Thursday, September 30, 2021

Sea Level Rise Now 4.7 mm/year

The University of Colorado Sea Level Research Group recently released their latest data update, with data up to August 6, 2021. As the figure shows, there is now a clear acceleration, of 0.098 mm/yr2. I fit a quadratic function to their data, and got the same result. And while the average rate of sea level rise over their dataset is 3.3 mm/yr -- that's the linear trend -- the current rate of sea level rise, i.e. the first derivative of the quadratic fit, is 4.7 mm/yr.


Mind you, this is the global average, and local rates are never this due to local and regional particular conditions.

I'm not going to extrapolate this curve out to 2100, because I don't think that's a smart way to calculate future sea level rise, which depends on future ice sheet melt, which may not be linear or quadratic. So you need real models, not curve fitting.

5 comments:

Layzej said...

"I'm not going to extrapolate this curve out to 2100, because I don't think that's a smart way to calculate future sea level rise"

But it's fun though right? I get 0.673 meters (~2.2 feet) further rise with a rate of ~12.5 mm/year in 2100.

Is that in the ballpark?

David Appell said...

You're a bad influence :-)

I get 0.741 m in 2100 with a rate then of 12.5 mm/yr.

A rise of half-inch a year. 6 inches in a decade.

David Appell said...

Oops. 5 inches in a decade.

Layzej said...

I trust your numbers more than mine :)

David Appell said...

Why??