Tuesday, August 16, 2016

Marine Heatwaves Are Spawning Unprecedented Climate Chaos

[Wired] First seabirds started falling out of the sky, washing up on beaches from California to Canada.
Then emaciated and dehydrated sea lion pups began showing up, stranded and on the brink of death.
A surge in dead whales was reported in the same region, and that was followed by the largest toxic algal bloom in history seen along the Californian coast. Mixed among all that there were population booms of several marine species that normally aren’t seen surging in the same year.
Plague, famine, pestilence and death was sweeping the northern Pacific Ocean between 2014 and 2015.
This chaos was caused by a single massive heatwave, unlike anything ever seen before. But it was not the sort of heatwave we are used to thinking about, where the air gets thick with warmth. This occurred in the ocean, where the effects are normally hidden from view.
Nicknamed “the blob”, it was arguably the biggest marine heatwave ever seen. It may have been the worst but wide-scale disruption from marine heatwaves is increasingly being seen all around the globe, with regions such as Australia seemingly being hit with more than their fair share.
It might seem strange given their huge impact but the concept of a marine heatwave is new to science. The term was only coined in 2011. Since then a growing body of work documenting their cause and impact has developed.
According to Emanuele Di Lorenzo from the Georgia Institute of Technology, that emerging field of study could not only reveal a hitherto underestimated source of climate-related chaos, it could change our very understanding of the climate.
On the other side of the Pacific from “the blob”, Australia has been buffeted by a string of extreme marine heatwaves. This year at least three parts of the coast have been devastated by extreme water temperatures.
Australia, it seems, could be smack in the middle of this global chaos. According to work published in 2014, both the south-east and south-west coasts are among the world’s fastest warming ocean waters.
“They have been identified as global warming hotspots,” says Eric Oliver, an oceanographer at the University of Tasmania. “The seas there are warming fast and so we might expect there to be an increased likelihood or increased intensity of the events that happen there.
“Certainly attention is being focused on ocean changes on the south-east and south-west of Australia.” Read More