Political and Natural Hazards, ARC Part 3

From Jennifer Marohasy’s Blog

Jennifer Marohasy

Before the advent of computer simulation modelling and the Intergovernmental Panel on Climate Change (IPCC), the past record of climate change was assembled from a variety of different types of evidence including chronicles, grain price records, radiocarbon dating, pollen analysis and vegetation history, tree rings, ocean bed deposits as well, of course, as meteorological instrument records.

Before the United Nation’s got involved through the IPCC, the general consensus amongst the geographers, drawing together evidence from these very different disciplines, was that there was a period about 2,000 years ago known as the Roman Climate Optimum, a period of unusually warm, wet, and stable temperatures at least in the Mediterranean. Then it got cold. Welcome to the Dark Ages.

About 1,000 years ago there was another warm period, when harvests were so good and summers so long that communities got together and build grand cathedrals across western Europe. That was known as the Medieval Warm Period. Then it got cold again.

On the third morning of the Alliance for Responsible Citizenship (ARC) conference in London, while I was high in the cable car over the Thames – traversing the river to the conference venue – I imaged the frost fairs that were held during that period after the Medieval Warm Period known as the Little Ice Age.

Paintings and engravings show an elephant being paraded, oxen being roasted, and horse drawn carriages being raced, all across the frozen Thames –beginning in about 1607 and continuing through until at least 1814. This period of some 200 years is thought to corresponds with climate change and there is some evidence it was global.

Indeed, I was recently reading about the excavation of now extinct Adelie penguin colonies in Antarctica with radiocarbon dating showing changes in the geographic range of the colonies beginning about 500 years ago, corresponding with the beginning of the Little Ice Age, more usually associated with freezing Europe.

During the Great Winter of 1683-84 in England, not only did the Thames freeze solid, but also the seas of southern Britain for some few kilometres from shore. Then there is the oil painting by Charles Mozin of the capture of the Dutch warships by the French cavalry when the seas surrounding Holland, suddenly froze solid some 100 years later, in January 1795.

Such is the settled science of climate change, that we don’t really know, what caused this part of the North Sea to freeze over. The story of the frozen armada captured by the French cavalry is not only detailed in the oil painting, but in a wonderful book by Erik Durschmied entitled The Weather Factor along with so many other weather events causing unexpected military defeat.

The IPCC mostly just flattens this entire period of European history, by which I mean the entire temperature record for the 2,000 years before 1800. Perhaps because if this climate change occurred, it was natural and therefore it doesn’t count.

The late 1700s, just before the uptick in global temperatures that is acknowledged by the IPCC, was a time of unusually volatile weather. There was the eruption of the Laki volcano in Iceland in 1783 that lasted for some eight months and then a very severe El Niño in 1791 that lasted for two years. That was when the trade winds stopped blowing across the Pacific and the newly settled colony of Sydney Cove in Australia sweltered. Then just a few years later, in 1795, Europe was plunged into cold again with the freezing over of Den Helder and the defeat of the Dutch armada.

I have a book, Abrupt Climate Change – Inevitable Surprises (US National Research Council in 2002) detailing the early twentieth century warming in Greenland. Specifically, temperature recordings from Danish stations on the west coast of Greenland show an abrupt warming at Upernavik with 4 degrees Celsius rise in air temperature between 1920 and 1930, accounting for all of the warming during the twentieth century – except that the official IPCC reconstructions undo this, turning what was abrupt warming early in the twentieth century into a slow and steady linear increase over the entire century.

I have long complained about a similar remodelling of the official instrumental temperature record for Australia, whereby the cooling trend so evident in maximum temperature records from at least 1920 to 1960 is changed into continuous warming. On and on, I lament that conservative politicians have had opportunity after opportunity to do something about this, but refuse, always finding some excuse.

Then I travelled to London for this ARC conference and I found so many of these past and present conservative Australian politicians being encouraged not only to believe that climate change is human-caused, but something that is essentially slow and steady in nature – not just in Australia, but globally. I now despair that they will ever do anything about restoring integrity into the historical temperature record – for anywhere, at any time.

This ARC conference, which conservatives from across the West are rejoicing about, and that was unashamedly about finding a better story, is telling a climate story that bears absolutely no relationship to the truth. And there is no real opportunity for dissent, not at that event, and not since within these same political networks.

A key message in the interview with physicist Steve Koonin on the afternoon of the second day is that there has been a slow and steady increase in global temperatures of exactly 1.3 degrees Celsius over the last 100 or so years. Nonsense. The more credible story, and as detailed in the book entitled Ice Ages, by John and Katherine Imbrie (published by Harvard University Press, 1979), is that there was thirty years of global cooling to about 1960 with the amassed technical literature thus forecasting a coming ice age at that time.

Complementing the nonsense idea of slow and steady warming from Koonin, Alex Epstein made the comment at the Energy and Environment dinner on the evening of the second day that Antarctica was melting albeit slowly. Never mind that even the IPCC reports acknowledge that Antarctica is likely to be gaining mass with the global warming as simulated by the IPCC computer models resulting in more snowfall. To be clear, Antarctica has made no, that is correct zilch, contribution to their official estimates of sea level rise through the twentieth century. That is, of course, before the recent significant reduction in sea ice beginning in 2016, which suggests a marked change in trend.

It is not as though the organisers of this conference, foremost amongst them former Australian Deputy Prime Minister, John Anderson, do not know better.

John Anderson is part of a network that has been repeatedly shown the extent of the remodelling of the official temperature records, and the impossible IPCC physics most recently in the form of a series of IPA sponsored lectures by Will Happer from Princeton University. And John Anderson has witnessed the devastating flooding along much of the east coast of Australia despite the IPCC forecasts that the new climate for Australia would be one of endless drought.

Continually on and off the stage across the three days of the ARC conference, John Anderson might have mentioned the spiking that is now occurring in the UAH satellite record of global temperatures – normally the go-to for conservatives interested in climate change. He never mentioned climate change, or covid-19 lockdowns or how his government rushed Australian troops into Iraq, or how, when he was deputy Prime Minister, the beginning of the destruction of the reliability of our energy network was instigated with the Renewable Energy (Electricity) Act 2000. More about this in an important new report launched on the sidelines of ARC by the IPA with Stephen Wilson. (I was going to make part 3 in this series about energy, but it can wait.)

As surely as the Earth rotates eastward, spinning on its axis creating night and day, the deceit out of ARC risks to hasten the downfall of Western civilisation; through the hubris and denial until we are so stuck in ice we are easily destroyed. Yet Western civilisation was the one thing that ARC claimed it was all about saving. Except that for redemption there must first be some acknowledgement of the mess that Anderson and his colleagues have created over the past few decades.

One of the few presentations that explained this core issue of the need for redemption was by theologian Amy Orr-Ewing. She asked that we acknowledge past injustices. Her presentation opened the second day. I cannot find it on the official ARC YouTube channel, perhaps because it was tangential to the official line, but it is available at ADH TV, click here.

While Jordon Peterson advocated the need for individual responsibility as the way to find meaning in life, Amy Orr-Ewing suggested that there was first a need for institutions to acknowledge past injustice and suffering. She also had much to say about the power of redemption and forgiveness for individuals and also communities, and even the South African nation. This would seem incredibly relevant given how much we now know, including about the abuse of children in church run schools across the Western world. (When I looked at the report that came out of the Royal Commission some years ago the most abused cohort by number were white boys born in 1963, my year.)

But I diverge.

On the energy and environment theme, there was also Michael Schellenberger, insisting that we must do away with pesky sceptics at that dinner as I explained in part 2 of this series, and on the Monday afternoon of the conference he claimed that the slow and steady increase in sea levels of about 25 centimetres since 1880 was not something to be too concerned about. Schellenberger was a darling for so many, not only at the conference, but last time I looked his presentation was one of the most popular at the ARC YouTube channel. (The lies they spread.)

In reality there has been nothing slow and steady about sea level rise, not even for the small Pacific Island nation of Tuvalu.

The media headlines scream rising sea levels. But the most obvious pattern in the first twenty years of official sea level data for Funafuti, the capital of Tuvalu, are three periods of abrupt sea level fall corresponding with the significant El Niño of 1983, the weaker El Niño of 1992, and then the very strong El Niño of 1998.

We only have reliable sea level data for Tuvalu beginning with the satellite record in 1979, and the first recorded very significant drop in sea levels at Tuvalu was in 1983 because of the collapse of the trade winds associated with that massive El Niño event.

El Niños are most obvious as the sloshing of great amounts of warm water from the western Pacific toward the Americas, followed by the shutting down of ocean currents along the west coast of South and Central America.

In the book El Niño, History and Crisis (edited by Richard Grove and John Chappell, The White Horse Press, 2000), there is a table of archive-based El Niño series for the past 500 years. They manifest when the trade winds stop blowing across the Pacific Ocean, then there is no upwelling of nutrient rich waters along the Peruvian coast, often with dire consequences for the local fishery, and also for global temperatures.

When the trade winds stop blowing, warm water will begin to pool across the equatorial Pacific and this water will start to move east, which is the direction in which the Earth rotates.

The most recent El Niño began in April just this year, and there is now a very large pool of quite warm water straddling the equatorial Pacific.

The Earth rotates eastward, spinning on its axis creating night and day. Then there are the seasons because as the Earth makes one revolution around the Sun in each 365-day period, its axis is tilted – with the southern hemisphere tilted towards the Sun as we approach summer here in Australia. And it is likely to be a scorcher, not because there is more carbon dioxide in the atmosphere, but because the trade winds stopped blowing across the Pacific Ocean earlier this year, with the spiking in the satellite temperature record a manifestation of this.

The Southern Oscillation Index, measured as the difference in air pressure between Tahiti and Darwin remains negative. And the warm waters spreading across the Pacific are becoming even warmer. The Nino 3.4 sea surface temperature index already exceeds 1.5 degrees Celsius. In fact, it has climbed from minus 0.5 degrees to plus 1.5 degrees just this year.

This warmth is spreading through the Earth’s atmosphere, as clouds are formed and also thunderstorms move the heat upwards, and the winds then blows it poleward.

This is manifesting as a growing spike in the satellite measures of global troposphere temperatures. According to the UAH Satellite temperature record, the world is the hottest it has ever been – or at least since the beginning of the satellite record in 1979.

There is no known physical mechanism whereby carbon dioxide can cause an El Niño. Climate change is a natural hazard.

This warming that reliably began in the central, equatorial Pacific Ocean when the trade winds stopped blowing in April, is caused by lunar tidal gravitational forcing. I am referring to the cyclical changes in the orbit of the moon about the Earth that follows an 18.6-year cycle and not always regular in magnitude because the strength of the forcing will change depending on its alignment relative to the Sun, and because the forcing reverses from a maximum to a minimum declination every 9 years, in the same way that the tilt of the Earth reaches a maximum of 23.45° on June 22 (summer solstice in the northern hemisphere) crossing over to a minimum of -23.45° on December 21-22.

There are cycles within cycles, and by their very nature they can appear to keep reversing and they do affect the climate. If we took notice of them, we might be able to forecast when the Thames is likely to next ice over.

To be continued.


The painting of the Dutch warships stuck in ice is on public display at the Chateau de Versaille, more information here.

In the photograph of me in red, I am with Australian Senator Matt Canavan.

The question of whether Antarctica is ‘melting’ or not, is both important and complex. According to Climate Change 2001, The Scientific Basis (page 665) and most treatments since by the IPCC, Antarctica is overall gaining in mass.

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Tom Halla
November 19, 2023 2:13 pm

But His Holiness, Michael Mann did away with the Little Ice Age with MBH98. All True Believers must acknowledge that undying Truth!

Reply to  Tom Halla
November 19, 2023 4:03 pm

Like the song says, making up data the old hard way.

Bryan A
Reply to  Scissor
November 19, 2023 4:38 pm

Reply to  Tom Halla
November 20, 2023 1:41 pm

And where are his disciple trolls that frequent this site, to defend His Holiness??

Richard Page
November 19, 2023 2:25 pm

So this ARC then is pretty much signed on with the whole climate change thing, they just want to preserve their way of life if things change. Kind of like finding out you’re going to hell, but trying to get a room with a nice view?

Reply to  Richard Page
November 20, 2023 3:07 am

It’s the WEFARC period

Gary Pearse
November 19, 2023 3:02 pm

From Shellenberger “…that we must do away with pesky sceptics.”

Jennifer, are you sure you understood what he meant? Michael S converted himself from a dyed in the wool climate alarmist to to authoring a book saying there is no climate crisis.

Both sides of the discussion have supporters who are strange bedfellows , purely political, cranks and others who say silly stuff with no understanding of the topic. It would make for a narrower solid target to get rid of such pesky types sceptics.

Reply to  Gary Pearse
November 19, 2023 4:02 pm

That’s a good question. Perhaps he was being sarcastic.

In any case, it’s wonderful that Marohasy was there to listen and to participate and to share her excellent meeting summaries with us.

Reply to  Gary Pearse
November 19, 2023 4:11 pm

There is a position which declares CO2 and friends are the cause of continuous warming but said warming isn’t a thing such that you should set your hair on fire and run through the streets screaming i.e. it isn’t a crisis, just a thing to take care of somehow – with more probity please.

Joseph Zorzin
Reply to  AndyHce
November 20, 2023 2:41 am

but… but… here in Wokeachusetss- the entire state government, and many local governments are screaming that it’s an emergency- everybody is panicking – including the entire media and even most businesses- we’re gonna rush to net zero and save the Earth and biodiversity! As crazy as that all sounds- it’s exactly what’s going on here. Seriously, I’m not exaggerating.

Tom Abbott
Reply to  Joseph Zorzin
November 20, 2023 4:37 am

What do those climate alarmist people say about China and India, and Indonesia, and the other nations that are using coal, oil, and natural gas as fast as they can, with no end in sight?

Anything Wokeachusetss does is irrelevant to the CO2 Big Picture.

Wokeachusetss could stop using all coal, oil and natural gas tomorrow and it wouldn’t make a bit of difference in the war on CO2.

The Elites in Wokeachusetss are wasting its time, money and future on this stupidity.

It’s really amazing: Millions of people all living in the same CO2-is-dangerous false reality.

Of course, the millions of people have had a lot of help, what with the internet’s reach, and leftwing billionaires funding enormous amounts of CO2 propaganda, it is not a surprise that many people are living based on false assumptions about CO2.

Joseph Zorzin
Reply to  Tom Abbott
November 20, 2023 6:24 am

Here, if you try to discuss what we discuss, you’ll be “shunned”. Seriously, it’s happened to me many times over the years- first, challenging idiotic forestry policies and now climate policies. They pretend they don’t know me- or look at me like I need to be put in a straight jacket. When I challenged forestry policies- twice I was investigated by the forester license board. I had to get the ACLU to help to get the state’s jack boots off my neck. I actually got 3 certified letters the last time- all saying they were going to investigate me! Now the state is working on updating forestry policies. They just ran a webinar- run almost entirely by woke females (who now run the entire state). It started with several “officials” discussing the urgent need to get to net-zero. No mention whatsoever of any reasons why maybe it’s not so urgent- all the things we talk about every day. Then they allowed people all of 3 minutes to comment. The people who hate forestry said we must lock up all the forests to save the planet. The pro forestry people all agreed that there is a climate crisis but that with good forestry- we can both produce wood AND save the climate. I keep telling the forestry people why they should stop thinking that there is a climate problem. Not only do they not attempt to dissagree- they just ignore me 100%. I think the reason is that they’re so stupid they know next to nothing about the issue and just can’t imagine challenging the almighty state government- forgetting just how revolutionary USED to be this state. I try to tell them that they’ll never win the forestry battle if they continue singing this climate opera. I didn’t participate in the webinar because I don’t think being limited to 3 minutes is sensible. So, I emailed the state a long essay- which, I bet, will be “lost” and not show up online where all the comments are supposed to go. I simply told them that there is no climate emergency- therefore forestry policies don’t need to be adjusted to deal with a non existent problem- and explained all that in detail.

One forestry organization, The New England Forestry Foundation, a non-profit, which has had a scam for almost a century of encouraging people to give them their land (and get tax breaks, etc.)- nice scam- allowing the outfit to pay themselves quite well indeed. Now, the USDA just gave them $30,000,000 to promote “climate smart forestry”. Now on their web site they talk about the wonders of climate smart forestry- basicly explaining good forestry and how it’ll help save the planet. So it’s fine that they’re promoting good forestry but for the wrong reason- plus, that 30 million will help them get nice pay raises and pump up their pension fund.

Richard Page
Reply to  Joseph Zorzin
November 20, 2023 5:55 am

Have you ever thought of just letting them get on with it, but to document the whole process? So if, at some point, the zealot’s do switch you have what they said, the documents they produced and when they said it as evidence? Might make a good book one day – Wokeachussets Madness!

Joseph Zorzin
Reply to  Richard Page
November 20, 2023 6:26 am

oh, that’s what I’m doing- and I’m making some videos to discuss the idiocy


I’ll be cranking up that channel soon- I need to start interviewing people. The software issues can be tricky- using Zoom and now OBS, a very powerful and free video capture program.

Richard Page
Reply to  AndyHce
November 20, 2023 5:48 am

That might be a fair interpretation of Shellenberger’s apparently contradictory positions – want’s to silence the alarmists on both sides and wants sceptics to pipe down so they don’t rock his personal boat.

Ron Long
November 19, 2023 3:13 pm

Great to have Dr. Jennifer laying out real data and facts, and I especially like the verification of the Little Ice Age on the Thames. As I sit here in west-central Argentina, that Good Boy (aka El Niño) is doing his thing. Putting El Niño and La Niña cycles on top of already chaotic trends and trying to make predictions is something best reserved for Carnival Barkers, like Mikey Mann and his assistant AlGore.

Reply to  Ron Long
November 19, 2023 4:44 pm

Any insight into Javier’s victory?

Ron Long
Reply to  Scissor
November 19, 2023 4:57 pm

Scissor, I remember you asked about Javier before. He has just won the Presidential election in Argentina, thus ending a crazy plunge deeper into Socialism. His victory was mostly due to the younger voters being alarmed at the prospects for their future. Here’s the good new relative to WATTS: Javier Milei is against the CAGW nonsense, especially as regards a country chasing after Net Zero.

Reply to  Ron Long
November 19, 2023 8:54 pm

Thanks, that’s great news.

President Biden says that a fentanyl overdose can cause young people to wake up dead. I’m happy that politically some wake up before they’re dead.

Richard Page
Reply to  Ron Long
November 20, 2023 5:58 am

So we should start looking out for media articles casting Javier Milei as a right-wing dictator, with the MSM’s usual heavy-handed but predictable bias?

Dennis Gerald Sandberg
November 19, 2023 3:54 pm

Thanks Jennifer, another layer of truth piled on top off the climate hoax, I’ll be using the below on my Quora postings:

…There is no known physical mechanism whereby carbon dioxide can cause an El Niño. Climate change is a natural hazard…
… – with the southern hemisphere tilted towards the Sun as we approach summer here in Australia. And it is likely to be a scorcher, not because there is more carbon dioxide in the atmosphere, but because the trade winds stopped blowing across the Pacific Ocean earlier this year, with the spiking in the satellite temperature record a manifestation of this.

This warming that reliably began in the central, equatorial Pacific Ocean when the trade winds stopped blowing in April, is caused by lunar tidal gravitational forcing…. End quote.

Reply to  Dennis Gerald Sandberg
November 19, 2023 4:43 pm

My daughter said it was windy in Western Australia today.

Reply to  Scissor
November 19, 2023 5:37 pm

Which part Scissor?
WA is a huge state.
I have rellies there too.

Reply to  Mr.
November 19, 2023 8:56 pm

Near Margaret River. I’ve heard it’s nice and hope to find out.

Dennis Gerald Sandberg
Reply to  Scissor
November 19, 2023 5:45 pm

Scissor, are you suggesting that the trade winds have returned so Jennifer is wrong about, “it is likely to be a scorcher”?

Reply to  Dennis Gerald Sandberg
November 19, 2023 7:39 pm

Er, I think Scissor was asking about wind conditions in Western Australia Dennis.
On the Indian Ocean and Southern Ocean sides of the continent.
The South Pacific trade winds don’t register much on anemometers there.

Reply to  Dennis Gerald Sandberg
November 19, 2023 8:59 pm

I was talking about the last day or two according to what my daughter reported to me. I told that here the weather in Colorado was about the same as in Sacramento for about the past week. That is, it’s been really nice and warm for the time of year.

I can’t imagine how much I’ll sweat when I have to shovel snow if it doesn’t cool down. 🙂

November 19, 2023 7:22 pm

The winter of 1609 in Jamestown Virginia almost finished the new settlement…it was cold….very cold.

Reply to  antigtiff
November 19, 2023 7:41 pm

Maybe their new-fangled heat pumps weren’t all they were cracked up to be?

Reply to  antigtiff
November 19, 2023 9:05 pm

Brave people back then. I wonder what happened to Virginia Dare.

Tom Abbott
Reply to  Scissor
November 20, 2023 4:42 am

Still don’t know.

Tom Abbott
November 20, 2023 4:52 am

From the article: “I now despair that they will ever do anything about restoring integrity into the historical temperature record – for anywhere, at any time.”

The Climate Alarmists cannot acknowledge the written temperature record. If they did, they wouldn’t have anything to be alarmed about with regard to CO2, since it is not any warmer today than it was in the past, and this would blow up their contention that CO2 is the control knob of Earth’s temperatures and would tell us that we don’t need to worry about regulating or limiting CO2, because even though there is more CO2 in the air today, it is no warmer today than in the past when there was less CO2 in the air, so CO2 has had no discernable effect on the Earth’s temperatures.

That being the case, the climate alarmists would be out of a job if they acknowledged the written temperature record, so they refuse to acknowlege it.

The only thing the Climate Alarmist have to point to showing CO2 levels and temperatures correlate is the bogus, bastadized, computer-generated global Hockey Stick charts which do not show that it was just as warm in the past as it is today. That’s the only “evidence” they have, and the written temperature record refutes the temperature profile of the bogus Hockey Stick chart, so Climate Alarmists won’t go anywhere near a written temperature record.

But I have noticed a lot more people questioning the Hockey Stick chart Lie recently. Maybe it’s a trend.

November 20, 2023 5:41 am
November 20, 2023 6:35 am

Here is Happer’s lecture in Australia about CO2, that Jennifer referred to…

November 20, 2023 7:15 am

It is quite clear that atmospheric CO2 levels are a proxy for ocean temperature. The question is what makes the oceans warmer or cooler? How much of the heat flux leaving the planet is associated with ocean vents at the various plate boundaries throughout the oceans. 50,000 years from now, there will more than likely be a huge glacial mass throughout the entire upper Northern hemisphere depressing the crust and consequently heating the near surface more which will melt the ice.

As the glacial rebound continues throughout the twilight of this interglacial, the ocean floor in the North Sea will be and is cooler than it was during the end of the last glacial epoch, and the process will start over. Until Antarctica drifts away from the South pole, the ice melts, sea levels rises 400 feet, and the oceans push down harder at the rifts and warm the oceans back up to Cretaceous temperatures. All of this debate is because a continent moved to the South Pole 35 million years ago and the chaos is still going on, we are still in an Ice Age.

Reply to  LT3
November 21, 2023 3:04 pm

Antarctica moved over the South Pole much longer ago than 35 million years. What happened then was formation of the Southern Ocean, with the opening of deep channels between Antarctica and South America and Australia.

Reply to  Milo
November 21, 2023 3:09 pm


It was there by at least the Late Cretaceous.

Ulric Lyons
November 20, 2023 10:48 am

“Such is the settled science of climate change, that we don’t really know, what caused this part of the North Sea to freeze over.”

The science of climate change can never be settled without knowledge of the discrete solar forcing of major heat and cold waves in the mid latitudes.
Being solar driven they are not constrained by climate, one of the coldest European winters of the last 1500 years, in 763-64, occurred during the decades of the warmest northwest European summers in the last 1500 years (see; Esper 2014).
In 830 and in 1010 the River Nile froze, and at the same type of configuration of the four gas giant planets in 1422, 1603, 1784 and 1963 were a series of extreme cold winters, the latter two being respectively the third and second coldest in England since 1659.
1683-84 winter was at a similar type of gas giant configuration. You can view them here:

(change date as required, change size to say 800, and click update)


Here is the apparent logic at play in the Jovian ordering of the solar forcing of major heat and cold waves. It also sheds light in why 1685-86 was about the second mildest English winter since 1659, it’s a heliocentric analogue of the 2003 summer heatwave, 317.7 years earlier.


Beta Blocker
November 20, 2023 12:06 pm

As part of my reading concerning the possibility of using solar radiation modification (SRM) to quickly reduce the earth’s global mean temperature by injecting millions of tons of SO2 directly into the stratosphere, I asked ChatGPT a series of questions about what might have caused GMT to cool between 1950 and 1975.

I used ChatGPT under an assumption that its answers reflect the consensus thinking of mainstream climate scientists, including the IPCC. My expectation was that the ChatGPT response would include the latest thinking about the role of aerosols in producing the 1950-1975 decline in global mean temperature.

To my surprise, the ChatGPT responses dispute the commonly held opinion that GMT had declined between 1950 and 1975. So I asked two unambiguous questions to confirm that the presence of the 1950-1975 cooling trend was in fact being disputed.

Question #1: “Did the earth actually cool between 1950 and 1975?”

ChatGPT’s response:

“The idea of a global cooling trend between 1950 and 1975 is a topic of some historical interest in climate science. While there were concerns and discussions about global cooling during that time, the evidence for a significant and sustained global cooling trend is not strongly supported by the scientific data.

Several studies and analyses of temperature records from that period have been conducted, and they generally show that the global mean temperature did not exhibit a consistent cooling trend during the 1950-1975 timeframe. Some regions experienced cooling, but others were warming. When considering the global average, the temperature trend was relatively flat or showed a slight increase.

The perception of global cooling during this period was influenced by specific regional climate variations, such as cooling in parts of the Northern Hemisphere and some unusually cold winters. Additionally, scientific understanding of climate at that time was not as advanced as it is today, and there were limitations in data coverage and accuracy.

It’s crucial to distinguish between short-term variability and long-term trends. Subsequent research and more extensive data collection have provided a clearer picture of long-term global temperature trends, which overwhelmingly indicate a warming trend over the past several decades, largely attributed to human activities and the increase in greenhouse gas concentrations in the atmosphere.” (End of 1st Response)

OK …. It appears that mainstream climate scientists do indeed dispute the presence of the 1950-1975 cooling trend. Under the assumption that ChatGPT is programmed to reflect their consensus position, I asked yet another question:

Question #2: “Does the IPCC state that the earth cooled between 1950 and 1975?”

ChatGPT’s response:

“No, the Intergovernmental Panel on Climate Change (IPCC) does not state that the Earth cooled between 1950 and 1975. In fact, the IPCC’s assessments consistently highlight the long-term warming trend in global temperatures, particularly since the mid-20th century.

The IPCC is a scientific body that assesses the latest research on climate change and provides comprehensive reports to inform policymakers. According to the IPCC’s assessments, the Earth’s climate has been warming, and this warming is largely attributed to human activities, such as the burning of fossil fuels and deforestation, leading to increased concentrations of greenhouse gases in the atmosphere.

The idea of global cooling in the mid-20th century was a perception that existed in some scientific discussions and the media at the time, but subsequent research and more extensive data analysis have debunked the notion of a significant and sustained global cooling trend during that period. The IPCC’s findings align with the scientific consensus that the Earth has been experiencing a warming trend, and human activities are a primary driver of this warming.” (End of 2nd Response)

Well …. There you have it …. Just as mainstream climate scientists have erased the Medievil Warm Period from the climate historical record, they are now attempting to erase the 1950-1975 cooling trend from the historical record.

The presence of the 1950-1975 cooling trend raises knotty questions about why it happened. Was it present because of some combination of natural and anthropogenic factors; and if so what specifically were those factors?

When I first saw the ChatGPT responses, I was somewhat surprised. But upon further reflection, it became apparent that what was being said was perfectly predictable.

If you are a mainstream climate scientist, the easist way to deal with this particular knotty scientific question is to deny that the 1950-1975 cooling trend ever occurred at all.

Richard Page
Reply to  Beta Blocker
November 20, 2023 9:00 pm

That is the essence of climate science – ignore or erase contradictory evidence or things that aren’t understood and dumb down the rest.

Reply to  Beta Blocker
November 21, 2023 3:15 pm

Look at NCAR’s graph from 1975, showing pronounced postwar global cooling.


Jennifer Marohasy
Reply to  Beta Blocker
November 21, 2023 9:17 pm

Thanks for the ChatGPT Info. The cooling is very marked in the maximum temperature series (not Tmin, that is often affected by UHI) for most eastern and northern Australian locations (including many cities, e.g. Brisbane and Melbourne). For these Australian locations it tends to begin by 1920 (considering annual data) and if often flattening by 1950, and ending by 1960. FYI.

November 20, 2023 4:28 pm

A good defence of science until Jennifer diverts to her promotion of the unscientific prevailing narrative of church-run schools. Quite ironic I think.

Jennifer Marohasy
Reply to  gc
November 21, 2023 9:22 pm


There is much our institutions could apologise for. The invasion of Iraq and the molesting of boys in Anglican and Catholic Churches across Australia, to begin with. More usually though I complain about the corruption of the historical temperature record, that to. On the issue that you find a diversion, and ironic, the number of times priests were moved rather than jailed is a disgrace. Not just reflecting so badly on these institutions, but on western civilisation more generally. And it is not that I have a problem with the church, as I made clear in the first post in my first post in this series, https://jennifermarohasy.com/2023/10/reconciling-with-nature-god-and-qantas-part-1-arriving-london/

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