Fig. 4: Detection of GHG signal in observed changes of SST.
From: Arctic marine heatwaves forced by greenhouse gases and triggered by abrupt sea-ice melt
a Observed trend in the month of August SST over 1995–2020, according to OISSTv2. Response of SST to GHG signal over 1995–2020 in August, derived from ensemble means of b 50 CanESM5 GHG-forcing only realizations, c 30 MPI-ESM-LR GHG-forcing only realizations. 1-year moving scaling factor of observed SST trends (derived from OISSTv2) onto the GHG signal derived from d MPI-ESM-LR (30 members), e CanESM5 (50 members) over 1982–2021. The gray shaded area displays the 95%-tile range of historical (transient) internal variability-generated uncertainty of scaling factors, derived from ALL-forcing experiments of 30 members of MPI-ESM-LR and 50 members of CanESM5. Detection of GHG signal is claimed when the gray shaded area does not include the zero line but is consistent with unity (ai ≠ 0 ⋂ ai = 1, with < 5% risk of error).
