Aug 5, 2021 10:32 PM
Collapse of ocean currents could freeze North America, Europe
https://futurism.com/collapse-ocean-curr...ica-europe
EXCERPTS: Scientists are warning that a key system that drives oceanic currents is being driven to the brink of collapse in large part due to human-caused climate change, The Washington Post reports — and it could cause a wave of freezing temperatures in Europe and North America.
The “Atlantic Meridional Overturning Circulation” (AMOC) system is a vital part of the way the world’s oceans function, transporting warm and much denser saltwater from the tropics to northern Europe, where it cools down and makes its long journey back along the ocean floor.
But according to a new study from the Potsdam Institute for Climate Impact Research in Germany and published in the journal Nature Climate Change today, this system is becoming increasingly more susceptible to disruptions. The research is a warning sign that the drastic effects of climate change may soon have some new — and very serious — consequences.
[...] The last time the AMOC was shut down was at the tail end of the last ice age roughly 12,000 years ago, triggered by the melting of a massive glacial lake. The extreme cold spell that hit Europe lasted for almost a millennium.
We’ve known that the AMOC has weakened as human activity and greenhouse gases are raising sea temperatures, and “the critical threshold is most likely much closer than we would have expected,” as Boers told the Post. The AMOC slowdown is already causing the Gulf Stream to lag behind, causing sea levels to rise along the US East Coast and fish populations to die off.
We don’t know when greenhouse gases might build up enough to cause the AMOC to shut off. One 2016 study suggests that the AMOC could collapse by the year 2300 without any meaningful attempts to cut down on greenhouse emissions before then. Reversing the trend would be impossible, according to Boers... (MORE -details)
Permafrost thaw in Siberia creates a ticking ‘methane bomb’ of treenhouse gases, scientists warn
https://www.smithsonianmag.com/smart-new...180978381/
EXCERPTS: In recent years, climate scientists have warned thawing permafrost in Siberia may be a “methane time bomb” detonating slowly. Now, a peer-reviewed study using satellite imagery and a review by an international organization are warning that warming temperatures in the far northern reaches of Russia are releasing massive measures of methane—a potent greenhouse gas with considerably more warming power than carbon dioxide.
[...] In 2020, temperatures in the basin rose nearly 11 degrees Fahrenheit above normal, causing the limestone to release ancient methane deposits that had been trapped inside. The data caught Fritzheim and other researchers by surprise, who anticipated finding gas in other locations. “We would have expected elevated methane in areas with wetlands,” he tells the Washington Post. “But these were not over wetlands but on limestone outcrops. There is very little soil in these. It was really a surprising signal from hard rock, not wetlands.” (MORE - details)
Survey suggests climate change has reduced the presence of invasive Argentine ants
https://phys.org/news/2021-08-survey-cli...ntine.html
INTRO: In 1993, Stanford University biology professor Deborah Gordon and her first graduate student, Katy Human, began a survey of ants at Stanford's Jasper Ridge Biological Preserve. Nearly 30 years, four more graduate students and scores of volunteers later, that survey continues on—and has recently yielded a surprising result.
"From 1993 until the time I was doing my dissertation work, about 2000, it seemed as if Argentine ants were marching across the preserve, taking out native ants along the way," said Nate Sanders, one of Gordon's former graduate students who led the survey in the late '90s and is now a professor of ecology and evolutionary biology at the University of Michigan. "Now, with an additional 20 years of data, we see the story is more complex."
That additional data, detailed in a paper published Aug. 3 in Ecology, has revealed that the distribution of Argentine ants in Jasper Ridge has actually receded, and further analysis suggested that climate change was a significant factor in this change. The researchers also found that over the span of the survey, overall native ant diversity increased and some native ant species have expanded their distributions.
However, the researchers caution against making this an optimistic story about the effects of climate change, which still overwhelmingly poses severe threats to native species... (MORE - details)
https://futurism.com/collapse-ocean-curr...ica-europe
EXCERPTS: Scientists are warning that a key system that drives oceanic currents is being driven to the brink of collapse in large part due to human-caused climate change, The Washington Post reports — and it could cause a wave of freezing temperatures in Europe and North America.
The “Atlantic Meridional Overturning Circulation” (AMOC) system is a vital part of the way the world’s oceans function, transporting warm and much denser saltwater from the tropics to northern Europe, where it cools down and makes its long journey back along the ocean floor.
But according to a new study from the Potsdam Institute for Climate Impact Research in Germany and published in the journal Nature Climate Change today, this system is becoming increasingly more susceptible to disruptions. The research is a warning sign that the drastic effects of climate change may soon have some new — and very serious — consequences.
[...] The last time the AMOC was shut down was at the tail end of the last ice age roughly 12,000 years ago, triggered by the melting of a massive glacial lake. The extreme cold spell that hit Europe lasted for almost a millennium.
We’ve known that the AMOC has weakened as human activity and greenhouse gases are raising sea temperatures, and “the critical threshold is most likely much closer than we would have expected,” as Boers told the Post. The AMOC slowdown is already causing the Gulf Stream to lag behind, causing sea levels to rise along the US East Coast and fish populations to die off.
We don’t know when greenhouse gases might build up enough to cause the AMOC to shut off. One 2016 study suggests that the AMOC could collapse by the year 2300 without any meaningful attempts to cut down on greenhouse emissions before then. Reversing the trend would be impossible, according to Boers... (MORE -details)
Permafrost thaw in Siberia creates a ticking ‘methane bomb’ of treenhouse gases, scientists warn
https://www.smithsonianmag.com/smart-new...180978381/
EXCERPTS: In recent years, climate scientists have warned thawing permafrost in Siberia may be a “methane time bomb” detonating slowly. Now, a peer-reviewed study using satellite imagery and a review by an international organization are warning that warming temperatures in the far northern reaches of Russia are releasing massive measures of methane—a potent greenhouse gas with considerably more warming power than carbon dioxide.
[...] In 2020, temperatures in the basin rose nearly 11 degrees Fahrenheit above normal, causing the limestone to release ancient methane deposits that had been trapped inside. The data caught Fritzheim and other researchers by surprise, who anticipated finding gas in other locations. “We would have expected elevated methane in areas with wetlands,” he tells the Washington Post. “But these were not over wetlands but on limestone outcrops. There is very little soil in these. It was really a surprising signal from hard rock, not wetlands.” (MORE - details)
Survey suggests climate change has reduced the presence of invasive Argentine ants
https://phys.org/news/2021-08-survey-cli...ntine.html
INTRO: In 1993, Stanford University biology professor Deborah Gordon and her first graduate student, Katy Human, began a survey of ants at Stanford's Jasper Ridge Biological Preserve. Nearly 30 years, four more graduate students and scores of volunteers later, that survey continues on—and has recently yielded a surprising result.
"From 1993 until the time I was doing my dissertation work, about 2000, it seemed as if Argentine ants were marching across the preserve, taking out native ants along the way," said Nate Sanders, one of Gordon's former graduate students who led the survey in the late '90s and is now a professor of ecology and evolutionary biology at the University of Michigan. "Now, with an additional 20 years of data, we see the story is more complex."
That additional data, detailed in a paper published Aug. 3 in Ecology, has revealed that the distribution of Argentine ants in Jasper Ridge has actually receded, and further analysis suggested that climate change was a significant factor in this change. The researchers also found that over the span of the survey, overall native ant diversity increased and some native ant species have expanded their distributions.
However, the researchers caution against making this an optimistic story about the effects of climate change, which still overwhelmingly poses severe threats to native species... (MORE - details)
