Comment by Jtsummers | Hacker News Reader

Comment by Jtsummers | Hacker News Reader

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Looking at the year over year data:

http://www.arctic.noaa.gov/Report-Card/Report-Card-2016/ArtM...

Greenland is losing ice at around 200Gt/year (this is also in your second link). And I don't see where you get the 50Gt/day gains. Unless the graph is lying, it's in Gt/day. Ranging from gains of about 12Gt to losses of about -8Gt over this past year. Quoting your source:

  Over the year, it snows more than it melts, but calving
  of icebergs also adds to the total mass budget of the ice
  sheet. Satellite observations over the last decade show
  that the ice sheet is not in balance. The calving loss is
  greater than the gain from surface mass balance, and
  Greenland is losing mass at about 200 Gt/yr.

It's all fine and dandy to link to data. It certainly makes your post look more legit. But when your links directly contradict your text you should either find other data, or reconsider your stated interpretation.

Greenland usually gains about 350-400 billion tons of ice over the summer, but this year, it gained 550 billion tons and is still gaining.

Temperatures in the center of Greenland's ice sheet never rose above -10C all summer, so it's hard to see how it could have lost any ice. Ice accumulation is nearly two standard deviations above the 1981-2010 mean for the same period, and it is very, very early in the season for such gains.

Both of Greenland's largest glaciers (Jakobshavn and Peterman) are growing at record rates, about 1km/year.

Icepacks and glaciers calve into the sea. That's what they do. It's Nature's way of moving the ice and snow away from the center and back into the ocean. If they didn't, the snowpack/ice would extend to the Equator, which is impossible, or the snowpack would be 5 miles high, which is not the case.

Unless I've misread your link, the 200Gt/year loss is the net between gain from snow and loss from calving. Your claim in your post was that Greenland was gaining 50Gt/day. This was not backed by your link. It literally isn't in there.

If it were true then the chart should show well in excess of 200Gt accumulated for this year so far, and it does not. In September they have so far accumulated 50Gt which is in line with previous years at this point.

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