'Marine heatwaves are projected to further increase in frequency, duration, spatial extent and intensity  . Climate models project increases in the frequency of marine heatwaves by 2081-2100, relative to 1850-1900, by approximately 50 times under RCP8.5 and 20 times under RCP2.6 .' 'Extreme El Niño and La Niña events are projected to likely increase in frequency in the 21st century and to likely intensify existing hazards, with drier or wetter responses in several regions across the globe. Extreme El Niño events are projected to occur about twice as often under both RCP2.6 and RCP8.5 in the 21st century when compared to the 20th century .' 'Limiting global warming would reduce the risk of impacts of MHWs, but critical thresholds for some ecosystems  will be reached at relatively low levels of future global warming .'
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report