What will the sea level be when the ice caps melt?

[farsideofourmoon]

What was the average sea level in Athens, Greece 2,720 years ago?

What was the average sea level in ancient Rome 2,420 years ago?

https://en.wikipedia.org/wiki/History_of_theatre

Ancient towns have been found that were built thousands of years ago when the towns were above sea level.   

My bet is the average sea level was at its lowers 2,720 years ago when most of the planet was covered in ice.

The sea will continue to rise until the ice caps melt. Will NY be under water then?

When the caps/glaciers melt, what will the average world sea level be considering the volume of the known ice caps today

What will the sea level be when the ice caps melt?

At the submerged date using the current rate of melt.

When will New York, Miami, and other coastal lined cities be underwater?

Anyone care to calculate the year when NY will be completely submerged?

-?

[StringJunky]

Sea level could rise 216 feet. NY is 33 feet above sea level, so it would be 183 feet underwater. That may take 5000 years... pulled that off National Geographic.

[HallsofIvy]

My bet is the average sea level was at its lowers 2,720 years ago when most of the planet was covered in ice.

I don't know where you got this idea!  The last ice age, "when most of the planet was covered in ice" ended about 3,000,000 years ago (perhaps you just dropped ",000").  There was a period, sometimes called "the little ice age" of lower than  normal tempartures but no ice sheets that only ended about 200 years ago (that's why the painting "Washington crossing the Delaware" shows ice  in the river).

[MigL]

"The Last Glacial Period (LGP) occurred from the end of the Eemian to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago."

https://en.wikipedia.org/wiki/Last_Glacial_Period

Which ice cap do you mean ?
If the North Polar Cap was to melt completely, it would not raise sea levels at all, because it is 'floating' ice.
The submerged part of floating ice displaces an equivalent weight of water ( ice is less dense ).
Only ice that raises sea levels is ice covering land ( glaciers and nost of South Polar Cap covering Antartica )

 

[Ken Fabian]

If all the ice sheets melt, about 70m of average sea level rise. Counter-intuitively the sea level closest to where the ice loss occurs will drop, with the highest average rise at the greatest distance. The sources would include Greenland and other glacial ice that is not at the poles - but if Antarctica can melt entirely the world will be too warm to support ice sheets or glaciers.

Predicting the rate of sea level rise - and therefore pin down when a specific location would be inundated - is difficult. We don't know how global warming will progress because we don't know what emissions will be; I would like to believe we can shift to low emissions energy within the next few decades. Then there are big unknowns about how ice sheet disintegration might proceed, with potential for rapid surges in sea level rise from ice sheet collapses. The current rate is above 3mm per year but has been rising - and is expected to keep rising.

Edited August 13, 2020 by Ken Fabian

[J.C.MacSwell]

I thought a significant part of the sea level rise was due to water expansion with increased temperature. Not sure where I read it but I'll look...

Wiki on Sea level rise has this 

" Between 1993 and 2018, thermal expansion of the oceans contributed 42% to sea level rise; the melting of temperate glaciers, 21%; Greenland, 15%; and Antarctica, 8%.^[3]:1576 Climate scientists expect the rate to further accelerate during the 21st century."

( mentions approx 3" rise between 1993 and 2017)

[Ken Fabian]

4 hours ago, J.C.MacSwell said:

I thought a significant part of the sea level rise was due to water expansion with increased temperature. Not sure where I read it but I'll look...

Wiki on Sea level rise has this 

" Between 1993 and 2018, thermal expansion of the oceans contributed 42% to sea level rise; the melting of temperate glaciers, 21%; Greenland, 15%; and Antarctica, 8%.^[3]:1576 Climate scientists expect the rate to further accelerate during the 21st century."

( mentions approx 3" rise between 1993 and 2017)

Currently sea level rise from thermal expansion is greater than that from ice sheet/glacier sources. However my understanding is the proportion from melting ice is expected to rise significantly. Between now and 2100 the rate of sea level rise is not much different between low emissions scenarios and high - mostly thermal expansion - but slows with low and accelerates due to ice sheet contributions with high emissions, with much higher rates of rise over the subsequent couple of centuries. There is also potential for ice sheet collapse that could result in surges in ice loss and sea level rise - and these resist reliable prediction.