On land, Australia’s rising heat is ‘apocalyptic.’ In the ocean, it’s worse.

https://www.washingtonpost.com/graphics/2019/world/climate-environment/climate-change-tasmania/?utm_source=pocket-newtab

By Darryl Fears
Dec. 27, 2019

Even before the ocean caught fever and reached temperatures no one had ever seen, Australia’s ancient giant kelp was cooked.

Rodney Dillon noticed the day he squeezed into a wet suit several years ago and dove into Trumpeter Bay to catch his favorite food, a big sea snail called abalone. As he swam amid the towering kelp forest, he saw that "it had gone slimy." He scrambled out of the water and called a scientist at the University of Tasmania in nearby Hobart. "I said, 'Mate, all our kelp's dying, and you need to come down here and have a look.'

"But no one could do anything about it."

Climate change had arrived at this island near the bottom of the world, and the giant kelp that flourished in its cold waters was among the first things to go.

Over recent decades, the rate of ocean warming off Tasmania, Australia’s southernmost state and a gateway to the South Pole, has climbed to nearly four times the global average, oceanographers say.

More than 95 percent of the giant kelp — a living high-rise of 30-foot stalks that served as a habitat for some of the rarest marine creatures in the world — died.

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Nearly a tenth of the planet has already warmed 2 degrees Celsius since the late 19th century, and the abrupt rise in temperature related to human activity has transformed parts of the Earth in radical ways.

In the United States, New Jersey is among the fastest-warming states, and its average winter has grown so warm that lakes no longer freeze as they once did. Canadian islands are crumbling into the sea because a blanket of sea ice no longer protects them from crashing waves. Fisheries from Japan to Angola to Uruguay are collapsing as their waters warm. Arctic tundra is melting away in Siberia and Alaska, exposing the remains of woolly mammoths buried for thousands of years and flooding the gravesites of indigenous people who have lived in an icy world for centuries.

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A stretch of the Tasman Sea right along Tasmania’s eastern coast has already warmed by just a fraction below 2 degrees Celsius, according to ocean temperature data from the Hadley Center, the U.K. government research agency on climate change.

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Two of the most severe marine heat waves ever recorded struck back to back in recent years.

In the first, starting in 2015, ocean temperatures peaked at nearly 3 degrees Celsius above normal in the waters between Tasmania and New Zealand. A blob of heat that reached 2 degrees Celsius was more than seven times the size of Tasmania, an island the size of Ireland.

The region’s past heat waves normally lasted as long as two months. The 2015-2016 heat wave persisted for eight months. Alistair Hobday, who studied the event, compared it to the deadly 2003 European heat wave that led to the deaths of thousands of people.

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