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Ocean acidification due to carbon emissions is at highest for 300m years

theguardian.com

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Re: Ocean acidification due to carbon emissions is at highest for 300m years

#31

Post by na85 »

protomyth wrote: post #18
na85 wrote: post #11

Earlier quoted context omitted.

Not without a significant energy expenditure. But most of our energy sources of course produce CO2 and other products.

I guess the Scifi question is can you build a nuclear ship with some apparatus that pulls the CO2 out of the ocean and breaks it into C (stored on ship) and O (released into atmosphere)?

I don't see why you couldn't.

Most large navies run nuclear reactors on board their ships. IIRC, nuclear submarines pull water and use a portion of reactor power to get fresh oxygen.

But I'm also not sure that the reaction is as easy as it sounds. First of all, manufacturing such a ship would likely cause a great deal of greenhouse emissions. Would the ship's benefit offset the pollution it implicitly creates as it is built? How about the pollution generated by its operation? No engine emissions, but when the reactor gets decommissioned it'll have to be buried, likely by diesel-powered equipment and covered in concrete which is manufactured in a dirty process. Tugboats aren't nuclear powered. Re-fuelling apparatuses aren't nuclear-powered. Crew will produce waste, reactor needs to be cooled which introduces unwanted heat to the water, etc etc etc.

Would it even be economically possible to build/operate?

How many ships would be required to make a measurable impact?

Re: Ocean acidification due to carbon emissions is at highest for 300m years

#32

Post by pygy_ »

protomyth wrote: post #18
na85 wrote: post #11

Earlier quoted context omitted.

Not without a significant energy expenditure. But most of our energy sources of course produce CO2 and other products.

I guess the Scifi question is can you build a nuclear ship with some apparatus that pulls the CO2 out of the ocean and breaks it into C (stored on ship) and O (released into atmosphere)?

You could build one ship, but you'd need to build and power millions of them to have any impact.

You'd have to reduce the CO2 resulting from the combustion of coal and oil during the whole industrial era, or maybe a bit less, but it gives you an idea of the magnitude of the task at hand.

Re: Ocean acidification due to carbon emissions is at highest for 300m years

#33

Post by dwiel »

hcarvalhoalves wrote: post #30

The short-term scenario is not good, but from the little I know about aquatic biology/chemistry, it might not be as catastrophical as the article pictures it. Increased CO2 levels should just cause algae/cyanobacteria blooms, which will balance CO2/O2 levels back again and foster primary consumers (solving over-fishing as a bonus). Also, H2CO3 gets buffered by all the Ca/Mg content in the ocean, so I don't think it's…

Do you know why this isn't already happening at a pace to keep up with the changes they are measuring? Do you expect that the effects you mention are currently, but will soon catch up? I am honestly curious.

Re: Ocean acidification due to carbon emissions is at highest for 300m years

#34

Post by j_baker »

They talk about the oxygen content falling by 7% by 2100. This makes me wonder: let's assume the worst and earth is headed for a mass extinction event. How long do these events usually take? Are they slow processes, or does everything just die one day?

Re: Ocean acidification due to carbon emissions is at highest for 300m years

#35

Post by Daishiman »

hcarvalhoalves wrote: post #30

The short-term scenario is not good, but from the little I know about aquatic biology/chemistry, it might not be as catastrophical as the article pictures it. Increased CO2 levels should just cause algae/cyanobacteria blooms, which will balance CO2/O2 levels back again and foster primary consumers (solving over-fishing as a bonus). Also, H2CO3 gets buffered by all the Ca/Mg content in the ocean, so I don't think it's…

The ocean's effect as a buffer is fading very rapidly.

The growth of cyanobacteria may have extremely harmful events. No organism on this planet has ever seen a rate of change as strong as this, so this is completely unpredictable territory.

Re: Ocean acidification due to carbon emissions is at highest for 300m years

#36

Post by thaumasiotes »

dwiel wrote: post #33
hcarvalhoalves wrote: post #30

The short-term scenario is not good, but from the little I know about aquatic biology/chemistry, it might not be as catastrophical as the article pictures it. Increased CO2 levels should just cause algae/cyanobacteria blooms, which will balance CO2/O2 levels back again and foster primary consumers (solving over-fishing as a bonus). Also, H2CO3 gets buffered by all the Ca/Mg content in the ocean, so I don't think it's…

Do you know why this isn't already happening at a pace to keep up with the changes they are measuring? Do you expect that the effects you mention are currently, but will soon catch up? I am honestly curious.

what you're looking for is: https://en.wikipedia.org/wiki/Lotka%E2%80%93Volterra_equatio...

A predator-prey model is essentially never just a stable population for both. Instead, you go through periods of increasing prey -> increasing predators -> decreasing prey -> decreasing predators.

Here the prey would be atmospheric carbon dioxide and the predators would be the plankton.

Re: Ocean acidification due to carbon emissions is at highest for 300m years

#37

Post by hcarvalhoalves »

dwiel wrote: post #33
hcarvalhoalves wrote: post #30

The short-term scenario is not good, but from the little I know about aquatic biology/chemistry, it might not be as catastrophical as the article pictures it. Increased CO2 levels should just cause algae/cyanobacteria blooms, which will balance CO2/O2 levels back again and foster primary consumers (solving over-fishing as a bonus). Also, H2CO3 gets buffered by all the Ca/Mg content in the ocean, so I don't think it's…

Do you know why this isn't already happening at a pace to keep up with the changes they are measuring? Do you expect that the effects you mention are currently, but will soon catch up? I am honestly curious.

Algae/cyanobacteria blooms are already a reality [1]. The ocean is such a big system though, that I wouldn't expect the long-term effects of these blooms to be observable in a timeframe measured in decades.

[1] http://blogs.smithsonianmag.com/smartnews/2013/07/chinas-mas...

Re: Ocean acidification due to carbon emissions is at highest for 300m years

#38

Post by Daishiman »

j_baker wrote: post #34

They talk about the oxygen content falling by 7% by 2100. This makes me wonder: let's assume the worst and earth is headed for a mass extinction event. How long do these events usually take? Are they slow processes, or does everything just die one day?

What would happen is that the rate of biodiversity drops drastically, and organisms that are simple and adaptable (like cockroaches, algae, jellyfich, certain classes of bacteria, small mammals, urban birds) adapt and thrive and consume the rest of the flora and fauna, and permanently adapt their environments making the situation extremely fragile for more complex and delicate birds and larger vertebrates.

Also, the system goes out of the equilibrium slowly developed in the last climate age.

As far as crops go, we'll see new varieties of plant illnesses appearing in places we hadn't seen them before. Unpredictable weather kills the more fragile species that depend on consistent climate.

Some ecosystems become simply uninhabitable; the Siberian bog swamps which are beginning to melt and release a greater amount of methane than ever before seen by humanity will not support the current crop of bacteria and plants. However there are no mammals and complex predators that can effectively fill the niche that will be created (at least not for potentially many thousands of years). So what you'll have is the growth of tall grasses and bushes that can survive on the new climate, but lacking a sustaining ecosystem, there won't be birds or large predators. Since insects develop very rapidly they will probably thrive, but their impact on the new ecosystem will not be predictable.

A lot of land probably won't be able to support crops, however the current state of industrial farming leaves the land depleted, so it will take many generations to replete the topsoil necessary for more balanced wildlife to survive.

Amphibians are already at a stage of mass extinction; their porous skin allows for a very large degree of exchange with chemicals in their environment, and are already suffering the effects of pesticides and herbicides in the environment. If those things biodegrade effectively that effect will not be felt in a few decades, but the change of climate will probably be too much (it already is).

Re: Ocean acidification due to carbon emissions is at highest for 300m years

#39

Post by hcarvalhoalves »

Daishiman wrote: post #35
hcarvalhoalves wrote: post #30

The short-term scenario is not good, but from the little I know about aquatic biology/chemistry, it might not be as catastrophical as the article pictures it. Increased CO2 levels should just cause algae/cyanobacteria blooms, which will balance CO2/O2 levels back again and foster primary consumers (solving over-fishing as a bonus). Also, H2CO3 gets buffered by all the Ca/Mg content in the ocean, so I don't think it's…

The ocean's effect as a buffer is fading very rapidly. The growth of cyanobacteria may have extremely harmful events. No organism on this planet has ever seen a rate of change as strong as this, so this is completely unpredictable territory.

> No organism on this planet has ever seen a rate of change as strong as this, so this is completely unpredictable territory.

It isn't unpredictable, it already happened, and still the world is not overtaken by cyanobacter.

http://en.wikipedia.org/wiki/Cyanobacteria#Earth_history

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