In northern winter, the Bering Sea, dividing Alaska and Siberia, becomes the most acidic region on earth (in purple) as shown in this February 2005 acidity map in pH scale. Temperate oceans are less acidic. The equatorial Pacific is left blank due to its high variability around El Niño and La Niña events. (Takahashi)A team of scientists has published the most comprehensive picture yet of how acidity levels vary across the world’s oceans, providing a benchmark for years to come as enormous amounts of human-caused carbon emissions continue to wind up at sea.
“We have established a global standard for future changes to be measured,” said Taro Takahashi, a geochemist at Columbia’s Lamont-Doherty Earth Observatory who published the maps with his colleagues in the August issue of the journal Marine Chemistry. The maps provide a monthly look at how ocean acidity rises and falls by season and geographic location, along with saturation levels of calcium carbonate minerals used by shell-building organisms. The maps use 2005 as a reference year and draw on four decades of measurements by Lamont-Doherty scientists and others.The oceans have taken up a quarter of the carbon dioxide humans have put in the atmosphere over the last two hundred years.
But their help in offsetting global warming has come at a price: the oceans are growing more acidic as they absorb our excess CO2. To what extent ocean acidification may harm marine life and ecosystems is still unclear, but already signs of stress have appeared in corals, mollusks and other shell-builders living in regions with naturally more acidic water. Since the industrial era began, average surface seawater pH in temperate oceans has fallen from 8.2 to 8.1 by 0.1 pH unit, equal to a 30 percent increase in acid concentration. (A lower pH indicates more acidic conditions.)The saturation state of the mineral aragonite, essential to shell-builders, tends to fall as waters become more acidic. The South Pacific Ocean is heavily oversaturated with respect to aragonite (in red) while the polar oceans (in blue) are less saturated, as shown in this February 2005 map. The pink lines represent approximate polar sea ice edges. (Takahashi)
Taro Takahashi has spent more than four decades measuring the changing chemistry of the world’s oceans. Here, aboard the R/V Melville, he celebrates after sampling waters near the bottom of the Japan Trench in 1973. (Lamont-Doherty archives)The vast tropical and temperate oceans, where most coral reefs grow, see the least variation, with pH hovering between 8.05 and 8.15 as temperatures fluctuate in winter and summer. Here, the waters are oversaturated with respect to the mineral aragonite—a substance that shell-building organisms need to thrive.Ocean pH fluctuates most in the colder waters off Siberia and Alaska, the Pacific Northwest and Antarctica. In spring and summer, massive plankton blooms absorb carbon dioxide in the water, raising pH and causing seawater acidity to fall. In winter, the upwelling of CO2-rich water from the deep ocean causes surface waters to become more acidic. Acidification of the Arctic Ocean in winter causes aragonite levels to fall, slowing the growth of pteropods, planktic snails that feed many predator fish. The maps reveal that the northern Indian Ocean is at least 10 percent more acidic than the Atlantic and Pacific oceans, which could be due to its unique geography. Cut off from the Arctic Ocean, the chemistry of the northern Indian Ocean is influenced by rivers draining the massive Eurasian continent as well as seasonal monsoon rains.By analyzing long-term data collected off Iceland, Bermuda, the Canary Islands, Hawaii and the Drake Passage, off the southern tip of South America,
Takahashi finds that waters as far north as Iceland and as far south as Antarctica are acidifying at the rate of 5 percent per decade. His estimate corresponds to the amount of CO2 humans are adding to the atmosphere, and is consistent with several recent estimates, including a 2014 study in the journal Oceanography led by Nicholas Bates, research director at the Bermuda Institute of Ocean Sciences.“This is exactly what we’d expect based on how much CO2 we’ve been putting in the air,” said Rik Wanninkhof, a Miami-based oceanographer with the National Oceanic and Atmospheric Administration (NOAA) who was not involved in the study. “This is an important point for scientists to underscore—these calculations are not magic.”If the current pace of ocean acidification continues, warm-water corals by 2050 could be living in waters 25 percent more acidic than they are today, said Takahashi.
While corals can currently tolerate shifts that big, marine biologists wonder if they can sustain growth at lower pH levels year-round. “In the long run it is the average pH that corals see that matters to their ability to grow and build a coral reef,” said Chris Langdon, a marine biologist at the University of Miami, who was not involved in the study.<Ocean acidification is already having an impact, especially in places where the seasonal upwelling of deep water has made seawater naturally more acidic. In a recent study by researchers at NOAA, more than half of the pteropods sampled off the coast of Washington, Oregon and California showed badly dissolved shells. Ocean acidification has been linked to fish losing their ability to sniff out predators, and the die-off of baby oysters in hatcheries off Washington and Oregon, where more acidic deep water comes to the surface each spring and summer.By 2100, ocean acidification could cost the global economy $3 trillion a year in lost revenue from fishing, tourism and intangible ecosystem services, according to a recent United Nations report.
The U.S. Government Accountability Office, the watchdog arm of Congress, has reached similar findings and recommended that President Obama create a research and monitoring program dedicated to ocean acidification.Other authors of the study: Stuart Sutherland, David Chipman (now retired), John Goddard and Cheng Ho, all of Lamont-Doherty; and Timothy Newberger, Colm Sweeney and David Munro, all of University of Colorado, Boulder.
phlogiston,
WOOOOSH!
The Late Devonian extinction was marked by what looked to be a period of glaciation. Extreme volcanism could have caused it, as could an impact event. Hard to know. Clearly the oceans experienced periods of extreme anoxia but the answers to the “why” questions remain unsatisfyingly inconclusive. CO2 dropped from 2k to 800 ppm running into the Carboniferous, but much of that can be explained by the explosion of terrestrial plant life.
[chortle] Yes, well adaptation does take time, doesn’t it.
Mainline several units of sterile distilled water via IV … enough so that your blood pH drops below 7.35. Marvel when the ER doc tells you that you’ve got acidosis even though your blood still constitutes a basic solution according to the oft-cited first year Chem text. Get back to me when you realize that you really can have too much of a seemingly benign thing.
In the case of modern corals that 0.1 downward change in pH isn’t so much a big deal in and of itself, it’s more an indication that the carbonate ions which would normally be available to react with dissolved calcium ions are instead buffering out the higher concentration of H+ ions. Corals can spit out H+ and keep the Ca2+ ions — they’ve been doing it a long time now — but as the relative concentration of H+ goes up they have to work harder to do it. Which means they need to consume more nutrients. As niche organisms, immobile ones at that, they don’t have the same adaptation/relocation options that other more generalist/mobile species do. In every mass extinction known, the niche species tend to be the hardest hit. As a keystone species, there’s a lot riding for we humans on keeping coral reefs healthy … we eat stuff that comes out of fisheries anchored by reef systems.
There are no simple answers here. You cannot arbitrarily twiddle the dials on the biosphere while copping an “aw shucks, CO2 concentration was 20 times higher a bazillion evolutionary years ago, wots the big deal” attitude and expect things to remain hunky dory with species that took several tens of thousands of years to adapt to present climactic conditions.
Brandon
“You cannot arbitrarily twiddle the dials on the biosphere while copping an “aw shucks, CO2 concentration was 20 times higher a bazillion evolutionary years ago, wots the big deal” attitude and expect things to remain hunky dory with species that took several tens of thousands of years to adapt to present climactic conditions.”
[chortle] Yes, well adaptation does take time, doesn’t it.
Actually – you can. Evolution can be fast. Satellite and other data shows “greening” of marginal ecosystems in the last half century (see e.g. Matt Ridley presentations) showing that plants are happily adapting to increased CO2 within a single human lifetime. A simple variable like stomatal density can change in very few generations. No deep time needed for this. Ratios of C3/C4 plants can also change practically in “real time” (evolutionarily speaking). The evidence is generally for good, not bad, effects on plants of currently increasing CO2. The only thing to which this is toxic is AGW alarmism.
BTW nice to see words made up by Lewis Caroll in “Jaberwocky” e.g. “chortle” entering the English language.
The big fall in CO2 caused by spread of trees in the Silurian-Carboniferous is indeed interesting, here is a paper about it. It shows that trees may exert a negative feedback in regard to any CO2 warming, since increased tree transpiration will have a cooling effect – provided enough trees remain of course.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC547859/pdf/pnas-0408724102.pdf
quote: “That would be like saying “80% oxygen is lethal to humans. Therefore 20% oxygen cant be good either.”
Mainline several units of sterile distilled water via IV … enough so that your blood pH drops below 7.35. Marvel when the ER doc tells you that you’ve got acidosis even though your blood still constitutes a basic solution according to the oft-cited first year Chem text. Get back to me when you realize that you really can have too much of a seemingly benign thing.
That was meant to be sarcasm but you appear to have taken it straight. Are you really saying that the 20% of oxygen in the atmosphere is harmful to us? There was me thinking that we needed it for old fashioned activities like breathing. But this is not surprising. This simply illustrates the scale of the epistemological collapse of modern science. Because the peddling of scare stories about everything connected with human industrial activity has become so profitable and such a pillar of “scientific” research output, most scientists have lost the ability to understand that something can be beneficial (or at least harmless) at low doses but harmful at high. No – as soon as we can show that force-feeding a rat with a huge dose of anything is harmful, it is not obligatory to believe on the utterly flawed basis of “safety first” that all doses of that substance, or agent, must also be harmful. In fields such as radiation biology – as corrupt as climate science – this logical and scientific fallacy takes the form of the linear no threshold or “LNT” delusion. So 10 Gy kills 100% of people, 1 Gy kills 10%. It “follows” that 100 mGy will kill 1 %, 10 mGy 0.1% and so on. This approach ignores with extreme predjudice the actual experimental data on rodents, plants and many other organisms that low doses below about 50 mGy generally are either harmless or even improve longevity, decrease (not increase) cancer incidence (in rodents by stimulating immune response – anything that does this generally improves health outcomes). Low doses can be really benign – not just “seemingly” so.
Anyway – enough biology. To repeat, your extinction event argument does not hold water. CO2 might have been elevated due to volcanism at certain mass extinctions but was not necessarily the primary cause. And since the palaeo record of CO2 concentration has low resolution, we cannot say that the current CO2 rise is unprecedented. The data is simply not there to claim that. Your comments and those of Joel Shore show that since the argument that currently rising CO2 levels per se are harmful is untenable in the light of history, the AGW position is having to take refuge in the rate of change argument, and morph into d/dt AGW. This refuge will also prove illusory.
well answered, and no good response will be forthcoming
phlogiston,
No. I’m saying that when human blood ph deviates from the range of 7.35 to 7.45 that Bad Things begin to happen. Note that the difference between them is 0.1 pH … where have we seen that number recently?
It’s a safe bet corals are far less sensitive to pH changes in the waters in which they live — most organisms have evolved to regulate their internals in response to the external environment. That doesn’t mean that environmental changes are always free of cost. Maybe most reef-builders have enough in the bank account to cover this one. Maybe not. Maybe something in between.
The canonical example when I was in school was the peppered moth. The thing to keep in mind there is that melanism in that species is controlled by very few genes and their alleles. As far as stomatal density in flora goes — my first question is which plants? How critical are they to their local biosphere? Stomal count in some (or many, do we know?) species may be able to adapt rapidly to changing atmospheric conditions, but what about root systems to changing soil chemistry and rainfall patterns? What about any changes in the mix of faunal species — will their predators increase or decrease? Will any symbiotic relationships with insects, fungi, bacteria change for the better or worse?
In areas not affected by droughts. Some areas have experience more rainfall than normal, does Ridley’s analysis control for either of these? I’m not entirely convinced that droughts are more than just weather (see the dust bowl era) so I’m loath to press this argument much further. I will say that if there is a way to maximize crop production to take advantage of rising CO2, you can bet big agra will find it. Whether they pull off that trick plus find a way to raise crop yields with less water … I’m gonna say not much of a chance.
At the surface via evaporation. That could be a zero-sum game … or not. Increased respiration = increased water demand and that might be an issue even without drought. Water vapor is a far more potent and prevalent greenhouse gas than CO2. Etc.
Nice paper though, thanks for the tip. The final sentence of the abstract summarizes it well I think: ” The existence of positive feedbacks reveals the unexpected destabilizing influence of the biota in climate regulation that led to environmental modifications accelerating rates of terrestrial plant and animal evolution in the Paleozoic.”
You really don’t see that your statement, “All marine calcified phyla such as corals and echinoderms evolved when the atmosphere contained 20 times more CO2 than today” is an example of the same fallacy in reverse, do you.
The first corals which evolved in the Cambrian when CO2 concentrations were an order of magnitude higher than today did so under that condition, plus whatever other state the land and oceans were in as well as whatever other contemporary biota they interacted with. Isn’t it because of such complexities (plus uncertainties and unknowns) that you keep bringing up other factors to rebut me? Why do you get to pluck “8,000 ppm didn’t hurt Cambrian corals one bit” and leave the analysis at that to make your argument, but you go to pointing out factor after other factor to address the “errors” in mine? Hmmm?
Bollocks. I defy you to find a statement in primary literature where “unprecedented” isn’t further and specifically qualified. And which paleo records are you talking about? There are a bazillion. As a practical matter, the first records I’d go to would cover the Holocene because that’s most representative of the climate to which we — human beings, the species I most care about — have optimized our vast amounts of infrastructure. The following link contains CO2 concentrations estimated from Antarctica EPICA Dome C going back 11 Ka:
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/epica_domec/dc_co2_hol_fl02.txt
The average annual resolution is 307.7 years. The lowest annual resolution is 602 years between 1948 and 2550 Ybp (from 1950). The earliest reported age is 435 Ybp, with a CO2 concentration of 281.9 ppmv. By year 0 (1950) CO2 had risen to 310.7 ppmv, an absolute change of 28.8 ppmv, which works out to a rate of change of 6.62 ppmv/century. What you’re trying to tell me here is that the EPICA Dome C ice cores don’t have enough resolution to determine if that 435 year change is unprecedented?
Very well. Explain to me the mechanism by which atmospheric CO2 spikes up and down on the order of 30 ppmv over the course of 400ish years. Next, tell me how it is that the EPICA Dome C ice cores happened to be unlucky enough to never pick up a single one of them. Finally, tell me why every other paleo study using proxies with similar resolution has been so freakishly unlucky to miss all those other extreme spikes as well.
LOL. You just spent several sentences lecturing me that proxies don’t have enough resolution to detect high rates of change. Now suddenly you know that rate of change is an illusory refuge. How? If you yourself tell me that the data don’t tell us anything about unprecedented rate of change, how in the heck can you claim that it’s not a concern?
Political sloganeering is toxic to critical thinking, comprehensive deliberation and scientific debate. If you think that reactionary AGW chicken littles are the only ones guilty of doing it, I just don’t know what else I can say.
There are better resolution ice cores which cover the Holocene, be it that the resolution get worse the longer the total time frame is (the reverse of the snow accumulation = layer thickness/year). Here for most of the Holocene:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/antarctic_cores_010kyr.jpg
Where the Taylor Dome ice core has a resolution of less than 40 years over the past 10,000 years and beyond…
Please, please, PLEASE stop the silly semantic arguments about using the term “acidic”. We sound like a pack of mindless jabbering macaws when we get caught up in meaningless minutiae. There are very real and obvious problems with the claims being made. The use of the term “acidic” is absurdly trivial compared to, for example:
1. The oceans cover two-thirds of the earth and the number of instruments providing a reasonably long-term measure of acidity is vanishingly small. Can you really claim to have a solid grasp of regional or global acidity and trends?
2. Instruments that measure acidity in a lab aren’t sensitive enough to show the tiny trends supposedly being measured. Can ones deployed in the oceans do better? Doesn’t the margin of error far exceed the supposed trend being measured?
Lauren,
Yep, we do talk of pH 7 being “neutral” because pOH 7 ≈ 14 – pH = 7. However oceans are a pretty far from reagent grade distilled water. They’re are not pH “neutral” by a litmus test, but then again neither are pH “balanced” hair and skin products for the simple reason that “natural” skin and hair pH ranges from 5 to 6. The phrase “more acidic” is only “scary” to people who are not well enough educated to understand the concept of relativeness to a beginning (or standard, expected, normal, “natural”) state — or who has never gotten burned by a high molar solution of strong base.
Which by the commentary is nobody here.
One paper isn’t going to answer that question; hundreds (at least) have been written. Also, reef corals — which are the greatest concern here — aren’t directly affected by ocean chemistry in the smack middle of the Pacific, but by the littoral waters they live in. Knowing something about what’s happening in the depths of the Mariana trench and other abyssals is definitely relevant for modeling, but I don’t think strictly critical for empirical observation of what has happened in the past or what’s going on now local to the corals in question.
A question you might want to ask yourself is why any supposed significant deviations have managed to dodge the sum total of our observations. Or pehaps this: what is your standard of reasonable coverage, and how much are you willing to pay to get it?
Says who? How is it that we know anything about a given instrument’s accuracy and precision in the first place?
This guy thinks so: http://scholarlyrepository.miami.edu/cgi/viewcontent.cgi?article=1903&context=oa_dissertations
See Chapter 2(p. 15). The gist is that shipboard analyses have suffered from non-standard protocols, researcher error, etc. — and that deployment of “semi-autonomous” devices might do better.
Trends are time senstive, so your question is missing a key component. If we were comparing last year’s global ocean pH to this year’s, you’d have a good point. If there was some sort of systemic bias over longer periods of time (a la UHI and surface station temperature records) you might also be onto something. Otherwise, measurement errors are expected to be off on the low side as much as the high side over time.
“I will say that if there is a way to maximize crop production to take advantage of rising CO2, you can bet big agra will find it. Whether they pull off that trick plus find a way to raise crop yields with less water … I’m gonna say not much of a chance.”
Elevated CO2 prompts stomata constriction and concomitant reduced transpiration.
pH increases with temperature. So pH is not only sensitive to absorbed CO2, but also the temp of water (the oceans.) We know that the arctic has been unusually warm for some time, hence its “purpleness”, according to the map.
mebbe,
Which implies an overall reduction in metabolism, does it not? This translates into increased crop yield how?
Brandon, it is proven that a lot of plants increase their growth with increased CO2. In ideal circumstances of temperature, water, fertilizers and minerals, crop yields increase in average 50% for a 100% increase of CO2, depending of the type of plant. Glasshouse owners pump 1000 ppmv and more CO2 in their glasshouses for that reason.
Besides that, more CO2 makes that the plants reduce their number of stomata (which makes it a proxy for CO2 levels of the past), with as result that they loose less water vapor. That is an advantage for plants which grow in semi-deserts: all drier places on earth show more greening, including the Sahel:http://wattsupwiththat.com/2011/03/24/the-earths-biosphere-is-booming-data-suggests-that-co2-is-the-cause-part-2/
There was a more recent article, but can’t find it now…
Ferdinand, ” … In ideal circumstances of temperature, water, fertilizers and minerals … ” is the key. Crop yield is a function of moisture and nutrients, and cannot be left out of the analysis. In short, “CO2 is plant food” is not a compelling argument because it’s one factor of many. Increased crop yields will require increased consumption of OTHER resources as well. Ain’t nuthin’ for free on this rock.
Plants typically evaporate much more water than they need to for the transport of nutrients. Evaporative surface area and atmospheric conditions mostly determine water loss from healthy plants.
CO2 can’t make up for an absolute deficiency of soil moisture but it does mitigate the tendency of the plant to squander water.
Mebbe; sure, however additional growth does require water. Evaporative losses are not the only concern.
“Since the industrial era began, average surface seawater pH in temperate oceans has fallen from 8.2 to 8.1 by 0.1 pH unit, equal to a 30 percent increase in acid concentration.”
Check out “Acid Seas – Back To Basic”
http://scienceandpublicpolicy.org/originals/acid_seas.html
Climate Change 2007: Working Group I: The Physical Science Basis, 5.4.2.3 Ocean Acidification by Carbon Dioxide.
The statement is made:
“The uptake of anthropogenic carbon by the ocean changes the chemical equilibrium of the ocean. Dissolved CO2 forms a weak acid. As CO2 increases, pH decreases, that is, the ocean becomes more acidic. Ocean pH can be computed from measurements of dissolved inorganic carbon (DIC) and alkalinity.
A decrease in surface pH of 0.1 over the global ocean was calculated from the estimated uptake of anthropogenic carbon between 1750 and 1994 (Sabine et al., 2004b; Raven et al., 2005), with the lowest decrease (0.06) in the tropics and subtropics, and the highest decrease (0.12) at high latitudes, consistent with the lower buffer capacity of the high latitudes compared to the low latitudes. The mean pH of surface waters ranges between 7.9 and 8.3 in the open ocean, so the ocean remains alkaline (pH > 7) even after these decreases.
The consequences of changes in pH on marine organisms are poorly known (see Section 7.3.4 and Box 7.3). For comparison, pH was higher by 0.1 unit during glaciations, and there is no evidence of pH values more than 0.6 units below the pre-industrial pH during the past 300 million years (Caldeira and Wickett, 2003)12. A decrease in ocean pH of 0.1 units corresponds to a 30% increase in the concentration of H+ in seawater, assuming that alkalinity and temperature remain constant.”
Hence we get the claim that “the ocean” has become 30% more acidic since the start of the industrial revolution. There are actually four oceans, five counting the Southern ocean and all are different. There can be no single pH value for the world’s oceans, any more than there can be a single surface-air temperature for the globe. The range of pH can vary extensively as described here:
Chris Jury, Center for Marine Science, Biology and Marine Biology, University of North Carolina,
“On some reef flats pH values have been measured to vary from as low as 7.8 to as high as 8.4 in a single 24 hr period (Yates and Halley, 2006). In some lagoons, pH has been measured to vary as much as 1 pH unit in a day (e.g., 7.6 to 8.6). Seasonal and even multi-decadal cycles of pH variation in reef water have also been measured (Pelejero et al., 2005).”
The pH changes of reefs are mainly caused by river discharge in near-coastal places. These are not included in the above research. pH changes over time in different oceans are about the same everywhere, independent of seasonal and latitudinal influences.
Ferdinand Engelbeen November 13, 2014 at 2:02 am Edit
I’m sorry, Ferdinand, but that is not true in the slightest. pH changes on a DAILY basis on many reefs. This is because during the day, coral reefs are a source of CO2, while at night they are a sink. This causes a daily swing which can be as large as 1 pH unit. In general it has nothing to do with rivers. Here’s a typical study.
You go on to say:
Also not true at all. pH is a local quantity that is affected by wind, temperature, currents, and most of all, life. The idea that the changes “are about the same everywhere” is easily falsified. Here are the changes off of the California coast …
Note the size of the pH change predicted for the coming century in the upper right …
Please point out to us the many other places where the changes in pH are “about the same” as that. While you are looking, here is an excellent study which says the exact opposite of your claims (emphasis mine)
So no … pH changes in different oceans are NOT “about the same everywhere” as you claim …
w.
Hello Willis,
You are right on point 1: although many reef systems are near coast or form lagoons themselves, it is biolife that makes the diurnal difference in pH…
Point 2 is more difficult: ships measurements go over different parts of the oceans, which each may show large (seasonal) differences and differences caused by upwelling and temperature and biolife. But if one measures at fixed places, or repeatable at the same trajectory over longer periods, the local (seasonal) variability still is high, but there is a similar trend, see fig. 7 and table 2 in:
http://www.tos.org/oceanography/archive/27-1_bates.pdf
In all cases pH declines with increasing DIC (total inorganic carbon). If temperature or internal decrease of pH (undersea volcanoes) were the cause, pH would drop but DIC would drop too, as more CO2 is released due to an increased pCO2. If CO2 is pressured into the oceans from the atmosphere, the pH drops with increasing DIC, which is the case nowadays.
Upwelling zones like the Monterey aquarium inlet are excluded from the above research because the pH is very variable due to changes in upwelling flux.
Thanks, Ferdinand. You say:
So what you are saying is that once we exclude the places in the ocean where pH is “very variable”, then in the remainder of the ocean, pH changes are “about the same everywhere”?
Dang … who knew?
w.
Willis,
Upwelling and downwelling zones from/to the deep oceans are each about 5% of the ocean surface. See:
http://oceanservice.noaa.gov/education/kits/currents/03coastal4.html
That is where the largest variability in all observations can be seen: pH, salinity, pCO2, temperature, biolife,…
90% of the ocean surface still shows seasonal changes, but far more regular and all with a steady change in different parameters caused by the increased CO2 pressure in the atmosphere.
Compare it to measuring CO2 levels in 5% of the atmosphere over land near huge sources and sinks with the CO2 measurements in 95% of the atmosphere at remote stations, ships and aircraft, including above a few hundred meters over land…
Ferdinand,
True, but anticipating that someone would bring up Vostok 400 Kyr cores, I figured I’d see if I could make the point stick on lower resolution data. Speaking of …
https://drive.google.com/file/d/0B1C2T0pQeiaST3RiNEczdEVGdmc
I added in several high resolution cores going back 22 Ka (Byrd, Siple) as well as Taylor (12 Ka). I threw in Law Dome (1000-1978 AD) for its overlap with the Mauna Loa instrumental record (1959-2014), which I also included. The Vostok data have been shifted forward so that the peak of each past interglacial matches the most recent one. You can see that the Holocene doesn’t look terribly unusual except for a small anomaly around year zero.
By the by, the lowest resolution in the Vostok data I’m using (Petit 2001) is 5,996 years and the average is 1,487. The second graph of my image is centered on year 0 again, covering a span of 6,000 years. I’m not exactly sure, but that little bump in the center of the graph would probably show up in a layer of ice spanning 6 Kyrs, even if for some wild reason CO2 went up and back down over that interval.
Willis,
What matters most is pH (as well as DIC and total alkalinity, plus nutrients, salinity, etc.) in locations where reef corals are living. There are no major coral reef systems in Monterey Bay last I checked.
Thanks, Brandon, but the pH over coral reefs changes both more and faster than the pH around Monterrey Bay. Nor are Monterrey Bay and coral reefs the only places that happens. See here for a study of the variability in a variety of ecosystems, and here for a study of just the reefs.
Here’re the numbers. Over many coral reefs, the pH changes by as much as 1 pH unit EVERY DAY … and they are hyperventilating over a predicted pH change of 0.002 pH units per year … you’ll excuse me if I don’t join the hyperventilation.
w.
Willis,
Thanks for the links, both are interesting and informative reading. The first one says:
From the second:
Both papers discuss the importance of DIC, total alkalinity and nutrient availability in addition to pH and emphasize high degrees of uncertainty about their effects on calcification due to complexity of the interactions as well as the wide differences between various locales … some of which are in close proximity to each other.
Takeaway: it’s wrong to hyperventilate about globally lower pH trends to the exclusion of all else — local environments must be evaluated individually, taking into account diurnal, monthly and seasonal “high frequency” fluctuations when defining “normal” for the organisms which live there. Only then does it make sense to discuss what might happen as any secular trends move the means and extremes one direction or another.
It’s also important to note that while some species may lose, others might benefit, even to the point of mitigating some otherwise deleterious effects. From the first link again:
May, might, perhaps, etc. One thing is for sure: reducing the discussion down to soundbites that conflate local high frequency and amplitude trendless fluctuations with long term (perhaps tolerable, perhaps not) secular net global trends does not give these issues the consideration required for true understanding.
I’ll remember this grave danger each time that I reach for a carbonated beverage….