Ocean Acidification to Hit 300 Million Year Max

It's been awhile since my last oceanography class, and you're likely focussed on the chemistry, but...we could probably add 'heat distribution' to the list. Oceans are also the source of precipitation.

 

Not necessarily; iron fertilization does not require much energy

 

Not all the iron fertilization tests have been great successes, but let's skip past that. THis is a matter of scale. If you want to 'draw down' a billion tons of C per year, I think you will need to add about 1/100 of that as small-particle or dissolved iron. That is 10 million tons.

So get it for free at the scrap yards (or pay), grind it up finely, take it to sea and spread it thinly in the right places. How's the budget so far?

 

I'll take a swag at that. Anything in the millions of tons is likely to be rounding error in the overall scheme of things.

Do we have to smelt it, or can we just grind up and spread the ore?

World iron ore production is 2.4 gigatons, steel production is 1.4 gigatons. So, 0.01 gigaton of ore or steel is negligible.

Steel industry says emissions amount to 1.8 tons of C02 per ton of steel, but it's unclear what that includes. Almost certainly that involves a lot of scrap.


World Steel Association - Climate change


EPA lists 38 MBTU/ton for producing steel cans from virgin materials.
http://www.epa.gov/climatechange/wycd/waste/downloads/Metals.pdf

If that were all coal, then coal is listed at 208,000 lbs C02 per billion BTU
http://www.physics.uci.edu/~silverma/units.html

Or about 4 tons C02 per ton of steel, all coal, all virgin materials. That should be a worst case.

So to some approximation, you'd guess that producing the ground steel would be in that neighborhood. So 0.04 gigatons of C02 for production.

Trains claim 500 ton-miles per gallon of fuel, ocean freighters are 1000 and up. If the material has to move an average of 1000 miles (say), mostly by freighter, then 10 m tons takes 10 m gallons of fuel to move 1000 miles. At about 20 lbs C02 per gallon, would be 100,000 tons of C02 (0.0001 gigatons) to move it.

If it worked, you've have an extremely favorable C02ROI. Your investment of maybe 0.04 gigatons C02 emissions would draw down a 1.0 gigatons of C02. Well worth it.

Now let's see what Wikipedia says:
Iron fertilization - Wikipedia, the free encyclopedia

I think the "favorable" statement stands. They seem to list a worst-case scenario for sequestering 3 gigatons having a cost of $27B dollars. Man, that's chump change in this scheme of things. That's about 0.2% of US GDP, under 0.1% of world GDP.

I mean, really, what would it take to fund that? Work back from 10 gigatons C emissions annually. That's $2.7 per ton C, or maybe $1 and change per ton of material (coal, oil). I mean, seriously, that's some pretty cheap disposal cost.

It may seem offensive to some, to once again use the ocean as our dumping ground, but consider this: By the time we get around to doing it, pretty much everything in the ocean will be dead anyway. At that point, the environmental harm argument will be moot. In fact, in that sense, you might even say that drawdown of C02 via ocean fertiliztion, if done early enough, might save ocean life. Because the consequences of failing to act certainly do appear to be near-extinction of ocean life, based on the paleological record (citation was given earlier in this thread).

Seriously, adequate emissions reductions aren't going to happen. I ran some "experiments" of sorts within my church congregation (a very smart and enlightened group, maybe 15% of the cars in the lot on any give day are Priuses), to see whether a smart group of people could see what needs to be done. Total failure. Almost nobody gets what's at stake, essentially nobody willing to make significant changes voluntarily. Add the 2nd world countries to that, and emission reductions ain't going to happen. We're going to have to go this way, and the sooner the better.

 

tochatihu,

the 1/100 ratio is off. You need 1kg of iron to fix 83,000kg of CO2.

http://priuschat.com/forums/environmental-discussion/94870-iron-fertilization.html

 

Although I think the FUD is way overblown,the problem then, is already solved.
There's already many tens or hundreds of millions of tons of shipwrecks oxidizing on the ocean floors.Add to that bridge pilings and misc

 

free?...you are messing with USA's No. 1 export (or close on weight basis). In South Jersey and South Philly they grind this stuff up for export.

>>The Number One U.S. Export To China: Waste Paper And Scrap Metal

I could not see in Wiki what iron compound we need for this. Presumably scrap iron is quickly redenered insoluble by odixation, and partcile size is too big. Ferric chloride or ferrous sulfate are soluble and probably also oxidize but if so the particle size would be microscopic.

 

yes, if you are willing to dive, grind it to in pieces 0.5-1 micron and deposit it on ocean surface.

for comparison regular filter efficiencies are rated at 20micron

 

World Climate Report » Acclimation to Ocean Acidification: Give It Some Time

"But the larger lesson is this: Don’t jump to conclusions based on an inadequate analysis of complex systems.
If everyone followed this advice, our future would certainly appear much less “alarming.â€"

 

I certainly agree with mojo about not jumping to conclusions. Neither that the ocean's biota will be just fine at a few tenths pH lower, nor that they will collapse.

The oceans now provide two irreplaceable services to humans: they sequester CO2 from the atmosphere and provide seafood protein to eat. One can find research indicating that all will be well, and others indicating some trouble ahead. This is the other difficulty (besides heat storage) that the earth's massive ocean presents to us. I remember providing the link to Doney's review here before, that all might want to read.

If you read the research, and conclude that all is well on the 'unlimited fossil CO2 emission path', then there is nothing more I can say to you. However, if you conclude that there seem to be good reasons to limit fossil CO2 emissions, we can talk about the most important thing, which is how to limit this without preventing economic advance in less-developed countries.

If you base your conclusions on affinity websites, well, you'll probably get what you pay for. There is much more 'paying' associted with understanding the original research.

Once again, I wish that we had a real oeanographer at PC to guide us through these matters. Is the ocean doing a better job of hiding heat than acidity, as it seems to me? Bother should be related to vertical mixing.

 

If you aren't terrified by the acidification issue,, you ought to be, if not for you then at least for you kids.

Icarus

 

Must hope that 'terrified' is too strong a term. Somehow, the ocean biota survived the PETM. Whether the oceans will continue to serve as a rich protein source for humans on the century scale is another matter though.

Reductions in pH, overfishing and anoxic zones from (excessive) fertilizer runoff might conspire against us. A shame, at least.

I watch for good (or less bad) news from the climate change and carbon cycle literature, to bring to your attention here. Nothing to report on recently, sorry.

Back to our thread starter, the 300-million year timescale is quite an interesting one. The great era of coal formation had just recently ended, that representing a large mismatch between plant production and decomposition. Atmospheric CO2 was reduced to (about) current levels. Nothing like that has happened since.

Our present, sudden return of a large chunk of fossil carbon to the atmosphere is also unprecedented. Maybe I'll go with terrified after all but not today, though.

 

Am I mistaken, or do oceans oceans contribute a significant portion of the oxygen to the Planet, through plankton photosynthesis? What happens if that plankton can't adapt to higher ocean acidity?

Icarus

 

plankton are important because they are the bottom of the food chain. Plankton growth is slow not because of acidification but lack of iron.

The coral reefs are in trouble from a double whammy of acidification and ocean temperatures. Some corals seem to do fine in the different environment, but others are at risk. Coral death on hot years is highly visible.

 

These days, photosynthesis exceeds decomposition both at land and at sea, both by similar and rather small amounts. Thus both land and sea biota are oxygenating the atmosphere.

But also the fossil fuel burn is taking O2 out of the atmosphere. Overall net effect is that O2 is decreasing. Not enough for us to notice lung-wise. In fact you need some pretty fancy equipment to measure the parts per million scale decrease. It is not as easy as measuring CO2 increases, because the latter gas has such strong and distinctive absorption bands in the infrared.

If you go to the Scripps CO2 website (this is not its name, but a useable Google (TM) search term), you can download both CO2 and O2 time series data. they match each other but go in opposite directions. Just as you'd expect if the net CO2 increase is all from burning. Understand that and you understand something that Salsby (of 'wow' fame) does not.

In terms of recent good news on ocean acidification, have a look at this:

ARC coral survive acid ocean

The paper discussed is in Nature Climate Change, not one that I can download directly. But any of us can go to the journal website and request a copy directly from the corresponding author. It would be rare for the author to not send it.

Well, maybe if you were to get abusive in the 'comments to the author' box...say that they are participating in the world's largest hoax, should be tried for fraud, or something along those lines

 

At least one species of planktonic calcifier can adapt to CO2 and acidity increases

Evolution at sea: Long-term experiments indicate phytoplankton can adapt to ocean acidification

Not satisfying detail in this press release though. The zooplankton - the cows that feed on the grass as it were - would put a lot of pressure on any adaptive shifts. Must read the article to see if they included cows.

 

On average, ocean phytoplankton (photosynthetic plankton) account for about half of global photosynthesis (and thus half of global carbon drawdown and half of global oxygen production). In terms of ocean acidification, phytoplankton can be divided into two groups: calcifiers and non-calcifiers.

Some calcifiers have been shown to have issues with low pH (while some have not, e.g. article linked a few posts up). Non-calcifiers typically do not have an issue with pH, but some have shown positive responses (in terms of growth or rate of photosynthesis) to elevated CO2 that comes along with lower pH.

Also, phytoplankton growth has been shown to be slow due to the lack of iron in some parts of the world's oceans (equatorial Pacific, subarctic Pacific, Southern Ocean). But large parts of the world's oceans have low plankton growth (note that I used 'low', not 'slow') due to N and P limitation.

Hope that helps...