Earthweek: Diary of a Changing World
Week ending Friday, April 20, 2018
Current Weakening
The long-feared weakening of the massive Atlantic Ocean circulation due to climate change appears to be underway.
The Atlantic Meridional Overturning Circulation (AMOC) carries warmth to high latitudes and makes Northern Europe far more temperate than it otherwise would be. It’s also crucial IRU ÀVKHULHV RII WKH FRDVWV RI New England and the Canadian Maritime Provinces.
But scientists from the Potsdam Institute for Climate Impact Research write in the journal Nature that the AMOC has declined in strength by 15 percent since the mid-20th century, reaching a new record low.
Changes in ocean salinity brought on by melting glaciers and ice sheets are blamed for the slowdown.
Antarctic Melt
Antarctica’s Larsen C ice shelf now melts in the dead of winter when the average temperature on the adjacent Antarctic peninsula is only 5 degrees Fahrenheit.
It’s been known for a while that Antarctic ice shelves are thinning and retreating, mainly because warmer currents below are melting them. But new remote sensors have found that downslope winds can also cause them to thin.
These “foehn winds” blowing off Antarctica’s mountains can cause air temperatures to rise several degrees, sometimes to above freezing. The phenomenon had earlier been observed in summer, but it’s now happening in the depth of winter. Dist. by: Andrews McMeel Syndication ©MMXVIII Earth Environment Service
Plastic Eaters
Mutant plastic-dissolving enzymes could help curb the increasing global plastic pollution that threatens marine life and even the humans who eat it.
Researchers from the University of Portsmouth were studying a bacterium discovered at a Japanese dump in 2016 that had naturally evolved to eat plastic.
While using ultra-intense beams of X-rays to examine the structure of the key enzyme produced by the bacterium, they accidentally improved the enzyme’s ability to break down the kind of plastic used to make beverage bottles.
Kenyan Fractures
A second massive crack has ripped through the Kenyan landscape, but geologists assure nervous residents that neither means their country will break apart anytime soon.
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Scientists say a growing split in the African tectonic plate will eventually cause a slice of Africa to break away.
Coral Shield
Australian scientists have developed a “sun shield” they hope can save the Great Barrier Reef from the coral bleaching that has ravaged the reef since 2016.
The shield is an ultraWKLQ ELRGHJUDGDEOH ÀOP WKDW ÁRDWV RQ WKH RFHDQ·V VXUIDFH The shield contains calcium carbonate — the same compound corals use to make their hard skeletons.
While it would be impracWLFDO WR GHSOR\ WKH ÀOP RYHU the entire 135,000-squaremile reef, the scientists say it could be selectively placed to protect the most precious or high-risk areas.
Eruption Migration
Heavy ash and hazardous fumes from an active volcano on Vanuatu’s Ambae IsODQG KDYH SURPSWHG RIÀFLDOV to permanently resettle most of the island’s 11,000 residents by the end of May.
Earthquakes
Eastern parts of Japan’s Hokkaido Island were EULHÁ\ MROWHG E\ D strong offshore temblor.
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