The ocean is warming, losing oxygen and being acidified, primarily as a result of anthropogenic carbon emissions. With ocean warming, acidification and deoxygenation projected to increase for decades, extreme events, such as marine heatwaves, will intensify, occur more often, persist for longer periods of time and extend over larger regions. Nevertheless, our understanding of oceanic extreme events that are associated with warming, low oxygen concentrations or high acidity, as well as their impacts on marine ecosystems, remains limited. Compound events - that is, multiple extreme events that occur simultaneously or in close sequence - are of particular concern, as their individual effects may interact synergistically. Here we assess patterns and trends in open ocean extremes based on the existing literature as well as global and regional model simulations. Furthermore, we discuss the potential impacts of individual and compound extremes on marine organisms and ecosystems. We propose a pathway to improve the understanding of extreme events and the capacity of marine life to respond to them. The conditions exhibited by present extreme events may be a harbinger of what may become normal in the future. As a consequence, pursuing this research effort may also help us to better understand the responses of marine organisms and ecosystems to future climate change.

Item Type:	Refereed Article
Keywords:	ocean warming, ocean acidification, climate change
Research Division:	Earth Sciences
Research Group:	Oceanography
Research Field:	Chemical oceanography
Objective Division:	Environmental Policy, Climate Change and Natural Hazards
Objective Group:	Adaptation to climate change
Objective Field:	Ecosystem adaptation to climate change
UTAS Author:	Boyd, PW (Professor Philip Boyd)
ID Code:	151397
Year Published:	2021
Web of Science® Times Cited:	36
Deposited By:	Ecology and Biodiversity
Deposited On:	2022-07-28
Last Modified:	2022-09-01
Downloads:	0