[RubenSandwich]

Because the IPCC didn't account for runaway positive feedback loops. So while the rise is slow, it is projected to increase exponentially as more of the Arctic melts: https://upload.wikimedia.org/wikipedia/commons/b/bc/Sea_Leve... which is from a 2017 NOAA study[1].

It's also worth noting that while 3.3mm a year seems low. That is the average, the sea level is not rising evenly across the world. To make this example a bit more real and close to home as HN is mostly US-centric. The current sea level rise is about ~8in/21cm[2], and Miami Beach is already flooding every year. This is because Miami Beach is experiencing almost a 1in of sea-level rise each year according to Hal Wanless, a coastal geologist at the University of Miami[3]. So using NOAA's own maps which show Miami Beach mostly underwater at 3ft we will hit that scenario in about 30 years at current rates[4], but once again sea level rise is not increasing linearly.

[1] https://tidesandcurrents.noaa.gov/publications/techrpt83_Glo...

[2] https://science2017.globalchange.gov/chapter/12/

[3] https://gizmodo.com/why-are-sea-levels-in-miami-rising-so-mu...

[4] https://coast.noaa.gov/slr/#/layer/slr/4/-8927570.466376439/... (You have to search for Miami Beach, the web app doesn't allow linking to locations.)

[kgwgk]

> [3] Throughout the record, they found that a combination of two naturally-occurring climate patterns—the El Niño Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO)—were associated with “hot spots” of sea level rise along the Eastern seaboard, including the southeastern hot spot from 2011 to 2015. (...) the Pacific Decadal Oscillation might also be playing a role.

> we will hit that scenario in about 30 years at current rates

Oscillation =/= Trend

https://xkcd.com/605/

[aldoushuxley001]

What about all the unaccounted negative feedback loops? Like e.g. increased low lying cloud cover formation. A lot of these aren't taken into account by the IPCC either.

[acqq]

> these aren't taken into account by the IPCC either.

But they are. I know for sure that water vapour is a part of the models.

[longtom]

What are some current plausible wost-case models that take the non-linearity of the sea level rise and any conceivable feedback loops into account?