[CliffordK (OP)]

One could potentially build pumping stations to pump water inland in the middle of the winter in Antarctica, but it would take a lot of energy considering the distance, volume, and altitude.

Solar power would be ineffective in the winter in Antarctica, but perhaps other power sources such as nuclear would be viable. 

Sea ice is made out salt water, with some snow on top, although there is a complex mechanism in which the brine drips out of the sea ice.  Bringing water up through the ice to the surface in the winter may in fact help build up thicker sea ice.  But, like BC says, it won't decrease the sea level.  It might help stabilize the sea ice though, but considering the millions of square miles in the arctic, it would be a big project for it to make any real difference.

Glacial ice is made out of fresh water.  I would be concerned about the effect of adding a layer of salt water on top of the glacial ice.  Distilling massive amounts of sea water would be very expensive, and best left to Mother Nature.

I presume there are many subglacial rivers in Antarctica, melted by geothermal heat.  The easiest source of water would be to tap into these rivers, and bring the water to the surface to expose it to the cold winter temperatures.  Thus, one would prevent the natural glacial fresh water from reaching the ocean in the winters, and consequentially reduce the water volume loss in Antarctica, causing increased glacial buildup.

What could be done to increase the antarctic winter humidity?

[Atomic-S]

In view of the threatened rise of the seas due to the melting of glaciers, inundating coastal areas and wreaking havoc, I have observed that winter Antarctic temperatures are unlikely to reach anything approaching or above freezing in the foreseeable future. So, a possible solution may be to pump seawater into the antarctic interior and there dump it, where it will freeze and restore the glaciation of that area while lowering sea level. The energy to do this would be provided by wind turbines. 

[Don_1]

I think its more a problem of the reduction in the area of sea ice which is the main concern. Though melting sea ice would not have an effect on sea levels, it does pose a problem for the Seals and Polar Bears. But it also results in less reflection of the Sun's rays. With less polar sea ice the Sun's rays get at the polar sea and cause a rise (albeit small) in polar sea temperatures, which leads to more melt of polar sea ice.

Pumping sea water to the top of the Greenland glaciers would not increase or even maintain the overall area of reflective snow and ice in the artic region, nor would it stop the Sun from having a warming effect on the Artic Sea.

Another point to consider, is that those Greenland glaciers are formed from snow falls, not sea water. The chances are, the pumped sea water would cause some melt at the top end of the glaciers. This would have a lubricating effect on the glaciers, thus they might move quicker toward the sea, not just defeating the object of the excersise, but producing exactly the wrong effect.

[Don_1]

I should add that not only seals and Polar Bears are affected by the loss of sea ice, Walrus and the Artic Fox are also dependant on sea ice, as are artic sea birds. And don't forget the subsurface life; fish, Bowhead Whale and Narwhal.

[Atomic-S]

It is evident that there are additional problems beyond the rise of sea level, which will not be helped by removing water from the ocean. However, the rise of sea level would be, and as you pointed out, could be made worse by pouring water onto glaciers, causing them to slip faster. However, what if the water were frozen before it reached the glacier? The way you do that is spray it into the cold atmosphere in small droplets, so that it falls as ice rather than liquid water.

[Atomic-S]

As for habitat for polar bears etc., a possible remedy for that is to create artificial ice floes, that could be made of recycled plastic bags.

[CliffordK (OP)]

In Greenland, there are ice melt ponds in the summer.  Central Antarctica does have that problem.  So, pumping fresh water into central Antarctica in the middle of the winter, at -80°C, and it would freeze pretty quickly. 

A few issues...
Keeping your pipes from freezing in the bitter cold weather without significant added heat.  Perhaps good insulation, or could ice a few feet below the surface give adequate insulation for fast flowing water?

While salt water would freeze in the Antarctic winter, it may form a layer of unstable ice which would be undesired.

The ice does, in fact, melt in Antarctica, but from the bottom up due to pressure and geothermal heat.  Significantly increasing the thickness of the ice  cap may accelerate this process.  HOWEVER, it may be much easier to pump fresh water from the natural Antarctic lakes and rivers than pumping and purifying sea water. 

Pumping water from the Antarctic lakes might reduce the water reaching the sea (effectively the same as pumping water from the sea.  It may also help stabilize the glaciers, and reduce "lubrication"....  not that the central Antarctic glaciers move much.  And, of course, it is fresh water, so no need for desalination.

Greenland has some large surface melt water lakes, at least in the summer.  I'm not sure what happens to these lakes in the winter.  Undoubtedly they form an ice cap.  Perhaps there would be a benefit of dispersing the water below the ice cap in the winter to force it to refreeze.

[CliffordK (OP)]

Sea ice is another issue altogether.  Of course, the melting of floating ice does not affect sea level.

The Arctic is a vast area, and home to a variety of species, not just polar bears.  Artificial rafts would be an interesting idea, but consider building a raft the size of the USA.  It would have to be segmented into floes with space in between the segments for wildlife, and would have to endure wind, storms, and being stacked one on top of another, or designed to resist stacking.

Polar Bears (which are hunted, but with globally regulated hunts), are at risk due to being ineffective summer hunters, and excellent winter hunters.  Other arctic species may in fact benefit from warmer arctic summers.

So far, while the summer sea ice has been reaching record lows, essentially the entire central arctic basin has been refreezing every winter.  And the melt season/freezing seasons seem to begin and end right around the equinoxes which aren't affected by global warming.  Just the same "extent" may melt a month or so earlier in the summer, and freeze a month or so later in the winter.

Anyway, if I was to try to increase Arctic sea ice, I would evaluate putting a series of well anchored buoys and drag chains across the Fram Strait with the purpose of slowing (but not stopping) the movement of sea ice out of the Arctic region.  Unfortunately, I'm not sure of the effect of decreasing ice along the eastern Greenland coast, or decreasing the amount of sea ice and glaciers melting in the Atlantic.  Perhaps if sea ice = albedo, then preserving more sea ice would have an overall cooling benefit.

[evan_au]

I think the whole pumping operation would need to be wind-powered, otherwise we would be using expensive fossil fuels to pump sea-water, producing more CO₂ in the process...

[Atomic-S]

Keeping your pipes from freezing in the bitter cold weather without significant added heat.  Perhaps good insulation, or could ice a few feet below the surface give adequate insulation for fast flowing water?

I would consider good insulation necessary. But then again, if the weather is cold enough to freeze the water in the pipes before it gets to the interior of the continent, the water could be sprayed into railcars nearer the coast and then hauled by rail to the interior.

[Don_1]

Keeping your pipes from freezing in the bitter cold weather without significant added heat.  Perhaps good insulation, or could ice a few feet below the surface give adequate insulation for fast flowing water?

I would consider good insulation necessary. But then again, if the weather is cold enough to freeze the water in the pipes before it gets to the interior of the continent, the water could be sprayed into railcars nearer the coast and then hauled by rail to the interior.

Build a railway on ice??? Not a good idea.

[SeanB]

IIRC Greenland was warm around 500 years ago, such that it was ice free in summer. The polar bears and such certainly survived that, they moved onto land as the ice melts anyway, and go out as it freezes, basically they are a coastal animal adapted for a cold environment.

[CliffordK (OP)]

Keeping your pipes from freezing in the bitter cold weather without significant added heat.  Perhaps good insulation, or could ice a few feet below the surface give adequate insulation for fast flowing water?

I would consider good insulation necessary. But then again, if the weather is cold enough to freeze the water in the pipes before it gets to the interior of the continent, the water could be sprayed into railcars nearer the coast and then hauled by rail to the interior.

Build a railway on ice??? Not a good idea.

If you could get your weight and temperatures matched, you could presumably build an excellent low resistance ski sled over the ice that could be organized with multiple cars like a train. 

One would still want to access fresh water rather than salt water.  But, one could mine glaciers that were flowing into the sea, or access rivers and streams.  However, I still think it would be best to do the short vertical drilling to rivers below the ice sheet that eventually would reach the sea, rather than carry water or ice thousands of miles overland.

[CliffordK (OP)]

IIRC Greenland was warm around 500 years ago, such that it was ice free in summer. The polar bears and such certainly survived that, they moved onto land as the ice melts anyway, and go out as it freezes, basically they are a coastal animal adapted for a cold environment.

There are 120,000 year old ice cores from central Greenland.  The 2 to 3 km thick ice cap over Greenland certainly hasn't significantly melted any time during the Holocene, and probably not for millions of years, with the thickness being limited by glacier flow and melt from the bottom.

It is, however, possible that the coastal environment varies significantly in Greenland.

Many migratory animals have evolutionary adaptations to partial arctic thawing in the summer.  Currents and wind tends to push the ice towards the Canadian coast, and it is unlikely that many polar bears will be caught drifting in the middle of the Arctic on a shrinking ice sheet.  Unfortunately the polar bears are rather poor summer hunters, but the near total darkness of the Arctic winter does force the central Arctic to refreeze every year.