This study investigates the impact of global warming on ocean heat transport (OHT) using coupled model intercomparison project phase 5/6 (CMIP5/6) climate projections. The results show a future decrease in poleward OHT across all Northern Hemisphere latitudes and south of 10°S. The reduction is driven by a decline in overturning circulation dampened by upper ocean warming. CMIP6 projects stronger reductions than CMIP5, even after correcting for its larger climate sensitivity. The Atlantic and Indo-Pacific Oceans exhibit notable decreases in OHT, with the Atlantic showing a particularly strong response due to a stronger decline in the Atlantic meridional overturning circulation (AMOC). Changes in the Southern Ocean also indicate a reduction in poleward OHT.

Jennifer V. Mecking, Sybren S. Drijfhout