Idea to save (rebuild) the polar ice caps

[ZeroNine8]

There's no free lunch, and heat transfer / thermodynamics is no different.

The short term result is that you would increase the amount of ice while increasing the overall temperature of the polar regions.

specific heat of air at polar temperatures (250K) is 1.006 kJ/kg*K with a density of 1.3947 kg/m^3

specific heat of water at 273K is 4.217kJ/kg*K with a density of 1000kg/m^3 the latent heat of fusion for water is 334.7kJ/kg (energy to change from water to ice).

specific heat of ice is 2.040kJ/kg*K with a density of 920kg/m^3, because you won't be stopping heat transfer until temperatures come close to equalizing.

So the water is 1000 times more dense and takes over 4 times as much energy as air to change the temperature by 1 degree K, not to mention the energy required to change it from a liquid to a solid.

Assuming some nice round numbers:
Polar air temp = 250K (-23C)
Freshwater incoming temp = 275K (2C)
final equilibrium temp of ice and air = 260K (-13C)

For every cubic meter of water you turn to ice in this manner, you raise the air temperature of 26195m^3 of air by 10 degrees C. If the amount of ice were to be significant on a global scale, I would think a temperature change of that magnitude for that much air would be catastrophic over a short (at least in a climate sense) timeframe.

those are just some 'back of the envelope' calculations, but for ballparking, you see what you're asking.

edit: if you find some actual air/ice/water temps, let me know, I can easily plug them in and find a more accurate result.

 

[DrPizza]

Decent enough calculations, except they neglect one thing: The arctic isn't a closed system... the earth radiates heat into space.

Similar back of the envelope calculations would also reveal that people in Buffalo, NY should be running around in shorts and bikinis due to all the heat released because Lake Erie freezes over. Just for the sake of data, as of today, the average surface temperature of Lake Erie is 72.91 degrees Farenheit. The average bottom temperature is 66.17 degrees F. It's by far the shallowest of the great lakes, with an average depth of only about 62 feet. There are approximately 116 cubic miles of water in the lake though.

Nah, lets use the water in all of the Great Lakes... Approximately 5472 cubic miles. 22,800,000,000,000 cubic meters of water. Now, all this water cools to between 0 C and (I believe at the bottom in the winter, the water is 4C?)

Converting that to cubic meters... roughly 483,500,000,000 cubic meters. That much water that goes from relatively warm, to ice cold (percent covered by ice varies, the mean for the great lakes is 55%. Erie usually comes pretty close to freezing completely over. Ice thickness varies greatly; I can't find any source (and doubt anyone has ever deployed the instruments to calculate it) for the average ice thickness. I know in many of the areas where ice fishing occurs, it's as thick as a couple of feet.

Where on Earth does all that heat go? Well, I guess it doesn't stay on Earth.

 

[ZeroNine8]

The calculations are just to show what kind of energy transfer is going on. There's a lot of stuff neglected, such as the existing ice cooling the air back down and warming up by a lesser amount, etc. etc. When fractions of a degree are significant in terms of global warming, if the proposal were feasible, it would not be without consequence, and potentially severe ones at that.

You would be more likely to melt more ice than you make in the long run (or at least that's my guess).

 

[Calin]

Originally posted by: Soccerman06
1) What is the point of drilling out ice from the artic? You just replace the ice when if falls back to the ground, and when the rain its the ground, the rain would partially melt the ice and it would fall off into the ocean, defeating the purpose of doing this.

2) Remember energy cant be made out of nowhere, if the rain freezes in the air, the energy used to cool it comes from the ice on the surface so the ice would melt even quicker.

3) You could freeze salt water but you would have to get rid of the salt content. You would also have to freeze the water. Simple physics and chem here, cooling (energy) goes somewhere, where would you put this excess heat (or exhaust gasses which would increase the greenhouse effect).

not real feasible

Salt water can freeze too. Not at freezing point of pure water, just a bit lower (several degrees lower, depends on the salt concentration)

 

[Woodchuck2000]

Originally posted by: DrPizza
Decent enough calculations, except they neglect one thing: The arctic isn't a closed system... the earth radiates heat into space.

Similar back of the envelope calculations would also reveal that people in Buffalo, NY should be running around in shorts and bikinis due to all the heat released because Lake Erie freezes over. Just for the sake of data, as of today, the average surface temperature of Lake Erie is 72.91 degrees Farenheit. The average bottom temperature is 66.17 degrees F. It's by far the shallowest of the great lakes, with an average depth of only about 62 feet. There are approximately 116 cubic miles of water in the lake though.

Nah, lets use the water in all of the Great Lakes... Approximately 5472 cubic miles. 22,800,000,000,000 cubic meters of water. Now, all this water cools to between 0 C and (I believe at the bottom in the winter, the water is 4C?)

Converting that to cubic meters... roughly 483,500,000,000 cubic meters. That much water that goes from relatively warm, to ice cold (percent covered by ice varies, the mean for the great lakes is 55%. Erie usually comes pretty close to freezing completely over. Ice thickness varies greatly; I can't find any source (and doubt anyone has ever deployed the instruments to calculate it) for the average ice thickness. I know in many of the areas where ice fishing occurs, it's as thick as a couple of feet.

Where on Earth does all that heat go? Well, I guess it doesn't stay on Earth.

The whole idea is completely flawed, as Peter has succintly explained. Yes earth radiates heat into space, but at a constant rate (unless you want to cover the artic in a giant heatsink). If you implement your idea, you are putting energy into the area. The area is still going to radiate heat into space at the same rate. You will therefore increase the average temperature. If it really were that simple, someone would have done it by now.

 

[Pythias]

Originally posted by: Atomicus

Originally posted by: The Boston Dangler
Why does everyone assume Polar ice cap melting is not 100% natural? I'm not saying we haven't totally screwed up the planet, because we have. But it is natural for climates to change. It used to be a lot colder on Earth. For that matter, it used to be 10,000 degrees hotter, too.

It is a widely accepted assumption because there is a trend of increasing global temperature and melting of glaciers as greenhouse gas emissions increased.

Oh yea, and check out the ever-increasing hole in the Ozone layer. Thank you man-made chemicals.

We havent kept records long enough for that to be a valid assumption.

 

[Snooper]

I always get amused by folks that make guesses about temperatures thousands of years ago and then turn around and state that fractions of a degree difference from their predictions means something. Heck, we can't even guess the daily high temps for a single town ONE DAY IN ADVANCE within one degree! But they can "postdict" the global average temperatures going back thousands and even millions of years ago. Right.

Oh, and about that hole in the ozone layer: given that we have only had the equipment to measure it for the last couple of decades, why does everyone just assume it didn't exist in the past? How do they know? Oh wait! It fits their assumptions, therefore it MUST be true...

 

[f95toli]

First of all, we have quite accurate climate data going back some 260 000 years.

About climate prediction: The fact that we can't predict the LOCAL temperature well is complettely irrelevant. There is HUGE difference between predicting the local weather and prediting the temperature over e.g. a continent averaged over a year, the latter is much easier and can be done quite accurately.
National weather services routinely predict the weather several weeks (and sometimes months) in advance, usually their customers want to know e.g. the average amount of rain that will fall over a certain (large) area. Information like that can be important if you are running a hydroelectric power plant. However, you would not be able to use the same prediction to plan your holiday because it won't tell you if/how much it will rain a certain day.

 

[gsellis]

Originally posted by: Peter
A brief look at the historical temperature records makes it quite obvious that there's an absolutely unnatural steep incline starting last century. Natural temperature changes of a couple degrees up or down occur over many millenia, not in half a century. No debate there, unless you're Mr. Bush.

The Hockey stick model is a very bad statistical model. Please try again.

 

[Pythias]

Originally posted by: f95toli
First of all, we have quite accurate climate data going back some 260 000 years.

About climate prediction: The fact that we can't predict the LOCAL temperature well is complettely irrelevant. There is HUGE difference between predicting the local weather and prediting the temperature over e.g. a continent averaged over a year, the latter is much easier and can be done quite accurately.
National weather services routinely predict the weather several weeks (and sometimes months) in advance, usually their customers want to know e.g. the average amount of rain that will fall over a certain (large) area. Information like that can be important if you are running a hydroelectric power plant. However, you would not be able to use the same prediction to plan your holiday because it won't tell you if/how much it will rain a certain day.

No we dont. And 260000 years is what compared to 6 bilion?

 

[f95toli]

http://www.nature.com/nature/journal/v429/n6992/abs/nature02599_fs.html

Btw, the earth is around 4.5 billion years old, and we have only had a "modern" amosphere (with oxygen) for something like 2 billion years.

 

[Pythias]

Originally posted by: f95toli
http://www.nature.com/nature/journal/v429/n6992/abs/nature02599_fs.html

Btw, the earth is around 4.5 billion years old, and we have only had a "modern" amosphere (with oxygen) for something like 2 billion years.

So out of the 2 billion years of habitable atmosphere, we can speculate on what the weather was like for what percentage of it?

 

[mdchesne]

why not just stop polluting to stop global warming in the first place? replace the rainforests and forests in general to remove the CO2 from the air?

 

[Pythias]

Originally posted by: mdchesne
why not just stop polluting to stop global warming in the first place? replace the rainforests and forests in general to remove the CO2 from the air?

The algae in the ocean produces more oxygen than the rain forests do. source

 

[DrPizza]

Originally posted by: Snooper
I always get amused by folks that make guesses about temperatures thousands of years ago and then turn around and state that fractions of a degree difference from their predictions means something. Heck, we can't even guess the daily high temps for a single town ONE DAY IN ADVANCE within one degree! But they can "postdict" the global average temperatures going back thousands and even millions of years ago. Right.

Oh, and about that hole in the ozone layer: given that we have only had the equipment to measure it for the last couple of decades, why does everyone just assume it didn't exist in the past? How do they know? Oh wait! It fits their assumptions, therefore it MUST be true...

Your argument about the ozone hole is about the same as saying "how do we know the rainforests were there millions of years ago? How do we know that it isn't a natural cycle that they seem to be disappearing?" We know, because we can observe what happens to the ozone when it meets hydrofluorocarbons. One hfc molecule can break up a whole lot of o3 molecules.

Another point: while meteorologists may not be able to predict daily temperatures to within 3 or 4 degrees for any particular city, they can predict, fairly well, the average temperature over a number of cities over the course of a year.

Perhaps you'll understand that a little better if I give you a mathematical example: If I flip a coin 2 times, I can predict that there will be about 1 head. However, there is a 50% chance that I am off by 100%. (2 heads 1/4 of the time and 2 tails 1/4 of the time) That's a huge amount of error. That's akin to predicting the temperature of a particular city for a particular day. Now, if I flip the coin 100 times, I would predict about 50 heads. The probability of being off by very much (as a percentage) is much much smaller. Scientists don't jump to conclusions based on just a few pieces of data; they draw their conclusions about global warming on massive amounts of data from all over the globe. Historical records, ice cores, tree rings from all over the planet, all serve as individual pieces of the puzzle. When you put those pieces together, they generally spell out "global warming."

 

[Pythias]

"Historical records" isnt saying a lot when they cover a VERY small percentage of the life of the planet.

 

[gsellis]

Originally posted by: Snooper
Oh, and about that hole in the ozone layer: given that we have only had the equipment to measure it for the last couple of decades, why does everyone just assume it didn't exist in the past? How do they know? Oh wait! It fits their assumptions, therefore it MUST be true...

JunkScience has this in the archives for September 14th

It is frequently alleged that the "ozone hole" (actually a seasonal thinning of stratospheric ozone in the South Polar region and not a "hole" at all) was "discovered" in the 1980s, subsequent to significant use of anthropogenic chlorinated fluorocarbons in the 1960s through 1980s. This is simply not true.

Atmospheric ozone is measured in Dobson Units, named for the Oxford academic Gordon Miller Bourne Dobson (1889-1976), one of the pioneers of atmospheric ozone research and inventor of the Dobson Spectrophotometer, used to measure atmospheric ozone from the ground. During the International Geophysical Year of 1956 there was a significant increase in the number of these devices in use around the globe and the Halley Bay (Antarctica) anomaly was discovered. Yes, that's 1956, three decades prior to the allegedly alarming "discovery." There was a significantly different perspective then because interest was focussed on the November increase - now called a "recovery" - in stratospheric ozone levels over Antarctica with the collapse of the South Polar Vortex.

In a paper titled "Forty Years' Research on Atmospheric Ozone at Oxford: A History" (Applied Optics, March 1968), Dobson described an ozone monitoring program that began at Halley Bay in 1956.

When the data began to arrive, "the values in September and October 1956 were about 150 [Dobson] units lower than expected. ... In November the ozone values suddenly jumped up to those expected. ... It was not until a year later, when the same type of annual variation was repeated, that we realized that the early results were indeed correct and that Halley Bay showed a most interesting difference from other parts of the world." [em added]

Although South Polar temperatures do not appear to have been quite as low in 1957-58 as they have in recent years (a critical factor in ozone destruction) Rigaud and Leroy [Annales Geophysicae (November, 1990)] reported atmospheric ozone levels as low as 110DU observed at the French Antarctic Observatory at Dumont d'Urville [opposite side of the South Pole from Halley Bay] in the spring of '58. The South Polar Vortex, where ozone destruction is greatest, was reportedly centred over Dumont d'Urville that year, which suggests any observed differences may be well within the bounds of normal variability.

Is the "hole" a new phenomenon? Apparently not - it's existed as long as anyone has paid significant attention to stratospheric ozone levels in the region and quite possibly for millennia before that. "Normal" ozone levels for the region are entirely hypothetical. Seasonal variations are huge (click here to see a series of graphics from Earth Probe TOMS spanning from the beginning of the series to December 2003, which adequately demonstrate the volatility and seasonality of atmospheric ozone).

Doubtless we'll get more hand wringing over poor irradiated Punta Arenas but everywhere around the world between 45N and 45S, where the bulk of the planet's human population lives, receives more solar radiation on any normal day than does Punta Arenas on the most severely irradiated day or two every few years when a patch of ozone-reduced atmosphere passes between the tip of South America and the sun.

Is said "hole" of any particular significance to humans? Probably not - unless you intend sunbathing in South Polar regions in September. Even so, you would be risking (besides frostbite) sunburn but apparently not an increased melanoma risk. Why? Because melanoma and genetic damage is primarily associated with tissue-penetrating UVA (ultraviolet radiation in the 320-400 nanometer [nm] band) exposure and alleged ozone depletion is completely irrelevant to UVA levels experienced at surface - UVA is simply not blocked by atmospheric gases. UVB (270-320nm), which causes sunburn, is both blocked by ozone (O3) and, if allowed to penetrate the atmosphere, creates ozone lower down where it can be an irritant in photochemical smog. It is also blocked by water vapour to some extent with thick cloud acting as a complete shield and thin cloud only a partial shield. UVB powers your skin's production of vitamin D from its cholesterol precursor. UVC (<270nm), which would cause severe burns with short exposure, does not penetrate the atmosphere, blocked completely by atmospheric oxygen (O2) and ozone (O3).

What an extraordinary fuss over a phenomenon possibly older than the Holocene and which can affect virtually no one, if it does at all.

 

[DrPizza]

edit: I believe gsellis has corrected me. I knew the ozone depletion at the poles was a periodic phenomenon, but thought the degree was shown to be getting worse. More info needed.

 

[Woodchuck2000]

Originally posted by: mdchesne
why not just stop polluting to stop global warming in the first place? replace the rainforests and forests in general to remove the CO2 from the air?

What a great idea! Everyone, let's stop all pollution now and head over to the tropics and replace all the rain forests! It's so very simple when you put it like that, I don't know why no-one has ever thought of it before...

 

[DrPizza]

Originally posted by: Woodchuck2000

Originally posted by: mdchesne
why not just stop polluting to stop global warming in the first place? replace the rainforests and forests in general to remove the CO2 from the air?

What a great idea! Everyone, let's stop all pollution now and head over to the tropics and replace all the rain forests! It's so very simple when you put it like that, I don't know why no-one has ever thought of it before...

Or... sequester the CO2 from the stacks.
Although, that method causes the same problem that nuclear waste causes... where do you put the sequestered CO2? (and it adds a lot of expense)

I think there was an article a month or so ago in (discover magazine?) that discussed the problems with sequestered CO2...

 

[Burkhead]

On the topic of global warming, I am going to college at appalachian state university(in the appalachian mountains) and today i walked into the hottest day of the year(or it felt that way). It has never been anywhere near this hot up here that i can remember and i hate hot weather. Some people say we are going to have a really cold winter this year(i hope we do) but it seems as though summer keeps getting longer and longer up here. I am scared......

 

[sao123]

the only problem i have with the entire theory is this... everything sounds great, and Dr Pizza is right about the heat radiating backinto space. IE, the process releases heat voer time (not instantaneously) and so is the radiative process. there should be no noticable change in temperature over time.

the issues I have, is this process will change the salinity factor of the ocean. From what I read, when the water freezes (naturally) and joins the polar cap, it does so a few molecules at a time, and leaves its salt still in the solution. IE, polar ice contains little if any salt. This is why, we are so worried about polar melting... It would dilute the oceans, weakening the cold upwelling, and killing the major currents. So, if we do what was suggested, arent we freezing salt with the water, and removing the concentrating effect of natural freezing. Thus we are manually diluting the oceans by freezing salted water.

 

[bisqeet]

Liu, J., Curry, J. A., and Martinson, D. G., 2004, "Interpretation of recent Antartic sea ice variability", Geographical Research letters 31:
10.1029/2003 GLO18732

Antartic sea ice has increased since 1979



why should we do anything sabout the ice, nature is working.