Latest news with #NerilieAbram
Irish Independent
2 hours ago
- Science
- Irish Independent
Rapid loss of Antarctic sea ice may be climate tipping point, new study reveals
The paper in the journal Nature aimed to describe in previously unseen detail the interlocking effects of global warming on the Antarctic, the frozen continent at the planet's South Pole. 'Evidence is emerging for rapid, interacting and sometimes self-perpetuating changes in the Antarctic environment,' it said. The study gathered data from observations, ice cores and ship logbooks to chart long-term changes in the area of sea ice, putting into context a rapid decline in recent years. 'A regime shift has reduced Antarctic sea-ice extent far below its natural variability of past centuries, and in some respects is more abrupt, non-linear and potentially irreversible than Arctic sea-ice loss,' it said, referring to melting at the North Pole. Changes are having knock-on effects across the ecosystem that in some cases amplify one another, Nerilie Abram, the study's lead author, said. A smaller ice sheet reflects less solar radiation, meaning the planet absorbs more warmth. And it will probably accelerate a weakening of the Antarctic Overturning Circulation, an ocean-spanning current that distributes heat and nutrients and regulates weather. Loss of ice is increasingly harming wildlife including emperor penguins, who breed on the ice, and krill, which feed below it. And warming surface water will further reduce phytoplankton populations that draw down vast quantities of carbon from the atmosphere, the study said. 'Antarctic sea ice may actually be one of those tipping points in the Earth's system,' said Ms Abram, a former professor at the Australian National University (ANU) and now chief scientist at the Australian Antarctic Division. Reining in global carbon dioxide emissions would reduce the risk of major changes in the Antarctic but still may not prevent them, the study said. 'Once we start losing Antarctic sea ice, we set in train this self-perpetuating process,' Ms Abram said.
AsiaOne
3 hours ago
- Science
- AsiaOne
Rapid loss of Antarctic ice may be climate tipping point, scientists say, World News
CANBERRA — Rapid loss of Antarctic sea ice could be a tipping point for the global climate, causing sea level rises, changes to ocean currents and loss of marine life that are impossible to reverse, a scientific study published on Thursday (Aug 21) said. The paper in the journal Nature aimed to describe in previously unseen detail the interlocking effects of global warming on the Antarctic, the frozen continent at the planet's South Pole. "Evidence is emerging for rapid, interacting and sometimes self-perpetuating changes in the Antarctic environment," it said. The study gathered data from observations, ice cores, and ship logbooks to chart long-term changes in the area of sea ice, putting into context a rapid decline in recent years. "A regime shift has reduced Antarctic sea-ice extent far below its natural variability of past centuries, and in some respects is more abrupt, non-linear and potentially irreversible than Arctic sea-ice loss," it said, referring to melting at the North Pole. Changes are having knock-on effects across the ecosystem that in some cases amplify one another, said Nerilie Abram, the study's lead author. A smaller ice sheet reflects less solar radiation, meaning the planet absorbs more warmth, and will probably accelerate a weakening of the Antarctic Overturning Circulation, an ocean-spanning current that distributes heat and nutrients and regulates weather. Loss of ice is increasingly harming wildlife including emperor penguins, who breed on the ice, and krill, which feed below it. And warming surface water will further reduce phytoplankton populations that draw down vast quantities of carbon from the atmosphere, the study said. "Antarctic sea ice may actually be one of those tipping points in the Earth's system," said Abram, a former professor at the Australian National University (ANU) and now chief scientist at the Australian Antarctic Division. Reining in global carbon dioxide emissions would reduce the risk of major changes in the Antarctic but still may not prevent them, the study said. "Once we start losing Antarctic sea ice, we set in train this self-perpetuating process," Abram said. "Even if we stabilise the climate, we are committed to still losing Antarctic sea ice over many centuries to come." [[nid:721368]]
News.com.au
5 hours ago
- Science
- News.com.au
Antarctic climate shifts threaten 'catastrophic' impacts globally
Abrupt and potentially irreversible changes in Antarctica driven by climate change could lift global oceans by metres and lead to "catastrophic consequences for generations", scientists warned Wednesday. More broadly, a state-of-knowledge review by a score of top experts revealed accelerating shifts across the region that are often both cause and effect of global warming, according to a study published in Nature. "Antarctica is showing worrying signs of rapid change across its ice, ocean and ecosystems," lead author and Australian National University professor Nerilie Abram told AFP. "Some of these abrupt changes will be difficult to stop." Shifts in different facets of Antarctica's climate system amplify each other and have accelerated the pace of warming globally as well, she said. The study looked at evidence of abrupt change -- or "regime shifts" -- in sea ice, regional ocean currents, the continent's ice sheet and ice shelves, and marine life. It also examined how they interact. Floating sea ice does not add to sea level when it melts. But its retreat does replace white surfaces that reflect almost all of the Sun's energy back into space with deep blue water, which absorbs the same amount instead. Ninety percent of the heat generated by manmade global warming is soaked up by oceans. - Retreating sea ice - After increasing slightly during the first 35 years that satellite data was available, Antarctic sea ice cover plunged dramatically over the last decade. Since 2014, sea ice has retreated on average 120 kilometres (75 miles) from the continent's shoreline. That contraction has happened about three times faster in 10 years than the decline in Arctic sea ice over nearly 50. The "overwhelming evidence of a regime shift in sea ice" means that, on current trends, Antarctica could essentially become ice free in summer sooner than the Arctic, the study found. This will speed up warming in the region and beyond, and could push some marine species toward extinction. Over the last two years, for example, helpless emperor penguin chicks perished at multiple breeding grounds, drowning or freezing to death when sea ice gave way earlier than usual under their tiny feet. Of five sites monitored in the Bellingshausen Sea region in 2023, all but one experienced a 100 percent loss of chicks, earlier research reported. Unlike sea ice, ice sheets and the ice shelves to which they are connected are on -- or supported by -- land. The world would need to heat up by five degrees Celsius compared with pre-industrial levels to melt the entire Antarctic ice sheet, which would lift global oceans an almost unimaginable 58 metres (nearly 200 feet). - Point of no return - But global warming to date -- on average about 1.3C -- is fast approaching a threshold that would cause part of the ice sheet to generate at least three metres of sea level rise, flooding coastal areas inhabited today by hundreds of millions, the study said. "Unstoppable collapse of the West Antarctic Ice Sheet is one of the most concerning global tipping points," said Abram. "The evidence points to this being triggered at global warming well below 2C." Another potential risk is the collapse of the Antarctic Overturning Circulation, a system of ocean currents that distribute heat and nutrients within the the region and globally. A "rapid and substantial slowdown" of the currents has already begun, and evidence from the previous interglacial period -- between two ice ages -- before our own, 125,000 years ago, points to an abrupt stagnation of the system under conditions similar to those seen today. "This would lead to widespread climate and ecosystem impacts," ranging from an intensification of global warming to a decrease in the ocean's capacity to absorb CO2, the study reported. Ultimately, the only way to slow down the interlocking changes is to stop adding more planet-warming gases into the atmosphere. "The greenhouse gas emission decisions that we make over the coming decade or two will lock in how much ice we will lose and how quickly it will be lost," Abram said. mh/jxb
Korea Herald
5 hours ago
- Science
- Korea Herald
Antarctic climate shifts threaten 'catastrophic' impacts globally
PARIS (AFP) -- Abrupt and potentially irreversible changes in Antarctica driven by climate change could lift global oceans by meters and lead to "catastrophic consequences for generations,' scientists warned Wednesday. More broadly, a state-of-knowledge review by a score of top experts revealed accelerating shifts across the region that are often both cause and effect of global warming, according to a study published in Nature. "Antarctica is showing worrying signs of rapid change across its ice, ocean and ecosystems," lead author and Australian National University professor Nerilie Abram told Agence France-Presse. "Some of these abrupt changes will be difficult to stop." Shifts in different facets of Antarctica's climate system amplify each other and have accelerated the pace of warming globally as well, she said. The study looked at evidence of abrupt change -- or "regime shifts" -- in sea ice, regional ocean currents, the continent's ice sheet and ice shelves, and marine life. It also examined how they interact. Floating sea ice does not add to sea level when it melts. But its retreat does replace white surfaces that reflect almost all of the Sun's energy back into space with deep blue water, which absorbs the same amount instead. Ninety percent of the heat generated by manmade global warming is soaked up by oceans. After increasing slightly during the first 35 years that satellite data was available, Antarctic sea ice cover plunged dramatically over the last decade. Since 2014, sea ice has retreated on average 120 kilometers from the continent's shoreline. That contraction has happened about three times faster in 10 years than the decline in Arctic sea ice over nearly 50. The "overwhelming evidence of a regime shift in sea ice" means that, on current trends, Antarctica could essentially become ice free in summer sooner than the Arctic, the study found. This will speed up warming in the region and beyond, and could push some marine species toward extinction. Over the last two years, for example, helpless emperor penguin chicks perished at multiple breeding grounds, drowning or freezing to death when sea ice gave way earlier than usual under their tiny feet. Of five sites monitored in the Bellingshausen Sea region in 2023, all but one experienced a 100 percent loss of chicks, earlier research reported. Unlike sea ice, ice sheets and the ice shelves to which they are connected are on -- or supported by -- land. The world would need to heat up by five degrees Celsius compared with pre-industrial levels to melt the entire Antarctic ice sheet, which would lift global oceans an almost unimaginable 58 meters. But global warming to date -- on average about 1.3 C -- is fast approaching a threshold that would cause part of the ice sheet to generate at least 3 meters of sea level rise, flooding coastal areas inhabited today by hundreds of millions, the study said. "Unstoppable collapse of the West Antarctic Ice Sheet is one of the most concerning global tipping points," said Abram. "The evidence points to this being triggered at global warming well below 2 C." Another potential risk is the collapse of the Antarctic Overturning Circulation, a system of ocean currents that distribute heat and nutrients within the region and globally. A "rapid and substantial slowdown" of the currents has already begun, and evidence from the previous interglacial period -- between two ice ages -- before our own, 125,000 years ago, points to an abrupt stagnation of the system under conditions similar to those seen today. "This would lead to widespread climate and ecosystem impacts," ranging from an intensification of global warming to a decrease in the ocean's capacity to absorb CO2, the study reported. Ultimately, the only way to slow down the interlocking changes is to stop adding more planet-warming gases into the atmosphere. "The greenhouse gas emission decisions that we make over the coming decade or two will lock in how much ice we will lose and how quickly it will be lost," Abram said.
DW
6 hours ago
- Science
- DW
Antarctic ice loss could have 'catastrophic' impact – DW – 08/21/2025
A study warned that Antarctic ice loss could cause more warming in the region and beyond, and could push some marine species toward extinction. Scientists on Wednesday warned that abrupt and potentially irreversible changes are occurring in Antarctica. They said the changes, which are driven by climate change, could lead to "catastrophic consequences for generations." The research was published in the journal Nature. It sought to describe the interlocking effects of global warming on the Antarctic, the frozen continent at the planet's South Pole. The "overwhelming evidence of a regime shift in sea ice" means that, on current trends, Antarctica could essentially become ice free in summer sooner than the Arctic, the study found. This will speed up warming in the region and beyond, and could push some marine species toward extinction. "Antarctic sea ice may actually be one of those tipping points in the Earth's system," said the study's lead author Nerilie Abram, a former professor at the Australian National University (ANU) and now chief scientist at the Australian Antarctic Division. The study warns that curbing global carbon dioxide emissions would reduce the risk of major changes in the Antarctic but still may not prevent them. "Once we start losing Antarctic sea ice, we set in train this self-perpetuating process," Abram said. "Even if we stabilize the climate, we are committed to still losing Antarctic sea ice over many centuries to come." Researchers gathered data from observations, ice cores, and ship logbooks to chart long-term changes in the area of sea ice. A "rapid and substantial slowdown" of the currents has already begun. "This would lead to widespread climate and ecosystem impacts," ranging from an intensification of global warming to a decrease in the ocean's capacity to absorb CO2, the study reported. Some 90% of the heat generated by manmade global warming is soaked up by oceans. Since 2014, sea ice has retreated on average 120 kilometers (75 miles) from the continent's shoreline. Loss of ice is harming wildlife, including emperor penguins, who breed on the ice, and krill, which feed below it. And warming waters will further reduce phytoplankton populations that draw down vast quantities of carbon from the atmosphere, the study reported.
