So how do we reconcile this with recent observations that sea levels are rising?

baobabaobab · on Nov 1, 2015

Sea levels are rising 2.6-2.9mm per year.

“The good news is that Antarctica is not currently contributing to sea level rise, but is taking 0.23 millimeters per year away,” Zwally said. “But this is also bad news. If the 0.27 millimeters per year of sea level rise attributed to Antarctica in the IPCC report is not really coming from Antarctica, there must be some other contribution to sea level rise that is not accounted for.”

Complete conjecture, but my money is on IPCCs estimates for other sources being a little too conservative, not some entirely new explanation.

kpil · on Nov 1, 2015

Yes, interesting question.

(Other sources are what? Arctics? Heat expansion?)

Anyway, I particularly like that they are doing observations rather than just faffing around with models. Models are good, but data is better.

baobabaobab · on Nov 2, 2015

The other sources are glacial melt, heat expansion, and water storage on land decreasing.

You need both the models and the data. Facts without theory answer only what happened, not why, you can't make projections without theory. Theory without facts... pretty obvious problem there.

ovis · on Nov 1, 2015

There are a few important processes that cause observed sea level rise. In order, with IPCC estimates on the magnitude:

- The ocean expands as it warms, which is the single largest contributor right now (1.1 mm/yr).

- Mountain glaciers are next, as they are very rapidly melting (0.76 mm/yr, with large uncertainties).

- Then Greenland, as mentioned by another poster (0.43 mm/yr).

DanBC · on Nov 1, 2015

Greenland is melting.

http://www.nytimes.com/interactive/2015/10/27/world/greenlan...

('greenland' in the search box returns a bunch of articles from a span of a few years)

partiallypro · on Nov 1, 2015

The sea level rise generally isn't because of ice melting, it's because the water is warmer and warmer water takes up more space.

adventured · on Nov 1, 2015

Supposedly it's explained through expansion from warming. I'm not a global climate scientist though, so I can't speak to the validity of that premise.