The Gulf Stream system could collapse as soon as 2025, a new study suggests. The shutting down of the vital ocean currents, called the Atlantic Meridional Overturning Circulation (Amoc) by scientists, would bring catastrophic climate impacts.
Amoc was already known to be at its weakest in 1,600 years owing to global heating and researchers spotted warning signs of a tipping point in 2021.
The new analysis estimates a timescale for the collapse of between 2025 and 2095, with a central estimate of 2050, if global carbon emissions are not reduced. Evidence from past collapses indicate changes of temperature of 10C in a few decades, although these occurred during ice ages.
Other scientists said the assumptions about how a tipping point would play out and uncertainties in the underlying data are too large for a reliable estimate of the timing of the tipping point. But all said the prospect of an Amoc collapse was extremely concerning and should spur rapid cuts in carbon emissions.
Amoc carries warm ocean water northwards towards the pole where it cools and sinks, driving the Atlantic’s currents. But an influx of fresh water from the accelerating melting of Greenland’s ice cap and other sources is increasingly smothering the currents.
A collapse of Amoc would have disastrous consequences around the world, severely disrupting the rains that billions of people depend on for food in India, South America and west Africa. It would increase storms and drop temperatures in Europe, and lead to a rising sea level on the eastern coast of North America. It would also further endanger the Amazon rainforest and Antarctic ice sheets.
“I think we should be very worried,” said Prof Peter Ditlevsen, at the University of Copenhagen in Denmark, and who led the new study. “This would be a very, very large change. The Amoc has not been shut off for 12,000 years.”
The Amoc collapsed and restarted repeatedly in the cycle of ice ages that occurred from 115,000 to 12,000 years ago. It is one of the climate tipping points scientists are most concerned about as global temperatures continue to rise.
Research in 2022 showed five dangerous tipping points may already have been passed due to the 1.1C of global heating to date, including the shutdown of Amoc, the collapse of Greenland’s ice cap and an abrupt melting of carbon-rich permafrost.
The new study, published in the journal Nature Communications, used sea surface temperature data stretching back to 1870 as a proxy for the change in strength of Amoc currents over time.
The researchers then mapped this data on to the path seen in systems that are approaching a particular type of tipping point called a “saddle-node bifurcation”. The data fitted “surprisingly well”, Ditlevsen said. The researchers were then able to extrapolate the data to estimate when the tipping point was likely to occur. Further statistical analysis provided a measure of the uncertainty in the estimate.
The analysis is based on greenhouse gas emissions rising as they have done to date. If emissions do start to fall, as intended by current climate policies, then the world would have more time to try to keep global temperature below the Amoc tipping point.
The most recent assessment by the Intergovernmental Panel on Climate Change concluded that Amoc would not collapse this century. But Divlitsen said the models used have coarse resolution and are not adept at analysing the non-linear processes involved, which may make them overly conservative.
The potential collapse of Amoc is intensely debated by scientists, who have previously said it must be avoided “at all costs”.
Privacy Notice: Newsletters may contain info about charities, online ads, and content funded by outside parties. For more information see our Privacy Policy. We use Google reCaptcha to protect our website and the Google Privacy Policy and Terms of Service apply.
after newsletter promotion
Prof Niklas Boers, from the Potsdam Institute for Climate Impact Research in Germany, revealed the early warning signs of Amoc collapse in 2021. “The results of the new study sound alarming but if the uncertainties in the heavily oversimplified model [of the tipping point] and in the underlying [sea temperature] data are included, then it becomes clear that these uncertainties are too large to make any reliable estimate of the time of tipping.”
Prof David Thornalley, at University College London, UK, agreed the study had large caveats and unknowns and said further research was essential: “But if the statistics are robust and a relevant way to describe how the actual Amoc behaves, then this is a very concerning result.”
Dr Levke Caesar, at the University of Bremen, Germany, said using sea surface temperatures as proxy data for the strength of the Amoc currents was a key source of uncertainty: “We only have direct observational data of the Amoc since 2004.”
The extrapolation in the new analysis was reasonable, according to Prof Tim Lenton, at the University of Exeter, UK. He said the tipping point could lead to a partial Amoc collapse, for example only in the Labrador Sea, but that this would still cause major impacts. Divlitsen said he hoped the debate would drive new research: “It’s always fruitful when you do not exactly agree.”
Prof Stefan Rahmstorf, at the University of Potsdam, Germany, said: “There is still large uncertainty where the Amoc tipping point is, but the new study adds to the evidence that it is much closer than we thought. A single study provides limited evidence, but when multiple approaches have led to similar conclusions this must be taken very seriously, especially when we’re talking about a risk that we really want to rule out with 99.9% certainty. Now we can’t even rule out crossing the tipping point in the next decade or two.”
Gulf stream goooooonnnnnnneeeee
- Uncle fester
- Posts: 4192
- Joined: Mon Jun 29, 2020 9:42 pm
https://www.theguardian.com/environment ... y-suggests
-
- Posts: 8663
- Joined: Tue Jun 30, 2020 11:48 am
Meawhile, a troubling number of people across the world, including those in power, still have zero urgency in doing anything substantial about our emissions.
- Torquemada 1420
- Posts: 11155
- Joined: Thu Jul 02, 2020 8:22 am
- Location: Hut 8
- Torquemada 1420
- Posts: 11155
- Joined: Thu Jul 02, 2020 8:22 am
- Location: Hut 8
I remember explaining this on PR way back around the very early 2000s to our coroner poster.Uncle fester wrote: ↑Tue Jul 25, 2023 7:03 pm https://www.theguardian.com/environment ... y-suggests
The Gulf Stream system could collapse as soon as 2025, a new study suggests. The shutting down of the vital ocean currents, called the Atlantic Meridional Overturning Circulation (Amoc) by scientists, would bring catastrophic climate impacts.
Amoc was already known to be at its weakest in 1,600 years owing to global heating and researchers spotted warning signs of a tipping point in 2021.
The new analysis estimates a timescale for the collapse of between 2025 and 2095, with a central estimate of 2050, if global carbon emissions are not reduced. Evidence from past collapses indicate changes of temperature of 10C in a few decades, although these occurred during ice ages.
Other scientists said the assumptions about how a tipping point would play out and uncertainties in the underlying data are too large for a reliable estimate of the timing of the tipping point. But all said the prospect of an Amoc collapse was extremely concerning and should spur rapid cuts in carbon emissions.
Amoc carries warm ocean water northwards towards the pole where it cools and sinks, driving the Atlantic’s currents. But an influx of fresh water from the accelerating melting of Greenland’s ice cap and other sources is increasingly smothering the currents.
A collapse of Amoc would have disastrous consequences around the world, severely disrupting the rains that billions of people depend on for food in India, South America and west Africa. It would increase storms and drop temperatures in Europe, and lead to a rising sea level on the eastern coast of North America. It would also further endanger the Amazon rainforest and Antarctic ice sheets.
“I think we should be very worried,” said Prof Peter Ditlevsen, at the University of Copenhagen in Denmark, and who led the new study. “This would be a very, very large change. The Amoc has not been shut off for 12,000 years.”
The Amoc collapsed and restarted repeatedly in the cycle of ice ages that occurred from 115,000 to 12,000 years ago. It is one of the climate tipping points scientists are most concerned about as global temperatures continue to rise.
Research in 2022 showed five dangerous tipping points may already have been passed due to the 1.1C of global heating to date, including the shutdown of Amoc, the collapse of Greenland’s ice cap and an abrupt melting of carbon-rich permafrost.
The new study, published in the journal Nature Communications, used sea surface temperature data stretching back to 1870 as a proxy for the change in strength of Amoc currents over time.
The researchers then mapped this data on to the path seen in systems that are approaching a particular type of tipping point called a “saddle-node bifurcation”. The data fitted “surprisingly well”, Ditlevsen said. The researchers were then able to extrapolate the data to estimate when the tipping point was likely to occur. Further statistical analysis provided a measure of the uncertainty in the estimate.
The analysis is based on greenhouse gas emissions rising as they have done to date. If emissions do start to fall, as intended by current climate policies, then the world would have more time to try to keep global temperature below the Amoc tipping point.
The most recent assessment by the Intergovernmental Panel on Climate Change concluded that Amoc would not collapse this century. But Divlitsen said the models used have coarse resolution and are not adept at analysing the non-linear processes involved, which may make them overly conservative.
The potential collapse of Amoc is intensely debated by scientists, who have previously said it must be avoided “at all costs”.
Privacy Notice: Newsletters may contain info about charities, online ads, and content funded by outside parties. For more information see our Privacy Policy. We use Google reCaptcha to protect our website and the Google Privacy Policy and Terms of Service apply.
after newsletter promotion
Prof Niklas Boers, from the Potsdam Institute for Climate Impact Research in Germany, revealed the early warning signs of Amoc collapse in 2021. “The results of the new study sound alarming but if the uncertainties in the heavily oversimplified model [of the tipping point] and in the underlying [sea temperature] data are included, then it becomes clear that these uncertainties are too large to make any reliable estimate of the time of tipping.”
Prof David Thornalley, at University College London, UK, agreed the study had large caveats and unknowns and said further research was essential: “But if the statistics are robust and a relevant way to describe how the actual Amoc behaves, then this is a very concerning result.”
Dr Levke Caesar, at the University of Bremen, Germany, said using sea surface temperatures as proxy data for the strength of the Amoc currents was a key source of uncertainty: “We only have direct observational data of the Amoc since 2004.”
The extrapolation in the new analysis was reasonable, according to Prof Tim Lenton, at the University of Exeter, UK. He said the tipping point could lead to a partial Amoc collapse, for example only in the Labrador Sea, but that this would still cause major impacts. Divlitsen said he hoped the debate would drive new research: “It’s always fruitful when you do not exactly agree.”
Prof Stefan Rahmstorf, at the University of Potsdam, Germany, said: “There is still large uncertainty where the Amoc tipping point is, but the new study adds to the evidence that it is much closer than we thought. A single study provides limited evidence, but when multiple approaches have led to similar conclusions this must be taken very seriously, especially when we’re talking about a risk that we really want to rule out with 99.9% certainty. Now we can’t even rule out crossing the tipping point in the next decade or two.”
- Guy Smiley
- Posts: 6014
- Joined: Mon Jun 29, 2020 7:52 pm
Temperature records being broken daily across multiple states including the USA, severe weather events across the world increasingly linked to ocean surface temperatures and we're entering an El Nino cycle....
I reckon it's going to be hard for them to ignore it within a few months. We have crossed a few scary tipping point indicators...including the Antarctic ice sheet thickness. If that lets go say goodbye to ocean front property everywhere.
- Guy Smiley
- Posts: 6014
- Joined: Mon Jun 29, 2020 7:52 pm
We won’t need boats to walk to Calais.Guy Smiley wrote: ↑Tue Jul 25, 2023 8:38 pmEurope starts turning back boat people trying to escape the UK.
- Torquemada 1420
- Posts: 11155
- Joined: Thu Jul 02, 2020 8:22 am
- Location: Hut 8
Yes. Look at where the UK is in terms of latitude. The conveyor keeps the UK warm but if the caps melt, it will be headed off/cut off before it reaches the coast here.
- Torquemada 1420
- Posts: 11155
- Joined: Thu Jul 02, 2020 8:22 am
- Location: Hut 8
I wish I had your optimism in the ability of the masses to change the vast corporate and wealthy's interests in watching us all burn.Guy Smiley wrote: ↑Tue Jul 25, 2023 8:33 pmTemperature records being broken daily across multiple states including the USA, severe weather events across the world increasingly linked to ocean surface temperatures and we're entering an El Nino cycle....
I reckon it's going to be hard for them to ignore it within a few months. We have crossed a few scary tipping point indicators...including the Antarctic ice sheet thickness. If that lets go say goodbye to ocean front property everywhere.
- Guy Smiley
- Posts: 6014
- Joined: Mon Jun 29, 2020 7:52 pm
I'm not optimistic mate... I think we're entering a stage where it will be hard to ignore the effects. I don't expect to see any major shift from our corporate overlords.Torquemada 1420 wrote: ↑Tue Jul 25, 2023 8:44 pmI wish I had your optimism in the ability of the masses to change the vast corporate and wealthy's interests in watching us all burn.Guy Smiley wrote: ↑Tue Jul 25, 2023 8:33 pmTemperature records being broken daily across multiple states including the USA, severe weather events across the world increasingly linked to ocean surface temperatures and we're entering an El Nino cycle....
I reckon it's going to be hard for them to ignore it within a few months. We have crossed a few scary tipping point indicators...including the Antarctic ice sheet thickness. If that lets go say goodbye to ocean front property everywhere.
Looks like Scotland temps would drop the most, not so much for the South East. However, the main issue would be the reduction in rain.
https://arstechnica.com/science/2020/01 ... -down/amp/Things are quite a bit different if the AMOC shuts down. Rather than rising, temperatures would actually drop by an average of 3.4°C. That drop would occur on a gradient, with northern Scotland cooling the most and southern England seeing the least impact and therefore seeing conditions similar to what it currently experiences. But, more dramatically, rainfall during the growing season is expected to drop by 123mm. That drop is enough to reduce the UK's percentage of arable land from 32 percent to just seven percent. Obviously, this would cause a big hit to the UK's agricultural productivity. Irrigation could again offset this, but the scale of the changes needed would be far larger; the authors estimate adding this irrigation at ten times the value of the crops that would be produced. But they note that it's not clear if the UK would have enough water to spare to fully reverse the loss of rain.
Kind of. We'll be more influenced by continental weather patterns so colder in winter and warmer in summer. Less rain, so exacerbating the already critical water situation in the south of England.Torquemada 1420 wrote: ↑Tue Jul 25, 2023 8:42 pmYes. Look at where the UK is in terms of latitude. The conveyor keeps the UK warm but if the caps melt, it will be headed off/cut off before it reaches the coast here.
And are there two g’s in Bugger Off?
- boere wors
- Posts: 1450
- Joined: Thu Jul 02, 2020 8:03 am
So is there any negative effect?!Biffer wrote: ↑Tue Jul 25, 2023 10:10 pmKind of. We'll be more influenced by continental weather patterns so colder in winter and warmer in summer. Less rain, so exacerbating the already critical water situation in the south of England.Torquemada 1420 wrote: ↑Tue Jul 25, 2023 8:42 pmYes. Look at where the UK is in terms of latitude. The conveyor keeps the UK warm but if the caps melt, it will be headed off/cut off before it reaches the coast here.
Parts of England will be in permanent drought. London and the south east gets around the same annual rainfall as the Lebanon at the moment, less than Sydney. In an area with 18 million people.boere wors wrote: ↑Wed Jul 26, 2023 7:00 amSo is there any negative effect?!Biffer wrote: ↑Tue Jul 25, 2023 10:10 pmKind of. We'll be more influenced by continental weather patterns so colder in winter and warmer in summer. Less rain, so exacerbating the already critical water situation in the south of England.Torquemada 1420 wrote: ↑Tue Jul 25, 2023 8:42 pm
Yes. Look at where the UK is in terms of latitude. The conveyor keeps the UK warm but if the caps melt, it will be headed off/cut off before it reaches the coast here.
Current infrastructure isn’t designed for those extremes.
And are there two g’s in Bugger Off?
Biffer wrote: ↑Wed Jul 26, 2023 7:41 amParts of England will be in permanent drought. London and the south east gets around the same annual rainfall as the Lebanon at the moment, less than Sydney. In an area with 18 million people.
Current infrastructure isn’t designed for those extremes.
Do you happen to know what percentage of rainwater is currently collected across the UK? I seem to remember that it was an incredibly low number but I forget and a quick Google doesn't tell me much. Then there is waste due to leaks in a Victorian water infrastructure.
Desalination isn't really a credible answer at any scale because of the hyper-salinated water pumped back into the sea
-
- Posts: 1148
- Joined: Sat Jul 04, 2020 9:31 am
The 9nly way to stop climate change is...
Last edited by Line6 HXFX on Wed Jul 26, 2023 8:32 am, edited 1 time in total.
It’s not high. The infrastructure is rubbish.Tichtheid wrote: ↑Wed Jul 26, 2023 8:09 am
Do you happen to know what percentage of rainwater is currently collected across the UK? I seem to remember that it was an incredibly low number but I forget and a quick Google doesn't tell me much. Then there is waste due to leaks in a Victorian water infrastructure.
Desalination isn't really a credible answer at any scale because of the hyper-salinated water pumped back into the sea
Other effects are the decrease of viable arable land and farming production, more storms, more climate refugees due to intensification of heat further south
And are there two g’s in Bugger Off?
Build dams people. In Wales. Generate power at the same time as catching rainfall & creating jobs. Simple. Except in UK apparently.Tichtheid wrote: ↑Wed Jul 26, 2023 8:09 am
Do you happen to know what percentage of rainwater is currently collected across the UK? I seem to remember that it was an incredibly low number but I forget and a quick Google doesn't tell me much. Then there is waste due to leaks in a Victorian water infrastructure.
Desalination isn't really a credible answer at any scale because of the hyper-salinated water pumped back into the sea
- Guy Smiley
- Posts: 6014
- Joined: Mon Jun 29, 2020 7:52 pm
Wales has 5 times the rainfall as Kent - the area where the drought is expected to be most severe. None is currently collected, it just runs into the sea.
Fair point. I lose on average 4 or 5 balls per round these days. And I was out of bed late on Sunday morning and missed the chance to get a lift to the course with a mate so took my own car.
Shameful stuff.
Ian Madigan for Ireland.
Impact on food production and supply chains will be first to go and we will probably all starve to death first. Perhaps Coffey the Slug knew all this and is already stockpiling turnips for the next armageddon? Crop/grain production already down due to Ukraine and now heatwave is resulting in a further 10% reduction in crop production around Mediterranean. Expect shortages and increased prices in lots of foodstuffs that will push inflation even higher. Brexit checks and tariffs on EU imports into UK will mean even more disruption and given demand will hugely exceed demand across northern Europe then I can see producers/suppliers just giving up trying to get produce to the UK unless they get huge price increases.
The UK has absolutely an abundance of fresh water. The problem is building reservoirs may upset people so we dont
It's a weird thing. A reservoir is probably the most attractive & least disruptive public works structure that you can possibly put into any landscape, but still there's massive resistance.tc27 wrote: ↑Wed Jul 26, 2023 9:30 amThe UK has absolutely an abundance of fresh water. The problem is building reservoirs may upset people so we dont
Are we going to have to build stuff and then all move to Wales?? Oh fuck.Sandstorm wrote: ↑Wed Jul 26, 2023 8:48 amWales has 5 times the rainfall as Kent - the area where the drought is expected to be most severe. None is currently collected, it just runs into the sea.
We need to send those Just Stop Oil bunch to China and fast.
British Nimbyism is truly world-beating.Sandstorm wrote: ↑Wed Jul 26, 2023 9:33 amIt's a weird thing. A reservoir is probably the most attractive & least disruptive public works structure that you can possibly put into any landscape, but still there's massive resistance.
robmatic wrote: ↑Wed Jul 26, 2023 10:04 amBritish Nimbyism is truly world-beating.
Add in celtic nationalism for a truly toxic mix.