Extended Data Fig. 7: Reversal in summer \({{\boldsymbol{p}}}_{{{\bf{CO}}}_{{\bf{2}}}}^{{\prime} }\) is driven by a threefold increase in summer T′, while other changes are much smaller.

Arctic domain averages of monthly anomalies of the CMIP5 mean under RCP8.5 are shown for the modern (2006–2015, solid) and future (2091–2100, dashed) climatologies for the four driving variables: sAT′ (cyan), sCT′ (green), T′ (blue), and S′ (red). The shading indicates model spread (±1 s.d., n = 9), which for sAT′ and sCT′ is shown only for the future.