Orbital Cycles are not the Cause of the current Global Warming

Superfact 122: We know that the current global warming, or if you call it Climate Change, or Climate Disruption, is caused by us primarily because of our burning of fossil fuels. It is not “natural causes”, and it is not orbital cycles, so called Milankovitch cycles. These orbital cycles include changes in orbital eccentricity, axial tilt, and axial precession.

Three illustrated orbital cycles. On the left orbital eccentricity, in the middle is the axial tilt and on the right axial precession.
Illustration of Milankovitch cycles from MIT’s Climate Primer.

The evidence that the current rapid global warming is chiefly caused by our burning of fossil fuels is extensive and for all practical purposes conclusive. One of the steps towards understanding this evidence is understanding why no known natural cause of climate change can explain the current warming, and that includes orbital cycles. Therefore, this post is just one small step towards preparing you for the evidence that the current rapid global warming is chiefly caused by us. However, there is a lot of disinformation around this specific topic.

Hockey stick curve going back 1,000 years. The recent uptick in global temperature is very sharp and very sudden.
The so-called hockey stick curve depicting the last 1,000 years. The blue line is the first hockey stick curve ever created (by Michael Mann). He used proxy measurements such as tree rings, green-dots 30-year average, red temperature measurements. Wikimedia commons <<https://creativecommons.org/licenses/by-sa/4.0/deed.en>>. This graph is taken from this page.
Again, hockey stick curve going back 1,000 years. This time human causes and natural causes are indicated with a black respective a red shape.
The so-called hockey stick curve depicting the last 1,000 years. In this graph I have indicated what part of the graph is climate change caused by natural causes respective climate change caused by human causes.

Very briefly; Earth’s orbital cycles, called the Milankovitch cycles are largely responsible for the ice ages, but they are not responsible for the current warming because the current warming is too rapid for the orbital cycles to be the cause, and the way the warming is happening is incompatible with how a warming caused by Milankovitch cycles would have happened. In addition, according to the Milankovitch cycles we should be cooling, not warming.

I am considering this a super fact because a lot of people have been fooled by the disinformation on this topic, and there is also a lot of gaslighting from less than reputable organizations and from politicians. They have bamboozled a lot of people. About 15 years ago, I was bamboozled by the disinformation myself. That was before I took the time to try to understand the topic. Understanding a topic, and understanding the evidence makes all the difference, and that is why climate scientists are near unanimous the world over that climate change / global warming is both real and caused by us.

Ask yourself, why would the climate scientists and the atmospheric physicists around the world, including scientists at NASA and NOAA, not investigate orbital cycles and other natural causes for climate change as a possible cause for our current warming? They are the experts on orbital cycles and past climate after all. We know that orbital cycles are not the cause of the current global warming, and this is important to know. Therefore, I think it is a super fact.

What Are Orbital Cycles?

One type of important type of climate forcing that’s been the cause behind the multiple ice ages that we’ve had over the last two million years are earth’s orbital cycles, or the Milankovitch cycles. There are primarily three orbital cycles, orbital eccentricity, change in axial tilt, and axial precession. Could they explain the current warming? No, they can’t because they are too slow, we are currently in a cycle that should be cooling the planet, and the way orbital cycles would warm the planet if they were responsible for the warming is very different from what we are witnessing.

Changes in Eccentricity

Earth’s orbit is not a perfect circle. Earth’s orbit varies from nearly circular to slightly elliptical and this change can cause climate change. This shift in Earth’s orbit takes place over periods of about 100,000 and 400,000 years. Click on the video from NASA below for an illustration of Earth’s eccentricity.

Changes in Obliquity (Tilt)

The angle Earth’s axis of rotation is tilted as it travels around the Sun is known as obliquity. Obliquity is why Earth has seasons. Over the last million years, it has varied between 22.1 and 24.5 degrees with respect to Earth’s orbital plane. The greater Earth’s axial tilt angle, the more extreme our seasons are. In addition, a larger tilt angle favor periods of deglaciation. The changes of Earth’s obliquity have a period of 41,000 years. Click on the video from NASA below for an illustration of the changes in obliquity.

Axial Precession (Wobble)

Earth wobbles slightly as it rotates, like a slightly off-center spinning top. The axis of Earth’s wobble changes slowly and is called axial precession. The corresponding cycle spans 25,771.5 years, or approximately 26,000 years. Click on the video from NASA below for an illustration of the changes in axial precession.

Video Explaining Earth’s Orbital Cycles

The video below from PBS gives an explanation and overview of earth’s three orbital cycles.

Orbital cycles are far too Slow to Cause the Rapid Global Warming Happening Today

The changes in Earth’s orbit and tilt operate over 20,000+ to 100,000-year periods, making Orbital Cycles unable to drive the sharp temperature spikes seen in a single century.

The graph shows the temperature since the last ice age. There is a maximum temperature about 6,000 years ago, then a cooling and then a sharp uptick in temperature.
Global temperature going back twenty thousand years, a hockey stick graph. Notice the stable temperature during the last 10,000 years, coinciding with the development of human civilization, and also notice the sudden sharp increase at the end. Orbital cycles can’t explain that, and it certainly does not look natural.

Orbital Cycles Predict Slow Cooling, not Rapid Heating

About 6,000 years ago Earth’s temperature was a bit warmer than it is today largely due to the climate fluctuations caused by orbital cycles. The warm period in the beginning of the Holocene epoch is referred to as the Holocene climatic optimum. Natural causes for climate change caused Earth’s temperature to slowly cool off until the recent very sudden uptick in average global temperatures.

Temperature record for the last 150,000 years. Notice the sharp uptick towards the end. This picture is taken from this article.
The graph shows wild swings over the last 50,000 years and then a very sharp uptick at the end, which as indicated in the graph is caused by us.
Temperature record for the last 50,000 years. Notice the sharp uptick towards the end. I have circled natural and human caused causes for the climate change. This picture is taken from this article.

Below is a video that explains in greater detail why orbital cycles cannot explain the current warming. You can also read more about it here.

The Cooling of the Upper Atmosphere Tells Us the Current Warming is not Caused by Orbital Cycles or the Sun

Yes, the cooling of the upper atmosphere (specifically the stratosphere above the troposphere) is a key sign that current global warming is not caused by Milankovitch cycles or changes in the sun. Instead, observations show a warming lower layer (troposphere) and a cooling upper layer, which is the exact “fingerprint” of human-caused greenhouse gases. Other evidence that the warming is caused by greenhouse gases and not orbital cycles or the sun is the distribution of the warming across the globe and over time.

A Couple of Videos

The video below is a short one-minute overview of the causes behind global warming.

The video below from NASA is a bit longer, 13 minutes, but it gives a more detailed overview. Click here to see the page from where this is coming from.

Conclusion

We know that Orbital Cycles are not responsible for the current rapid global warming because Orbital Cycles operate on tens of thousands of years or hundreds of thousands of years, not a couple of centuries.

We know that Orbital Cycles are not responsible for the current rapid global warming because the effects of Orbital Cycles are slowly cooling Earth, not warming it.

We know that Orbital Cycles are not responsible for the current rapid global warming because if it was orbital cycles (or the sun) the upper atmosphere would not be cooling and the temperature increases would be distributed differently across Earth and distributed differently with respect to time.

Other super facts related to global warming

To see the other Super Facts click here

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Author: thomasstigwikman

My name is Thomas Wikman. I am a software/robotics engineer with a background in physics. I am currently retired. I took early retirement. I am a dog lover, and especially a Leonberger lover, a home brewer, craft beer enthusiast, I’m learning French, and I am an avid reader. I live in Dallas, Texas, but I am originally from Sweden. I am married to Claudia, and we have three children. I have two blogs. The first feature the crazy adventures of our Leonberger Le Bronco von der Löwenhöhle as well as information on Leonbergers. The second blog, superfactful, feature information and facts I think are very interesting. With this blog I would like to create a list of facts that are accepted as true among the experts of the field and yet disputed amongst the public or highly surprising. These facts are special and in lieu of a better word I call them super-facts.

30 thoughts on “Orbital Cycles are not the Cause of the current Global Warming”

  2. Excellent article. It’s really important to present this information since, as you rightly point out, it’s used by some to obfuscate and distract from the real issues in climate change – which is wholly anthropogenic.

    The very sober body “The Institute and Faculty of Actuaries” have recently published a detailed and alarming risk analysis of climate change entitled “Planetary Solvency – finding our balance with nature. Global risk management for human prosperity”. You can find it here: https://actuaries.org.uk/media/ni4erlna/planetary-solvency.pdf

    It’s very clearly written and the stuff of nightmares.

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    1. Thank you so much Craigavad / Pete and you are certainly right, we know it is anthropogenic, but “it is natural / climate has always changed” always comes up and next those who know a little bit more (but still too little) says “have you ever heard of the oribital / Milakovitch cycles and ice ages” because that is effective disinformation that you see on social media. But it easy to look up, google, wikipedia, ask AI, check NASA, meteorlogical organizations, etc., but people don’t check. Anyway, thank you for the article. It looks like a great article. I did not read the whole article yet but I will.

      I should mention that the Scenario Model Intercomparison Project (which works for IPCC) recommended to remove the RCP8.5 emissions scenario, which is the worst case emissions scenario. The reason being that renewables and EVs are spreading around the world and becoming cheaper and more common. It only means that the doomsday emissions scenario has become implausible, which is a silverlining in this big problem. Our current administration misinterpreted that as IPCC backtracking on the science (not surprising), which never happen.

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  3. Thank you for taking the time to explain this in a clear and understandable way. It’s easy to be misled by misinformation, especially on complex scientific topics. Learning how Earth’s orbital cycles work and why they cannot explain the rapid warming we’re seeing today helps separate evidence from speculation.

    Healthy discussion is important, but it should always be grounded in credible research and an openness to follow where the evidence leads. Education and critical thinking remain our strongest tools for understanding challenges that affect us all.

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    1. Thank you so much Mihran and you are so right. We know our current global warming is anthropogenic, but “it is natural / climate has always changed” always comes up in any discussion and next those who know a little bit more, but still too little, bring up the orbital cycles, “have you ever heard of the oribital / Milakovitch cycles and ice ages”, and I say I have certainly heard about them, but we know it is not orbital cycles. Discussion is good but the facts are so confused. Also, it is easy to look up the science, Universities, NASA, NOAA, meterological organizations, AI, wikipedia, etc., but people don’t look it up, they just trust Facebook memes and political organizations they align with.

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  5. Really interesting to hear about Earth’s orbital Milankovitch cycles. I had no idea they are largely responsible for the ice ages, but aren’t also responsible for the current warming. There’s so much disinformation around this subject, which always makes it great to check out your blog to gain some perspective/clarity!

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    1. What’s even sadder than the existence of misinformation is the number of bloggers, many of whom live and thrive in WordPress, are complicit in spreading it, mostly for their own political purposes. The oil companies have spent millions of dollars over the past few decades to pooh-pooh all the studies on human-made climate change, and many conservatives (some of whom have a financial stake in Big Oil) go along with the claims that Thomas’ Super Fact is refuting.

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      1. Thank you so much Alex. You are so right, (except it is many billions more than millions). Anyway, we know our current global warming is anthropogenic based on the evidence, but the “it is natural / climate has always changed” trope always comes up and the oribital / Milakovitch cycles and ice ages are mentioned. There are politicial organizations that spread lots of disinformation and conspiracy theories. But we need to learn to look up what NASA, NOAA, the world’s meteorological organizations, Universities, climate scientists say, or just check wikipedia or AI, etc., instead of blindly trusting political sources that align with your politics. Also believing your favorite politician over scientists is extremely irrational.

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    2. Thank you so much Ada and you are right, there is a lot of disinformation. We know our current global warming is anthropogenic, but “it is natural / climate has always changed” always comes up in any discussion and next those who know a little bit more, but still too little, bring up the orbital cycles, “have you ever heard of the oribital / Milakovitch cycles and ice ages?”, and they often got that from some Facebook memes or politicial organization that misrepresented the orbital cycles. But NASA, NOAA, the world’s meteorological organizations, Universities, climate scientists, etc., know about this.

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  6. Interesting. This I never herd of but it does seem like this is what people talk about with the crazy notion I see on LinkedIn and some saying yea 1500 years ago they grew wheat in Norway. People will hijack anything for a cause regardless of fact and people believe it. I think a big issue is two fold, first people like John Kerry went nuts with the world will end in 20 years he started that in 2000 and the nonbelievers leverage that. two they need to get out one clear message. I have heard there is no disagreement that it will happen the issue is the scientist do not agree so much on the impact, the when or where. A clear message needs to be pushed.

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    1. Thank you, Kevin. Like you say there is a lot of misinformation and disinformation out there. I should say that people do grow wheat in Norway and Sweden where I grew up so this is not strange. However, I think what you mention probably refers to the Medieval Warm Period, which was likely caused by a combination of decreased volcanic activity, shifts in ocean circulation patterns, and perhaps increased solar activity,  but not orbital cycles. Also, the effects were smaller and tended to be local to certain regions. Natural climate change is real, but the various natural causes cannot explain what is happening now (future posts coming).  I don’t remember John Kerry saying the world will end in 20 years, but he is a politician and they tend to not get things exactly right. The “doomers” are typically not scientists.

      You are right. It is one thing to know that climate change is real and caused by us, chiefly because of the burning of fossil fuels and another to know what the impacts will be. The biggest uncertainty is the emissions scenarios. Basically, how much greenhouse gases will we emit. The good news is that it seems like emissions have finally peaked. EVs, renewable energy, battery technology, etc., has become much cheaper and is spreading around the world, especially in Europe, China, some of the developing countries, and in other places. I was reading that projections for temperature increases by 2100 (over pre-industrial) have changed from 4-6 Celsius to 3 Celsius, not because the climate science changed but because our emissions trajectory has changed. 3 Celsius still means a lot of damage though, but not the end of the world.

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        1. Yes there are so many incorrect claims out there that it is impossible to address them all. People get stuck on them, and then they won’t try to understand the evidence that the current rapid warming is due to our greenhouse gas emissions. They won’t move on from some piece of disinformation they come across. It is one reason I am going to first debunk various “natural causes”, today it was orbital cycles, then the sun, then volcanoes, etc., before presenting the long list of evidence that it is our emissions.

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  7. Great article Thomas. It is baffling that there is still so much misinformation about Climate Change, and that people are willing to believe it over real science. I hope this article is read by many. Maggie

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    1. Yes you are right Maggie. I also think it is baffling that there is still so much misinformation about Climate Change. However, the issue was turned into a political issue, a political football, in the 1990’s and now many people reject the science and believe their political tribe / political organizations / their favorite politician instead, which is a recipe for getting bamboozled. Like I mentioned I fell in this trap myself about 20-15 years. The cure for me was to learn something about the issue. Understanding makes a world of difference.

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    1. Yes you are absolutely right Robbie. Unfortuntaley, the issue has become so politicized and therefore people believe the politics over the science. This gives me the opportunity to state true things that many will refuse to believe, which is one type of “super fact”. The same goes for vaccines and evolution.

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    1. Thank you Linda. I forgot you live in Australia and that there’s winter there right now. It’s been hot every day for long time here in north Texas too. Luckily we have air conditioning and beer. I feel sorry for the homeless and for animals. I put out bowls with water that I switch every day.

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