Aug 6, 2024 03:59 PM
Modern hurricanes are rewriting the rules of extreme storms
https://www.bbc.com/future/article/20240...eme-storms
EXCERPTS: The behaviour of the world's most powerful storms is evolving. To adapt to more destructive hurricanes, we need to know how they're changing.
Fuelled by heat from ocean waters, hurricanes are sometimes known as nature's steam engines. As they barrel over the oceans, they turn its heat into brutal kinetic energy that flattens islands and inundates coastal cities, taking months of urgent repair work to heal. Ocean temperatures are now breaking all records, and these "engines" are responding accordingly, cutting different paths across the ocean, slowing down, and becoming less predictable and more dangerous.
Now there's a race to understand exactly how hurricanes are rewriting the rules and patterns we've seen before, in the hope of learning how we can adapt.
[...] Storms are now 25% more likely than they were 40 years ago to reach the threshold of 111 mph (180km/h) required to be classified as a major hurricane. "The ocean temperature defines the maximum intensity the hurricane can reach," says Willoughby.
[...] Even as the wind speeds within a hurricane speed up, the movement of hurricanes along their paths over ocean and land is slowing down.
In a 2018 study, Kossin found that hurricanes near the US have slowed by around 17% since the beginning of the 20th Century. Tropical cyclones in the western North Pacific slowed down by as much as 20%.
It's thought that the reason for the slowdown is the uneven way that climate change is heating the globe, with the Arctic warming nearly four times faster than the rest of the world... (MORE - missing details)
Greenland fossil discovery reveals increased risk of sea-level catastrophe
https://www.eurekalert.org/news-releases/1053249
INTRO: The story of Greenland keeps getting greener—and scarier.
A new study provides the first direct evidence that the center—not just the edges—of Greenland’s ice sheet melted away in the recent geological past and the now-ice-covered island was then home to a green, tundra landscape.
A team of scientists re-examined a few inches of sediment from the bottom of a two-mile-deep ice core extracted at the very center of Greenland in 1993—and held for 30 years in a Colorado storage facility. They were amazed to discover soil that contained willow wood, insect parts, fungi, and a poppy seed in pristine condition.
“These fossils are beautiful,” says Paul Bierman, a scientist at the University of Vermont who co-led the new study with UVM graduate student Halley Mastro and nine other researchers, “but, yes, we go from bad to worse,” in what this implies about the impact of human-caused climate change on the melting of the Greenland ice sheet.
The study, published in the Proceedings of the National Academy of Sciences on August 5th, confirms that Greenland’s ice melted and the island greened during a prior warm period likely within the last million years—suggesting that the giant ice sheet is more fragile than scientists had realized until the last few years.
If the ice covering the center of the island was melted, then most of the rest of it had to be melted too. “And probably for many thousands of years,” Bierman said, enough time for soil to form and an ecosystem to take root.
“This new study confirms and extends that a lot of sea-level rise occurred at a time when causes of warming were not especially extreme,” said Richard Alley, a leading climate scientist at Penn State who reviewed the new research, “providing a warning of what damages we might cause if we continue to warm the climate.”
Sea level today is rising more than an inch each decade. “And it’s getting faster and faster,” said Bierman. It is likely to be several feet higher by the end of this century, when today’s children are grandparents. And if the release of greenhouse gases—from burning fossil fuels—is not radically reduced, he said, the near complete melting of Greenland’s ice over the next centuries to a few millennia would lead to some 23 feet of sea level rise.
“Look at Boston, New York, Miami, Mumbai or pick your coastal city around the world, and add twenty plus feet of sea level,” said Bierman. “It goes underwater. Don't buy a beach house.” (MORE - details, no ads)
https://www.bbc.com/future/article/20240...eme-storms
EXCERPTS: The behaviour of the world's most powerful storms is evolving. To adapt to more destructive hurricanes, we need to know how they're changing.
Fuelled by heat from ocean waters, hurricanes are sometimes known as nature's steam engines. As they barrel over the oceans, they turn its heat into brutal kinetic energy that flattens islands and inundates coastal cities, taking months of urgent repair work to heal. Ocean temperatures are now breaking all records, and these "engines" are responding accordingly, cutting different paths across the ocean, slowing down, and becoming less predictable and more dangerous.
Now there's a race to understand exactly how hurricanes are rewriting the rules and patterns we've seen before, in the hope of learning how we can adapt.
[...] Storms are now 25% more likely than they were 40 years ago to reach the threshold of 111 mph (180km/h) required to be classified as a major hurricane. "The ocean temperature defines the maximum intensity the hurricane can reach," says Willoughby.
[...] Even as the wind speeds within a hurricane speed up, the movement of hurricanes along their paths over ocean and land is slowing down.
In a 2018 study, Kossin found that hurricanes near the US have slowed by around 17% since the beginning of the 20th Century. Tropical cyclones in the western North Pacific slowed down by as much as 20%.
It's thought that the reason for the slowdown is the uneven way that climate change is heating the globe, with the Arctic warming nearly four times faster than the rest of the world... (MORE - missing details)
Greenland fossil discovery reveals increased risk of sea-level catastrophe
https://www.eurekalert.org/news-releases/1053249
INTRO: The story of Greenland keeps getting greener—and scarier.
A new study provides the first direct evidence that the center—not just the edges—of Greenland’s ice sheet melted away in the recent geological past and the now-ice-covered island was then home to a green, tundra landscape.
A team of scientists re-examined a few inches of sediment from the bottom of a two-mile-deep ice core extracted at the very center of Greenland in 1993—and held for 30 years in a Colorado storage facility. They were amazed to discover soil that contained willow wood, insect parts, fungi, and a poppy seed in pristine condition.
“These fossils are beautiful,” says Paul Bierman, a scientist at the University of Vermont who co-led the new study with UVM graduate student Halley Mastro and nine other researchers, “but, yes, we go from bad to worse,” in what this implies about the impact of human-caused climate change on the melting of the Greenland ice sheet.
The study, published in the Proceedings of the National Academy of Sciences on August 5th, confirms that Greenland’s ice melted and the island greened during a prior warm period likely within the last million years—suggesting that the giant ice sheet is more fragile than scientists had realized until the last few years.
If the ice covering the center of the island was melted, then most of the rest of it had to be melted too. “And probably for many thousands of years,” Bierman said, enough time for soil to form and an ecosystem to take root.
“This new study confirms and extends that a lot of sea-level rise occurred at a time when causes of warming were not especially extreme,” said Richard Alley, a leading climate scientist at Penn State who reviewed the new research, “providing a warning of what damages we might cause if we continue to warm the climate.”
Sea level today is rising more than an inch each decade. “And it’s getting faster and faster,” said Bierman. It is likely to be several feet higher by the end of this century, when today’s children are grandparents. And if the release of greenhouse gases—from burning fossil fuels—is not radically reduced, he said, the near complete melting of Greenland’s ice over the next centuries to a few millennia would lead to some 23 feet of sea level rise.
“Look at Boston, New York, Miami, Mumbai or pick your coastal city around the world, and add twenty plus feet of sea level,” said Bierman. “It goes underwater. Don't buy a beach house.” (MORE - details, no ads)