CO2 makes life difficult for algae

The acidification of the world's oceans could have major consequences for the marine environment. New research shows that coccoliths, which are an important part of the marine environment, dissolve when seawater acidifies.

Associate Professor Tue Hassenkam and colleagues at the Nano-Science Center, University of Copenhagen, are the first to have measured how individual coccoliths react to water with different degrees of acidity.

Coccoliths are very small shells of that encapsulate a number of species of alga. Algae plays an important role in the global carbon-oxygen cycle and thus in our ecosystem. Our seawater has changed because of our emissions of and therefore it was interesting for Hassenkam and his colleagues to investigate how the coccoliths react to different types of water.

"We know that the world's oceans are acidifying due to our emissions of CO2 and that is why it is interesting for us to find out how the coccoliths are reacting to it. We have studied algae from both fossils and living coccoliths, and it appears that both are protected from dissolution by a very thin layer of that the algae formed, even though the is extremely unsaturated relative to calcite. The protection of the organic material is lost when the pH is lowered slightly. In fact, it turns out that the shell falls completely apart when we do experiments in water with a that many researchers believe will be the found in the world oceans in the year 2100 due to the ," explains Tue Hassenkam, who is part of the NanoGeoScience research group at the Department of Chemistry, University of Copenhagen.

Professor of Biological Oceanography Katherine Richardson has followed research in the acidification of the oceans and in general and she hopes that the results can help to bring the issue into public focus.

"These findings underscore that the acidification of the oceans is a serious problem. The has enormous consequences not only for coccoliths, but also for many other marine organisms as well as the cycle," explains Katherine Richardson, professor of biological oceanography and vice dean at the Faculty of Science at the University of Copenhagen.

Tue Hassenkam is a nano-specialist and has been working for several years with the AFM (Atomic Force Microscope), which is an important instrument for nano researchers, because they can see and manipulate very small samples of, for example, geological materials like coccoliths.

"Using the AFM I weighed the coccoliths before and after they have been immersed in water with different compositions. The coccoliths weigh around 500 pg (0.0000000005 g). Specifically, I have set a coccolith on tip of an AFM and immersed the tip in water and looked at and weighed the coccolith afterwards. In that way I can say something about how much and how long it takes for a coccolith to dissolve in water with different degrees of acidity. I can use these results to say something about how important the water acidity is for the ," explains Tue Hassenkam, who has just had his results published in the journal PNAS.

Measurements of such small materials are unique and very precise and there is therefore great potential in using the technique on other materials. For example, Tue Hassenkam has recently measured the dissolution of salt in ash from the Icelandic volcano Eyjafjallajökull which erupted last year.

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May 10, 2011
Mass of Earth atmosphere is 5E18kg.

In order to have a partial pressure of 3.5E-4 of CO2, that would be 1.75E15kg of CO in the atmosphere.

Allegedly, about 3/4 of this is man made in the past 100 years.

If you take our energy consumption of 510 exajoules, and, just for the sake of argument, assume 100% of it comes from coal, then coal produces 940g CO2 per kilowatt hour produced, which is 3600000joules.

This would come to 1.34E14kg CO2 per year.

Which means that at that rate you could produce all the CO2 in the atmosphere in about 13 years.

However, this is hugely misleading, since we do not get 100% from Coal. We also use gasoline, which is about 20% cleaner per unit energy than is coal, and we also already get huge amounts of our power from Hydro electric and nuclear.

In order to change partial pressure enough to effect ocean acidity we'd need an order of magnitude more CO2, which would take 130 years even if 100% of energy came from Coal.

May 10, 2011
For example, the answer on "Answers dot com" is bullshit.

It claims that fossile fuels provide 66% of world electricity and 95% of world energy budget. This is pure BS.

All of the oil used world wide per year is around 21 billion barrels. If all of it is burned, which it isn't, much of it is used in plastics or as coolant/lubricant... but if it were all burned, that would only be 106 exajoules, which is only 20% of world energy budget, not the ~30% leap they did from the 66% for electricity to 95% for total...

Which is to say, whoever posted that response lied.

Additionally, many of the most developed nations which are by far the highest consumers of energy get a large portion of their budget from carbon neutral sources to begin with, and always have, namely hydro and nuclear.

1.8% of world energy comes from Nuclear
~70% of France and Japan energy comes from Nuclear
20% of U.S. energy comes from nuclear.

May 10, 2011
And when you examine hydro-electric:

19% of U.S. energy comes from hydro power

So nuclear + hydro = 39%

So right away, the U.S., which is the largest consumer of Oil, is still beating the world average in clean energy.

In fact,the pollution is actually coming from the non-developed nations who are still burning almost 100% wood and coal for everything.

Yet all the sanctions get placed on the U.S. and Europe, when the reality is Africa, South America, and Indonesia are doing most of the polluting, at least as a percentage of their energy budget...

May 10, 2011
The U.S. produces 70% of world's total food supply.

the U.s. consumes 22% of world's total energy supply.

So already we are doing far, far better in terms of productivity per unit pollution that pretty much anyone on the planet.

Since 40% of our energy already comes from carbon neutral sources, water, nuclear, and start up technologies, this means that no more than 60% of that 22% is polluting, which is 13.2%.

But the U.S. also has much cleaner coal, natural gas, gasoline, and deisel restrictions than many of the other developed nations,s o this number is actually skewed as well.

Therefore, the U.S. is producing 70% of world food supply, but produces 13% of world CO2 emissions, in spite of consuming 22% of energy.

Anyone who complains about that is a dumbass.

Its a 3 to 1 ratio of production vs consumption, and a 5 to 1 ratio of production vs pollution.

May 10, 2011
That means the remaining 95.5% of freeloaders on the planet consume 90% of food while producing only 30%.

They consume 78% of energy while producing 87% of pollution, and again, only 30% of food.

The U.S has a 5 to 1 ratio of production vs pollution.

The rest of the world has a 1 to 3 ratio...

5 to 1


1 to 3

Makes the U.S. 15 times more productive per unit pollution than the average of the remainder of the world...

May 10, 2011
QC - Instead of calculating the values and making theoretical back of an envelope calculations such as you have done here, its also useful to go back to direct experimental measurements.

We know as a fact that CO2 levels today are about 30% higher (or so) than preindustrial age levels. We can measure the CO2 in the atmosphere very easily and see that each year the CO2 levels are rising a few ppm.

So what is causing it? It is relatively easy to measure sources of carbon using isotope ratios. So we can tell that most of the carbon in the atmosphere is from burning fossil fuels.

But the ocean acidification is being measured all the time. I assume you have heard of a pH meter? This is also direct experimental validation. When in doubt, its always best to rely on real objective data instead of conjecture.

May 10, 2011

The data itself was not really in quesiton.

The interpretation was in question.

Carbonic Acid is not a strong acid. It takes a LOT of CO2 to lower the pH of all the world's oceans, my numbers were based on obtaining a significant decrease, i.e. 0.1 pH decrease.

Additionally, the Oceans have a LOT of buffers in the sea floor and other mineralogy in the form of limestones and other forms of Calcium and Magnesium and other minerals, which are basic and react with CO2 to make weak bases and salts.

May 10, 2011
"acidification of the world's oceans could have major consequences. . ."

What acidification of the world's oceans?

Where are the numbers?

May 11, 2011
The numbers? Current (at the time of publication I suppose) oceanic pH 0.1 lower than preindustrial levels (Orr et al. 2005 in the peer reviwed publication "Nature" volume 437, page 681) with predicted levels to be 0.3 to 0.4 units lower by the end of the century (Haugan and Drange 1996; Brewer 1997 as cited in Orr et al. 2005). Which according to Orr et al. (2005) is a 100 - 150% increase in oceanic [H+].

May 11, 2011
Then they should be welcoming global warming!

Ice-core data proves, that every 800 or so years of warming, the CO2 concentration rises (as it is expelled from the oceans).

A simple experiment you can do at home will prove this property of CO2:

Take an unopened bottle of carbonated water.

-If you put it in the fridge, then open it once it's cold, there will be a short gasp, and maybe some smoke, but nothing really fancy. That's because CO2 is more soluble in colder water.

-If on the other hand you place the unopened bottle in direct sunlight, or on your heater, then upon opening it you might find yourself in a puddle of water. That's because warm (or dare I say hot) water releases most of it's dissolved CO2. (and the pressurized container will force out lots of water once opened)

I'm sorry to say that this simple experiment is all I have to offer, but I'm sure y'all can come up with some nice fancy numbers if you measure the results right.


May 11, 2011
RegenegeR, there's a difference between super-saturation and under-saturation which renders your point moot.

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