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It's called the albedo effect. White surfaces reflect heat back into space while dark surfaces absorb the heat instead. It's like getting into a black car on a hot day versus getting into a cooler, light colored car.
Sorry to melt on your parade.
"Melting glaciers contribute to rising sea levels and warming oceans."
Melting glacier water doesn't make oceans darker. As for the albedo effect, if you check some of my past posts, one of the things I brought up was that the intercontinental flights over the arctic might have an effect on the reflectivity of the snow, as incomplete combustion creates soot, which would lie on the top of snow. Perhaps you confuse snowpack on sea ice with glaciers, which are two completely different things.
You aren't melting on my parade, just misunderstanding that news media isn't factual on many stories. Bad reporting does no one any favors. Those who have a basic understanding of reality see through the spin, and are more inclined to disbelieve everything on the subject, while the gullible will start regurgitating the nonsense, adding to the confusion.
Yes. And what causes lack of dissolved oxygen which causes dead zones? Heat. Cold water holds dissolved oxygen. If water is too warm it cannot hold enough oxygen for aquatic organisms to survive. The more warm water there is, the more and bigger the dead zones become. The lower organisms in the food chain die, and consequently in ascending order all the higher organisms in the food chain die, all the way up the chain to the apex predators at the top of the chain.
Have you heard about the newest "Blob" (a marine heat wave) that has appeared in the Pacific just this late summer? It's so big this time (and it's only a baby right now, still growing) presently its length stretches from Baja to Alaska and its width is from the west coast of North America to Hawaii. It's just getting started, only confirmed in the past couple of days as having definitely formed. It's being called the “north-east Pacific marine heatwave of 2019” .... aka The Blob. These things kill marine life, and that's including marine mammals.
I'm aware of "the blob" (mental images of the sci-fi movie aside). You did not offer a direct rebuttal to my previous post, so the glacial melt contribution to warmer oceans may now appear specious to you as well, which was my original point. Yes, higher water temps mean less oxygen can be dissolved, just as warm soft drinks hold less carbonation. Higher water temps contribute to dead zones, but the causal factors are more complex. Example: You likely saw the water temps in the Atlantic during the reporting on Hurricane Dorien. Yet the Caribbean is teaming with aquatic life and more threatened by Lionfish than dead zone effects.
Dead zones also exist in some of the "holes" in the Pacific, zones that are oxygen deprived by other mechanisms. Meaningful science tends to be pedantic with word usage and sentence structure - precisely to avoid confusion and false assumptions. If you want to state that warmer waters are a significant contributory factor to many ocean dead zones, I'll readily agree.
I think you guys are overthinking what happened on NBC news. Either the writer or the announcer transposed the phrase. It should have been: ""Melting glaciers and warming oceans contribute to rising sea levels."
You are being kind. If NBC had a better history on the subject, I would be more inclined to accept that as what happened. The segment was not a breaking news story, but part of a "journalistic" series, so the excuse of a rush to screen is not viable. The screen grab I uploaded from NBC news on the Greenland melt story a few years back shows the type of fear-mongering hyperbole and inaccuracy that is the standard there. I wish that I could accept that the confusion was as simple as you suggest.
I think the dead zones exist more due to the dirt (literally) blocking sunlight thus disrupting the photosynthetic portion of the food web.
The dead zone in the Gulf of Mex is a good example. The Miss. Delta was growing naturally as most eroded soil was deposited there and only a small portion made it out into the gulf. (There was always a dead zone there due to that dirt.)..Then the Army Corp of Eng dredged the channel for shipping and the delta has stopped growing. The faster, deeper river effluent now is thrown farther out into the gulf ,increasing the size of the dead zone....Sure there's more chemicals and such, but Nature has away of adapting to that. It can't get by without sunlight.
We went form less than 50 dead zones in 1950 to around 500 presently. while everybody wants to blame farming and the fertilizer runoff; I think we also have to look at the garbage we dump into our oceans. It was not too many years ago that you could watch one barge after another being hauled out to sea to be dumped in the NYC area. Even without regular dumping; we 'dump' every time we flood. Flooding has become pretty common place lately. When that happens everything imaginable goes down our rivers and into our oceans. We have many chemical plants located close to the shore or rivers and that sometimes ends up in our oceans.
Just look at the map in this link (https://www.sciencealert.com/dead-zo...ng-marine-life) and it is easy to see that many of these dead zones can be explained by everything that runs off from flooding. I just don't think it's fair to only blame farming.
We went form less than 50 dead zones in 1950 to around 500 presently. while everybody wants to blame farming and the fertilizer runoff; I think we also have to look at the garbage we dump into our oceans. It was not too many years ago that you could watch one barge after another being hauled out to sea to be dumped in the NYC area. Even without regular dumping; we 'dump' every time we flood. Flooding has become pretty common place lately. When that happens everything imaginable goes down our rivers and into our oceans. We have many chemical plants located close to the shore or rivers and that sometimes ends up in our oceans.
Just look at the map in this link (https://www.sciencealert.com/dead-zo...ng-marine-life) and it is easy to see that many of these dead zones can be explained by everything that runs off from flooding. I just don't think it's fair to only blame farming.
The phosphorous content of fertilizer has been cited for algae growth in runoff areas, leading to dead zones and accelerating eutrophication of lakes and ponds, but modern farming uses much less of it because of the cost/effectiveness ratio. Manure runoff is also decreased because of laws and economics, where composted manure has been recognized as a valuable commodity.
I'm starting to share some of your concerns, although perhaps for different reasons. There was strong flooding along the Elk River watershed this year, inundating fields. That is a normal occurrence for bottomlands that generally enriches the soil. What I noticed instead this year were some fields that suffered from the deposits and were not growing the usual healthy cotton crops. Were chemicals in the water poisoning the soil? I don't know. I hope that the possibility is being checked out.
Flood insurance that encourages rebuilding in flood zones without resolving the flood issues is counterproductive. The contaminants you suggest flow into the Gulf and oceans, often ending up in fish we eat. Dead spots or no, the Canadians have a much more pragmatic and sensible approach to limiting flood zone development.
I think you guys are overthinking what happened on NBC news. Either the writer or the announcer transposed the phrase. It should have been: ""Melting glaciers and warming oceans contribute to rising sea levels."
I tend to agree with TwoByFour. A story on NBC news is hardly the same as a peer reviewed paper published in Nature or Science. Sloppy sentence structure is annoying but hardly criminal. It would be extremely helpful if Harry would give us an actual link to the story in question.
Quote:
Originally Posted by harry chickpea
"Melting glaciers contribute to rising sea levels and warming oceans."
Melting glacier water doesn't make oceans darker. As for the albedo effect, if you check some of my past posts, one of the things I brought up was that the intercontinental flights over the arctic might have an effect on the reflectivity of the snow, as incomplete combustion creates soot, which would lie on the top of snow. Perhaps you confuse snowpack on sea ice with glaciers, which are two completely different things.
You aren't melting on my parade, just misunderstanding that news media isn't factual on many stories. Bad reporting does no one any favors. Those who have a basic understanding of reality see through the spin, and are more inclined to disbelieve everything on the subject, while the gullible will start regurgitating the nonsense, adding to the confusion.
Let us check our premises and agree upon what we are actually discussing. Again, if you could provide links to both the original story and your other posts in regard to the albedo effect, it would be very helpful.
An ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than 50,000 km2 (19,000 sq mi).
Ice sheets are bigger than ice shelves or alpine glaciers. Masses of ice covering less than 50,000 km2 are termed an ice cap. An ice cap will typically feed a series of glaciers around its periphery.
Although the surface is cold, the base of an ice sheet is generally warmer due to geothermal heat. In places, melting occurs and the melt-water lubricates the ice sheet so that it flows more rapidly. This process produces fast-flowing channels in the ice sheet — these are ice streams.
There is an excellent discussion of ice shelves, icebergs and sea ice at Antarctic Glaciers. org. Do you wish to differentiate in this regard? The physics remains the same regardless.
BTW, I thought posts about global warming are discouraged on this forum?
Last edited by Colorado Rambler; 09-17-2019 at 10:02 AM..
I tend to agree with TwoByFour. A story on NBC news is hardly the same as a peer reviewed paper published in Nature or Science. Sloppy sentence structure is annoying but hardly criminal. It would be extremely helpful if Harry would give us an actual link to the story in question.
Let us check our premises and agree upon what we are actually discussing. Again, if you could provide links to both the original story and your other posts in regard to the albedo effect, it would be very helpful.
There is an excellent discussion of ice shelves, icebergs and sea ice at Antarctic Glaciers. org. Do you wish to differentiate in this regard? The physics remains the same regardless.
The story was in a tv newscast, as I mentioned clearly in the OP. You have enough info to find it if you want. I am not a search engine, nor is the rest of the story as offensive as the line I singled out as poor journalism. It shows a receding glacier in Alaska.
I will provide one link to a thread I started on NBC reporting, as it is relevant to the consistent editorial attitude of the news division there, as well as a previous attempt to excuse their errors, as 2x4 did. Other than that, you can use the advanced search function, put my user name in, and search on whatever you want.
The story was in a tv newscast, as I mentioned clearly in the OP. You have enough info to find it if you want. I am not a search engine, nor is the rest of the story as offensive as the line I singled out as poor journalism. It shows a receding glacier in Alaska.
I will provide one link to a thread I started on NBC reporting, as it is relevant to the consistent editorial attitude of the news division there, as well as a previous attempt to excuse their errors, as 2x4 did. Other than that, you can use the advanced search function, put my user name in, and search on whatever you want.
When I wish to discuss a given subject, I like to include the relevant link(s) in my OP to ensure that we are all on the same page. But that's just me.
Frankly, given the rules in the sticky for the Green Living Forum, I do not feel comfortable here debating a mod on the the causes of global warming. Plus, I'm not out to either attack or defend NBC and its reporting.
Land-based glaciers effectively lock up water that would otherwise have made its way back to the sea. When they melt, the amount of water in the oceans increase, resulting in a higher sea level. However, the added mass is also lowering the sea floors, resulting is slower (but still non-zero) increase.
Melting sea-based glaciers lower the effective albedo and decreases the salinity.
Harry, the person who said that was speaking non-comprehensively and maybe didn't have enough time to explain how it happens, but he wasn't entirely wrong, it's a real thing. It's called thermohaline circulation.
Good scientific explanation.
Quote:
Originally Posted by harry chickpea
However, the upwelled water it displaces is not heated by that.
The sinking of cold water and upwelling of displaced water does not cause heating, but the displaced water coming into contact with warmer water does "heat" it.
Quote:
Originally Posted by TwoByFour
I think you guys are overthinking what happened on NBC news. Either the writer or the announcer transposed the phrase. It should have been: ""Melting glaciers and warming oceans contribute to rising sea levels."
I agree it was poor copy. That's one reason I abandoned NBC years ago, plus abandoned newspapers. I got tired of the spelling, grammatical and punctuation errors.
Quote:
Originally Posted by rjshae
Land-based glaciers effectively lock up water that would otherwise have made its way back to the sea. When they melt, the amount of water in the oceans increase, resulting in a higher sea level. However, the added mass is also lowering the sea floors, resulting is slower (but still non-zero) increase.
Melting sea-based glaciers lower the effective albedo and decreases the salinity.
That's normal.
In every previous Inter-Glacial Period, the sea level normally rose 3 meters to 14 meters. The level of CO2 is irrelevant, since sea levels rise 3 meters to 14 meters even when CO2 levels are around 280 ppm CO2.
It is perfectly normal for the Greenland Ice Sheet and Western Antarctic Ice Sheet to melt 80%-95% during an Inter-Glacial Period.
Occasionally, the Eastern Antarctic Ice Sheet also undergoes substantial melting during Inter-Glacial Periods.
Any claims that rising sea levels or melting glaciers are abnormal are scientifically false claims.
NBC would never discuss this on their newscast:
Palaeo data suggest that Greenland must have been largely ice free during Marine Isotope Stage 11 (MIS-11). The globally averaged MIS-11 sea level is estimated to have reached between 6–13 m above that of today.
“Even though the warm Eemian period was a period when the oceans were four to eight meters higher than today, the ice sheet in northwest Greenland was only a few hundred meters lower than the current level, which indicates that the contribution from the Greenland ice sheet was less than half the total sea-level rise during that period,” says Dorthe Dahl-Jensen, Professor at the Niels Bohr Institute, University of Copenhagen, and leader of the NEEM-project.
So, what's happening now would happen whether humans existed or not.
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