Subject: Re: Things That AI Won't Change
In its 2019 report, the IPCC projected 0.6 to 1.1 meters (1 to 3 feet) of global sea level rise by 2100 (or about 15 millimeters per year) if greenhouse gas emissions remain at high rates. The high end, 1.1 meters, does not pass the test for a reasonable scenario, yet it is widely quoted in media.

The forecast range is, as you say, 0.6 to 1.1 metres, under "business as usual" (the scenario I expect) by 2100.
Since that's the forecast range, I'm not sure why you'd suggest it doesn't pass the test for resonableness...it's in the range built from the best data available.

A better way to think of it is this way:
Sea levels are pretty darned certain to rise by at least a metre. It's mainly just some uncertainty of how long that will take.
From the latest IPCC report: "Over the next 2000 years, global mean sea level will rise by about 2'3 m if warming is limited to 1.5°C and 2'6 m if limited to 2°C (low confidence)."

So, we only have guesses as to when the one metre rise might happen.
Under RCP 8.5 scenario, central guess is some time around 2112. Uncertainty range is large, something like 2055-2152.
Under RCP 4.5 scenario, central guess is around 2195.
Under RCP 2.5 scenario, I think it's some time after 2300.

So, no, we're not going to see all of Florida vanish soon. You're right that way too many writers mention only the very highest and relatively unlikely estimates. But we are definitely going to see SOME of Florida disappear. Florida does somewhat justifiably get mentioned the most because of the large aggregate market value of the property that will go away, not the area.

And the chipper bit from the same report:
"The probability of low-likelihood outcomes associated with potentially very large impacts increases with higher global warming levels (high confidence). Warming substantially above the assessed very likely range for a given scenario cannot be ruled out, and there is high confidence this would lead to regional changes greater than assessed in many aspects of the climate system. Low-likelihood, high-impact outcomes could occur at regional scales even for global warming within the very likely assessed range for a given GHG emissions scenario. Global mean sea level rise above the likely range ' approaching 2 m by 2100 and in excess of 15 m by 2300 under a very high GHG emissions scenario (SSP5-8.5) (low confidence) ' cannot be ruled out due to deep uncertainty in ice-sheet processes 66"

Let's hear it for already having used up most of my life expectancy!

Jim