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Putting the Heat on Climate Dogmatism

04 Jul 2022 | Backgrounders

Putting the Heat on Climate Dogmatism Transcript


You often hear it announced that this or that recent year was the “the hottest year ever.” But how far back is “ever”?

The modern mercury thermometer was invented by Daniel Fahrenheit in the early 1700s, and it wasn’t until the mid-1800s that systematic weather records began being collected around the world. But even then, it was mainly in Europe and the U.S., with a few scattered places on other continents.

By 1900 more places were recording temperatures. But for the world as a whole, over the 20th century, there are reliable records for less than 50 percent of the Earth’s surface, especially over the oceans.

Here in Canada, while some places have data back to the late 1800s, official Canada-wide weather records only begin in 1948.

The world’s atmosphere now has complete coverage from weather satellites, but that record only starts in 1979.

John Robson:

So, “the hottest year ever” is not since the world began, or even since the end of the last ice age, it’s more like since… a few decades ago.

So you might ask what evidence exists that it was as warm or warmer than today in past centuries before thermometers were invented. And I’m glad you asked.

Because for the Climate Discussion Nexus I’m John Robson, and this is a CDN Backgrounder video on past climate warming episodes.


When we try to figure out what happened to the climate in the distant past, we have to decipher indirect clues left behind in things like tree rings, sediment layers in lake beds, deep ice cores, movements of tree lines across the landscape, and even observations in ancient writings. It’s a fuzzy, grainy picture, and it leaves out a lot of important detail.

John Robson:

I mean, it would be like trying to reconstruct all of 20th century U.S. history from Hollywood films. You’d get some things right, but you’d leave a lot out, and you’d have to rely on a lot of guesswork. But no matter how uncertain the science of climate reconstruction is, one thing that emerges very clearly is that the climate is not stable.

It has a long and complex pattern of warming and cooling that, throughout the history of our planet, has seen temperatures most of the time higher than today. And until we can explain why it used to be so much warmer than it is now, we shouldn’t assume that we know what’s behind any warming we’re currently observing or have seen in the last 50 or even 100 years.


Here’s a quick overview of the past 500,000 years as recorded in ice core layers in Antarctica. Scientists look at the chemical composition of each layer of ice and infer what the air temperature likely was when the layer formed.

What we see are repeating patterns of cold conditions that last for about 100,000 years, interrupted by warm conditions that last for about 10,000 years.

The current warm period, called the Holocene, is noticeably cooler than the previous four. And here’s a closeup of Holocene temperatures as recorded by ice core layers in Greenland.

Notice that the climate warmed rapidly as the ice age ended and reached a peak warming in an interval called the Holocene Climate Optimum between 8,000 and 7,000 years ago. Ever since then it’s gradually been cooling, except for the Minoan warm period 3,000 years ago, the Roman warm period 2,000 years ago, the Medieval warm period 1,000 years ago, and the modern warm period.

John Robson:

Now I should mention that that chart has been criticized because the elevation of the ice cap changed over time, and adjustment needs to be made to correct for it. So here’s another Greenland chart from elevation-adjusted records covering the same time interval.


While that record is noisier, the same periodic warming and cooling events are there. If anything it shows a stronger overall cooling trend since the mid-Holocene period, and it shows that it’s been underway now for about 9,000 years.

For those who insist the world is warmer today than ever before, the biggest problem isn’t just the periodic warming and cooling episodes over the past nine millennia, it’s the Holocene Climatic Optimum itself. Not just because its name suggests a belief that warmth is good, but because this episode was so much warmer than today. And it gives us some insight, if we care to look, into what a warmer world would look like.

John Robson:

Do we see runaway warming, a greenhouse effect, extreme weather, crop failure? Do we see hurricanes, wildfires, floods, and droughts causing mass extinction? Coral reefs dying along with polar bears?

No. We don’t see anything of the sort. So we can refute predictions of catastrophes to come if it goes up by another degree by looking at the past that already came, where it was more than a degree warmer, and we find that the Holocene Climatic Optimum was indeed optimal for life, including the Sahara being a moist and verdant land of charismatic megafauna and humans spreading and flourishing as agriculture took hold.

Here we’re not even getting into what happened before the Pleistocene ice age began around two and half million years ago. But we do encourage you to look into it and see that an earth far warmer even than the Holocene Climatic Optimum was also very hospitable to life, not Al Gore’s nature height through the Book of Revelation. And you’ll also find that there is really no correlation between carbon dioxide in the atmosphere and temperature through almost all of it. That is important. But the Holocene alone, a brief and unusually chilly slice of our planet’s history, tells enough of a story all by itself.

And now a word from our sponsor, and yes, it's still you. And we want to thank all the people who’ve responded to our appeals by making a one-time or monthly pledge. For the rest of you, I really want to emphasize for us to produce the videos, for us to produce the newsletters, and keep injecting sanity into the climate debate, what we need is for one in six of our YouTube subscribers to click here and make a pledge of two dollar a month, three dollars a month, five dollars a month. That’s what it’s going to take to sustain our efforts for as long as they’re needed. So click here, cup of coffee a month, that’ll keep us in business.


Within the Holocene, if you look closely, you’ll see that very early in the current interglacial warming there’s a sudden drastic shift called the “Younger Dryas Event”, which was a dramatic cooling, after an even more dramatic warming, larger and faster than anything we’re seeing now. And it all occurred thousands of years before humans started using fossil fuels.

John Robson:

Now let’s step away from deep ice cores for a moment and ask what other clues we have about past climates. Again one, after writing is invented, is written records, not primarily of it being hot or cold at some time or another but agricultural records reflecting amounts collected in tithes, things that indicate where grain or other crops were growing well or poorly.

And also things like the Viking voyages to and settlements in places like “Iceland” and “Greenland” which, even if the latter name reflected wishful thinking or PR rather than accurate reporting, certainly did happen and led to flourishing farming communities that later shrank or, in Greenland’s case, disappeared as temperatures fell after 1300.


The other is physical proxies such as tree lines moving north and south, and up and down hills and mountains, indicating warmer and cooler periods. For instance, a 1997 study of remains of black spruce buried in northern Quebec suggest that it was warm enough for a forest to grow there for at least 1800 years prior to the mid-1500s, but ever since it’s been too cold.

John Robson:

So there you have it. If someone tells you that some recent year is the “hottest ever”, it’s like a clock striking 13, it calls into question everything you’ve heard from them before and everything they’re going to say afterward. That year was far cooler than the Eocene, the Paleocene or Mesozoic.

It may not even be the hottest in the last century given the 1930s unadjusted version. It’s very likely not the hottest in the last thousand years given the Medieval Warm Period. And it’s certainly nowhere near as hot as the Holocene Climatic Optimum.

Hottest year ever? Pfui.

For the Climate Discussion Nexus I’m John Robson, and that’s our Backgrounder on past warming periods.

15 comments on “Putting the Heat on Climate Dogmatism”

  1. Thank you John and team for putting this current warming into perspective! Every time I hear the alarmists talk of hottest ever this or that my blood boils! Now I have some very compelling ammo to refute the verbiage with.

  2. What to do about Climate Change? Below are a series of questions I would challenge you to consider in assessing the severity of climate change and the ability to effectively do anything about it. I will assume that for each question that we answer in support of climate change. Just realize that at any point of the questions that a no, maybe, or not sure invalidates any logic that we should spend billions or trillions of dollars. Key Questions to Ask about the Truth of Climate Change

    1) Is the world actually warming? The earth was recently in a cooling phase, or at least a pause, (1998-2015) for 18 years; thus global warming became climate change. Hurricanes, tornadoes, and droughts have actually decreased in recent decades, not become more severe. If we pull back a million years, or even better, a billion years, we see a steady swing of temperature changes that make Al Gore's hockey stick look insignificant. Did you know that roughly 60% of the last 10,000 years it was actually warmer than today? We are actually at the tail end of an interglacial period (free of an ice age), and are likely to see significant cooling in decades to come. But let us say the earth is warming, then the question is:

    2) Is the climate change significant enough to pose a threat to the planet? The earth has been going through changes in climate constantly, from seasons to decades to eons. Normal fluctuations have been occurring forever without humans being the cause. 80,000 years ago Kansas was under over a mile of ice. 80,000,000 years ago Kansas was a sea over 1,000 feet deep! This all occurred without a single SUV or smokestack, imagine that. But again let’s assume there is some sort of threat that we should pay attention to.

    3) Is the climate change being caused by humans? By far, the largest factor affecting world temperatures is the sun. Just notice the difference in temperature between day and night or winter and summer. The amount of irradiance the earth receives has a dramatic effect on temperature. The yearly cycle of orbiting the sun as significant effect on temperature. But, there are other longer cycles in play as well. The 11-year sun spot cycle affects earth’s temperature. During solar flares, cosmic rays that normal bombard the earth freely, are greatly diminished (pushed aside) by the energy coming from the sun spots. This effects cloud formation. From Google: “Cosmic rays are charged particles that bombard the Earth's atmosphere from outer space. Studies suggest they may influence cloud cover either through the formation of new aerosols (tiny particles suspended in the air that can grow to form seeds for cloud droplets) or by directly affecting clouds themselves.” Clouds can reflect heat entering the earth’s atmosphere (the albedo effect: the measure of diffusive reflection of solar radiation out of the total solar radiation received by a body) or they can help to trap heat beneath them and raise temperature. The balance between lower temperatures ((albedo effect) and raising temperature via entrapping surface heat is not well known. But suffice it to say the sun, cosmic rays and clouds are integral to varying temperatures. The Milankovitch cycle describes the ever-changing relationship between the earth and the sun. The elliptical orbit we have around the sun varies over tens of thousands of years and becomes nearly circular. The 23.5-degree tilt of the sun varies over thousands of years. The “wobble” of the earth changes such that Vegas not Polaris will be true north at some point, and then back again. All of these factors contribute more to changes in temperature cycles than CO2. CO2, the culprit most cited by global warming alarmist, is only about 420 parts per million (PPM) in the atmosphere. The vast majority of CO2 comes from the oceans, decaying biomass, and volcanoes. Only one-tenth of CO2 comes from humans or 42 PPM. Just as a reference, that is like one penny out $250 worth of pennies…very small. CO2 has ranged from 7,000 parts per million to as low as 180 parts per million - and life survived. In fact, in times of higher CO2 concentrations, agriculture flourished, famine was reduced and human advancement increased. Humankind was freed from spending all their time tilling the land and was able to contemplate the stars, write poetry, advance science and ponder the meaning of life. Did you know that greenhouses intentionally pump in CO2 to levels of 1,200 PPM or more because plants thrive in a CO2-enriched environment? Arctic and Antarctic ice cores conclusively show over and over that periods of significant temperature rise always precede the rise in CO2; why? Because the oceans, by far, the largest repository of CO2, release it as temperatures rise. It takes the ocean much longer to warm up (several hundred years). But when it does, what happens? It releases prodigious amounts of CO2? Why? Like a warm soda, it can not keep the trapped and dissolved CO2, it must be released. This leads to massive increases in vegetation (they love CO2) which, as it dies, also releases prodigious amounts of stored CO2. CO2 continues to rise, as a lagged effect, for decades or centuries after a cooling period has started. The causality is just the opposite as expounded by climate alarmist. CO2, as a greenhouse gas (GHG), is a poor retainer of heat. Yes, it does, as a GHG, elevate temperature especially between zero and 400 PPM. However, it is an ever-decreasing asymptotic curve of diminishing affect. It is estimated that a doubling of CO2 to 800 PPM would only have a .7-degree C impact on global average temperatures. Why? Because the bandwidth spectrum that CO2 resides within is nearly saturated at 400 PPM. Let's not forget that water vapor is by far the most abundant GHG (about 85% of GHGs). It has far greater impact on heat absorption in the atmosphere than CO2. But let us for argument sake say that global warming is real, it poses a threat, and it is man-made. Next question.

    4) Is there something that we can practically do to change the threat of global warming? Short of shutting down all fossil fuel consumption, what is it we can do? Will better MPG or electric cars (which use energy from electric plants that predominately burn fossil fuels) stop climate change? Will going to all solar and wind help? Only about 3% of US energy comes from these highly subsidized yet unprofitable businesses. These technologies do not have the ability or resources to provide the energy needed to run the U.S. economy, and won’t have it for decades. If we shut everything down will it make a difference? What data, analysis, or studies show that a 100% effort by humans would change the natural temperature cycles the earth has experienced? But let’s assume we can, next question.

    5) If there are practical things we can do, are they affordable? Who is going to pay for all this climate change remediation? Do we even have a plan of what actions we would take, what the timeline would be, or most importantly how much it would cost? What is the plan except invoking mammoth carbon taxing? Will the poorest 180 countries contribute any money? Probably not. In fact, they likely will receive a massive influx of cash to “fight” global warming. Can you guess why they signed the Paris treaty? One perspective is that climate change is really just a justification and means to help redistribute the wealth of the 20 richest countries, mostly from the U.S., to the poorest nations. Will India or China (who both of whom out pollute the U.S.) agree to divert huge national resources away from their growing economies to solve a problem that many believe doesn’t exist? Does the U.S., which is already $30T in debt, have the resources? All the billionaires in the U.S, only have about $2.5T and all the millionaires only about $20T. So, where does the money come from? Especially if we want to continue to increase U.S. entitlements? President Trump rightly pulled out of the Paris Accord because the U.S. was being forced to pay the preponderance of the costs, and countries like China and India were being allowed to continue to pollute. But let’s assume we can afford it. Next question.

    6) Do we as citizens of the world have the political will to allow our leaders to effect massive changes that would directly affect our pocketbooks, our lifestyles, consumption patterns, and freedoms? Would we be willing to go back to the lifestyle of the pre-industrial world? No electricity, no cars, no iPhones, no lights, no A/C? Okay, maybe not that drastic - how about limiting car usage, rationing electricity, or moving us all into smaller “sustainable” 1970 era Russian-like apartments? If we restrict fossil fuels won’t people start cutting down trees to heat their homes and doing other unhealthy environmental things? What do we do when nations ignore the rules? Do we succumb to a one-world government that has the power and control to force us to give up modern conveniences? It is a lot of ifs, and I for one am not willing to give our government further control of my life on a bunch of flimsy ifs. Who benefits if climate change is a hoax or is being vastly overblown? Government! It gives them more power, more control; and for us, less personal freedom and ultimately, a world dominated by elites and not of, for and by the people. I am not a climate denier; I am a government skeptic! Do we need to be prudent proactive stewards of the earth? Do we need to combat pollution? Of course! Do we need to be told to change our lives based on politicized science - not on my watch! There is no such thing as settled science, that is a non-sequitur. Is global warming real? Is it a threat? Are humans a significant cause? Is there something we can do about it? Can we afford to fix it? These are some of the questions we should all be demanding be answered before we are shackled with the consequences of trying to battle the climate change phantom.

  3. Thank you, Ron Robins, for a very comprehensive and thorough analysis (and refutation!) of AGW conventional alarmist junk science, vs real science. We need a lot more (and more widespread!) of such articles. And many thanks to CDN and John Robson for your excellent and ongoing efforts.

  4. I thought your post addressed the primary "gaps" in the AGW-founded Climate Change narrative. Though there are a few areas that need a bit of polishing, you nailed it! I have very similar conversations with government colleagues, university scientists, and Joe at the bar; and, in 95% of the instances when I bring up the same issues you have articulated in your post, I get one of two responses: 1) "you are NOT a climate scientist...how dare you questions the consensus?", or 2) "WOW...I didn't know that." My point, it's worth having these discussion because there is a large portion of the general public who is NOT hearing the other side of the argument. LEARN ... EDUCATE!!!

  5. Excellent, as always. One thing of serious importance is that the IPCC is mandated to only look at human influences on the climate. It completely ignores natural climate variability. Jim Steele has an excellent 5 part series on YouTube entitled "The big 5 natural causes of global warming.

  6. Yup. That sounds right. From the most basic law of physics we can keep on pumping gigantic amount of co2 in the atmosphere. It won’t impact our atmosphere, and will do absolutely nothing to our climate. Nothing.
    Let’s go with that narrative. Climate change, the best hoax in the world? Or the most fundamental truth grounded in science and vetted by 99.9% of scientists.
    PS: where did you get your stats showing a slow down in extreme weather events. Hopefully not from another “thetruthaboutclimate.org”

  7. 1 Create a scare.
    2 Use something that everyone can experience , but rely on "experts" to interpret.
    3 Rant in public and to politicians. Giving very SELECT facts and LOTS of opinion.
    4 Rant to exceedingly wealthy individuals. ( wealthy people are not the smartest people on Earth.)
    5 Scream until government policies are changed to suit the climate radicals.
    6 Rack in the money !

  8. I too get nervous when people throw up graphs without pproviding their sources, but what do you care what are the sources so long as they are not proven to be fraudulent like that of Michael Mann, Phil Jones, and James Hansen, et. al.

  9. I have always been struck by Patrick Moore's observation that CO2 levels are basically at the lowest they have ever been. We reached 180 and the death of plants is 150. What has been the cause of this fateful natural sequestration? The same process that created the White Cliffs of Dover. Tiny calcium carbonate shelled creatures, Coccolithophores, rain down by the trillions and settle on the ocean floors. This carbon never returns to the cycle, like carbon released by plants when they die or burn. So our release of fossil fuels emissions (which are also permanently sequestered) is reestablishing a much needed level for all life to thrive. Even James Lovelock said at one point: “It is worth thinking that what we are doing in creating all these carbon emissions, far from being something frightful, is stopping the onset of a new ice age.”https://www.express.co.uk/news/uk/162506/How-carbon-gases-have-saved-us-from-a-new-ice-age

  10. David Bennatar; 'gigantic' amounts of CO2? Where did you get the impression that human CO2 outputs are 'gigantic' compared to natural sources?
    Not from some 'WeAreAllGoingToDie' alarmist site, I hope?
    Reality is that nobody knows the level of natural CO2 emissions, but the last real-world experiment, where human emissions dropped by 8%, resulted in no change in the level of CO2 increase as measured by the Mauna Laua observatory...so human emissions are trivial.

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