Ocean Acidification to Hit 300 Million Year Max

I really don't trust the figures older than 18,000 years, and going past 180 million just seems like pure guess work. Anybody have a a feeling about how accurate these estimates are?

Its still important that its the most acidic in the last 18K years.

 

that is a good question.

From practical point of view you'd more care if it is sufficiently accurate for last 180K-1.8M years when the climate cycles were more or less consistent. If the acidity levels substantially higher, then the is no doubt that we are heating alot quicker then we did in this period.

The next question would be if the natural mechanism regulating icing/warming (thermohaline circulation) are capable of cooling this warming cycle, or we on completely new trajectory to something new with potentially complete ice cap meltdown.

and yes high acidity may trigger the increased species die out, specifically coral reefs (big carbon sinks) which are sensitive to acidity. Die out will increase methane output, and eventual carbon dioxide release when ocean warms up.

 

"Anybody have a a feeling about how accurate these estimates are?"

I've said before that PriusChat needs an oceanographer We have had some, self-described, but they have not commented on these matters.

I read the Hönisch paper, and based on my limited knowledge of the field, I cannot answer the question well. First thing I'll say is that Richard Zeebe and Dana Royer are among the long list of co authors. My impression is that they are among the best paleo-carbonate chemists.

Second is that the text is rather circumspect. They plead for more cores and additional geochemical proxies. They specify that going older than about 180 million years has additional limitations, because sea-floor sediments are subducted on that time scale. All the older cores come from continental shelves.

If in the dangerous position of trying to summarize this research, I'd say that they have not found evidence of marine chemistry ever having changed so rapidly.

They do stress that the current rate of increase of atmospheric CO2 seems unprecidented. other studies have as well, and based upon other lines of evidence. This rate thing seems quite important, because the rate of resupply of Ca and Mg ions to the ocean is from terrestial mineral weathering. If those don't balance, then the calcifiers see hard times.

Obviously, on the very long term, weathering can 'keep up'. but on shorter timescales you really need orogenic uplift episodes to accelerate that process. Rain, acidified by CO2, falling on stable land just can't seem to keep up.

That was an unspoken sad message I took from the recent GRACE study suggesting that Himalayan glaciers are not melting. Melt off exposes a lot of weatherable minerals, quite apart from the hydrologic and albedo effects. So, go, you melting Alaskan glaciers, go! the N. Pacific needs your Ca and Mg.

Finally, the logarithmic nature of pH and the the use of the term 'acidification' to describe changing from pH 8.2 to 8.1 both seem to lead to confusion. Better perhaps to say that transition represents a 30% increase in (surface seawater) hydrogen ion concentration, and it has happened during a time that atmospheric CO2 has also increased by 30%. Saying it that way seems a lot simpler to me. Not a comment on this paper; just a mini-editorial.

 

It is hard for me to know if this article is a significant new piece of info.
Sounds like this paper attempts to be the ocean acidification equivalent of the hockey stick, complete with the warning we are in uncharted territory re: planetary chemistry. Assuming the human race has no choice except to continue burning fossil fuels, we need the planet to be able to sequester the excess CO2 being released. The ocean uptake of CO2 is the first step. We entered unchartered territory the day the first lump of coal was burned and world population exceeded 1 billion. I don't like loss of eco-quality of life either, but since the OP posted, Earth now has 200,000 more people in one day.

 

I re-read Doney et al 2009 review of ocean acidification

Annu. Rev. Mar. Sci. 2009. 1:169–92
DOI: 10.1146/annurev.marine.010908.163834

to see whether I could perhaps convice people here to read it, given an increased PC interest in marine chemistry. The answer is, well, maybe. The fundamental points are all there, but not quite apparent as they might be. A shame perhaps; often articles in the "annual reviews" series are aimed more towards the interested general public.

I'd make those points as follows, with a clear recognition that PC's as-yet unrecognized oceanographer might say them very differently:

Ocean H+ concentrations do track atmospheric CO2

On long timescales, terrestrial supply of Ca and Mg vary a lot, and modify the H+/CO2 relationship.

That gets bundled into the aragonite saturation index (ASI), which seems to be an irreducible concept: If you don't understand that area of chemistry, it is mumbo-jumbo. I am not really apologizing for this. We'd all agree that if you cannot write at least one language you are illiterate. Science literacy is no different to me, but I certainly recognize that people 'on the outside' can (and do) act upset about it. When it is portrayed as elitism, I get sad. Oops, kind of an aside there.

Some marine calcifiers are very sensitive to ASI and others much less so. I can't see that general patterns have yet emerged from those observations. But if it turns out that the more sensitive species play key ecological roles, the sturdier species won't matter so much. Non-linear system responses and all that.

Doney's expectations for ocean pH changes in this century (loss of 0.3 or 0.4 pH units) depend only upon increasing CO2 in the atmosphere. The supply of Ca and Mg simply cannot change fast enough (in the absence of large-scale geoengineering). Surface ocean temperatures will also not change fast enough to have large effects on this chemistry (ocean thermal inertia is really large).

+++
What is new about Hönisch is that they use the widest suite of available geochemical proxies and the largest coverage of sediment cores. They analyze it all and conclude that nothing in the paleo record known so far equals the current rate of ocean chemistry change.

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At present, land and sea ecosystems are sequestering half of fossil-C emissions, with nearly equal shares. There are clear ways to increase that on land, but they cost money and so we come up against not monetizing carbon and not acting upon the Kyoto Protocol.

There are theoretical ways to increase C sequestration at sea, but the fertilization tests so far have had variable results. That activity would also cost money.

Crushing vast quantities of limestone rock and dumping it at sea could resolve the looming ASI problem. My guess as to why nobody has suggested it is that they hanven't found a way to do it that doesn't require a lot of energy. As long as 'energy' means 'burning fossil C', that would seem to remain futile.

 

Unlike wjtracy, I wouldn't indict that first-lump-of-coal burner. That was the beginning of the industrial revolution. Led to unimaginable economic advances and most of modern science. Gotta love that

Neither the first oil-well-driller, who broadened the economic advances (arguably leading to USA predominance). Saved a lot of whales from being killed for their fat, and I have sung that praise here before.

Rather, it was when our rate of net CO2 injection to the atmosphere exceeded the ability of ecological and geochemical systems to handle it. All about rates. We might have been forgiven then, for not knowing those natural rates. But now we do, so pleading ignorance no longer seems viable.

According to Ruddiman, anthropogenic 'takeover' of the atmosphere began with large-scale clearing of forests for agriculture 1000s years ago. Fascinating, and still controversial. Yet I shouldn't blame first-farmer either. I really enjoy eating.

Humans are go-go-go, more-more-more, and it is hard to see the value of trying to deny or deflect that. I'd only want to add think-think-think to the list. That might really be a great strategy for Sustainable Planetary Domination.

Ultimately there are no externalities. That's all you need to know. Policy and politics are details.

 

I 'did time' in grad school at Dartmouth, which claims Theodor Giesel as a favorite son. So there is some faint connection. But I am not a cartoon character, and if I were one I would not want to be a marketing tool for green or 'greenish' products.

I do know one ecologist who is much more of a spokesperson for tress than am I. Years ago, Toyota wanted to give her a 4runner or Land cruiser (forget which) as a prize. She said "no, how about a Prius?" Toyota said no.

So that Lorax is still driving her own car

My work has much more to do with dead trees than live ones. Decomposition has yet to be featured in childrens' literature. The only exception I know is Gary Larsen's "There's a hair in my dirt". From which I have purloined images for powerpoint presentations.

 

how much (overall quantity) are we talking about?
Is it something on a scale making it economically feasible to geoengineer?


Also side comment: it is hard to buy that ocean acidification is solely due to CO2 increase. There is enough SO2 pumped out but perhaps its contribution is relatively small. Also increased CH4 presence cannot be easily discarded.

 

In the Adirondacks in NY hundreds of beautiful small lakes unfort long since devoid of fish due to acid rain. The bigger lakes are treated with limestone to improve pH. That was one of our first canoe trips, but I ain't saying when that was. But my info is possible out-dated.

 

An NYT editorial take
A CO2 Warning Etched in Stone and Sediment - NYTimes.com

T

 

Not solely caused by CO2, but the physics is rather straight forward 1/4 of the CO2 is sequestered in the oceans. Eventually this will precipitate out, but they can look at the geology of how much goes into sediment, the rest must go into the water.

The video in the NYT editorial above talks about CCS to reduce CO2 in the air. If we do use CCS the oceans will give up some of the CO2 to the air also.

 

Why not?

Are you an oceanographer, or a climate scientist with better information?

The concept of 'one person, one vote' makes good sense in a democracy, but the idea that all opinions are equally valid is nonsense and madness.

 

Pauline, please don't back off because of hyo's questions. I reckon that you are not "in the business", and instead more like a regular person. PriusChat is a great place for discussion, and we can learn from everyones' viewpoints here.

Under discussion here is whether marine chemistry is changing unusually quickly. You say that you don't trust the figures. Please tell us the basis for your feelings, and what other sort of data you would find more convincing.

Besides any of that, we would be most interested in your experiences with that solar roof Prius. Let no one forget that this is Danny's web site to talk about Prius, in the first case.

We just wrangle about environmental issues because we have too much time on our hands

 

Cyclo, as near as I can figure from the river flow and river chemistry people, there are now about 6 million tons of dissolved Ca+Mg being transferred from land to sea by mineral weathering. If I wanted to make the Aragonite saturation index more comfortable for the calcifiers, I guess I'd want to double that flux.

Leaving out the details of limestone chemistry, doubling would mean powdering about 12 million tons of limestone per year and dumping it into rivers near the coasts. I don't know how to do that w/o using a lot of fossil fuels. I guess we don't use prisoners to hammer rocks anymore.

We'd also want to know how much Ca+Mg is transferred to oceans via 'Sahara dust' and "Asian dust'. Sorry, I don't know (maybe Duce does) but I guess it is much smaller than the riverine flux.

Acid from industrial sulfurics and nitrates was also mentioned. Those are 'near-field' fluxes because they get rained out, well, as soon as rain hits them. Most industrial acids fall on land, unless I am quite mistaken. On the scales we are discussing here, land-falling acids would tend to increase Ca+Mg inputs to the seas. The world is not simple; sorry about that

Wjtracy, the limestone to neutralize Adirondack watersheds was spread on the land, not in the lakes. But the last time I did sampling there was about 1991, so I may also be behind the times.

AustinG, the net marine C sequestration is *all* going to sediments. Lovell is one of the proponents of CCS. If that ever gets going on a large enough scale such that atmospheric CO2 is reduced, then for sure surface ocean waters would 'degas' CO2. There is a *huge* amount of dissolved inorganic C in marine surface water. It is just waiting for physics and chemistry and biology to tell it where to go.

 

Billion. I started to do the math, and got all interested, but millions of tons would be too easy -- US produces 1000 million tons of crushed rock annually, of which 70% is already limestone. World cement production is 3300 million metric tons, and that's only 5% of GHGs.

I should have looked it up first, e.g.
http://www.wired.com/wiredscience/2008/07/new-geoengineer/
http://www.treehugger.com/clean-tec...e-into-the-oceans-to-fight-acidification.html

So we're talking about an additional volume of crushed rock that is on-the-order of doubling world cement production. That's pretty significant.

 

...that may be easier than stopping CO2 production unfort

 

Poor word choice on my part. What is the proper term for the CO2 that goes into the water+sediments in the oceans?

He is an interesting guy. I had the opportunity to talk with him over dinner some years ago, my cousin who researches sequestration pulled me along when we were both on business trips in the same city. Its fascinating to me that the one author from the OP focused on the "we have never been here before" and its worse today. Lovell in the piece I posted looks at the data and says, we have had huge influxes of CO2 before, and this is what the rocks tell us happened. Then he looks at the rocks some more, and interprets that what has happened with the natural high levels of CO2 was not good, so the man made spike must also not be good.

 

There is a fellow named Manning at Newcastle upon Tyne. (sounds like a limerick I know)

He has demonstrated that adding crushed concrete to soil leads to the formation of carbonate. The soil consumes CO2, more exactly the high concentration of CO2 present in soil is made smaller.

We discussed this in connection with China. Most of you know that there is now a huge building boom in literally 100's of Chinese cities. Old buildings are being demolished and the debris is buried in large landfills. However, if that dust was spread more thinly in soils and mixed in, it would absorb CO2. Manning thought it was a good idea. There may not be any place in the world with so much 'powdered buildings', just waiting the opportunity to absorb CO2.

It is on my list for future research. If anybody else wants to do it sooner, have at it. Plenty of other ideas kicking around here

But the fundamental is not so different from adding a lot of calcium (it must have lots of surface area) to ocean surface water.

All the geoengineering ideas deserve consideration. They all seem to present large energy requirements, so powering with fossil-C might leave us spinning our wheels to little net effect.

Can't afford to ignore ocean chemistry though. Oceans provide at least 3 incomparable ecosystem services:

1. Sequestering a lot of newly released fossil fuel C
2. Major source of protein to the global human diet.
3. The amount of CO2 dissolved in the oceans (especially deep water) is enormous. Seems to be happy enough just sitting there. But if we find a way to upset that, well I don't want to talk about it. Really alarmist.