What would it take to melt the Greenland ice sheet in a few days?

Based on the thread Greenlands ice sheet has pretty much entirely melted this year. It hasn’t. There’s some melting over 97% of it. A lot of that occurred in just a few days. But what would it take to melt the entire ice sheet. In the other thread the frozen lake in the middle of the island is said to be 900+ feet deep, and the ice sheet up to 1 mile thick altogether. Instead of just 4 days, let’s say anything less than a month.

Paint it black?

According to this source (using the second cite, as the first just multiplies the area and maximum thickness), Greenland has about 2.8 million cubic kilometers of ice; assuming that the ice was at -20C (assuming from what Wikipedia says), it would take about 40 j/g (specific heat of ice is about 2 j/g*k) to raise it to the melting point, and another 334 j/g to melt the ice, for a total of 374 j/g. Ice has a density of 0.917 g/cm^3, so it takes about 343 j to melt a cubic centimeter of ice; multiply this by the number of cubic centimeters per cubic meter, etc and you get 9.6 x 10^23 joules of energy needed to melt all of the ice on Greenland. For perspective, the Earth receives about 5.5 x 10^24 joules of energy from the Sun every year (see list, also equivalent to about two dinosaur-killer asteroid impacts, or four times the global uranium reserves), so it would take about 64 days to melt all of the ice even if all of the sunlight hitting Earth was directed onto the ice sheet (and it was made completely nonreflective).

What Michael63129 said. Temperatures of +30 and hurricane winds would be completely insufficient to melt the Greenland ice cap in any reasonable length of time.

I was just thinking about the snowy winter we had a few years ago. Excess snow was collected and trucked to snow dumps around the city, where it was piled and left to melt. By spring, the snow dump near Six Points in Etobicoke had reached a height of six storeys, dwarfing buildings nearby.

Even though a hot summer followed, that snow pile didn’t completely melt until October, even though it rapidly darkened as the surface layers melted away and all the dirt and crud carried in the snow was exposed. I was half-expecting the pile to last long enough for new snow to fall on it at the beginning of the following winter, but it didn’t quite make it.

(Nitpick: the symbol for joule is J, not j. :slight_smile: )

Related Straight Dope - If I were an Evil Genius, How Would I Go About Melting the Ice Caps?