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jim10940 at 07:58 AM on 1 August 2014State Department cuts through the acid political environment on oceans and climate
@ Rob P Thank you for the comments, very helpful. The visiting scholar was a seagrass expert and well regarded. I didn't want to put his name out because I might be misrepresenting his arguments. The context was in a closed student question and answer session and he was giving many reasons why he was optimistic about global warming. He gave the two reasons above plus a bunch of evidence that I can't remember the reference for as to why he thought there was a lot of adaptation potential in the ocean ecosystems. I would call him a climate change optimist. He seems to think that nutrient pollution is a huge problem while climate change CO2 is a minor problem. I dont want to attribute anything I just said to him because I am sure he would be much more nuanced. However that was my take away.
Here is an article in his own words:
http://theconversation.com/is-the-ocean-broken-19453There is obviously a lot of unknowns about how the ocean ecology will respond in the future. It seems in the dearth of evidence there is room for both optimistic and pessimistic arguments. I honestly dont know how to approach this except to keep an open mind and ask for more research.
Moderator Response:(Rob P) - Fair enough Jim - something nuanced can certainly get lost in translation. Don't get me wrong, as far as ocean acidification is concerned we are not locked into an extinction scenario, but we had better start taking it very seriously very soon.
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Stephen Baines at 06:06 AM on 1 August 2014State Department cuts through the acid political environment on oceans and climate
jim,
De'ath et al did not consider acidification effects on reefs, and they explicitly state that they probably underestimate coral reef decline on the Great Barrier Reef as a result. Just because a study only focusses on some factors affecting coral reefs does not mean that it concludes others are not important.
Also, it's important to realize that while human nutrient pollution, resource harvesting and land use have been fairly advanced for some time, ocean acidification is in many ways only beginning. Negative effects on corals are likely, and sometimes observed, but many won't be fully manifest for some time, prehaps until pH in these regions approaches the saturation point for calcite/aragonite. Unlike those other problems, which we largely dealt with post-hoc, we are a touch ahead of the curve in assessing the impacts of ocean acidification, even if we're not necessarily coming up with solutions.
The fact that waters off the east coast of the US are acidifying faster than elsewhere means only that factors other than the increase in atmospheric CO2 also influence local patterns in pH, as I pointed out, and it is important to understand those other factors. However, it also means that fully one third of the increase in LIS and Chesapeake Bay ecosystems is directly attributable to increased CO2 in the atmosphere. This effect exacerbates the effect of the other factors on pH, and it will only increase in importance in the future. It makes it much more likely that critical thresholds will be crossed under extreme conditions. Future increases in CO2 may also render attempts at remediation of pH through pollution control unworkable.
In short, I'm not sure it makes sense from a risk avodance point of view to think about ocean acidification as a process that is important in one place and not another. Yes, organisms adapted to more constant conditions are likely to be more vulnerable, but so may be organisms in cold areas that are already acidic, or organisms at the northern ends of their ranges who may be near thresholds. Moreover, the combination of local variation with a longterm trend in pH could mean that critical thresholds could be crossed sooner in coastal systems under extreme conditions. Since we depend heavily on the living resources of coastal ecosystems, it would be unwise to deny that risk until we know more.
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jim10940 at 04:51 AM on 1 August 2014State Department cuts through the acid political environment on oceans and climate
@ Stephan just saw your second post. Thats helpful. I just found this feely paper that i am reading that seems to answer some of where these effects are occurring. however its a broad simulation not detailed. http://www.tos.org/oceanography/archive/22-4_feely.pdf
From figure 7 perhaps the greatest concern is arctic waters. This is a complex issue.
Im still not sure how to refute my initial statement that ocean acidification due to CO2 is primarily a problem in the open ocean and not near coastal waters.
I guess my answer will be that more needs to be done on specific areas. Also, it's wrong to imply that most of the ocean community we are concerned with is dominated by the effects of runoff.
What i can find on corals seems to indicate it is nutrient run off, invasive species and warming water that is a problem. http://www.pnas.org/content/109/44/17995.full
Moderator Response:(Rob P) - Eutrophication (excess nutrient run-off) of coastal waters simply accelerates the acidification process, it doesn't mean that CO2 is somehow magically not dissolving into coastal seawater.
Ocean acidification is indeed a global phenomenon, but some areas - such as the polar seas where colder water is able to absorb more carbon dioxide - are more susceptible. The same applies to polar land regions which are now undergoing thaw.
All that extra organic material being flushed into the ocean is broken down by bacteria and releases CO2 into the water column - thus accelerating the acidification process. This is soon going to be a huge problem in the Arctic.
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jim10940 at 04:25 AM on 1 August 2014State Department cuts through the acid political environment on oceans and climate
@ John H Thanks for the article it is helpful. However, the upwelling along the pacific coast supports the case was arguing. "Although seasonal upwelling of the undersaturated waters onto the shelf is a natural phenomenon in this region, the ocean uptake of anthropogenic CO2 has increased the areal extent of the affected area." http://www.ncbi.nlm.nih.gov/pubmed/18497259
The acidified ocean off the pacific coast is natural unique feature to the area that CO2 increase has enhanced, not a general feature coastal waters.
from your link: "On the East Coast, instead of upwelling, acidification is a result of nutrification - adding nutrients like agricultural waste, fertilizers and waste water treatment facilities. The Chesapeake Bay, which receives runoff from one of the most densely-populated watersheds in the United States, is acidifying three times faster than the rest of the world's oceans. Long Island Sound, Narragansett Bay and the Gulf of Mexico are all showing signs of rapid acidification."
Again this seems to support the case that it is coastal features that are important to the ocean acidification problem. In the east coast the acidification is due to nutrient run off and not atmospheric CO2.
I suppose my question is where will ocean acidification from atmospheric CO2 be a problem? As far as i can tell it is only in specific locations where that deep ocean water is brought near the coasts. I would still like to have a better idea where this process is occurring.
@ Stephan that was the study I saw. I appreciate the answer.
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Stephen Baines at 03:48 AM on 1 August 2014State Department cuts through the acid political environment on oceans and climate
jim @16,
I'm not sure what your question is, but the basic story is that it depends on where you are.
Variations in pH in coastal regions reflect the balance of respiration in plankton and in deep sediments (which produces CO2), photosynthesis (which consumes CO2), upwelling of deep water (which has lots of CO2) and inputs of rivers (which often also have a fair amount of CO2 as well as other inorganic and organic acids). As a result, pH can vary a fair amount (easily 0.5 units) over time scales of days in coastal systems with variable upwelling, high algal growth, shallow water columns and large rivers. It's also true that organisms growing in such environments are often capable of handling, and even preferring, variations in pH that result, while open ocean species are typically less equipped to handle such variation.
However, its also true that progressive acidification combined with such variation makes it more likely for pH to drop to levels that may be outside the typical environmental conditions to which these organisms are adapted. The parallel with how gradual atmospheric warming combines with weather variability to produce a large increase in the probability of damaging extreme temperature events is obvious. We don't know in many cases what the critical pH thresholds are for many species, or how long pH must stay below them to have a significant impact.
Also, as indicated by the article to which John Hartz points, atmospheric CO2 in the past influences the pH of deep water brought to the surface now, and current CO2 will lead to lower pH in such water in the future in regions exposed to upwelling, so the the effects of upwelling and atmospheric CO2 on acidification are not really independent, just lagged in time.
The generalization about coral reefs is completely off the mark. There is a reason we don't see coral reefs off of heavily populated temperate coasts. Reef building corals require warm waters with relatively high pH that are not subject to upwelling of deep water. They also do not like the extra nutrients and sediments that are brought in by rivers or are introduced as a result of human activity. Because they prefer those factors be absent, and because they need relatively high pH to build calcium carbonate shells, corals in particular are likely to be directly affected by ocean acidification.
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Stephen Baines at 02:58 AM on 1 August 2014State Department cuts through the acid political environment on oceans and climate
John H.,
He's probably referring to this Nature communications article by Irigoien et al from February of this year. It's an attempt to estimate mesopelagic fish biomass from acoustic data rather than trawls, which are presumed to be biased. These fish are presumed to be so abundant because they feed low down on the food chain (being small) and are not preyed upon very heavily because of their nightly migration from the deep. I'm not sure how they ground truth the acoustic scattering data since all other methods are considered biased.
In any case, they are a giant red herring (so to speak). We don't know if the mesopelagic fish are "untouched." It's possible humans have had a positive impact on these organisms by removing large pelagic predators. That could in turn have effects on the extent and intensity of oxygen minumum zones at depth, through respiration. It's also possible there are negative consequences of ocean acidification on the food base of these organisms, which are organisms in the surface layers to which they migrate daily. Then there is also the general increase in gelinous zooplankton in many region sof the world.
Basically, the biology of the "mesopelagic twlight zone," as it's called, is all up for grabs and subject of an extensive research effort right now. To use that lack of knowledge as proof that all is alright is profoundly silly.
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John Hartz at 02:03 AM on 1 August 2014State Department cuts through the acid political environment on oceans and climate
@ Jim #16: Your second paragraph includes the following:
Most of the ocean fish biomass is in middle deep living fish that can't be caught in nets (i looked it up its true), and this ecology has been basically untouched by humans.
Please provide the source of your information.
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John Hartz at 01:56 AM on 1 August 2014State Department cuts through the acid political environment on oceans and climate
@ Jim #16: The assertions contained in your first paragraph do not seem to square with what's happening up and down the Pacific Coast, from California to British Columbia to Alaska.
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jim10940 at 01:47 AM on 1 August 2014State Department cuts through the acid political environment on oceans and climate
I hope someone can answer this question about ocean acidification. An oceanographer/ecologist that visited our university claimed that ocean ph around the coasts is mostly controlled by runoff and ocean acidification wont have a strong effect. The only places ocean acidification will have strong effects is away from coasts and where deep ocean upwelling occurs next to coasts. Since most corals are in coastal waters ocean acidification is not an important problem for corals.
also
Most of the ocean fish biomass is in middle deep living fish that can't be caught in nets (i looked it up its true), and this ecology has been basically untouched by humans. Since the largest amount of ocean fish biomass is untouched the oceans are better off than we think and the fish we do take are such a small part of the ecosystem that its not a real problem. I guess my answer is just because its the largest biomass does not mean its the only important thing about the ocean but maybe someone can add to this.Moderator Response:(Rob P) - Why would an oceanographer/ecologist speak at your university on a topic they clearly know very little about?
The geological record indicates that ocean acidification was a kill mechanism in 3 of the 5 major extinction events, and contrary to popular belief, reef-building coral of today are not the same ones which lived in the oceans hundreds of millions of years ago - those ancient coral became extinct when the tropical surface ocean became too warm and too corrosive. This is why there are a number of 'reef gaps' in the fossil record.
The oceans are now acidifying faster than at any time in the last 300 million years and, as might be expected, coral worldwide are in rapid decline (not only due to acidification though).
It would be nice to be optimistic about all of this, but the evidence paints a rather gloomy future.
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Joel_Huberman at 23:56 PM on 31 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
scaddenp @ 15:
Thanks very much for the clarification. I found Wunsch's letter. For the benefit of other readers, here's Wunsch's letter (The Australian, July 28, 2014):
Understanding the ocean
THE article by Graham Lloyd will likely leave a mis-impression with many of your readers concerning the substance of our paper that will appear in the Journal of Physical Oceanography (“Puzzle of deep ocean cooling”, 25/7).
We never assert that global warming and warming of the oceans are not occurring — we do find an ocean warming, particularly in the upper regions.
Contrary to the implications of Lloyd’s article, parts of the deep ocean are warming, parts are cooling, and although the global abyssal average is negative, the value is tiny in a global warming context.
Those parts of the abyss that are warming are most directly linked to the surface (as pointed out by Andy Hogg from the ANU).
Scientifically, we need to better understand what is going on everywhere, and that is an issue oceanographers must address over the next few years — a challenging observational problem that our paper is intended to raise.
Carl Wunsch, Harvard University and Massachusetts, Institute of Technology -
denisaf at 21:28 PM on 31 July 2014State Department cuts through the acid political environment on oceans and climate
The article contains the comment 'Unlike marine pollution and overfishing, which require multifaceted solutions, ocean acidification has only one primary cause: excess carbon dioxide in the atmosphere. It therefore has an obvious solution: limit carbon emissions.' There is no possible solution in the time frame relevent to civilization. The current carbon dioxide concentration level is 400 ppm, well above the preindustrial level, and this excess carbon dioxide is causing the ocean acidification. Limiting future (rates of) carbom dioxide emissions will only slow down the the rate of increase of the concentration level, so the rate of ocean acidification.
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Ken in Oz at 17:50 PM on 31 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
Ocean heat content - or more correctly, global heat content within the climate system, of which ocean is the largest component - is a more direct measurement of something fundamental. I also think it's more generally comprehensible as direct evidence of a warming world. And I don't think you can pick out a period even as short as 5 years within the past few decades that could be claimed to show a pause or slowdown. Meanwhile, surface air temperatures look more like a secondary consequence of sea surface temperatures and subject to a lot of variability because of phenomena that move and mix ocean water around.
We can and should try for more ocean temperature coverage, especially of deep ocean that is not well covered but what is known surely does not, for example support Ian Plimer's undersea volcanoes heating the world from below; on the contrary it is quite consistent with warming from above.
What we can't or shouldn't do is vacillate whilst we wait for every cubic metre to be measured continuously and every cool spell, cold spot or instance of glacial advance is understood and explained to the satisfaction of people like Nigel Lawson. We know more than enough to know we need to commit to action on emissions reductions.
Of course, in the current political climate - at least in my nation of Australia, and apparently in USA and Canada - if any part of the ocean, or world for that matter, doesn't show continuous and incremental warming it will be used by opponents of action on climate to distract and deceive and promote inaction. Recall the "world is cooling" hype when the eastern USA had a winter that was colder than average, despite far more of the world simultaneously showing much warmer than average conditions.
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scaddenp at 12:09 PM on 31 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
It links to letters to editor. Go to the bottom for the Wunsch letter.
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Joel_Huberman at 11:02 AM on 31 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
Scaddenp @ 13:
I would like to see the response by Wunsch. Unfortunately, the current link directs me to an article in The Australian about the Gaza conflict. Please help.
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Tom Curtis at 09:54 AM on 31 July 2014State Department cuts through the acid political environment on oceans and climate
Russ R @7, as one of the original respondents to your first post, I trust the moderators will not see me as "piling on".
1 a) In fact it is very difficult to get good proxies with millenial resolution in the distant past, let alone decadal. However, your original question was focussed on episodes of sustained depressed ocean pH. During those sustained periods there were shell building organisms present (made possible by buffering by increased weathering). You have now switched your question, and you are no longer entitled to your assumption of onging existence of shell building organisms.
For example, there have been sustained periods in the past with a noted absence of reef building organisms in the ocean:
(Source)
Several of these events are associated with periods of rapid increase in CO2 levels in geological terms, on which more below.
The question will obviously arise, if the corals go extinct, how do they come back in 5 million years. The obvious answer is that while members of the same family, or order of corals survive, members of the same genus and species do not. In particular, what probably has occured is that either a related soft coral has evolved to occupy the vacated niche; or a surviving species or small number of species of hard corals have successfully made the transition to a soft coral niche, and then reevolved the reef forming habit once conditions were more suitable.
We can be sure that some measure of evolution was involved because of the 5 million year gaps. Had a small number of hard corals retained the hard coral habit in refugia (isolated areas were pH is sustained and higher levels by local geochemistry), restoration would have been almost instantaneious in geological terms (100,000 years or less).
So, on the plus side, rapid ocean acidification will likely only eliminate coral reefs for the next five million years. Is that really any different from eliminating them forever in human terms? And once the five million years are up, related corals may take up the reef forming habit. Or perhaps not. After all, to previous forms of corals (Rugosa and Tabulata) did not come back after the end Permian extinction, being replaced by an entirely different form of coral.
1 b) It is highly unlikely that many past excursions in CO2 concentration have been as rapid as the current excursion. Among the most rapid (geologically speaking) causes of increased are large igneous provinces such as the deccan traps, of which wikipedia says:
"The Deccan Traps are a large igneous province located on the Deccan Plateau of west-central India (between 17°–24°N, 73°–74°E) and one of the largest volcanic features on Earth. They consist of multiple layers of solidified flood basalt that together are more than 2,000 m (6,562 ft) thick and cover an area of 500,000 km2 (193,051 sq mi) and a volume of 512,000 km3 (123,000 cu mi)."
(My emphasis)
The CO2 content of flood basalts as a proportion of mass is well known. So also are the timings of eruptions in flood basalts (igneous rock being the easiest to date). That has allowed Self et al (2006) to estimate the rate CO2 emissions as a result of the formation of the Deccan traps:
"This calculation shows that approximately 1.4×1010 kg, or 14 Tg of CO2, could be released for every 1 km3 of basaltic lava erupted (assuming a density of 2750 kg m−3), thus the total release from an erupted lava volume of 1000 km3 would be "14×103 Tg CO2. Whilst this is a very large mass, it should be noted that it represents less than 1/200th of the CO2 present in the modern atmosphere ("3 million Tg, or 3×1015 kg), and
only about 3% of the current annual land–atmosphere CO2 flux. In effect, even an instantaneous release of this quantity of CO2 would increase the content of the current atmosphere (i.e. "365 ppmv) by only 1.7 ppmv. This compares with the current, largely anthropogenic, annual increase of 1 ppmv since 1958."Even assuming the entire Deccan traps were formed over the 33 million years of peak erruption, that amounts to an annual average emission rate equivalent to of 0.03 ppmv. Human emissions are currently 100 times that rate.
If even the formation of the Deccan traps cannot hope to match current human emission rates, and hence current rates of change in ocean pH, rates of change in ocean pH equivalent to the modern must be rare to non-existent in the past. It is possible that such rates have been matched by either large scale clathrate release (PETM) or large igneous provinces igniting larger reservoirs of fossil fuels (suggested for the end Permian extinction), but all such potential instances are associated with large scale extinction events, particularly among animal types known to be vulnerable to ocean acidification.
2 a) You cite pH values for water intake at Monterey bay. In enclosed waters such as bays, pH values are often far lower than in the open ocean, and are far more variable. A more appropriate comparison (because not all threatened species live in bays) is with monthly variations in open ocean pH:
There you see a peak intra-annual increase of just 0.07 pH over four months, and peak declines of slighty less magnitude. That is, the peak monthly change in open ocean pH is less than the change in open ocean pH already brought about by anthropogenic emissions of CO2.
2 b) scaddenp @13 correctly notes that changes in seasonal values do not have the same impact as changes in annual averages. Specifically, molluscs in Monterey bay, for example, may have an annual cycle in which they build up shell thickness during periods of high pH, can loose shell thickness during periods of low pH. A general lowering of pH may then restrict the build up in one season and increase the decline in shell thickness in the other - weakening shells overall and (if sustained) eventually eliminating them.
You can reasonably point out that that is a hypothetical mechanism, but what you cannot reasonably do is ignore the numerous examples of recorded shell loss, or depleted reef construction rates, and of inability of reefs to colonized otherwise suitable areas with low pH in the wild. The adverse impacts of low pH on a number of marine animals is not hypothetical. It is observed.
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scaddenp at 07:58 AM on 31 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
And see the response by Wunsch to mispresentation of the paper here.
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KR at 07:22 AM on 31 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
bjchip - I've seen the 'buzz', and it's based on a nonsense interpretation of Wunsch 2014.
From the abstract:
Interpretation requires close attention to the long memory of the deep ocean, and implying that meteorological forcing of decades to thousands of years ago should still be producing trend-like changes in abyssal heat content. At the present time, warming is seen in the deep western Atlantic and Southern Ocean, roughly consistent with those regions of the ocean expected to display the earliest responses to surface disturbances. Parts of the deeper ocean, below 3600 m, show cooling. (emphasis added)
In short, while there are sections of the abyssal ocean that show cooling, they are consistent with the timescale for long past temperature changes to reach those sections (LIA?), while those portions of the ocean expected to be responding to recent changes are indeed warming.
The current portrayal of this paper on the denialist blogs relies on taking portions of it out of context, which is just sad. But not IMO terribly surprising...
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bjchip at 06:59 AM on 31 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
One observes that if we are to discuss ocean heat content we're also going to have to address Wunsch's recent paper. My cursory read was that he is saying that he can't say... but a more authoritative and deeper analysis is going to be needed. The echo chamber is alread abuzz with the notion that the "ocean is cooling".
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scaddenp at 05:56 AM on 31 July 2014State Department cuts through the acid political environment on oceans and climate
We can cope with a 10 degree difference in temperature between spring and summer but we surely cant cope with a 10 degree change in average temperature. Ditto to seasonal change in pH. Most shellfish also have a highly seasonal pattern to shell growth as well.
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CBDunkerson at 04:41 AM on 31 July 2014State Department cuts through the acid political environment on oceans and climate
Russ R asked: "Since the ocean pH at >8 isn't in the "acidic" range of the scale, and since pH isn't even the primary issue here, isn't the term "Ocean Acidification" more than a bit misleading?"
As Tom & KR explained, 'acidification' is the correct term. It's the claims to the contrary which are, "more than a bit misleasing". Whereever you are getting this stuff... skepticism ought to impel you to start asking why they are feeding you nonsense.
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KR at 04:20 AM on 31 July 2014State Department cuts through the acid political environment on oceans and climate
A side note on terminology.
"Acidic" describes chemicals that are currently of low pH, defined as below 7.0. It is an adjective modifying the noun, the chemical. "Acidification" describes shifting from current pH to a lower one, the change thereof, and is an adverb for changing pH, modifying the implicit verb and indicating direction.
Different parts of speech entirely. Yes, the oceans are currently about pH 8.1, alkaline. Which is roughly a 30% change in H+ ion concentration since pre-industrial levels (Jacobson 2005), an acidification. People who object to properly discussing the direction of that change are missing some essentials of grammar.
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MA Rodger at 03:43 AM on 31 July 2014Southern sea ice is increasing
Klaus Flemløse @12.
What exactly is it you are hoping your last graph demonstrates? I recognise the first three of your graphs. I am not sure of the purpose of the fourth, which appears to be some spectral analysis.
But the last graph, and I may be mistaken, is plotting Antarctic SIA against SST (90S-60S) and in my book simply demonstrates that ice cover around Antarctica is greater when SST is lower, ie during the Antarctic winter.
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John Hartz at 01:44 AM on 31 July 2014State Department cuts through the acid political environment on oceans and climate
Ocean acidification imperils Alaska’s fishing-dependent economy, says a new study funded by the National Oceanic and Atmospheric Administration.
For details, see:
Southeast, southwest Alaska communities at highest risk from ocean acidification, study says by Yereth Rosen, Alaskan Disptach News, July 29, 2014
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KR at 01:42 AM on 31 July 2014State Department cuts through the acid political environment on oceans and climate
Russ R. - Regarding past episodes of acidification, Hönisch et al 2012, The Geological Record of Ocean Acidification, is a recent and relevant paper. They examine among other data boron isotope composition for pH, calcium-to-trace element ratios for ambient CO2, and alkenone carbon isotope composition for aqueous CO2.
In table S1 of the paper (supplemental data) they compare these past episodes to the present, and find the only really comparable episode is the Paleocene–Eocene Thermal Maximum (PETM). The PETM notably had a mass extinction of shell-forming foraminifera. This recent work with direct proxies for pH and CO2 changes agrees with previous research on the PETM and its similarities to the present.
Regarding your "hard to believe" question (Argument from Incredulity?) on pH swings, seasonal variations are short term and can be managed by many organisms, while longer term average pH changes induce energy costs (energy of fixation in shells) and the lifespan availability of aragonite and calcite needed to build shells. And yes, there are nonlinear thresholds (Ries et al 2010) for many organisms.
Finally, the correct and proper chemical terminology for lowering pH is indeed "acidification" - semantic arguments in that regard don't affect changing H3O+ concentrations, and are irrelevant red herrings. If you start at the South Pole and travel a few hundred km in any direction, you are moving north (northification?) despite still being in the Southern Hemisphere, and the weather will be correspondingly different there.
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Tom Dayton at 01:28 AM on 31 July 2014State Department cuts through the acid political environment on oceans and climate
Russ R., regarding your question #3: No, "acidification" is not misleading. It was a common term long before the human cause of ocean acidification was a hot topic. Saying "it is acidifying" instead of saying "it is becoming less alkaline" is no more misleading than saying "it is warming" instead of "it is becoming less cold."
Also, please do follow Dikran's advice about the background reading.
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Russ R. at 00:40 AM on 31 July 2014State Department cuts through the acid political environment on oceans and climate
Good responses all. Highly informative.
Three followup questions, two scientific and one semantic.
- The argument that "the rate of change is higher today than in the past" rests on an unstated premise that the rate of change in the past was actually low. What proxies (of atmospheric CO2, seawater pH, or carbonate ion concentrations) have resolution to decades and can show that the rate of change in the geological past was consistently low?
- The man-made rate of change in average pH today (around -0.19 pH units per century)
is miniscule compared to the range of natural variability of pH (often more than 0.3 ph units in a month) http://sanctuarymonitoring.org/regional_docs/monitoring_projects/100240_167.pdf I find it hard to believe that marine species which have adapted to deal with such a large pH variations from month to month and from year to year somehow can't deal with a much smaller shift over a century. Is there some sort of non-linearity or threshold level that comes into effect? - Since the ocean pH at >8 isn't in the "acidic" range of the scale, and since pH isn't even the primary issue here, isn't the term "Ocean Acidification" more than a bit misleading?
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Klaus Flemløse at 20:14 PM on 30 July 2014Southern sea ice is increasing
Southern Ocean: Sea Ice Concentration and Sea Surface Temperature
Recently there has been a discussion about the link between SST and SIC in the Southern Ocean around Antarctica. It is claimed that there has been a drop in temperature in the Southern Ocean with a consequent increase in ice concentration. This is contrary to what you can read on the SKS. However, there are conflicting data.If you use data from GISS, HADLEY or Berkeley, it seems that SST is growing in the Southern Ocean. If you are use data from NOAA you arrive at the opposite conclusion, namely that the SST is decreasing.
So there is a reconciliation issue between the different data sources. At present I have not found any discussions that shed light on the causes of this. NOAA, however, stresses a possible cause:
“The optimum interpolation (OI) sea surface temperature (SST) analysis is produced weekly on a one-degree grid. The analysis uses in situ and satellite SST's plus SST's simulated by sea-ice cover. Before the analysis is computed, the satellite data is adjusted for biases using the method of Reynolds (1988) and Reynolds and Marsico (1993).”
This means that you start with ice cover and then you simulate the SST and let this go into calculating the SST. In this way there will be a strong correlation between SST and SIC.
The following graph shows the development of SST around Antarctica (60S-90S) using data from NOAA monthy sst and sic
There is at strong correlation beween SST and SIC
My questions are:
Is the NOAA data a fact or an artifact?
Is this in general a story of bad data? -
Dikran Marsupial at 20:12 PM on 30 July 2014State Department cuts through the acid political environment on oceans and climate
Russ R, Doug Mackie wrote an excellent series of blog posts called OA is not OK that is well worth reading to understand the basics (there are 20 posts, which show there is quite a lot you need to know and "simple chemistry" isn't quite enough).
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Tom Curtis at 17:05 PM on 30 July 2014Challenges in Constraining Climate Sensitivity: Should IPCC AR5’s Lower Bound Be Revised Upward?
Victor @5, I assume by "the computation", you are referring to that in Otto et al. In that case, their preferred value is that derived from the difference between the 1860-1879 to the 2000-2009 intervals. Using HadCRUT4 the trend over 2000-2009 is 0.087 C/decade. The interval is bracketed by the end of the 1999/2000 La nina at the start, and the 2008 La nina, and is either ENSO neutral (NINO 3.4) or has a negative ENSO trend (SOI). For comparison, the BEST trend is 0.116 C/decade over the same interval.
Recalculating the climate sensitivity (ECR) and transient climate response (TCR) using BEST data rather than HadCRUT4, but otherwise using Otto et al's data and methods, I find the following temperature differentials for the various periods used by Otto et al:
Interval_____|__HadCRU__|__BEST
1970-79___|__0.22_____|__0.27
1980-89___|__0.39_____|__0.44
1990-99___|__0.57_____|__0.60
2000-09___|__0.75_____|__0.81
1970-2009_|__0.48____|__0.53
That in turns results in the following ECS and TCR estimates, for HadCRUT4:
Interval____|__ECS__|__TCR
1970-79___|__1.40_|__1.01
1980-89___|__1.86_|__1.38
1990-99___|__1.92_|__1.62
2000-09___|__1.98_|__1.32
1970-2009_|__1.92_|__1.36And for BEST:
Interval____|__ECS__|__TCR
1970-79___|__1.70_|__1.23
1980-89___|__2.10_|__1.56
1990-99___|__2.04_|__1.72
2000-09___|__2.13_|__1.42
1970-2009_|__2.12_|__1.51From these figures I would find it difficult to argue the slight plateau in temperature increase. One obvious factor is that the difference in ECS or TCR calculated for different periods is entirely a function of differences in temperature. That temperature differential was greatest in the 2000s. Had the temperature differential in the 2000s been at the average value, the ECS calculated would have been 1.2% higher, a difference reasonably attributed to the "hiatus". Further, the RCP 4.5 forcings from CMIP 5 used in the method over estimate forcings in the last 2-4 years of the 2000s, so that there use would underestimate climate sensitivity. This is an indirect consequence of the "hiatus" in that lowered temperaures in those years are partly a consequence of the reduced forcings.
All in all, the temperature difference due to the hiatus may account for a 2% understatement of ECS, suggesting your insight was more perceptive than I allowed.
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Andy Skuce at 11:42 AM on 30 July 2014State Department cuts through the acid political environment on oceans and climate
The science is not yet definitive, but there have been some big die-offs of scallops and oysters offshore British Columbia, warming and acidifying waters appear to be prime suspects.
Mystery surrounds massive die-off of oysters and scallops off B.C. coast
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One Planet Only Forever at 11:33 AM on 30 July 2014Rupert Murdoch doesn't understand climate change basics, and that's a problem
Donny, My apologies for the lack of thought flow in the opening of my comment. It should have been:
"Please elaborate on what you consider to be the uncertain or doubtful aspects of the rather thoroughly researched and presented information about the accumulation ..."
I am genuinely interested in any new information or thoughts you can share.
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Tom Curtis at 08:21 AM on 30 July 2014State Department cuts through the acid political environment on oceans and climate
Further to my post @3, here are pictures of reef growth near a volcanic vent in New Guinea, along with a map of local ocean pH:
(Source)
Frame B corresponds to the ocean pH projected by the end of this century with BAU.
The volcanic vents have existed long enough that any preexisting adaptive mechanism would have been able to kick in. Never-the-less, there is a substantial reduction in coral diversity with low pH, and an almost complete absence of branching corals. The idea that vulnerable organisms will simply adapt to low pH is already refuted in reality by their failure to do so in situations of already existing low pH.
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Tom Curtis at 08:09 AM on 30 July 2014State Department cuts through the acid political environment on oceans and climate
Russ R @1:
1) When CO2 is dissolved in sea water, its tendency to acidify the water is buffered by other chemical compounds, including Aragonite (CaCO3). Those compounds are replenished by weathering, which increases with increased temperature. For most periods in the past the two are balanced.
If you have a very rapid increase in CO2, the buffering agents will be exhausted allowing a far greater drop in ocean pH (ocean acidification). An equivalent increase over a long period will allow an increase in weathering that limits the fall in pH. Therefore ocean pH in times of high CO2 concentrations in the past will have been much higher than they will be if we achieve the same levels over the next century.
Further, with slow increase of atmospheric CO2, there is a build up of aragonite. That is, while ocean pH is lower, aragonite concentrations are also higher which makes shell building easier at a given pH level. In constrast, with a very rapid rise in CO2 concentration, both pH and aragonite concentrations fall, with both effects making shell building harder.
2) The organisms and species alive today are not the same as their ancestors in the distant past. They have evolved for different conditions, including for higher ocean pH. Potentially, given sufficient energy, mechanisms existed to build shells in the past with lower pH, but those mechanism would have been energetically expensive, and cannot be presumed to have been preserved in situations with high pH.
Assuming that because ancesttors of modern species were capable of forming shells survived with low pH in the past, their descendants can do so today is like assuming that because humans are descedant from brachiating apes, we can swing through the trees in a jungle as rapidly as a chimpanzee or orangoutang. It simply does not follow.
Potentially, the ability to construct shells with low pH could evolve again. Evolution, however, is a process that occures over tens of thousands of years - far to slow to help species at risk over the next couple of centuries.
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scaddenp at 07:49 AM on 30 July 2014State Department cuts through the acid political environment on oceans and climate
Sure and freshwater molluscs can survive with pH as low as 5. However, the problem is the rate of change. OA requires higher energy levels from organisms to do calcification and that requires adaptions. When OA is happening 100x faster than it has for millions of years, then you have a problem. Previous rapid changes in OA (ie the PETM) nearly wiped out corals.
Like just about everything with climate change, if it happens slowly then it doesnt cause a problem. It is the rate of change, especially compared to rate at which adaption can occur, that it is the issue.
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Russ R. at 07:16 AM on 30 July 2014State Department cuts through the acid political environment on oceans and climate
I have a problem with the theory that molluscs and corals are suddenly at risk from ocean acidification due to CO2 at 400ppm (though I don't doubt that they are threatened by many other man-made risks).
These two life-forms evolved over the last half billion and quarter billion years respectively.
- http://en.wikipedia.org/wiki/Mollusca#Evolution
- http://en.wikipedia.org/wiki/Coral#Evolutionary_history
Over almost all of that time period, atmospheric CO2 levels were much, much higher than they are today.
"Simple chemistry" would imply lower pH levels in the geologic past, far below what we're likely to cause with CO2 emissions. And yet, molluscs and corals survived and are still with us.
I can't explain it.
Moderator Response:(Rob P) Actually the basics are rather straightforward. As far as many marine calcifiers are concerned, it is calcium carbonate saturation state that poses the strongest control on shell building - not the excess hydronium ions (low pH). Carbonate ions are one of the building blocks of calcium carbonate shells/skeletons, and one of the chemical reactions that takes place when CO2 dissolves into seawater is the lowering the carbonate ion concentration (technically activity).
Change in atmospheric carbon dioxide on geological time scales allows enhanced chemical weathering of rock to supply carbonate and bicarbonate ions back to the ocean. Furthermore, the total dissolved inorganic carbon (DIC) in the ocean undergoes a large increase due to the increased weathering that accompanies the ramped-up hydrological cycle (lots more rain dissolving lots more minerals into the ocean).
The net effect is an ocean very hospitable to calcification despite the low pH. The Cretaceous Period (the 'K' symbol in your graphic) is a classic example. Cretaceous is derived from the Latin word for chalk, as in the huge chalk deposits that formed during that time. These chalks deposits, such as the White Cliffs of Dover, are of coccolith shells - tiny marine plankton that thrived in the Cretaceous. Ginormous shellfish, Rudists, were the dominant reef builders of that time too.
During times of geologically-rapid increases in CO2, such as now, the ocean carbonate system can't keep up and the oceans become corrosive. Carbon dioxide dissolves rapidly in the ocean, but there is an insufficient increase in the rate of chemical weathering because it takes millennia for the enhanced rainfall to flush sufficient carbonate & bicarbonate ions back into the oceans. The sum effect is that ocean pH and calcium carbonate saturation decline in tandem.
This is why ocean acidification (corrosive seawater) only develops with geologically-rapid increases in atmospheric CO2, but doesn't otherwise. I've simplified this a bit, e.g. leaving out dissolution of carbonates on the ocean floor during periods of lowered atmospheric CO2, but that's the general picture. SkS will have rebuttals to this common misconception in the near-future.
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VictorVenema at 05:57 AM on 30 July 2014Challenges in Constraining Climate Sensitivity: Should IPCC AR5’s Lower Bound Be Revised Upward?
Tom, you are right, the computation uses the temperature difference and not the energy increase. Does it really just use the temperature difference at the end of the time series? A method that would use the full temperature signal might be less sensitive to natural variability.
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MA Rodger at 03:12 AM on 30 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
Ken in Oz @7.
If we shift from surface temperatures to Ocean Heat Content as the measure of global warming, we are still at odds with Lawson of Blaby. In his appearance on BBC Radio 4 back in February he contradicted Prof Brian Hoskins by insisting that any rise in OHC was but speculation.
Of course this wasn't the only point that his Lordship got wrong. And that was why in my own complaint to the BBC over his appearance I pointed out that almost everything he said was woefully wrong.
So if he is continually and systematically wrong with everything he says, that makes two reasons why Lawson would surely deny he is a denier.
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One Planet Only Forever at 23:50 PM on 29 July 2014Rupert Murdoch doesn't understand climate change basics, and that's a problem
Donny@38,
Please elaborate on what aspects of the rather thoroughly researched and presented information about the accumulation of total heat content of the planet continuing to rise as the cooler than neutral Tropical Pacific ocean during the period since 1998 has led to more heat capture in the ocean depths, and that a lower global average surface temperature has also been produced by the 'temporary' cooling effect of that cooler Tropical Pacific surface. Note thta the swing of the average surface temperature of the Tropical Pacific from La NIna to El Nino is about 4 degrees C which clearly can have a significant effect on the temporary values of a global average (that global average has been increased by less than a degree so far).
It would also seem that the recent very high monthly global surface temperature averages could be correlated with the slight warming of the Tropical Pacific that has recently occured. Using the NASA GISTEMP data set, the global average of 12 months ending in March 2014 was a match for the highest that occured during the massive El NIno event of 1997/98. And the highest 12 month averages due to the 1997/98 event were in Aug and Sep of 1998, months after the end of the El Nino condition (As can be seen in the NOAA history of the ONI the 97/98 El Nino event ended when the April/May/June average surface temp of the Tropical Pacific droped to less than 0.5 degree C above the long trem average from its peak of 2.4 C above the that average). And the 12 month averages ending since March 2014 have been increasing. And the coming potential El Nino has barely reached a neutral El Nino/La Nina state.
I am also very interested in best understanding what is going on. And so far I find the explainations developed to date indicating the warming has not stopped, that the global average will continue to increase as CO2 increases, to be quite 'compelling'. But I am open to input that would help me even better understand things.
p.s. I am fairly certain that the most likely cause of reluctance to accept the unacceptability of human activity that produces excess CO2 is a desire to benefit from activity that would lead to excess CO2 being produced. That powerful desire can affect a person's 'scientific objectivity'.
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scaddenp at 12:50 PM on 29 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
Ken,"As an aside, how do models include oscillations like ENSO? Random but bounded by statistical likelihoods of strength, duration and change? "
ENSO is an emergent feature in the models. It may be more accurate to say the the models demostrate ENSO-like features. I understand that they still leave a lot to be desired. eg see here.
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Tom Curtis at 12:34 PM on 29 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
johnthepainter@6, the video I embedded is the current annual series from the BEST website. It's URL on Youtube is:
https://www.youtube.com/watch?v=ts0OVXLY5yE
It was published in February of this year, whereas the one you link to was published in July of last year. Therefore I must presume the video to which I linked to be the more accurate of the two.
As to matching the graph, the video shows the annual average surface temperatures. In the graph, that is shown by the thin black line, which indeed matches the video. You were probably looking at the 10 year moving average (in red).
The high temperatures in the 18th century are irrelevant. They are based on solely western europe and east coast of the US stations in the first case, and on western europe alone in the second. In the both cases they rely on approximately thirty thermometers, or which (in the first case) just three were in the US (see graphs below). They are strictly regional temperatures and provide almost zero information about actual global temperatures.
As I noted in my previous post, I do not think any global instrumental temperature series prior to 1880 is realiable enough to be scientifically usefull. They simply record too little of the lands surface temperature to be reliable.
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Ken in Oz at 12:15 PM on 29 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
Two communications problems -
Surface air temperatures as the measure of global warming. I think heat content is a more direct measure of actual change to the climate system, with a trend showing less variability. I'm interested to know how much variability within heat content estimates and what physical processes drive it.
The broad misunderstandings tha projections/predictions based on an average of many models and model runs where reality will look like some of the model runs but will never look like that smoothed average. The expectation that failure of reality to follow that smooth average is portrayed as a failure of reality to follow prediction. I understand about short term variation vs longer term trend, but arguments such as Lawson use only work because it's not broadly understood.
I understand reality will look most like the model runs that put oscillations like ENSO in the right places but for most people, who get their information via media interpretations that may or may not include biases as well as simple failure of journalists to be well informed, the idea of "IPCC prediction" that has "failed" can look compelling. I like the analogy of the "prediction" of summer being warmer than winter based on an planetary tilt theory having a smooth transition, one day warmer than the one before, and a cool few weeks in spring 'proving' the prediction and theory is wrong... is clearly wrong - but analogy is less than best and only works in some contexts, such as a lecture without the media's requirements for brief (one or two lines) and clear and unambiguous content.
As an aside, how do models include oscillations like ENSO? Random but bounded by statistical likelihoods of strength, duration and change?
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johnthepainter at 10:44 AM on 29 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
Tom, the video shown doesn't match the BEST graph: some of the early temperatures in the video are higher than present-day ones, which is not true in the static graph. But they did another one covering the same period in which the modern ones are highest: https://www.youtube.com/watch?v=DHKGbxfiJ-k
I can't account for the difference.
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scaddenp at 09:48 AM on 29 July 2014We're coming out of the Little Ice Age
Donny, estimates of forcings operating from AR4 below:
and for the current best estimates with error bars of forcing now, see:
Solar and volcanic are clearly natural but not long term players. Again, see the WG1 for estimates of forcings at play during LIA and for how the model perform.
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Tom Curtis at 09:47 AM on 29 July 2014We're coming out of the Little Ice Age
Donny @69, a forcing is the change in net energy flux at the top of the atmosphere. The Sun provides essentially all of the energy that warms the Earth, but is very constant. Over the solar cycle, it changes its output by only around 0.1%, so the change in forcing is small. Short term (decade to millenia) changes in solar output in addition to the solar cycle are not much larger. More importantly, the greatest solar output in this century was acheive around 1958, with a slight decline thereafter, becoming more rapid over the last decade. Therefore the change in solar ouput, ie, the solar forcing, since 1950 has been very close to zero, and perhaps slightly negative.
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Tom Curtis at 09:39 AM on 29 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
Roger D @4, the IPCC conclusion is that humans are responsible for 50% plus of global warming since 1950. In fact, they think that humans are responsible for around 100%, indeed, possibly more than 100% of warming since 1950 as shown in this IPCC figure, but allow with very low probability that it could be as low as 50% due to uncertainty:
ANT is anthropological, OA is Other Anthropological, ie, anthropological other than greenhouse gases, and NAT is Natural.
From a survey of climate scientists, it has been determined that the mean estimate of anthropological contribution since 1850 is 80%, with most of that coming since 1950. Prior to 1940, natural contributions dominate but anthropogenic factors still make a substantial contribution. Further, from 1850 to 1910, natural factors overwhelmed the then relatively weak anthropogenic forcing to cause a net cooling.
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Donny at 09:39 AM on 29 July 2014We're coming out of the Little Ice Age
How can you say there are no solar forcings today?
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Donny at 09:37 AM on 29 July 2014We're coming out of the Little Ice Age
Scaddenp. ...
Are you suggesting that there are no natural forcings now?
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Roger D at 08:20 AM on 29 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
Donny - others with more detailed knowledge can add to my 'answer', but i believe the IPCC has done your "survey" already by literature review and determined that responses from experts attribute from more than half to more than 100% of the observed global average temperature increas to anthropogenic sources. Also, I suspect there are better ways to look at the problem than simply projecting a post LIA temperature trend into the 1900's and assuming the difference between that and observed is anthropogneic, if such a projection even made sense.
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scaddenp at 08:19 AM on 29 July 2014Nigel Lawson suggests he's not a skeptic, proceeds to deny global warming
Donny, I have replied to you here which is the appropriate thread. Please also read the main article. You can use the Search function on top left page to find appropriate places for comments.
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scaddenp at 08:17 AM on 29 July 2014We're coming out of the Little Ice Age
Replying to comment from here.
Donny, first point of call for any question like this has to be IPCC WG1. You want the chapter of paleoclimate, and eg Fig 5.7.
Do you accept the physics law of conservation of energy? Assuming you do, then warming of the surface is a change in the energy flow. Apart from ocean-atmosphere heat exchanges, then warming or cooling are due to changes in forcings. These can be natural or man-made. To accept the idea that "half the change" is natural, then you need evidence that there is a natural forcing, operating since LIA, of about the same magnitude as anthropogenic forcing. That evidence is tough to find.
Instead LIA (which is much more pronounced in NH) is adequately accounted for by changes in volcanic and solar forcings, certainly not operating today.
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