophic beliefs about ocean acidification. Furthermore because CFCs have accumulated near the surface with only miniscule amounts in the deeper ocean, the tracer provides absolutely no indication of how upwelling brings ancient DIC to the surface. So by relying on a CFC tracer, their models will mistakenly assume that increased concentrations of DIC near the surface must be due to accumulating anthropogenic carbon, and not upwelled ancient carbon.

The Ocean’s Biosphere Steady State?


Given a steady export percentage of primary productivity, increasing amounts carbon will be exported in proportion to increasing productivity. Thus it is reasonable to hypothesize that if marine productivity has increased since the end of the Little Ice Age (LIA) aka pre-industrial times, that increased production will have sequestered the increasing amounts of anthropogenic carbon. Although there are only a few anoxic (depleted oxygen) ocean basins, where organic sediments can be well preserved, those basins all reveal that since the Little Ice Age, marine productivity and carbon export has indeed increased as the oceans warmed.

Research from Chavez 2011 is illustrated below and demonstrates that during the LIA, marine primary productivity (d) was low, but has increased by 2 to 3 fold over the recent 150 years. Sediments reveal that fast sinking diatoms increased 10 fold at the end of the LIA, but likely due to silica limitations, since 1920 diatom flux to ocean sediments has been reduced to about a 2-fold increase over the LIA. Nonetheless numerous studies find estimates of sedimentary diatom abundance is representative of carbon export production in coastal upwelling regions.


The increased primary production coincides with over a hundred-fold increase in fish scales and bones (f). And consistent with the need for increased nutrients to support increased primary production, proxy evidence suggests a 2-fold increase in nutrients in the water column (c). Such evidence is why researchers have suggested their observed decadal increases in upwelled DIC and nutrients might be part of a much longer trend. Finally in contrast to the global warming explanation for depleted ocean oxygen, the decomposition of increased organic carbon provides a more likely explanation for observations of decreased oxygen concentrations in the water column (a) and sediments (b). Because primary production had doubled by 1900, long before global warming or before anthropogenic CO2 had reach significant concentrations, it is unlikely anthropogenic CO2 contributed to increased upwelling, increased primary production or any other trends in this region

However increased primary production alone does not guarantee that sinking particulate carbon is removing enough carbon to counteract anthropogenic additions. However there are dynamics that suggest this must be the case. First consider that an examination of the elements constituting a phytoplankton community, there is a common ratio of 106 carbon atoms detected for every 16 nitrogen atoms (aka a Redfield ratio). Given that nitrogen typically limits photosynthetic production, if carbon and nitrogen are upwelled in the same Redfield proportion, unless other dynamics cause an excess of nitrogen, photosynthesis might only assimilate upwelled carbon but not enough to account for all the additional anthropogenic carbon.

However calcifying organisms like pteropods, coccolithophores and foraminifera export greater proportions of inorganic carbon because their sinking calcium carbonate shells lack nitrogen. This can create an excess of nitrogen relative to upwelled carbon in surface waters. Second diazotrophs are organisms that convert atmospheric nitrogen into biologically useful forms. Free-living diazotrophs like the cyanobacterium Trichodesmium, can be so abundant their blooms are readily observed. (The blooms of one species are primarily responsible for the coloration of the Red Sea.) Some diazotrophs form symbiotic relationships with diatoms and coral. So diazotrophs can cause an excess of nitrogen that allows photosynthesis to assimilate both upwelled carbon and anthropogenic carbon. Furthermore as discussed in Mackey 2015 (and references therein) “To date, almost all studies suggest that N2 fixation will increase in response to enhanced CO2.”

With all things considered, the evidence suggests NOAA scientists have an upside down characterization of the ocean’s “steady state.” There is no rigid rate of primary production and export that prevents assimilating anthropogenic carbon and pumping it to depth. On the contrary the combined dynamics of nitrogen fixation and the biological pump, suggest the upper layers of the ocean have likely maintained a pH homeostasis, or a pH steady state, at least since pre-industrial times. Increases in atmospheric CO2, whether from natural upwelling or from anthropogenic sources, are most likely assimilated quickly and exported to ocean depths where they are safely sequestered for centuries and millennia. As also discussed in the article How Gaia and Coral Reefs Regulate Ocean pH, claims that the upper ocean has acidified since preindustrial times are not measurements, but merely results from modeling a “dead” ocean and ignoring critical biological processes.

Jim Steele is author of Landscapes & Cycles: An Environmentalist’s Journey to Climate Skepticism


40 thoughts on “How NOAA and Bad Modeling Invented an “Ocean Acidification” Icon: Part 2 – Bad Models

  1. Great stuff. OA via atmospheric human CO2 contribution is just nonsen.. non-science.

    Interesting read, thanks.

    It’s policy based science

  2. Why I don’t trust NOAA is comments like this “highest concentrations of anthropogenic CO2” This is basically unscientific “all things being equalism” ie any change is anthropogenic without any real evidence to back it up, just model output, models that don’t fully define the system they are meant to be modeling

    • Since the environment can’t tell the difference between anthropogenic CO2 and non-anthropogenic CO2, all that matters is total CO2 levels. And total CO2 levels have been much much higher in the past.

    • Also comments like “Because anthropogenic CO2 invades the ocean by gas exchange across the air-sea interface…”. Why use the emotive “invades” when “enters” is much more appropriate?

  3. Another great post. Important subfact addendum. The reported correlations between rising ocean pCO2 and declining pH come from two primary places: Station Aloha north of Hawaii in the North Pacific, and BATS off Bermuda in the North Atlantic. At both locations, the ocean is relatively barren (mainly lack of trace iron from wind blown dust) so the biological pump is minimized at both locations. Most ocean is much more fertile. Mid Atlantic fertilized by Sahara. Western Pacific fertilized by Gobi. Southern and Indian oceans fertilized by Australian outback and India outside the monsoon season.
    So the ‘acidification’ observations and papers flowing from those two locations have a large intrinsic bias. Proof: Station Aloha seasonal pH variation is 0.1. In the more fertile Southern Ocean it is 0.5. Direct evidence of the importance of the biological pump.

    • Ristvan

      Thanks for that set of important details from the more fertile regions. I also note that the areas where iron fertilization has been done experimentally were selected on the basis of their local depletion, not randomly.

  4. Depths of 1000 meter are considered to sequester carbon relatively permanently, as waters at those depths do not recycle to the surface for 1000 years.

    In aggregate, that may be true. I can’t tell. There seems to be plenty of evidence that one shouldn’t ignore vertical transport at any ocean depth due to downwelling and geothermal heating.

    • The vertical transport in the up direction cannot be close to that,in the down direction. Part of the biological pump is organic matter and that can conceivably be biologically recycled and upwelled. But part is carbonate ( e.g. From coccolithophores and faraminifera). We know from massive limestone formations that it reaches the seabed and over geological time forms carbonate rock. which then gets tectonically uplifted where we can quarry it. Such rock only gets recycled into CO2 by subduction zone volcanism. No reason to think that indisputable geological fact is not still operating today. So a lot of biologically sequestered DIC is sequestered for much muchnlonger than a 1000 years.

      • Les, hard to argue with those facts. Bakken has only 5 sweet spots that paid when oil was $100/bbl. They comprise about 25% of the total unit. Another 25% might pay to be drilled in the future when oil is again over $100/bbl. there will be less oil/well and steeper decline curves in those. When I published on this in 2012, there was room for about 10000 more wells beyond the 6000 drilled in those spots at the then accepted lateral spacing. Lateral spacing has gotten tighter since, but OTH a lot more wells have also been drilled since. I don’t think you can write Bakken off, but it may well have already seen its best days. More marginal plays beyond sweetspot edges, steeper decline curves…and Bakken needs higher prices than the Permian because less pre-existing infrastructure. Permian has been producing since 1916 from conventional reservoirs.

      • My quibble was with:

        … waters at those depths do not recycle to the surface for 1000 years.

    • Bob, I agree and I would never suggest ignoring vertical transport anywhere, but at each region we can estimate the depth from which upwelling waters originate

      A general rule of thumb is transport moves along planes of similar density. It takes a lot of energy to raise a denser layer above a less dense layer. So identifying a permanent pycnocline suggests the limits of upwelling source waters. The powerful winds driving the Antarctic Circumpolar Current plus the cold dense water around Antarctica makes that region one of the few places where dense deep waters can be brought to the surface. So this region has a deeper sequestration depth.

      Relatively shallow subsurface layers can more easily outcrop during the winter as the surface layers become colder and denser in the winter. Coastal upwelling typically draws from source waters at 100 to 200 meters deep.

      In subtropical gyres, the pycnocline may be very shallow, and stratification is strong such that upwelling waters originate from very shallow layers.

      • My guess is that the tropics is a place where upwelling is sourced from about 1km deep. A while ago, I took gridded Argo data, averaged out the longitudinal dimension and generated the following plot. At each level, I normalized the temperature to +/- 2 s.d. Naively it looks like 1km deep water is upwelled into the well mixed layer at the tropics.

  5. Cannot understand how CFCs can be used as hints to proxies for CO2. CFCs are very nonpolar molecules compared to CO2. The surface water film on top of, or around, any water body from aerosols (the potentially most CFC transporter due to surface area) to the Pacific Ocean, has this film. It is a very hydrophobic film soaking up gases at rates pending on molecular specific properties (here polarity), concentration and saturation in a three phase compartment at the border of an water body. The CO2 is moreover, as described, modulated by both biological activity and the DIC compartment system. Seems like two very different and not comparable stories to me.

    • Nutty, I had the same thought about using CFCs as proxies. I also have a problem with:

      1) Models assume surface layers absorb anthropogenic CO2 by reaching equilibrium with atmospheric concentrations.

      As the concentrations approach equilibrium, the diffusion and convective absorption rates diminish due to the reduction in the concentration difference driving force. Reaching equilibrium should be proven instead of assumed.

    • CFCs are very nonpolar molecules compared to CO2.
      You appear to have this backwards, CO2 does not have a permanent dipole whereas Freon 12 has a permanent dipole.

  6. Interesting analysis. It sounds like NOAA does not know about marine snow and its complications and interactions with larvae as one example. If this is an ignorance of lesser, but increasingly better, known biological processes that can modify physical rather than the opposite, it looks like we have a long way to go. Although not oceanic, mullet change clay minerals which are difficult to model even in a sterile setting. Not very definitive, but just looking at all the adaptations organisms developed to try to stay afloat suggests that sinking is a big problem. I seem to recall being taught something like that.

    • There’s also the Fecal Express:
      Fecal Express was discovered in the late 60s-early70s by studying the fate of Hanford production radionuclides carried by the Columbia River out into the Pacific. The radionuclides reached the botom sooner than Stokes settling velocity would predict. It turned out that plankton fecal pellets which carried the radioactivity were falling to the bottom faster than the marine snow.

  7. Finally I get where we (skeptic) are wrong! We don’t understand that “man made” CO2 is extremely worst than “natural” CO2!!!! The two CO2 molecule are “physically” equal but not “qualitative”.
    There must be an “invisible” characteristic like “dark matter” or “dark energy” that made the difference between the two.

  8. However, unlike inert CFCs, any CO2 entering sunlit waters is quickly converted to heavy organic matter by photosynthesis.

    As I posted twice yesterday this statement is incorrect!
    Mods: perhaps you could retrieve them from whatever black hole they ended up in?

  9. Dr. Steele,

    May I disagree on this topic?

    The ocean surface mixed layer contains about 1000 GtC, the atmosphere currently around 800 GtC. The seasonal exchanges are around 50 GtC two-way due to temperature changes, thus around 5%. As both are thouroughly mixed, any change in the atmosphere is rapidly distributed into the ocean surface with a half life time of less than a year, With one restriction: due to buffer chemistry, the change in DIC in the ocean surface is about 10% of the CO2 change in the atmosphere.

    The distribution of human introduced CO2 is not only based on CFC’s but also on -limited- direct measurements over time:

    1) Models assume surface layers absorb anthropogenic CO2 by reaching equilibrium with atmospheric concentrations.

    Not only do they assume that, it is backed by some 7 stations and further repeated ships measurements on the same tracks where DIC was measured over longer time spans, of which Bermuda has the longest record. That confirmed the 10% ratio between the CO2 increase in the atmosphere and the increase of DIC in the ocean surface plus the drop in pH. Here the synthesis of the 7 stations:

    That includes both high productivity areas (Iceland) and less productive areas (Hawaii).

    Models assume biosphere is in a steady state. Thus they do not take into account increased primary production and the rapid export of carbon to depth.

    There are several investigations about primary production and its effect on DIC, pH, pCO2,… as one can already see in the seasonal graphs of the 7 stations above, but here is a detailed one of the Bering Sea shelf:

    Further, that the surface waters follow the atmospheric change in human CO2 can be seen in the 13C/12C ratio change of coralline sponges (Bermuda and Jamaica):

    graph from:

    Even with an enhanced biological pump, it is clear that human CO2 increased DIC in the ocean surface and lowered the pH at every place where was measured…

  10. A limiting factor in the biologic pump is the availability of iron. The few experiments I’ve seen of purposefully salting the ocean with iron have been hugely successful in stimulating biologic activity. I haven’t heard much about this recently.

    One study showed we could reduce CO2 by 33ppm and another claimed 41.8ppm. I don’t know why those concerned about AGW aren’t pushing for this? Maybe they don’t actually want a solution?

    The Haida had record returns from their un-authorized experiment. It seems to be a solution to over-fishing. This seems to be a win win endeavor so I don’t know why it’s no being pursued?

    • gyan, Indeed can be a limiting factor along with DIC, silicic acid and inorganic notrogen. Anthony post a summary of the iron experiment on WUWT in 2012. The iron fertilization experiment supported my arguments here that carbon can be rapidly exported to depth and contrasted to other studies showing less export:

      “We were able to prove that over 50 per cent of the plankton bloom sank below 1000 metre depth indicating that their carbon content can be stored in the deep ocean and in the underlying seafloor sediments for time scales of well over a century”, says Smetacek.”

  11. So, Ferd, you are assuming the entire ocean is characterized by 7 stations and a few ships? One could argue the ships typify the uncertainty principle by causing the mixing during their passage through the waters.

    BTW, Ferd, I appreciate your comment backed up with data and the reasonable tone. Flame wars get tiring.

    • oeman50,

      Indeed only 7 fixed stations with sufficient long sample periods, but e.g. Bermuda reflects the trends of the whole subtropical Atlantic Gyre, as was tested with seaship measurements. Several more have too short periods or have gaps in occupation, but all show similar trends.

      More and more commercial ships are equipped with maintenance free apparatus which takes lots of measurements from the seawater (motor cooling water) inlet. That includes pCO2 (some already over three decades), and more recently pH (colorimetric, accurate to 0.001 pH unit), so that at least for the main ship lanes there will be a continuous monitoring. The same for moored buoys at fixed places and floating buoys…

      While that is – just like the ARGO floats – still an absolute minimum in the wide oceans, the important point is that everywhere where is measured similar trends are found. It would be quite strange that in un/undermeasured parts of the oceans one may have the opposite trends…

  12. Ferdinand asks, “May I disagree on this topic?”

    By all means, please do. You have always been a respectful and knowledgeable poster.

    That said, depending on the author the literature reports between 50-70Pg of carbon entering and 50-70Pg leaving the surface.

    I am very familiar with the Bates paper and its assertion that 7 stations confirm anthropogenic acidification predictions.

    My question to you is why are you so certain that measurements of increased DIC means that DIC is coming from the atmosphere and not due to increased upwelling, or winter mixing, or advection?

    Subtropical gyres pump waters towards the center where stations like BATS and HOT are located. Of those 7 stations BATS has the longest record which goes back to 1982, and thus observed increases in DIC can be attributed to changes in natural oscillations. In Long-term increase in mesozooplankton biomass in the Sargasso Sea: Linkage to climate and implications for food web dynamics and biogeochemical cycling by Steinberg 2012, they show “Significant correlations exist between multidecadal climate indices–the North Atlantic Oscillation plus three different Pacific Ocean climate indices, and BATS zooplankton biomass, indicating connections between patterns in climate forcing and ecosystem response.”

    For example in the 2016 paper Long-term variability of phytoplankton carbon
    biomass in the Sargasso Sea, Wallhead reports ” an increasing trend (~3% per year) in total phytoplankton carbon, apparently driven by increasing nutrient supply by vertical mixing associated with a shift to a negative phase
    in the winter North Atlantic Oscillation index. Also, the reconstructed eukaryote biomass fraction shows a multiannual shift from~45%in the early 1990s/late 2000s to ~70%in the late 1990s/early 2000s.” This readily explains the trends at BATS.

    From Astor 2013, Interannual variability in sea surface temperature and
    fCO2 changes in the Cariaco Basin, due to changing locations and strength of the InterTropical Convergence Zone (ITCZ), trade winds over northern Venezuela’s Cariaco Basin undergo decadal and centennial shifts in strength. When the ITCZ moved south during the Little Ice Age, upwelling and productivity in the Cariaco Basin declined. At the end of the LIA, the ITCZ began moving northward and upwelling and productivity increased (Gutierrez 2009). Recently the ITCZ moved further northward due to more La Niña’s and the negative Pacific Decadal Oscillation, and regional winds declined. Consequently researchers reported anomalously shallow seasonal upwelling that brought more DIC to the surface but fewer critical nutrients that reside at lower depths. This resulted in decreased productivity and a decrease in diatom populations. Less productivity and less carbon export did not offset upwelled DIC, so the regional pH declined.

    Around the Hawaiian stain HOT in Dore 2009 Physical and biogeochemical modulation of ocean acidification in the central North Pacific they reported “Air-sea CO2 fluxes, while variable, did not appear to exert an influence on surface pH variability. For example, low fluxes of CO2 into the sea from 1998–2002 corresponded with low pH and relatively high fluxes during 2003–2005 were coincident with high pH; the opposite pattern would be expected if variability in the atmospheric CO2 invasion was the primary driver of anomalous DIC accumulation.”

    • Dr. Steele,

      My question to you is why are you so certain that measurements of increased DIC means that DIC is coming from the atmosphere and not due to increased upwelling, or winter mixing, or advection?

      Mainly because of the fast exchanges between ocean surface and atmosphere. Not fast enough to neutralise relative huge changes due to (seasonal) temperature and bio-life, but rapidly following CO2 in the atmosphere.

      Increased upwelling does affect mainly the upwelling zones which are about 5% of the ocean surface, but as that are the zones with abundant biolife, thanks to the minerals and nutrients from the deep, to the joy of fishermen (especiaaly off the coast of Chili and Peru), that pulls DIC quite fast down at one side but the warming up of the upwelling waters gives a lot of CO2 free in the atmosphere. DIC in tropical waters is lower than more polewards (see Feely e.a.).
      Anyway you can’t generalise what happens in the upwelling zones of Oregon to what happens in the rest of the ocean surfaces…

      Winter mixing was studied for the North Atlantic by Gruber e.a.:
      That shows huge variability (including the NAO), but still a continious sink on yearly averages. Moreover pCO2 of the oceans surface follows pCO2 in the atmosphere with a similar trend.

      Deep ocean water exchanges may influence the δ13C level of the surface somewhat, as that is around zero per mil, while the surface in average is +1 to +5 per mil, depending of the abundancy of biolife. For Bermuda at 4.95 per mil, that seems a quite active region…
      Humans did burn fossil fuels with an average of -24 per mil, thus that shows up far more easily in the ocean surface waters with a drop of -1.1 per mil since ~1850. That is more than even a complete overturning of the surface by the deep oceans could give.

      Further over extreme long periods, like glacial – interglacial transitions and back, where the deep oceans probably are highly involved, the change in δ13C in the atmosphere, according to ice cores, is not more than 0.2 per mil and the same for the whole Holocene. That includes the MWP-LIA period, which we now should see in reverse…

      Thus despite a huge natural variability in year by year uptake, it is quite certain that the increase in DIC at all measured places is from the increase in the atmosphere…

      This readily explains the trends at BATS.

      Biolife probably has increased over the past decennia over many seas, but that decreases DIC in the surface waters and increases the δ13C level, That is opposite to the observed trends…

      Most of the examples you show are about the variability around the trends, but that says nothing about the trends themselves or the cause of the trends…

      With all due respect, I am clueless regards your reasons for linking to this paper.

      Because you were saying that CO2 doesn’t follow the same patterns as CFC’s, but such paper shows that both the physical “pump” near the poles is as good working the same way for CFC’s as for CO2, be it aided by the biological pump…

      So theoretically the biological pump can neutralize any anthropogenic CO2 entering the ocean. DIC increases at depth but not at the surface. Observed increases in upper layer DIC corresponds with a balance between upwelling events and rates of photosynthesis.

      As explained above, the difference in δ13C between surface and deep oceans is too small to have much influence. Further, if all human CO2 input from the atmosphere (as mass) was removed by biolife in the ocean surface, δ13C in the surface wouldn’t go down, as that is as (more or less) as discrimatory for 13C as land organics or fossil fuels, except for the inorganic part: the shells of coccoliths, which are δ13C neutral vs. the surrounding waters. The fact that the drop in δ13C in the ocean surface closely follows the drop in the atmosphere shows that by far not all human CO2 is removed by biolife and that most remains in the surface…

      DIC hardly increased at depth: even if all human emissions since 1850 now remained in the deep oceans, that is only an 1% increase of the total carbon mass there. On the other side, all surface waters where is measured show an increase in DIC of around 10% of the increase in the atmosphere…

  13. Ferdinand says ,”As both are thouroughly mixed, any change in the atmosphere is rapidly distributed into the ocean surface with a half life time of less than a year, With one restriction: due to buffer chemistry, the change in DIC in the ocean surface is about 10% of the CO2 change in the atmosphere.”

    Again the literature offers various estimates, but I used the estimate from Sabine 2010 in Estimation of Anthropogenic CO2 Inventories in the Ocean:

    “The equilibration timescale for this exchange is about one year, so on a global scale surface water CO2 generally increases at close to the same annual rate as CO2 in the atmosphere (Takahashi et al. 2009). On a finer scale, local physical or biological perturbation events can make surface water CO2 significantly deviate from atmospheric equilibrium.”

  14. Ferdinand writes, “here is a detailed one of the Bering Sea shelf:

    With all due respect, I am clueless regards your reasons for linking to this paper. If anything it reinforces everything I have argued, stating “We found that DIC concentrations were drawn down 30–150 μmoles kg−1 in the upper 30m of the water column due to primary production and calcium carbonate formation between the spring and summer occupations.”

    Regards carbon export of DIC from the surface to bottom waters they say “The coupling of NCP [net community productivity] at the surface to increases of DIC in bottom waters has also been observed in the Chukchi Sea (Bates and Mathis, 2009). Similarly, this remineralized DIC lowers the pH of these bottom waters suppressing the carbonate mineral saturation states (Mathis et al., 2010).” and “Enhanced export production in the Bering Sea could also lower DIC concentrations in the surface waters and thereby increase the CO2 sink in the ocean.”

    However the study is only for one year and tells us nothing about any trends in surface or subsurface pH. The authors offer several possible climate scenarios and possible effects on carbon export but make no claims one way or the other, signalling the science is far from settled. Nothing in the paper disagrees with my assertions that the biological pump exports carbon from the surface waters, and can maintain a degree of pH homeostasis.

  15. With all due respect Ferdinand I think you totally misunderstood my essay. Your graph from: clearly shows a decrease in delta C13. That is excellent evidence that fossil fuels as well as upwelling has increased the proportion of C12 in the atmosphere and that change is preserved in coralline algae. But that does not address the issues in my essay.

    I demonstrated that coinciding with the increase in anthropogenic carbon (C12) there has been an increase in primary production and an increase in carbon export as illustrated n Chavez 2013. So theoretically the biological pump can neutralize any anthropogenic CO2 entering the ocean. DIC increases at depth but not at the surface. Observed increases in upper layer DIC corresponds with a balance between upwelling events and rates of photosynthesis.

    Theroetically without ANY change in surface DIC, or the biological pump, or atmospheric invasion of CO2 , delta C13 will change as more anthropogenic CO is released. Whether its 50 or 70 Pg entering surface waters, that rate of CO2 invasion could remain absolutely constant, while the proportion of C12 increases resulting in decreasing delta C13 results in the graph you present.

  16. I’m surprised at how sharply defined the end of the Little Ice Age is in the Chavez et al. chart, especially since we’re told that it’s a ‘regional phenomenon.’ There’s a better image in the paper pdf.

  17. “In regions where strong upwelling of DIC from the deeper ocean overwhelms the ability of photosynthesizing organisms to sequester carbon, surface pH drops and CO2 is outgassed to the atmosphere.”

    Does this allow us to go to such a region and see what effects there are on marine life due to having too much CO2 around? Do shells dissolve in the sea water or does life thrive and even more CO2 is taken away as limestone?

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