[Newsbot]

Title: Crumbling icebergs are actually SLOWING global warming
Category: Environmental
Posted By: N_Fiddledog
Date: 2016-01-12 13:10:44
Canadian

[Canadian_Mind]

Isn't this the same thing as when you sweat you cool off? Yes the dissipating ice is slowing the heating, but when the ice runs out wont things will be back to their normal pace again?

Nevermind, read the article. Read something similar recently that compared the ice breaking off and melting to water evaporating from our skin, both processes resulting in a cooling of the body/earth. I thought they were the same thing.

[Delwin]

During the phase change from solid to liquid, there is energy absorbed from the surroundings. This is known as the enthalpy of fusion. So heating ice from 0c to 10c for example, requires more energy than heating water from 0c to 10c. You are correct that if this water freezes again, the same amount of energy will be released from the enthalpy of fusion meaning that the surrounding system will contain more energy than it would if there was no phase change and you were simply cooling water.

[PublicAnimalNo9]

If you look back at previous periods of "rapid" warming, the warming was immediately preceded by a quick cooling of temperatures as the melt water cooled the oceans.

[DrCaleb]

Canadian_Mind Canadian_Mind:

Isn't this the same thing as when you sweat you cool off?

No.

$1:

This activity, known as carbon sequestration, contributes to the long-term storage of atmospheric carbon dioxide, therefore helping to slow global warming.

Here's the study they refer to:

https://www.sheffield.ac.uk/news/nr/gia ... e-1.538818

It means that the heat is removed from the atmosphere by reducing the CO2 concentrations in the air, but in the process it can increase ocean acidification. That means many organisms that produce oxygen that we breath will also die. And the organisms that rely on them for food will die . . . and on up the food chain.

Not really a winning scenario.

[andyt]

DrCaleb DrCaleb:

Canadian_Mind Canadian_Mind:

Isn't this the same thing as when you sweat you cool off?

No.

$1:

This activity, known as carbon sequestration, contributes to the long-term storage of atmospheric carbon dioxide, therefore helping to slow global warming.

Here's the study they refer to:

https://www.sheffield.ac.uk/news/nr/gia ... e-1.538818

It means that the heat is removed from the atmosphere by reducing the CO2 concentrations in the air, but in the process it can increase ocean acidification. That means many organisms that produce oxygen that we breath will also die. And the organisms that rely on them for food will die . . . and on up the food chain.

Not really a winning scenario.

Neither one of you seems to have read the article. The nutrients contained in the bergs remove a limit to algal growth. The algae take up increased CO2 as the nutrients spur more photosynthesis. So it would actually extract CO2 from the ocean, not increase it, ie reduce ocean acidification. It's the same mechanism as forests play on land - we don't see increasing forest cover as something to worry about either, it's a way of reducing atmospheric CO2.

[DrCaleb]

andyt andyt:

DrCaleb DrCaleb:

Canadian_Mind Canadian_Mind:

Isn't this the same thing as when you sweat you cool off?

No.

$1:

This activity, known as carbon sequestration, contributes to the long-term storage of atmospheric carbon dioxide, therefore helping to slow global warming.

Here's the study they refer to:

https://www.sheffield.ac.uk/news/nr/gia ... e-1.538818

It means that the heat is removed from the atmosphere by reducing the CO2 concentrations in the air, but in the process it can increase ocean acidification. That means many organisms that produce oxygen that we breath will also die. And the organisms that rely on them for food will die . . . and on up the food chain.

Not really a winning scenario.

Neither one of you seems to have read the article. The nutrients contained in the bergs remove a limit to algal growth. The algae take up increased CO2 as the nutrients spur more photosynthesis. So it would actually extract CO2 from the ocean, not increase it, ie reduce ocean acidification. It's the same mechanism as forests play on land - we don't see increasing forest cover as something to worry about either, it's a way of reducing atmospheric CO2.

I actually did read the article.

$1:

Previous studies have suggested that ocean fertilization from icebergs makes relatively minor contributions to phytoplankton uptake of CO2.

However this research, published today (11 January 2016) in Nature Geoscience, shows that melting water from icebergs is responsible for as much as 20 per cent of the carbon sequestered to the depths of the Southern Ocean.

[BartSimpson]

PublicAnimalNo9 PublicAnimalNo9:

If you look back at previous periods of "rapid" warming, the warming was immediately preceded by a quick cooling of temperatures as the melt water cooled the oceans.

And you know this....how?

[andyt]

Then you misunderstood. The sequestered carbon is not in the form of CO2, that would lead to acidification, but in biologic carbon incorporated in the algae. No doubt some of this is released during decomposition, but the net effect is it is stored in the biomass in the ocean. Same as happens on land. We don't cry because somebody plants a forest that it will lead to greater CO2 down the road, because as the trees die they release nutrients that further stimulate plant growth and CO2 uptake.

One interesting factoid is that Redwood forests are at their most productive the older the trees get.It was always thought that net biomass increase more or less came to a stop with mature Redwood forests, but turns out the opposite is true. Since this idea has been held for all mature ecosystems, maybe it's time to re-evaluate it for others than the Redwoods as well.

[DrCaleb]

andyt andyt:

Then you misunderstood. The sequestered carbon is not in the form of CO2, that would lead to acidification, but in biologic carbon incorporated in the algae.

I understood that part. I also understood that most studies found a negligible effect, but this one found up to a 20% reduction in atmospheric CO2. Leaving 80% to continue it's usual function of ocean acidification.

[andyt]

DrCaleb DrCaleb:

andyt andyt:

Then you misunderstood. The sequestered carbon is not in the form of CO2, that would lead to acidification, but in biologic carbon incorporated in the algae.

I understood that part. I also understood that most studies found a negligible effect, but this one found up to a 20% reduction in atmospheric CO2. Leaving 80% to continue it's usual function of ocean acidification.

DrCaleb DrCaleb:

$1:

This activity, known as carbon sequestration, contributes to the long-term storage of atmospheric carbon dioxide, therefore helping to slow global warming.

Here's the study they refer to:

https://www.sheffield.ac.uk/news/nr/gia ... e-1.538818

It means that the heat is removed from the atmosphere by reducing the CO2 concentrations in the air, but in the process it can increase ocean acidification. That means many organisms that produce oxygen that we breath will also die. And the organisms that rely on them for food will die . . . and on up the food chain.

Not really a winning scenario.

I think you've confused yourself, not the first time. Re-read your first post.

This study shows a benefit, in that CO2 is taken up by algae and thus sequestered in a form that causes no harm, no acidification. So I'm not sure why you're bringing up acidification here? The study doesn't say that everything is rosy, or there's no ocean acidification, only that it would be worse if this ocean fertilization by the icebergs wasn't happening.

[DrCaleb]

andyt andyt:

DrCaleb DrCaleb:

andyt andyt:

Then you misunderstood. The sequestered carbon is not in the form of CO2, that would lead to acidification, but in biologic carbon incorporated in the algae.

I understood that part. I also understood that most studies found a negligible effect, but this one found up to a 20% reduction in atmospheric CO2. Leaving 80% to continue it's usual function of ocean acidification.

DrCaleb DrCaleb:

$1:

This activity, known as carbon sequestration, contributes to the long-term storage of atmospheric carbon dioxide, therefore helping to slow global warming.

Here's the study they refer to:

https://www.sheffield.ac.uk/news/nr/gia ... e-1.538818

It means that the heat is removed from the atmosphere by reducing the CO2 concentrations in the air, but in the process it can increase ocean acidification. That means many organisms that produce oxygen that we breath will also die. And the organisms that rely on them for food will die . . . and on up the food chain.

Not really a winning scenario.

I think you've confused yourself, not the first time. Re-read your first post.

This study shows a benefit, in that CO2 is taken up by algae and thus sequestered in a form that causes no harm, no acidification. So I'm not sure why you're bringing up acidification here? The study doesn't say that everything is rosy, or there's no ocean acidification, only that it would be worse if this ocean fertilization by the icebergs wasn't happening.

I may have skipped some steps of my thought process in my explanation. There may be an upswing in algae, but there will still be sustained and ongoing ocean acidification. That's where CO2 goes when it leaves the atmosphere - into the oceans.

So there may be more algae - short term, according to this one study. But the acidification means that they'll still die. Just, slower.

[andyt]

OK, get it now. Good point.