Demographic resilience may sustain significant coral populations in a 2°C-warmer world.

Projections of coral reefs under climate change have important policy implications, but most analyses have focused on the intensification of climate-related physical stress rather than explicitly modelling how coral populations respond to stressors. Here, we analyse the future of the Great Barrier Reef under multiple, spatially-realistic drivers which allows less impacted sites to facilitate recovery. Under an RCP2.6 climate ensemble, where warming is capped at ~2°C, Great Barrier Reef mean coral cover declined mid-century but approached present-day levels towards 2100. This is considerably more optimistic than most analyses. However, under RCP4.5, mean coral cover declined by > 80% by late-century, and reached near zero under RCP≥6.0. While these models do not allow for adaptation, they significantly extend past studies by revealing demographic resilience of coral populations to low levels of additional warming. Substantive coral populations under RCP2.6 would facilitate long-term genetic adaptation, adding value to ambitious greenhouse emissions mitigation.