All Climate Events
Webinar: Marine Heatwaves under Global Warming: Discovering Risks for Marine Ecosystems
Thursday, 15 November 2018, 12:00
Thursday, November 15, 2018. 12:00PM. Webinar: Marine Heatwaves under Global Warming: Discovering Risks for Marine Ecosystems. Thomas Froelicher, University of Bern, Switzerland. Sponsored by NOAA. More information here.
Extreme climate and weather events shape the structure of biological systems and affect the biogeochemical functions and services they provide for society in a fundamental manner. There is overwhelming evidence that the frequency, duration and intensity of extreme events on land are changing under global warming, increasing the risk of severe, pervasive and in some cases irreversible impacts on natural and socio-economic systems. In contrast, we know very little about the past occurrences and the future progression of marine heatwaves. This knowledge gap is of particular concern as some of the recently observed marine heatwaves revealed the high vulnerability of marine ecosystems and fisheries to such extreme climate events.
Here Froelicher uses satellite observations and a suite of Earth system model simulations to show that the number of marine heatwave days doubled between 1982 and 2016, and this is projected to increase further if global temperature continue to increase. If temperature were to rise by 3.5 degrees Celsius relative to preindustrial levels, as is predicted to result from current national policies for the reduction of global carbon emissions, the average probability of marine heatwaves occurring would be 41 times higher than in preindustrial times. Such an increase in marine heatwaves will probably increase the risk of severe and long-lasting impact on marine organisms, such as coral reefs and those living at low latitudes, where many marine species live close to their upper thermal limits. Potential impacts on physical and human systems will also be discussed.