Earthweek: Diary of a Changing World
Week ending Friday, February 16, 2024
Polar Hunger
With Canada’s Arctic region becoming ice-free longer in summer due to global heating, polar bears are facing even more desperate struggles to find enough food to survive.
A new study says that the 25,000 surviving polar bears are forced to scavenge and swim longer distances to find food but are not having much success with either.
Historically, in late spring and early summer, the bears used sea ice as floating platforms to hunt seals. But human-caused climate change is extending the ice-free summer across the Arctic.
Bears that now spend more time on land in summer are losing weight, with a higher risk of starvation.
Earthquakes
A moderate quake along the U.S.-Baja California border was felt from Arizona to Palm Springs and San Diego.
• Earth movements were also felt in Los Angeles, South Texas, Hawaii’s Big Island, the southern Philippines, South Asia’s Hindu Kush region and India’s Assam state.
Current Collapse
Scientists developing an early warning system for the breakdown of the Atlantic meridional overturning circulation (AMOC) say the complex network of ocean currents is nearing a “devastating tipping point.”
Writing in the journal Sciences Advances, they say the AMOC, of which the Gulf Stream is a part, is on track toward an abrupt shift — something not seen for more than 10,000 years.
It has already declined by 15% since 1950 and is being eroded by a faster-than-expected melt of Greenland’s glaciers and the Arctic ice sheets in recent years.
The conveyor belt of currents moderates the climate of Britain and northern Europe, and its collapse would result in climate consequences from Europe to South America.
Eruptions
Another fissure opened up in southwestern Iceland’s Reykjanes Peninsula, spewing lava over the eruptionweary area for several hours.
Geophysicist Benedikt Ófeigsson of the Icelandic Met Office told reporters that the area can expect an eruption every month or so during the next few months.
• Rumblings at Grenada’s nearby Kick ’em Jenny undersea volcano were felt in northern parts of the Caribbean island.
• Southern Japan’s Sakurajima volcano spewed plumes of ash high above the summit crater for the first time since 2020.
Migratory Decline
A landmark U.N. report warns that migrating animals, from humpback whales to seabirds, are under mounting threat from human activities. THE STATE OF THE WORLD’S MIGRATORY SPECIES says that almost half of those species are in decline, with about a quarter at risk of extinction.
The report concludes that pollution, hunting and killing of animals, habitat destruction, climate change and the noise and light pollution brought on by human development are major threats to the migrators.
Greener Greenland
The area of Greenland covered in vegetation roughly doubled over the three decades between the late 1980s and the late 2010s as an estimated 11,000 square miles of the island’s ice sheets and glaciers melted.
A new study published in the journal SCIENTIFIC REPORTS says the melt has created wetlands that are increasingly home to species of grasses and grasslike plants capable of living in the newly icefree and waterlogged soil.
Since the green landscapes absorb more energy from the sun than areas covered in ice, they have the potential to speed up Greenland’s already rapid melt.
The expanding wetlands are also becoming a significant source of methane, a potent greenhouse gas that could further amplify Greenland’s melt.
South Sea Cyclone
An unnamed, short-lived and minimal tropical storm drenched central parts of the Vanuatu archipelago before dissipating near Fiji.