How warm does the earth have to get for the polar ice caps to melt?

Well lets use some calculatons for a fixed land mass Lets take an engineer's view of melting Greenland's Ice Sheets. You can look these numbers up on the internet and wade through the math yourself to check the calculations: * Area of Greenland Ice: 1,710,000 square kilometers * Thickness of Ice: 1.666 kilometers (average) * Volume of Ice: 2,848,000 cubic kilometers o (Source: Wikipedia) If it all melted, worlds oceans would rise by: * Area of world's oceans: 361,000,000 square kilometers (Wikipedia) * Calculated sea level rise from melt: 7.26 meters (2.848 million cu-km of ice spread across 361 million sq-km of ocean, including the loss of volume from melting---ice shrinks when melted.) Oh-oh, that looks like a real problem--it's nearly 24 feet of rise!!! But, hold on a minute: How long would it take to melt that much ice? That depends on how much ice there is and the physical properties of water, particularly the latent heat of fusion: * Volume of Ice: 2,848,000 cubic kilometers * Mass of Ice: 2,848,000,000,000,000,000 kilograms * Heat of Fusion: 334 kiloJoules/kilogram (a physical property of water; this must be added to ice at 0 deg-C to cause the phase change to liquid water) * Heat of Fusion Required for Melting: o 951,519,000,000,000,000,000 kiloJoules = 15,849,000,000,000,000,000 kwh (One kiloJoule is 1 kilowatt applied for 1 second, or a kilowatt-second or 0.0166 kilowatt-hours--the same unit as on your electric bill.) That's a lot of energy and it must all come from somewhere. The sun is really the only source available. Barrow, Alaska, is at about the same latitude as the middle of Greenland. Solar radiation falling on Barrow averages about 2 kwh/square-meter/day (Funny; no one seems to know the insolation for Thule, Greenland.) (Source: http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/serve.cgi) * Area of Greenland Ice: 1,710,000 square kilometers= 1,710,000,000,000 square meters * Greenland Solar Radiation: 3,420,000,000,000 kwh/day So if all the solar radiation that hits Greenland is totally devoted to melting ice (no reflection, no heating of air) , the time required is 4,637,000 days, (Heat of fusion required divided by the available average solar radiation). That is a little over 12,700 years. And this is just to melt the ice that has already reached 0 deg-C; it takes more to raise the temperature from ambient to the melting point. (What's the average temperature of the ice today? I dunno...)

You would need the Sun to produce an average of 900 sunspots or more per sunspot cycle for a century. That is why we will never see the Arctic melt. Solar radiation is in a nice balance right now contrary to the Global Warming alarmists. The seas will never rise enough to put Rush Limbaugh out of his ocean side condo or force Al Gore out of his ocean side villa. Enjoy your days at the beach.

It means the glaciers have to be exposed to temperatures over 33 degF for hundreds of years or thousands of degrees for a much shorter time

Does it mean that the temperature will have to rise that much in order to melt? Yes. If you mean by ambient temperature. But there are other ways that a glacier can disappear. Wind can atomize the glacier's surface and erode the glacier. The Sun's rays can strike the surface of the of the glacier and a certain portion of the Sun's rays will not be reflected back but turned into heat. It is a low percentage because it is white but it still will convert to heat. The oceanic movement with salty water can lower the melting point. The earth's core is very hot and underground geysers can cause the lower extremities to melt and thus huge masses of ice can be separated. The problem with the greenies is that they equate the ice caps to the ice in their drink when they go to their conferences. To them the ice cap is one gigantic ice cube for their drink. Now it is only reasonable that those few influences described above are natural and would have more of a direct influence that all of our SUVs. Al Gore's hot air has more of an influence in melting those ice caps than all the SUVs in the world. EDIT VAMPIRE: Regarding your statement: >>AGW is a Religion to promote Socialism.<< That is a lie. Quote by Mikhail Gorbachev, communist and former leader of U.S.S.R.: "Nature is my god. To me, nature is sacred; trees are my temples and forests are my cathedrals." >>The point is to criminalize the use of energy,<< That is a lie. Quote by Paul Ehrlich, professor, Stanford University: “Giving society cheap, abundant energy would be the equivalent of giving an idiot child a machine gun.” Read your what your own leaders have to say.

When Earth was 7 degrees C cooler than it was today, most of Canada and the Northern United States was under a sheet of ice. http://upload.wikimedia.org/wikipedia/commons/5/53/MilankovitchCyclesOrbitandCores.png A 7 degree C rise in the Earth's temperature should melt the ice cap in Greenland and much of the ice in Antarctica. I suspect that to melt all of the ice in Antarctica, we would probably need to raise Earth's temperature by 14 degrees C. (Note that the South pole rarely rises above -30 degrees C because of the high albedo of the ice. To melt the ice, above freezing temperatures are only needed at the margins.) Sagebrush Gorbachev is not a climatologist. And doesn't Paul Ehrlich have the right to be concerned about global warming?

Don't know, but whatever it is it will be reached next year, there is no repeat no wriggle with this nonsense from the warmies, none whatsoever. http://news.bbc.co.uk/1/hi/7139797.stm http://www.treehugger.com/clean-technology/arctic-ice-free-by-2013.html

about 2 degrees

The polar ice caps are already starting to melt. Each year through the summer the ice caps melt, then in winter they grow back, however there has been a trend over the last few decades that in summer the caps are melting slightly more and growing back slightly less in winter. This will (and already is) contributing in sea level rise. Also thermal expansion of the oceans due to increased heat increases the sea levels even more. There are quite different trends in the Southern and Northern hemisphere though. The tips of both the South and North Pole stay frozen year round, but the surrounding ice is closing in slowly.

I've been studying this for a long time and there is never a certain answer, with the population sky rocketing and the demand for natural resources growing, there are a lot of factors to consider. If each and every single person was to recycle we'd be looking at cutting down pollution dramatically. There's many things that you can do, go solar for one!