5 ms·

The math: (1) the linked article says there is 24e6 km3 of water in ice caps, glaciers, and permanent snow. (2) Area of Oceans from Wikipedia is 360e6 km2. (3)

by cjensen 11y ago

The math: (1) the linked article says there is 24e6 km3 of water in ice caps, glaciers, and permanent snow. (2) Area of Oceans from Wikipedia is 360e6 km2. (3) The statue of liberty is about 93m, (Base is 46m, Statue is 47m) Division gives 0.066km of sea level rise if all of item #1 melts into the oceans, which is 66 meters. (In a more complex model, warmer atmosphere would adsorb some of it as increased absolute humidity.) For the Statue of Liberty, that's enough to cover the entire base plus ~40% of the statue. The movie AI is wrong, but it's a lot closer to correct than the "10m" you quote.

mturmon 11y ago
In addition, the parent comment has omitted groundwater. Good current estimates for groundwater volume (in the OP, http://water.usgs.gov/edu/earthhowmuch.html http://water.usgs.gov/edu/earthhowmuch.html) are very close to icecap volume (24e6 km^3). And we are pumping this groundwater (~700 km3/yr as of 2000, and increasing [ * ]), which raises water levels and at the same time lowers land elevation as ground subsides. Depending on the Hollywood disaster scenario, that could play a role. Atmospheric water, on the other hand, is a rounding error in this context. [*]: See fig. 3 of http://onlinelibrary.wiley.com/doi/10.1029/2010GL044571/full http://onlinelibrary.wiley.com/doi/10.1029/2010GL044571/full
logfromblammo 11y ago
Rise in ocean level increases the surface area of the ocean, because most coastlines are not vertical cliffs. What is the average slope of dry land between 0m and 10m above sea level? Reviewing the math, I concede that I may have been off by a factor of 4. But not 6.6! The estimate for the amount of water needed to cover all land but the summit of Everest is easier, since the upper limit is an ellipsoidal shell 8848m thick. That's about 4.5x10^9 km^3, which is 3.4 times the current ocean volume. Then it's just a matter of estimating how much of that volume is already full of solid matter, and reducing the amount of water needed by the rock that is already there.
- cjensen 11y ago
  Indeed the model I used was simplistic. I doubt Ocean area would change much with sea level rise on a percentage basis. A more realistic model would have to try to make a better guess at the amount of permanent ice. The South Polar ice cap isn't going away completely because (1) with a six-month darkness, it will remain cold enough to hold ice (2) enormous storms in the Southern Ocean will generate plenty of precipitation over the pole.

by cjensen 11y ago

mturmon 11y ago

In addition, the parent comment has omitted groundwater. Good current estimates for groundwater volume (in the OP, http://water.usgs.gov/edu/earthhowmuch.html http://water.usgs.gov/edu/earthhowmuch.html) are very close to icecap volume (24e6 km^3). And we are pumping this groundwater (~700 km3/yr as of 2000, and increasing [ * ]), which raises water levels and at the same time lowers land elevation as ground subsides. Depending on the Hollywood disaster scenario, that could play a role. Atmospheric water, on the other hand, is a rounding error in this context. [*]: See fig. 3 of http://onlinelibrary.wiley.com/doi/10.1029/2010GL044571/full http://onlinelibrary.wiley.com/doi/10.1029/2010GL044571/full

logfromblammo 11y ago

Rise in ocean level increases the surface area of the ocean, because most coastlines are not vertical cliffs. What is the average slope of dry land between 0m and 10m above sea level? Reviewing the math, I concede that I may have been off by a factor of 4. But not 6.6! The estimate for the amount of water needed to cover all land but the summit of Everest is easier, since the upper limit is an ellipsoidal shell 8848m thick. That's about 4.5x10^9 km^3, which is 3.4 times the current ocean volume. Then it's just a matter of estimating how much of that volume is already full of solid matter, and reducing the amount of water needed by the rock that is already there.

cjensen 11y ago
Indeed the model I used was simplistic. I doubt Ocean area would change much with sea level rise on a percentage basis. A more realistic model would have to try to make a better guess at the amount of permanent ice. The South Polar ice cap isn't going away completely because (1) with a six-month darkness, it will remain cold enough to hold ice (2) enormous storms in the Southern Ocean will generate plenty of precipitation over the pole.