The Medieval Warm Period In Germany: Inconvenient And very Real

The Medieval Warm Period In Germany: Inconvenient And very Real

Grok AI generated image.

Hans-Joachim Dammschneider has written a book about the climate history of the southern Harz region. In the historical weather data, he discovered climatic fluctuations that, according to the Intergovernmental Panel on Climate Change (IPCC), should not exist.

Long before industrial CO2 accumulated in the atmosphere, there were already alternating warm and cold phases.

Here is the book description:

The so-called Medieval Warm Period (MWP) has been the subject of scientific debate for years. It is not so much a question of whether this warm period actually took place in Europe, but rather how it took place. Was it a local phenomenon that was limited in time and predominantly restricted to Europe, or was it a period of intense climatic change that also had a global impact?

One thing is certain: from around 950 AD, there was a rise in temperature in Germany lasting at least 300 years, which resulted in a marked warm phase favorable to agriculture and life. However, from the beginning of the 14th century at the latest, this period was replaced by a relatively rapid drop in temperature and climatic turbulence in the direction of the so-called Little Ice Age.

In the early reports, the IPCC (1990, AR1) still devoted relatively much attention to the MWP. Over the years, however, this focus diminished, and in the most recent assessment (2021, AR6) little space was given to the Medieval Warm Period. Studies often even question whether it was a global phenomenon. However, a mapping of the available scientific publications (as of 2022) initiated by S. Lüning shows that the Warm Period certainly left evidence across continents.

From the perspective of natural and cultural history, many accounts show that Germany was in a phase of intense cultural and economic growth from around 1000 AD. This period is characterized by the founding of numerous towns, the expansion of agricultural land and strong population growth. Forests were cleared, building methods influenced, and rising temperatures and the resulting positive agricultural economy contributed to prosperity.

Of course, there were no scientific methods for recording the weather, but modern climate research uses so-called “proxies” to derive the climate parameters of the time. For example, the cultivation of figs north of Cologne, successful wine production as far as Schleswig-Holstein and (overall) the PFISTER index resulting from numerous features indicate a longer phase of mild temperatures and favorable climatic conditions. Climate-numerical backward simulations basically confirm this ‘warm period’.

Historically, such periods were often periods in which life flourished – an idea that plays a rather ambivalent role in the climate debate for the 21st century.

The example of Walkenried Monastery and the southern Harz monastery landscape shows the solid consequences of the MWP: the reclamation of swampy areas, the development of the Upper Harz water management system, the promotion of mining and the intensive use of wood for construction and energy purposes are just a few examples.

However, this phase of monastic prosperity between 1130 and 1300 AD was apparently brought to an end by a rapid drop in temperature. The onset of the ‘Little Ice Age’ brought very uncomfortable weather conditions that lasted until the end of the 18th century. As early as the beginning of the 14th century, the country was hit by destructive rainfall and floods (“Schluchtenreisen” / Magdalenenflut), failed harvests followed intense droughts (Dante anomaly) and devastating plagues with millions of deaths in epidemics partly destroyed social structures. These instabilities and hardships, which were not least determined/induced by the climate, certainly had devastating effects on the livelihoods of the monasteries in the southern Harz region. They led to considerable internal crises (including the loss of converts and lay brothers) and ultimately the end of the Walkenried monastic ‘group’ (with the abandonment of large areas of the Harz ore mining industry) in the 15th century.

If this was the case, what overarching climatic processes contributed to this? It can be assumed that, in addition to temperatures, other factors such as the duration of sunshine also played an important role in the living conditions: The sun indeed seems to have been ‘the’ factor of the MWP, whereas CO2 is that of modern times … .

Recent analyses and the AMO (Atlantic Multidecadal Oscillation) index, which can be traced back to 900 AD, indicate that cyclical SST (Sea Surface Temperature) energy influences from the Atlantic could have significantly influenced cloud cover and thus sunshine duration and temperatures in Europe. These interactions were also important for the southern Harz and Walkenried. Can evaluations of current climatic processes indirectly allow conclusions to be drawn about past physical and social changes with associated phases of ascent and descent between 1000 and 1400 AD?

The present study examines these questions and attempts to draw conclusions for the interactions of the medieval climate from large-scale processes of potential ‘teleconnections’ and oceanic cycles. The book is intended, among other things, as a sequence of steps that helps to better understand the complex interrelationships of medieval climate change. It shows which ‘natural’ parameters could have contributed to the rise and fall of Walkenried Monastery.”

Hans-J. Dammschneider (2025)
Klimageschichte der Südharzer KlosterlandschaftKloster Walkenried
ISBN 9783759779878, 106 pages, Hamburg/Norderstedt 2025
Order at AMAZON or all bookshops





German Droughts Were Much More Common Back In The Old Days, Before 1980!

Central Europe has been experiencing a bout of dry weather since February. Germany’s DWD national weather service reported in a recent press release that just 19 liters per square meter (l/m²) fell in March compared to the approx. 60 liters that normally fall in the month. This made last March one of the driest since measurements began in 1881.

“The pronounced drought, which had already lasted in some regions since the beginning or middle of February, was caused by high-pressure areas that repeatedly settled over Central Europe or in the surrounding area,” reports the DWD.

Not surprisingly, the media are making alarmist claims of unprecedented drought, and all hinting it’s due to climate sins by mankind.

Driest years overwhelmingly before 1980

So is drought in rainy Germany something new that we have only begun to experience, like the media and pols suggest?

The historical data show that the answer is clearly NO.

Four of the 5 driest years on record in Germany occurred before 1960. Eight of the top 9 occurred before man-made climate change was ever an issue (before 1980).

Annual precipitation of the 9 driest years since 1881. Hat-tip: Stefan Homburg 

And when we look at Germany’s long-term precipitation trend since data began to be recorded, we see the trend is in fact becoming wetter:

Chart: DWD.

Yet, green politicians in Germany have begun calling for a “masterplan” for water-saving and, not surprisingly, more restrictions on how we use water.

Dr. Stefan Homburg summarizes at the end of his video: “I just can’t get my head around it, ladies and gentlemen. I personally don’t understand as a final evaluation why we allow politicians to really ignore real, existing problems and instead invent problems that don’t exist at all in order to derive restrictions on our lives and, above all, to make life more and more expensive through CO2 taxes certificates and so on.





New Study: Plant Remains Embedded In A Modern Glacier Evidence A Warmer Antarctica 1000 Years Ago

Leafy moss dated to the Medieval Warm Period (MWP) has been found embedded in Antarctic glacier ice that today is “permanently snow-covered” with “no evidence of meltwater.” This affirms a warmer MWP and that “the summer melt during the MWP was greater than today.”

According to a new study, moss samples with intact leaves and stems 10 to 13 mm long have been discovered embedded in glacier ice – the Boulder Clay Glacier (BCG) – in Antarctica’s Victoria Land.

The surface of this glacier is currently not undergoing melt. It is instead permanently snow-covered.

“It is also noteworthy that under current climate conditions…there is no evidence of meltwater on the BCG, and the surface of the glacier is permanently snow-covered.”

The leafy moss samples have been dated to about 1,000 years ago, which is consistent with the timing of the Medieval Warm Period.

“…an unprecedented palaeo-erosion event occurred on the surface of an Anarctic glacier (northern Victoria Land, continental Antarctica) during the Medieval Warm Period (MWP) between 900 and 989 cal BP.”

“The period between 831 and 1140 cal BP is characterized by reduced sea ice in northern Victoria Land, which is consistent with the occurrence of a brief event of warmer conditions around 1000 cal BP…”

The presence of thousand-year-old plant remains in a modern glacier strongly suggest the climate was warmer (and thus there was less glacier ice) during the Medieval Warm Period.

“Further support for the occurrence of this short warming period was provided by the largest uplift event for the frost mound in the lake…observed only a few hundred metres from borehole B1 and dated between 790 and 1070 cal BP. Therefore, the past frost mound uplift documented at BCG may indicate that the summer melt during the MWP was greater than today.”

The warmth during the Medieval Warm Period has been suggested to be driven by ENSO, which is linked to solar activity. In other words, greenhouse gas concentrations played no identifiable role in this “huge warm pulse event.”

“The MWP in Victoria Land has been reported to be mainly driven by the El Niño Southern Oscillation (ENSO), which is linked to changes in solar activity through non-linear dynamics.”

Image Source: Forte et al., 2025

Wake Physics: Large Wind Farms Are Making Downstream Turbines Unprofitable

A Wake-Up Call

By Klimanachrichten

A virtual wake-up call for the wind power industry. Two companies are sounding the alarm as they risk losing a lot of money.

Although they are not making losses yet, they are earning less. It’s about the the wake effect on wind farms by other wind farms.

Windmesse.de

The expansion of offshore wind energy in the North Sea is a central component of the European energy transition. However, two of the biggest players in the industry are now warning of negative effects: Ørsted and Equinor have jointly calculated that the planned 1.5 gigawatt wind farm ‘Outer Dowsing’ could cause significant so-called wake losses. These are yield losses that occur when the wind is weakened by upstream wind farms, causing downstream turbines to produce less electricity.

The two companies estimate that their existing wind farm projects in the British part of the North Sea could lose up to 361 million pounds – the equivalent of around 422 million euros – in the long term as a result of the new wind farm. The wind farms already in operation, which are dependent on constant wind conditions in order to achieve their planned output and ensure profitability, will be particularly affected.”

The phenomenon is called the wake effect and it is by no means new, as you can see in the Sciencemediacenter, an article from 2012:

The existence of wind turbine wakes has been known for decades. For smaller wind turbines and onshore wind farms, it for a long time was not considered to be so important. With the increasing size of individual wind turbines (multi-MW turbines) and larger wind farms in recent years, the size and length of the wakes are increasing and becoming increasingly relevant. I pointed this out back in 2010 and developed a simple model that can be used to estimate the length of wind farm wakes. This model shows the dependence of the length of wakes on subsurface roughness and thermal stratification of the air. Wakes of tens of kilometers in length can be predicted for offshore wind farms with stable stratification. Ms. Lundquist’s working group already presented simulation results with the WRF flow model in 2012, some of which show even longer wakes.“

The topic is also covered by basicthinking, and the losses could be significantly higher than scientists first thought in 2012.

Based on the results of their study, the researchers estimate that offshore turbines take the wind away from each other. As a result, wind farms in the Atlantic lose more than 30 percent of their output. The scientists call this the “wake effect”.

It occurs when the wind flows through the turbines and the forward or upstream turbines draw energy from it. As a result, the wind speed behind the turbines slows down. The result: lower power generation.

The wake effect is particularly pronounced with offshore wind turbines, as there are no houses or trees to swirl the air. This would help to disperse the wakes. Under certain weather conditions, they can also reach up to 55 kilometers and affect other wind farms.

Especially on hot summer days, when the air above the cool sea surface remains stable, wakes can persist for longer and spread further.”

Last year, public broadcaster mdr had a very interesting article about this. It is interesting that this problem was not considered when the energy transition was being planned. However, it is not surprising.

Axel Kleidon sees offshore turbines, i.e. those at sea, as a particular challenge. These are often only just being built and many wind turbines are planned in relatively small spaces. And in an environment where, according to Martin Dörenkämper, losses are generally more pronounced. “Over the sea, the flatter surface leads to a more constant wind speed distribution with height and therefore a considerably less turbulent wind resource than at onshore locations.” In other words, the almost unbraked wind power hits the rotor blades, generating more power there, but then returns to its former strength less quickly due to the lack of ambient turbulence and corresponding mixing: as a result, the wake effects last longer and can still be felt over longer distances.

According to Axel Kleidon, this may lead to a legal problem, as the longer the distances, the more likely it is that wind farms operated by different operators will ‘steal the wind’ from each other. This makes it all the more important to coordinate, especially at national borders such as in the North Sea between Germany, Denmark and the Netherlands: ‘The slice of the North Sea that is managed by Germany is relatively small. The area of the Netherlands and Denmark is much larger. It would make sense to coordinate this instead of somehow focusing on a national level. If you want to expand 70 gigawatts in the North Sea, you can say that it doesn’t all have to be in the German sector, but can also be in the exclusive economic zone of Denmark or the Netherlands.'”

Source: Klimanachrichten.





“Solar Madness In Germany”: Gigawatt-Hours Of Subsidized Electricity Gets Dumped Abroad For Free”

Blackout News here reports on how Germany’s uncontrolled solar production without appropriate storage and consumption models is putting a huge burden on the domestic market and consumers.

At the same time, neighboring countries are benefiting from all the free electricity Germany uncontrollably overproduces and consumers just don’t need!

Image generated by Grok AI

Experts are warning of the collapse of an over-regulated energy system that is increasingly moving away from reality. Germany has significantly expanded its solar PV capacity in recent years. According to the Federal Network Agency (Bundesnetzagentur), the total installed solar PV capacity in Germany reached 99.3 GW at the end of December 2024.

The country’s massive solar power production is leading to a growing problem due to mass overproduction and the resulting negative electricity prices, which occur particularly when the sun is shining midday and demand is low: all the surplus electricity flows abroad – free of charge! This sort of absurdity is what happens when politicians and bureaucrats take over energy engineering.

In 2023, the proportion of hours with negative prices averaged 18%, in May it was as high as 31%. Despite billions being invested in the expansion of photovoltaics, basic measures such as storage technologies and smart meters are being neglected.

Experts criticize the lack of powerful battery storage systems and the sluggish expansion of smart electricity meters, which could enable the flexible use of surplus electricity. Energy market expert Björn Peters criticizes the current legal situation, which does not allow operators of solar systems to participate in negative prices and thus creates false incentives.

He is calling for a halt to the expansion of PV and the abolition of the EEG green energies feed-in act.

Peters advocates a fundamental change of course towards a more reliable energy supply, including a return to nuclear power, the expansion of coal-fired power generation and the use of domestic gas reserves. The current energy system is neither sustainable nor financially viable. So far, politicians have not provided any clear answers or concrete measures to relieve the burden on citizens and companies.

Originally reported on by Bild.

New Study Finds The Anthropogenic ‘Pressure’ On Climate Is Too Small To Play A ‘Dominant Role’

Even if the entirety of the modern CO2 concentration increase is due to human activity, the impact (pressure) on global temperatures amounts to no more than 15-18%.

In a new study, geology professor Dr. Wojciech Stankowski  has summarized some of the reasons why the prevailing narrative that says humans can drive climate change by burning more or less fossil fuels cannot be supported by the evidence.

Past natural climate changes such as Greenland’s “temperature increases of up to 10°C within just 50 years” 14,700 and 11,700 years ago confirm that the modern climate change rate (just o.05°C per decade since 1860) falls well within the range of natural variability.

Further, a CO2 concentration change from 0.03% to 0.04% (300 ppm to 400 ppm) is not significant enough to impact temperature change in the global ocean, which covers 71% of the Earth’s surface.

“If carbon dioxide were the main driver of temperature fluctuations, its concentration variations would have to be enormous.”

“Currently, CO2 levels are around ~400 ppm. If this entire difference [the ~100 ppm CO2 increase since the early 20th century] is attributed to human activity, anthropogenic pressure accounts for no more than 15-18%.”

Natural factors such as tectonics, changes in galactic phenomena, and the Sun’s magnetic fluctuations continue to modulate changes in climate. Human activity can only play a non-dominant modifying role at most.

“The overall trends in climate change rhythms will continue to be determined by the complex nature of galactic phenomena, the energy-magnetic fluctuations of the Sun, and their interactions with Earth’s magnetic field.”

“The ever-increasing intensity of anthropo-pressure does not hold a dominant role in climate change.”

Image Source: Stankowski, 2025

Only Four Electric Car Manufacturers Worldwide Are Making A Profit!

Germany’s Blackout News here reports that only 4 electric car manufacturers world wide are managing to make a profit, three of which are Chinese: BYD, Li Auto and Seres. And all the rest “are struggling to survive.”

Only four electric car manufacturers are managing to make a profit. Image generated by Grok AI. 

“Chinese brands are increasingly taking the lead in the global market. More than 120 brands are competing in the electromobility segment,” reports Blackout News. “Many benefit from low production costs and massive government support. BYD is expanding aggressively, including in Europe, and is becoming a real threat to Tesla.”

Tesla still leads with an operating margin of 7.2 percent, but its growth has stagnated. China’s BYD is expanding aggressively and benefiting from innovation and government support.

Many other manufacturers, especially start-ups such as Lucid Motors and Rivian, are posting high losses. Traditional car manufacturers are also under pressure as electrification incurs high costs. The EU is forcing the switch to e-mobility by 2035, which increases the pressure to adapt. The future of the electric car market depends on innovation, scaling and political framework conditions.

If left to the free market forces and consumer wishes, electric cars would fare very poorly. Few people really want them,  and they really are neither good for the environment nor the economy.





New Study, Good News Greenland’s Ice Loss Likely Won’t Disrupt Atlantic Current

“Will dissuade people from climate doomism,” researcher hopes.  Ice sheet runoff at the coast has much less impact on the AMOC than melting ice bergs ou to sea do. 

We hear it again and again: the melting ice in Greenland due to global warming will soon lead to a collapse of the Gulf Stream system, with the result that it would be difficult to restart. Then we would see great disasters like those depicted in Roland Emmerich’s dramatic climate movie  “Day after Tomorrow”.

Hat-tip: EIKE

The seawater salinity in the north is critical because the salt-rich tropical water cools and sinks due to the higher salt content. This acts as the pump that makes circulation possible in the first place. This serves to transport very large amounts of heat into the North Atlantic, keeping Europe on the mild side in the wintertime. Scenarios have been published recently that calculate a drastic cooling of the large area (especially Europe) around it if the Gulf Stream system got “switched off”.  But those scenarios are proving to be over-dramatic and alarmist.

Yuxin Zhou, a postdoctoral researcher in UC Santa Barbara’s Department of Earth Science, recently went back in history to study when the AMOC was severely weakened, from 68,000 to 16,000 years ago, when the Laurentide Ice Sheet existed and thick ice covered northern North America and even New York City. Today that massive ice shelf of course no longer exists and thus there is no longer the potential of an ice melt and ice berg release of that scale.

Very different, less dramatic circumstances today

By analyzing sea sediment deposited by floating ice bergs out to sea in the North Atlantic, Zhou found that AMOC heat transferring oceanic current had been already moderately weakened back then before all the icebergs floated over the North Atlantic. Comparing the situation to today: “In contrast, the circulation is very vigorous right now, which suggests the melting of Greenland is not likely to plunge the North Atlantic into another deep freeze of the sort the alarmists fret about all the time.

Moreover, Technology Networks here adds (emphasis added):

Not all melting has the same effect on the Atlantic circulation. Freshwater released as icebergs has a much larger impact on the AMOC than runoff, which is released after melting on land. Icebergs can cool the surrounding seawater, causing it to freeze into sea ice. Ironically, this ice layer acts as a blanket, keeping the ocean surface warm and preventing it from plunging down to the depths and driving the Atlantic circulation. What’s more, icebergs travel much farther out to sea than runoff, delivering freshwater to the regions where this deepwater formation occurs.”

The AMOC circulates water in the Atlantic basin.
Today’s Greenland’s freshwater runoff won’t have the anywhere near same impact as the mass icebergs of the last age. Image: Yuxin Zhou et al.
Thus, should Greenland’s glaciers further recede inland, they would only melt on land and release freshwater at the coast rather than release icebergs far out to sea. This would mean a considerably smaller impact on the AMOC.

Stop the doomism

Zhou summarizes: ““We have a lot of anxiety about how fast climate change is happening and how dramatic the changes could be. But this is a piece of good climate news that hopefully will dissuade people from climate doomism, and give people hope, because we do need hope to fight the climate crisis.”





Near Disaster: German Wind Turbine Sees Brake Failure, Impossible To Stop

Maintenance on the cheap. Poorly maintained turbines in Germany posing a hazard. 

German online energy news site Blackout News reports on how an old wind turbine spun completely out of control near motorway at a wind farm near Großweitzschen in Central Saxony – and couldn’t be stopped!

Image attempt by Grok AI. 

“The approximately 30-year-old turbine went into an uncontrolled spin in strong winds after the braking systems failed,” reports Blackout News. “Despite several attempts, technicians were initially unable to stop the rotor blades spinning unchecked. Only when the wind died down did the turbine gradually come to a standstill.”

The incident worries the wind industry as the runaway wind turbine could not be stopped due to an emergency brake failure and thus “posed a serious safety risk.”

“Experts attribute the failure to a combination of factors, including material fatigue after decades of operation, inadequate maintenance of the braking systems and extreme gusts of wind at the time of the incident,” writes Blackout News.

As older turbines age, they become uneconomical to operate. Operators tend to cut corners when it comes to maintenance and repairs, which can be extensive for the older ones.

Local mayor Jörg Burkert called for immediate action, and authorities are now pushing for an immediate plant shutdown and dismantling of the rogue turbine – also an expensive step.

Early stage investigations point to an emergency brake fault and that a “complete failure of the system” could have occurred. Experts are calling for consequences.

“Energy experts are now calling for stricter maintenance regulations for older turbines and regular load tests of the braking systems. Clear decommissioning criteria in the event of technical defects should prevent similar incidents in future,” adds Blackout News.

That the authorities are worried is completely reasonable as turbines cannot be left to spin out of control and collapse catastrophically near people and infrastructure because no one is adequately maintaining them.





New Study: Corals Thrived When Global Sea Levels Were Meters Higher Than Today 6000 Years Ago

Coral reefs expand and thrive as sea levels rise, whereas they undergo millennia of growth hiatuses and “turn-off” or “mass mortality” phases when sea levels fall.

According to a new global sea level reconstruction (Feldman et al., 2025), global sea levels were meters higher than today 7000 to 5000 years ago. Global sea levels fell thereafter throughout the late Holocene.

From approximately 4500 years ago until 640 years ago, previously thriving coral reefs endured “mass mortality” and “turn-off” phases due to incrementally declining accommodation space in the Red Sea region.

This millennial-scale “turn-off” reef growth period was not just limited to this study area, but coral cover decline has been a global phenomenon associated with global sea level fall throughout the late Holocene.

“A global hiatus in coral reef development […] was largely driven by eustatic sea level drop during the late Holocene and caused a lack of vertical accommodation space…”

“In this study, we propose not just a local sea level condition causing specific reef turn-offs or hiatuses, but rather a global phenomenon of sea level fall.”

“A reduction in accommodation space through receding sea levels resulted in mass mortality or sea level constrained corals.”

Considering rising sea levels are advantageous to corals and falling sea levels largely eliminate the potential for growth, future sea level rise may lead to a “significant increase in coral cover”.

“Future sea level rise could provide additional accommodation space for currently sea level-constrained reef systems, potentially leading to a significant increase in coral cover.”

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Image Source: Feldman et al., 2025

Great Barrier Reef Corals Are Growing And Thriving…Earlier Damage Not Climate Related

German language RTV here reports: All the talk in the media of a dying Great Barrier coral reef near Australia is “a media swindle”.

Symbol image, provided by Grok AI

The facts: Record numbers of coral reefs were already measured in 2024 and the coverage has indeed tripled over the last 12 years.

According to RTV, “coral bleaching due to high water temperatures has been proven to be a lie” and the claim of damage to the reef in recent years said to be due to climate change has in fact a completely different background and has the reef has recovered.

According to Report 24, all the media claims made on a yearly basis, e.g. from the Guardian and CBS, of the Great Barrier reef near Australia dying at a record speed and being irreversible is “a fairy tale” and “false, misleading or simply a lie.”

Report 24 writes that the damage to the reef was caused by a tropical cyclone that moved across across the reef in 2009 and caused immense damage. A study by the Australian Institute of Marine Science summarized the damage which ranged from exfoliation, scouring, which removed all living tissue from the corals, and included coral breakage where both massive coral heads and more fragile branching corals broke off.

It had nothing to do with CO2 and climate change.

Moreover, according to scientists, coral bleaching is by no means a sign of a dying reef and does not produce a white dead coral lump like the ones you can buy in a souvenir shop on the beach. Instead, bleaching means that the coral has lost the algae living in it, usually due to various stress factors such as fluctuations in light or changes in water temperature. This  causes the living coral to turn white but not necessarily die.

Report 24 adds that occurrences of coral bleaching could become even more frequent due to the record growth of recent years.

The dying reef narrative began 12 years ago when the reef was severely damaged by the cyclone, with up to 85% of the coral cover gone. At the time, real scientists stated that recovery could take up to 15 years, and this is exactly what has since happened.

The reef has not only recovered, but also continued to expand.





Scientists ‘Unexpectedly’ Find The Declining Sea Ice Trend Since 1980 Has Radiatively Cooled The Earth

The alarmist narrative that says disappearing sea ice serves to enhance and worsen global warming may now be discarded.

For decades it has been assumed the sea ice concentration (SIC) reduction trend in the the Arctic over the first 30 years of the satellite era (1979-2007, with a flat trend since then) would lead to a precipitous decline in reflective albedo. Consequently, with more open water rather than brightly reflective ice, the Arctic would perpetually warm even more than it already has.

But now, according to analysis found in a new Science Advances study, this assumption may no longer be valid.

Image Source: Zhou et al., 2025

The global top of atmosphere (TOA) radiative effect of SIC changes, Δ𝑅, is dependent not just on SIC trends in the Arctic, but on SIC trends in Antarctica as well. The Southern Hemisphere’s SIC has been increasing throughout most of the satellite era, especially from 1979 to 2015.

Globally, then, the Δ𝑅 of Antarctic SIC gains asymmetrically offsets the Δ𝑅 stemming from Arctic SIC reduction due to SIC-induced albedo feedback processes. Thus, the modern era global SIC trends have served to “cool Earth.”

“[N]umerical simulations indicate that the bulk radiative effect of SIC reduction with certain spatial patterns (e.g., trends during 1980–2008) could even cool Earth due to the hemispheric asymmetry of SIC change.”

“[T]he negative trend during this period [1980-2008] is primarily induced by the SIC increase in the Antarctic regions. … [T]he radiative cooling induced by Antarctic SIC growth is greater than the radiative heating induced by Arctic SIC reduction.”

To reiterate, the Δ𝑅 of declining global sea ice concentration (SIC) from 1980-2008 has led “to planetary cooling” due to the “radiative cooling induced by Antarctic SIC growth”. This is the opposite of what promulgators of disappearing-sea-ice alarmist narratives have been claiming for decades.

The authors of the paper accordingly describe the SIC-induced global cooling radiative effect stemming from declining global SIC as an “unexpected” development.

“Unexpectedly, the trend of global Δ𝑅 [radiative effect of sea ice changes] is negative despite the statistically significant decrease of global SIC between 1980 and 2008, implying that global SIC reduction leads to planetary cooling during this period.”

Finally, it is interesting that the chart shown in the top right (Fig. S3) indicates not only has the SIC-induced Δ𝑅 change been flat to declining in recent decades, there also has been no obvious SIC-induced Δ𝑅 change or trend since ~1875.

Could sea ice alarmism be disappearing?

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