The oceans have experienced longer and more frequent ocean heat waves over the past century due to the global warming, which can have “devastating long-term impacts,” according to a study released Tuesday in Nature Communications.
Between 1925 and 2016, the frequency of marine heat episodes increased by an average of 34% and their duration by 17%, with an acceleration since 1986, according to this study, presented as the first of its kind in the world.
An ocean heat wave is represented by at least five consecutive days when the surface of the water is “abnormally hot”.
The oceans play a vital role in regulating the planet’s climate
Oceans store a part of the solar radiation at the equator, then the water moves towards the poles and releases heat, thus regulating the temperatures.
“Some of us will be able to enjoy warmer waters when we go swimming but these heat waves have significant impacts on ecosystems, biodiversity, fisheries, tourism, and aquaculture,” warns Eric Oliver from the Canadian University of Dalhousie. “These impacts often go hand in hand with profound economic consequences,” he added but not before blaming global warming for these abnormal ocean heat waves.
These heat waves episodes are linked to a general rise in average temperatures of the ocean surface, according to the study
While the oceans absorb more than 90% of the heat due to the greenhouse effect, “it is likely that frequent episodes of marine heat waves will continue to progress,” says a co-author of the study, Neil Holbrook, from the University of Tasmania.
These abnormal heat can cause coral bleaching, mass death of invertebrates, or the disappearance of kelp forests (seaweeds).
“We are just starting to reconstruct the impact of climate change and global warming on our marine ecosystems,” says Eric Oliver.
The researchers relied on data collected from ships and ground stations as well as satellite data, removing the effects of exceptional phenomena such as El Niño. The result showed that abnormal ocean heat waves due to the global warming cause lots of negative changes in the oceans’ habitat, from coral bleaching to fish species extinction.