That was what we thought ten years ago. There has been considerable and surprising progress on ice sheet dynamics. Basically, ice sheets do not melt from the top. They crack, fail mechanically, and slip into the sea. This is especially true of those whose base is below sea level, specifically the West Antarctic Ice sheet (WAIS).
14 Ka ago sea level rose by several meters per century for several centuries. The mechanism was the partial failure of the WAIS. There’s still some left.
Don’t get me wrong; this will not happen next week, and there will be no resulting tsunami. But a meter of sea level rise in this century is likely, two is plausible, and four isn’t totally excluded.
You seem fond of don’t-worry arguments. This makes you an instance of Eliezer’s point.
You sound as though you are arguing with something in my post—but it is not clear what—since you don’t really present much of a counter-argument. Greenland and Antarctica really do have enormous thermal inertia. Ice really does take a long time to melt—and Antarctic ice really is an average of 2 kilometres thick.
You are arguing with the “it will probably take tens of thousands of years to melt it”? Consider that a ballpark figure. Currently the Antarctic ice sheet is getting thicker and thicker—and it is −37 degrees C down around the pole. So: it is not going anywhere anytime soon.
You seem fond of don’t-worry arguments.
Perhaps paranoia has its place—but I think it is best recognised as such.
Those who make calls to action often distort the picture—to make their cause seem more urgent.
So: such causes become surrounded with distortions and misinformation designed to manipulate others.
Global average sea level rose at an average rate of around 1.8 mm per year over 1961 to 2003 and at an average rate of about 3.1 mm per year from 1993 to 2003.
That seems pretty slow to me.
It is true that the record—at the peak of the last glacial retreat—was some 65mm / year—but there was a lot more ice all over Russia and Canada back then—and we are unlikely to see anything like that with today’s much-smaller ice caps.
That was what we thought ten years ago. There has been considerable and surprising progress on ice sheet dynamics. Basically, ice sheets do not melt from the top. They crack, fail mechanically, and slip into the sea. This is especially true of those whose base is below sea level, specifically the West Antarctic Ice sheet (WAIS).
14 Ka ago sea level rose by several meters per century for several centuries. The mechanism was the partial failure of the WAIS. There’s still some left.
Don’t get me wrong; this will not happen next week, and there will be no resulting tsunami. But a meter of sea level rise in this century is likely, two is plausible, and four isn’t totally excluded.
You seem fond of don’t-worry arguments. This makes you an instance of Eliezer’s point.
You sound as though you are arguing with something in my post—but it is not clear what—since you don’t really present much of a counter-argument. Greenland and Antarctica really do have enormous thermal inertia. Ice really does take a long time to melt—and Antarctic ice really is an average of 2 kilometres thick.
You are arguing with the “it will probably take tens of thousands of years to melt it”? Consider that a ballpark figure. Currently the Antarctic ice sheet is getting thicker and thicker—and it is −37 degrees C down around the pole. So: it is not going anywhere anytime soon.
Perhaps paranoia has its place—but I think it is best recognised as such.
Those who make calls to action often distort the picture—to make their cause seem more urgent.
So: such causes become surrounded with distortions and misinformation designed to manipulate others.
We don’t need to melt them to raise the sea level. All that ice floating around does just as well.
We have had around 1.7 mm per year for the 20th century.
That seems pretty slow to me.
It is true that the record—at the peak of the last glacial retreat—was some 65mm / year—but there was a lot more ice all over Russia and Canada back then—and we are unlikely to see anything like that with today’s much-smaller ice caps.