Projections of future coral bleaching conditions using IPCC CMIP6 Models: climate policy implications, management applications, and Regional Seas summaries

Abstract

The third global coral bleaching event, which started in 2014 and extended well into 2017, was the longest coral bleaching event on record. The length of the event means corals in some parts of the world had no time to recover in 2014, 2015 or 2016 during the cool/winter season, prior to experiencing bleaching the following year. This recent global bleaching event of 2014-2017 represents what climate model projections presented in this Report suggest may become the norm over the coming two decades. Importantly though, great spatial variation exists in the projected timing of the onset of annual severe bleaching (ASB) conditions among the world’s coral reefs. This report updates the UNEP 2017 report with projections of the timing of severe coral bleaching conditions using the new generation of climate models used by the IPCC – the CMIP6 generation of models.