Why we need to start categorising marine heatwaves like hurricanes

The public discussion of climate change is often loudest in the aftermath of extreme events, especially those that break records or cause mass destruction. No one forgets Hurricane Katrina or Hurricane Ivan. Their names, and the familiar category system used to describe their severity, also serve as an important aid for forecasters to communicate to affected communities.

Marine heatwaves can cause loss of ecologically crucial kelp forests. 

But marine heatwaves – extreme warm-water events in the ocean that may last many months and extend over thousands of square kilometres – lack any naming or categorising conventions. The most famous marine heatwave, dubbed “The Blob” in the media, began in 2014 and persisted for 711 days in the northeast Pacific Ocean, with local sea temperatures reaching 2.56 degrees Celsius above average. Birds and mammals along an extensive stretch of Pacific coastline died in large numbers. Around the world, other marine heatwaves have caused mass coral bleaching and loss of large underwater habitats, such as kelp forests. Climate change is, unsurprisingly, expected to intensify these events and exacerbate their effects.

Read the report from the CSIRO blog by Alastair Hobday - “Why we need to start categorising marine heatwaves like hurricanes.”