Climate Change

[Azeem]

On 16/01/2021 at 19:30, Mpache said:

Not going to lie, the weather here in Canada these past 2 years have been very concerning.

Last year we only had 1 day go below -20, and this year we haven't had any -20 days yet. We were supposed to get a harsh winter and we haven't had that yet. Lakes don't freeze up like they used to either. The effects of climate change are evident. 

 

https://amp.theguardian.com/commentisfree/2021/jun/30/canada-temperatures-limits-human-climate-emergency-earth?__twitter_impression=true

 

[CaaC (John)+]

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Ancient human body size linked to climate change

The temperature may have driven fluctuating body sizes across human history.

The average body size of humans over the past million years is strongly linked to temperature, according to an international team of scientists.

Over the course of human evolution, our bodies and brains have generally been increasing in size. But the driving mechanisms behind these changes are not well understood; hypotheses range from environmental factors to social complexity to diets to the development of tool technology.

Now, researchers led by the Universities of Cambridge and Tübingen have found that temperature plays a vital role: larger bodies evolved in colder, harsher climates, while smaller bodies evolved in warmer ones.

In their study, published in Nature Communications, they analysed the body and brain size of more than 300 fossils from the genus Homo – including Homo sapiens and other extinct species such as Neanderthals, Homo habilis and Homo erectus – and compared their measurements with regional climate reconstructions over the past million years. This allowed them to determine what type of climate each species lived in.

“Our study indicates that climate – particularly temperature – has been the main driver of changes in body size for the past million years,” says lead author Andrea Manica from the University of Cambridge.

“We can see from people living today that those in warmer climates tend to be smaller, and those living in colder climates tend to be bigger. We now know that the same climatic influences have been at work for the last million years.”

The researchers suggest that a bulkier build could be an adaptation to survive more extreme temperatures: by reducing surface area compared to weight, less heat is lost through the skin.

These findings are consistent with Bergmann’s rule, proposed by 19th-century anatomist Carl Bergmann. He found that in closely related species of warm-blooded animals, the cooler the climate, the larger the body size – although researchers are cautious when extending this rule back through time.

This new study also examined whether brain size has changed in tandem with the climate, but the links were weak.

“We found that different factors determine brain size and body size – they’re not under the same evolutionary pressures,” explains co-author Manuel Will from the University of Tübingen, Germany. “The environment has a much greater influence on our body size than our brain size.”

Although they found that humans with larger brains did tend to live in areas with less vegetation, like grasslands – where perhaps the complex task of hunting large animals for food may have influenced noggin size – the researchers suggest that other factors like diet, tool development and increasingly complex social lives were more important in the evolution of our brains.

Interestingly, our brain and body sizes are still changing today – but in the opposite direction. In general, humans are shorter and lighter than our ancestors, and our brain size appears to have been shrinking since the end of the last ice age, around 11,500 years ago.

“It’s fun to speculate what will happen to body and brain sizes in the future, but we should be careful not to extrapolate too much based on the last million years because so many factors can change,” notes Manica.

To build on this study, the researchers suggest it would be fruitful to look back further in time to up to four million years ago to see if this temperature-body size trend holds for our earlier ancestors such as Ardipithecus, Australopithecus or Paranthropus. But both the fossil record and paleoclimate record of this earlier era are sparser.

“Improved paleoclimate models and new discoveries with good chronometric ages and taxonomic information will eventually allow for such studies,” the researchers conclude in their paper.

https://cosmosmagazine.com/history/archaeology/ancient-human-body-size-linked-to-climate-change/

 

[CaaC (John)+]

Climate change

Researcers begin discussions on vital report.

https://www.bbc.co.uk/news/science-environment-57944015

 

[nudge+]

 

 

[Bluewolf]

This makes for pretty grim reading... Looks like we have gone beyond the tipping point now

Nations have delayed curbing their fossil-fuel emissions for so long that they can no longer stop global warming from intensifying over the next 30 years, though there is still a short window to prevent the most harrowing future, a major new United Nations scientific report has concluded.

A Hotter Future Is Certain, According to Climate Change Report (msn.com)

[RandoEFC+]

I am really at a loss with it all. I feel absolutely powerless to make significant change myself. I know everyone is individually. I try to recycle, cut down on how much I use my car to get around, and I vote for my local green party candidates in council and general elections.

It needs international leadership which just won't happen. Major Western economies need to enact radical change to make a difference. Considering how much bed wetting there's been over wearing a piece of cloth over your face for the past 18 months I really can't see much electoral success for parties who promise to regulate the companies and people causing all the damage. Even 'progressive' administrations like Biden's are a million miles away from the targets set by experts.

We're driving ourselves off the edge of a cliff with this. It's really worrying and I wish there was a way I could feel like I could make a significant difference. There really needs to be a massive international movement that makes this battle its sole purpose.

[Azeem]

On an individual level our habits are certainly wired for excessive consumption. I have my smart phone for three years now and many people are shocked or surprised I haven't changed it. It is working fine and I like it. I may change it in a year but I don't understand people who do it every year or two. 

Some of our habits are unconsciously excessive and we don't realise it. 

[Happy Blue]

  

Over the last 800,000 years, there have been natural cycles in the Earth's climate. There have been ice ages and warmer interglacial periods. After the last ice age 20,000 years ago, average global temperature rose by about 3°C to 8°C, over a period of about 10,000 years.

 

31,000 scientists say "no convincing evidence".

31,000 scientists reject global warming and say "no convincing evidence" that humans can or will cause global warming

http://ossfoundation.us/projects/environment/global-warming/myths/31000-scientists-say-no-convincing-evidence

 

 

Most the people in the world are just stupid, no common sense whats so ever   the earth goes through natural cycles of warming and cooling due to that big star that we see everyday

 

[Guest]

On 14/08/2021 at 11:23, Happy Blue said:

  

Over the last 800,000 years, there have been natural cycles in the Earth's climate. There have been ice ages and warmer interglacial periods. After the last ice age 20,000 years ago, average global temperature rose by about 3°C to 8°C, over a period of about 10,000 years.

 

31,000 scientists say "no convincing evidence".

31,000 scientists reject global warming and say "no convincing evidence" that humans can or will cause global warming

http://ossfoundation.us/projects/environment/global-warming/myths/31000-scientists-say-no-convincing-evidence

 

 

Most the people in the world are just stupid, no common sense whats so ever   the earth goes through natural cycles of warming and cooling due to that big star that we see everyday

 

When ever anyone says that they can be dismissed as not knowing what they are talking about.  Scientists have never said the climate doesn't change they have always said it doesn't change that fast.  Also they know that greenhouse gasses trap heat. There is tons of evidence for it. It is almost universally agreed by climate experts(around 97%) that climate change is man made. You dont have a phd you dont know what you are talking about. If you got into a debate with an expert you would be embarrassed 

[Honey Honey]

On 14/08/2021 at 11:23, Happy Blue said:

  

Over the last 800,000 years, there have been natural cycles in the Earth's climate. There have been ice ages and warmer interglacial periods. After the last ice age 20,000 years ago, average global temperature rose by about 3°C to 8°C, over a period of about 10,000 years.

 

31,000 scientists say "no convincing evidence".

31,000 scientists reject global warming and say "no convincing evidence" that humans can or will cause global warming

http://ossfoundation.us/projects/environment/global-warming/myths/31000-scientists-say-no-convincing-evidence

 

 

Most the people in the world are just stupid, no common sense whats so ever   the earth goes through natural cycles of warming and cooling due to that big star that we see everyday

 

You do realise the link takes you to a page which tears apart the 31,000 "scientists" and the bogus nature of the petition? Right? 

[Guest]

1 hour ago, The Premier Steve's said:

You do realise the link takes you to a page which tears apart the 31,000 "scientists" and the bogus nature of the petition? Right? 

I didnt even look at it. Climate change deniers are always made to look silly when they debate scientists. Even someone with modest knowledge can defeat a lot of arguments because they have already been debunked 

[Honey Honey]

24 minutes ago, Gunnersauraus said:

I didnt even look at it. Climate change deniers are always made to look silly when they debate scientists. Even someone with modest knowledge can defeat a lot of arguments because they have already been debunked 

If you are smart enough you can manipulate the vast amount of ambiguity and unknown to stay in a debate on something like vaccines and climate change. You're basically making a bed against the favourite so to speak. However the majority aren't smart enough and fall for and promote misinformation.

Is Piers Corbyn a Man City fan? 

[CaaC (John)+]

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CFC ban bought us time to fight climate change, say scientists

A worldwide ban on ozone-depleting chemicals in 1987 has averted a climate catastrophe today, scientists say.

The Montreal Protocol on Substances that Deplete the Ozone Layer, banning chemicals such as chlorofluorocarbons, has now simulated our "world avoided".

Without the treaty, Earth and its flora would have been exposed to far more of the Sun's ultraviolet (UV) radiation.

Former UN Secretary General Kofi Annan has called it "perhaps the single most successful international agreement".

Tortured plants

Continued and increased use of chlorofluorocarbons (CFCs) would have contributed to global air temperatures rising by an additional 2.5°C by the end of this century, the international team of scientists found.

Part of that would have been caused directly by CFCs, which are also potent greenhouse gases.

But the damage they cause the ozone layer would also have released additional planet-heating carbon dioxide - currently locked up in vegetation - into the atmosphere.

"In past experiments, people have exposed plants - basically tortured plants - with high levels of UV," lead researcher Dr Paul Young, of the Lancaster Environment Centre, said.

"They get very stunted - so they don't grow as much and can't absorb as much carbon."

The scientists estimated there would be:

• 580 billion tonnes less carbon stored in forests, other vegetation and soils
• an extra 165-215 parts per million (40-50%) of carbon dioxide in the atmosphere

"What we see in our 'world-avoided experiment' is an additional 2.5C warming above any warming that we would get from greenhouse-gas increases," Dr Young said.

But similar collective action to limit greenhouse-gas emissions was likely to be much more challenging.

"The science was listened to and acted upon - we have not seen that to the same degree with climate change," he told BBC Radio 4's Inside Science programme.

The experiment could appear to suggest hope for an "alternative future" that had avoided the worst consequences of climate change.

"But I would be cautious of using it as a positive example for the climate negotiations," Dr Young said.

"It's not [directly] comparable - but it's nice to have something positive to hold on to and to see that the world can come together."

https://www.bbc.co.uk/news/science-environment-58248725

 

[Azeem]

Appreciate Khan's government for taking climate change seriously with his plantation drives. Getting globally recognised as well. 

There isn't much small countries can do. Take every measure for bracing any kind of impact and hope major contributors change course.

[CaaC (John)+]

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‘Climate windows’ allowed the first human migrations

New modelling reveals when conditions were favourable for ancient humans to leave Africa.

Migration is part of the great evolutionary story of our species – humans first evolved in Africa several million years ago, before leaving those homelands and spreading across the world in a series of epic journeys.

But there has long been debate about exactly when humans left Africa and the routes that were taken. This is partly because the evidence, including fossils and artefacts found outside Africa, is scarce.

“We have to work with very fragmentary bits of information,” says Andrea Manica, a professor of evolutionary ecology at the University of Cambridge.

“We often lack archaeological sites in the interesting places – the coastlines that might have acted as corridors are now underwater, and, in general, the areas that might have been important don’t have very favourable climates to preserve ancient remains.”

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Read more: Oldest human burial in Africa unearthed

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Manica has co-authored a new study in Nature Communications that uses a different approach to narrow down early human migration. It models the climate over the past 300,000 years to pinpoint when conditions might have made it easier for humans to move.

“To move out of Africa, you need to cross large areas that, at times, are very inhospitable,” he explains. “The main barrier for the exit are very dry regions in North Africa and the Arabian Peninsula, so we looked specifically at variation in precipitation.”

By combining past climatic conditions with the distributions of contemporary hunter-gatherers, the team determined that humans can survive in areas that receive more than 90 millimetres of rain per year. This provided a threshold, above which were lusher, wetter conditions that the researchers suggested created ‘corridors’ along which humans could travel out of Africa.

So, when did those conditions occur?

“We found that there were a number of time windows that were suitable (for) human migration out of Africa well before the major exit that happened approximately 60,000 to 50,000 years ago – from which all contemporary humans descend, based on genetics,” explains Manica.

They looked at the conditions along two potential routes from Africa into Eurasia: one along the Nile (northern route), and the other along the narrow Bab-el-Mandeb Strait (southern route).

They found several windows where a wet corridor opened up along the northern route, including between 246,000 and 200,000 years ago, a number of times between 130,000 and 90,000 years ago, and around 78,000 to 67,000 years ago.

“After that, this route likely remained closed until the wet Holocene,” the team writes in the paper.

Whether humans seized these opportunities remains to be seen.

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Read more: Meet the new relative: ‘Dragon Man’

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On the other hand, the team says, “provided that maritime travel was in principle possible, climatic conditions would have made southern exits feasible for a substantial proportion of the last 300,000 years.”

The largest climate window occurred between 65,000 and 30,000 years ago along this southern route, which coincides with previous genetic and archaeological research showing that this was the most successful human migration out of Africa.

“Our work provides a catalogue of favourable periods when exits might have happened, which helps assessing how plausible some of the other lines of evidence for earlier exits are,” says Manica.

Michelle Langley, an archaeologist from the Australian Research Centre for Human Evolution at Griffith University, comments that “new analyses which narrow down the possibilities are very useful for working out where we should focus our investigations”.

“The several early dates (windows of opportunity) that the authors suggest are interesting to consider in light of what we know and emerging evidence from a number of different sites,” adds Langley, who was not involved in the research.

The big question now, he says, is why the exit around 65,000 years ago was so successful, leading to the full colonisation of the Eurasian continent and then the world.

“Something must have happened, because there were plenty of previous opportunities,” Manica says. “Changes in competition with other hominins (Neanderthals and Denisovans were on their way out at that time) might have been the key, but we really don’t know at the moment.”

https://cosmosmagazine.com/history/archaeology/climate-windows-allowed-humans-to-migrate-out-of-africa/

 

[Waylander]

I was reading about the demise of the Mayans the other day.

They were pointing out that they cut down all the trees and this led to droughts and local temperature increases of 20%.

Rain forest in the Amazon for about 40 years has been cutting down annually areas like the size of Wales, though now they say the size of Belgium.

If scientists were going to plot on a graph cumulative rain forest destruction by area for the last century it would go off the chart and show a correlation with temperature.

They never plot this graph publicly.........

Add to this more fossil fuel sources are also being discovered with a view to exploit.

Not sure what to believe anymore...........

I do agree with replacing petrol or diesel engine with BEVs or Hydrogen fuel cell cars because of the need to improve air quality.

 

 

 

 

 

 

[CaaC (John)+]

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How will El Niño and La Niña events change with the climate?

High-resolution simulations suggest rising temperatures may end the ENSO cycle.

For the last 11,000 years, the southern Pacific Ocean has cycled between warm El Niño and cold La Niña conditions, driving the climate on both sides of the ocean. But new modelling suggests that these cycles may be interrupted as a world warms under human-induced climate change.

An international team used one of South Korea’s fastest supercomputers to create a series of global climate model simulations. These simulations had unprecedented spatial resolution – of 10 km in the ocean and 25 km in the atmosphere – able to capture small-scale climatic processes like tropical cyclones and instability waves.

“Our supercomputer ran non-stop for over one year to complete a series of century-long simulations covering present-day climate and two different global warming levels,” says co-author Sun-Seon Lee from the IBS Centre for Climate Physics (ICCP) at Pusan National University in South Korea. “The model generated two quadrillion bytes of data; enough to fill up about 2,000 hard disks.”

The resulting study is published in Nature Climate Change.

The simulations add a new piece in the long-standing puzzle of how El Niño and La Niña events (commonly known as the El Niño-Southern Oscillation, or ENSO) will be affected under climate change.

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Read more: New IPCC report issues global climate change warning

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“Two generations of climate scientists have looked at this issue using climate models of varying complexity,” explains Axel Timmermann, director of the ICCP. “Some models simulated weaker; others predicted larger eastern Pacific temperature swings in a future warmer climate. The jury was still out.”

He notes that most of these previous models always produced temperatures in the equatorial Pacific that were colder than observations.

“This prevented them from properly representing the delicate balance between positive and negative feedback processes that are important in the ENSO cycle,” Timmermann explains.

The new model addresses these temperature anomalies, and concludes that increasing CO2 concentrations will weaken the intensity of the ENSO temperature cycle.

The mechanism? Evaporating water will cause future El Niño events to lose heat to the atmosphere more quickly; plus, in the future, the temperature difference between the eastern and western tropical Pacific will be reduced, in turn decreasing the development of temperature extremes during the ENSO cycle.

But the new simulations also show the detailed structure of tropical instability waves that usually hasten the demise of a La Niña event – they are projected to weaken, partially offsetting the two above factors.

“There is a tug-of-war between positive and negative feedbacks in the ENSO system, which tips over to the negative side in a warmer climate,” explains Malte Stuecker, co-author from the University of Hawaiʻi at Mānoa. “This means future El Niño and La Niña events cannot develop their full amplitude anymore.”

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Read more: Yes, Australia is a land of flooding rains. But climate change could be making it worse

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However, even though this model predicts long-term weakening in the ENSO cycle, the authors say that El Niño and La Niña-related rainfall extremes will continue to increase in coming years.

But this model is far from the only one addressing these questions.

Earlier this month, Australian scientist Wenju Cai from the Centre for Southern Hemisphere Oceans Research at CSIRO released a paper that reviewed 50 recent models. Overall, they showed that El Niño and La Niña events are expected to increase in frequency and intensity as a result of climate change.

Cai, who was not involved in these new simulations, says that they add necessary complexity and resolution, in particular incorporating ocean meso-scale eddies.

But he cautions that “it is just one model. We need 20 or more models to see if there is an inter-modal consensus. In our series of papers, there are still 20% of models generating a reduction in ENSO.”

He also notes that this new simulation considers the situation after the climate has stabilised, while other models examine how the ENSO system changes as CO2 in the atmosphere is still increasing.

“There are suggestions that ENSO in transient and stabilised climate could be different, including my own work,” Cai says.

But he praises the new methods presented in this work. “We need more of such models with a transient CO2 increase to see if there is inter-model consensus,” he concludes.

https://cosmosmagazine.com/earth/oceans/el-nino-and-la-nina-cycles-to-diminish-under-climate-change/

 

[CaaC (John)+]

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Climate Change Study Shows Arctic Warming Leads To Extreme Winters In United States

A new study, published in the journal Science, shows that rapid warming of the Arctic region is leading to extreme winter weather in parts of the US.

A new study revealed that rapid warming of the Arctic region is leading to extreme winter weather in parts of the United States of America. The study published in the academic journal of the American Association for the advancement of Science found that a circular pattern of winds was also disturbed by the heat in the region, resulting in severe winter weather in a few states in the US. The study further stated the same reason behind the extremely cold wave which was witnessed in Texas in the month of February, which usually experiences humid weather. According to BBC news, the rapid warming in the Arctic region has also caused a rapid shrinkage of summer sea ice and scientists have often shown their concerns about the implications of this global change. It further reported that satellite records are testimony of how global temperatures have had an extreme effect on the Arctic over the past four decades. 

'Changes in the Arctic having a significant impact on cold weather' 

The researchers found that changes in the Arctic are having a significant impact on cold weather in Nothern part of America as well as East Asia and noted that warming will see more extreme winters in some locations in future. According to Dr Judah Cohen, director of Atmospheric and Environmental Research (AER) and lead author of the study, the increase in temperature difference leads to more disruptions of the polar vortex and when it weakens, it leads to more extreme winter weather, reported BBC news. The researchers further claimed that their findings, which are based on both observations and modelling, also show a physical link between Arctic's climate change, the stretching of the polar vortex and the impacts on the ground. 

'Melting of ice in Barents and Kara seas led to increased snowfall over Siberia'

The study also shows that increased snowfall over Siberia is the result of the melting of ice in the  Barents and Kara seas. It further shows that heat ultimately causes a stretching of the polar vortex which led to extremely cold weather in the US. Since satellite observations began in 1979, there has been an increase in these stretching events, claimed researchers. They also believe that their work would also help in predicting the onset of extreme cold winter weather. Besides, the research team also believes that their findings will help people understand global warming in a better way and remove the misunderstanding that climate change does not lead to colder winters, reported BBC news. 

https://www.republicworld.com/world-news/rest-of-the-world-news/climate-change-study-shows-arctic-warming-leads-to-extreme-winters-in-united-states.html

 

[nudge+]

 

 

Hypocrisy at its best. I guess environmental, ecological and climate protection policies to cut emissions are only there for the masses, not for political elites and the superrich... Over 400 private jets and Biden with an 85 car motorcade in the COP26. Truly leading by example  "Please keep using paper straws and riding a bicycle to work so I can fly around with my private jet, you peasants."

[Stan]

43 minutes ago, nudge said:

 

 

Hypocrisy at its best. I guess environmental, ecological and climate protection policies to cut emissions are only there for the masses, not for political elites and the superrich... Over 400 private jets and Biden with an 85 car motorcade in the COP26. Truly leading by example  "Please keep using paper straws and riding a bicycle to work so I can fly around my private jet, you peasants."

Pathetic isn't it?

The hypocrisy of it all is so angering.

[Azeem]

I miss TAD in this thread. His initial post in the thread pretty much summed up everything 

[Happy Blue]

How do you stop the planet going through natural cycles of heating & cooling like it has done for millions of years? tricky   ...we got a giant fireball above us that goes through periods of heating up and cooling down, i really wonder whats making the ice melt right now 

"Threat level: Not only is CO2 now at its highest levels in human history, but one would have to go all the way back beyond the beginning of human history — to the Pliocene Epoch, between 4.1 to 4.5 million years ago — to find a time when Earth's atmosphere held a similar amount of carbon."

So, 4 million years ago the Earth had the same level of carbon 2 million years before the first humans, interesting  ..the Oceans were also 80ft higher back then too so better get higher than that to be safe on-less we can find a way to deflect the heat coming from our star 

[Azeem]

They failed to reach an agreement in the Glasgow summit. Shocker

[Happy Blue]

James Madden, forecaster for Exact Weather, told the Express : “The cold is likely to win out before the end of November bringing an early taste of winter and the risk of snow.

“Waning solar activity means chances are high for a 'little ice age' winter this year with notable periods of cold and snow.

“We have high confidence for the most cold and wintry conditions since December 2010 developing towards the end of the year."

That could bring extreme cold temperatures and spells of widespread snow, he added.

[Happy Blue]

Melting icebergs in the Antarctic are the key to an ice age, say the team from Cardiff University, triggering a series of chain reactions that plunges Earth into a prolonged period of cold temperatures.

The findings have been published today in Nature from an international consortium of scientists from universities around the world.

It has long been known that ice age cycles are paced by periodic changes to Earth's orbit of the sun, which subsequently changes the amount of solar radiation that reaches the Earth's surface.

However, up until now it has been a mystery as to how small variations in solar energy can trigger such dramatic shifts in the climate on Earth.

In their study, the team propose that when the orbit of Earth around the sun is just right, Antarctic icebergs begin to melt further and further away from Antarctica, shifting huge volumes of freshwater away from the Southern Ocean and into the Atlantic Ocean.

As the Southern Ocean gets saltier and the North Atlantic gets fresher, large-scale ocean circulation patterns begin to dramatically change, pulling CO2 out of the atmosphere and reducing the so-called greenhouse effect.

This in turn pushes the Earth into ice age conditions.

As part of their study the scientists used multiple techniques to reconstruct past climate conditions, which included identifying tiny fragments of Antarctic rock dropped in the open ocean by melting icebergs.

The rock fragments were obtained from sediments recovered by the International Ocean Discovery Program (IODP) Expedition 361, representing over 1.6 million years of history and one of the longest detailed archives of Antarctic icebergs.

The study found that these deposits, known as Ice-Rafted Debris, appeared to consistently lead to changes in deep ocean circulation, reconstructed from the chemistry of tiny deep-sea fossils called foraminifera.