The number of marine heatwaves doubled in mediterranean north Africa and along the Somalian and southern African coastlines from 1982-2016 , very likely as a result of human-caused climate change . Marine heatwave intensity has increased along the southern African coastline . In the ecologically sensitive region west of southern Madagascar, the longest and most intense marine heatwave in the past 35 years was recorded during the austral summer of 2017 in the region, it lasted 48 days and reached a maximum intensity of 3.44℃ above the 35- year average . Satellite-derived measurements of coastal marine heatwaves may under-report their intensity as measured against coastal in situ measurements .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report