Marine heatwaves hide months of extra warming, study finds

Research from William & Mary's VIMS & Batten School, published in Communications Earth & Environment, shows that treating marine heatwaves as isolated events underestimates total heat exposure to ocean ecosystems by more than 150% on average. The team analyzed 2,580 heatwaves across 20 U.S. estuaries over two decades.

• 2,580 marine heatwaves analyzed across 20 U.S. estuaries over 20 years
• Conventional assessments underestimate cumulative heat exposure by over 150% on average
• Two thirds of events were 'individual', one third 'compound' with ~90 days of warming
• Compound events produced over three times the cumulative heat of the heatwave itself