«Warming over the past 100 years is
consistent with high climate sensitivity to atmospheric carbon dioxide combined with a large cooling effect from short - lived aerosol pollutants, but it could equally be attributed to a low climate sensitivity coupled with a small effect from aerosols.
In their figure 7 they seem to view about 25m of SLR by the year 3000 as a worst - case scenario under BAU and
with high climate sensitivity.
And
with high climate sensitivity, a risk - averse target for 2 ˚C is around 350ppm CO2e — and all this is necessary just to meet a 2 ˚C target that is actually dangerous.