Why natural cycles only play small role in rate of global warming(carbonbrief.org)
carbonbrief.org
Why natural cycles only play small role in rate of global warming
https://www.carbonbrief.org/guest-post-why-natural-cycles-only-play-small-role-in-rate-of-global-warming
64 comments
Just from a first look, the caption of the figure references Figure 5 in Haustein et al 2019 [1]. You can see that this figure is way more detailed and includes a confidence interval. This article is clearly not a scientific publication but aimed at a broader audience. As for your other questions about the details of the methods used to gather and analyse this dataset, I am sure you can find plenty of information in the actual paper and references therein.
Generally speaking however let me comment that you will not be able to formulate a meaningful critique of the nitty gritty details you inquire about without the equivalent experience of at least a PhD in the specific subfield.
[1] https://sci-hub.tw/https://doi.org/10.1175/JCLI-D-18-0555.1
Generally speaking however let me comment that you will not be able to formulate a meaningful critique of the nitty gritty details you inquire about without the equivalent experience of at least a PhD in the specific subfield.
[1] https://sci-hub.tw/https://doi.org/10.1175/JCLI-D-18-0555.1
"it's for a popular audience" is a bad justification for publishing misleading or wrong information that teaches people a wrong headed view of what a science is. It's not just poor quality, it's a actively harmful to culture and social progress. It's a supernormal stimulus, the journalism equivalent of replacing real foods by sugar and oil mixes -- it pushes people toward preferring wrong things over right things.
The general public care about conclusions of the science, not making up their own minds about what the science says. The overall article does a very good job of summarizing the paper. I'm not sure that what you're looking at as "wrong information" actually qualifies as such.
I'm so glad to see you bring this up. In my graduate physics training, I was taught to be extremely cautious about statistical significance, error propagation, and error bars. I remain skeptical of our conclusions about AGW, not because I have a political view on the subject, but because I'm skeptical that our temperature measurements from 120 years ago have a precision of less than 1 degree C.
But I (sincerely) assume that the climate scientists working in this space have compensated for this lack of precision in their conclusions. Right?
But I (sincerely) assume that the climate scientists working in this space have compensated for this lack of precision in their conclusions. Right?
Hyperskepticism run wild. You, an outsider, doubt the science because you think that the people who have specialized in the field and have spent their careers collecting data are not as smart as you and have overlooked the quality of their data sets.
I'll go farther and say nobody better understands the limits of their data sets than the people who work with them.
I'll go farther and say nobody better understands the limits of their data sets than the people who work with them.
I think my problem with the whole thing is how politicized AGW has become. There are supporters saying 'temperature is not climate when it comes to disproving climate change, yet try to use the same argument when proving that it exists.
Many supported laws for trying to reduce emissions are nothing more than wealth transfer schemes used by one group to take power from another.
I also would like to know how so many experts in their field missed the fact that they were using incorrect data sets for so many years. Google 'climate gate'. Nobody talks about it anymore, but it was a serious enough problem that hundreds of universities had to come out with retractions/explanations.
If you are a scientist that doesn't support the current narrative about climate change, you will have a difficult time getting funding and your career will most likely be over the second you submit anything for review. I've noticed that scientists that do have contrary theories are either retired or plain on retiring..for this very reason.
If scientists are going to be the authority now, what about things like the definition of sex/gender? Is it only an authority when it suits our political needs?
I don't deny that climate change is happening. There is just too much noise to really know the actual truth about the extent of the damage and what we can do to prevent it.
Many supported laws for trying to reduce emissions are nothing more than wealth transfer schemes used by one group to take power from another.
I also would like to know how so many experts in their field missed the fact that they were using incorrect data sets for so many years. Google 'climate gate'. Nobody talks about it anymore, but it was a serious enough problem that hundreds of universities had to come out with retractions/explanations.
If you are a scientist that doesn't support the current narrative about climate change, you will have a difficult time getting funding and your career will most likely be over the second you submit anything for review. I've noticed that scientists that do have contrary theories are either retired or plain on retiring..for this very reason.
If scientists are going to be the authority now, what about things like the definition of sex/gender? Is it only an authority when it suits our political needs?
I don't deny that climate change is happening. There is just too much noise to really know the actual truth about the extent of the damage and what we can do to prevent it.
> Eight committees investigated the allegations and published reports, finding no evidence of fraud or scientific misconduct. The scientific consensus that global warming is occurring as a result of human activity remained unchanged throughout the investigations.
https://en.wikipedia.org/wiki/Climatic_Research_Unit_email_c...
https://en.wikipedia.org/wiki/Climatic_Research_Unit_email_c...
I was away for a few days so I didn't respond to your comment immediately.
Yes, AGW has become a political football. The fact that Al Gore is a democrat and popularized the issue has probably hurt the issue more than anything. But politics is beside the point. What does the science say? The peer-reviewed stuff where they publish there data and methodology?
You say you don't deny that climate change is happening, yet everything you point to are talking points of deniers. Climate gate was a non-scandal. Yes, data collection is a messy and expensive business, and a lot of reconciling of various data sets has to be done. Yes, one of the people doing that work found a "trick" to figure out how the unannotated data set could be interpreted to explain why the paper which was associated with that data set arrived at the conclusion it did. That doesn't mean they were tricking the public.
Then you go off on a tangent about scientists and gender issues, which makes me think that you are really trying to address some wider point than that of climate change denial.
You conclude with the same FUD that the smoking lobby used -- sure there are lots of studies that seem to indicate that smoking causes cancer, but you know there are some studies (paid for by the tobacco industry) that show it isn't a problem, so geez, it seems like we don't know enough yet to do anything about it.
I thoroughly reject that stance. Businesses of all kinds have to make decisions based on incomplete and even contradictory data every day; we put people in jail for life or even kill them based on evidence which is not 100.00000% proven. Why, when it comes to climate change, are some people holding out for a mathematical proof or something? Why shouldn't we proceed based on the best available information? Why should the claims of climatologists, with thousands of man-years of research and published data be insufficient, yet a nay-sayer can say without any proof that addressing climate change would be disastrous to the economy?
Yes, AGW has become a political football. The fact that Al Gore is a democrat and popularized the issue has probably hurt the issue more than anything. But politics is beside the point. What does the science say? The peer-reviewed stuff where they publish there data and methodology?
You say you don't deny that climate change is happening, yet everything you point to are talking points of deniers. Climate gate was a non-scandal. Yes, data collection is a messy and expensive business, and a lot of reconciling of various data sets has to be done. Yes, one of the people doing that work found a "trick" to figure out how the unannotated data set could be interpreted to explain why the paper which was associated with that data set arrived at the conclusion it did. That doesn't mean they were tricking the public.
Then you go off on a tangent about scientists and gender issues, which makes me think that you are really trying to address some wider point than that of climate change denial.
You conclude with the same FUD that the smoking lobby used -- sure there are lots of studies that seem to indicate that smoking causes cancer, but you know there are some studies (paid for by the tobacco industry) that show it isn't a problem, so geez, it seems like we don't know enough yet to do anything about it.
I thoroughly reject that stance. Businesses of all kinds have to make decisions based on incomplete and even contradictory data every day; we put people in jail for life or even kill them based on evidence which is not 100.00000% proven. Why, when it comes to climate change, are some people holding out for a mathematical proof or something? Why shouldn't we proceed based on the best available information? Why should the claims of climatologists, with thousands of man-years of research and published data be insufficient, yet a nay-sayer can say without any proof that addressing climate change would be disastrous to the economy?
> There are supporters saying 'temperature is not climate when it comes to disproving climate change, yet try to use the same argument when proving that it exists.
Everywhere I've seen both these arguments used, the attempted-disprovers are using something like "worst snowstorm ever in X location means it can't be getting warmer", whereas the supporters are talking about the average temperature of the whole planet, and how the increase in energy in the system is causing extreme weather, both hot and cold.
tl;dr– local temperature vs average temperature: not the same argument.
If you have counter-examples, I'd welcome them.
Everywhere I've seen both these arguments used, the attempted-disprovers are using something like "worst snowstorm ever in X location means it can't be getting warmer", whereas the supporters are talking about the average temperature of the whole planet, and how the increase in energy in the system is causing extreme weather, both hot and cold.
tl;dr– local temperature vs average temperature: not the same argument.
If you have counter-examples, I'd welcome them.
Dunning Kruger
I'm curious if you extend that attitude of "outsiders should believe what we tell them" to other fields? Nutrition science or social psychology, perhaps. What about the humanities?
I'm not convinced that a well-educated observer from outside of a field must be incapable of spotting flaws in the reasoning of professionals or the evidence they use to support it.
I'm not convinced that a well-educated observer from outside of a field must be incapable of spotting flaws in the reasoning of professionals or the evidence they use to support it.
Dr. Valentina Zharkova & Dr. Henrik Svensmark refute this fallacy.
Dr. Svensmark lost his institutional funding when he found & published experimental evidence & a model that cosmic radiation seeds clouds. This highlights the monetary & career incentive to hold a certain position. Any deviation from that position will result in a loss of funding.
Dr. Svensmark is now independently funded. Here is one of his presentations.
https://www.youtube.com/watch?v=Rg3MqdBX0_k
Dr. Svensmark lost his institutional funding when he found & published experimental evidence & a model that cosmic radiation seeds clouds. This highlights the monetary & career incentive to hold a certain position. Any deviation from that position will result in a loss of funding.
Dr. Svensmark is now independently funded. Here is one of his presentations.
https://www.youtube.com/watch?v=Rg3MqdBX0_k
Precision thermometry is an old science. Fahrenheit obtained a precision less than 1 °C using a mercury-in-glass thermometer in 1714. Platinum resistance thermometers were developed around 1900. These technologies are still used today.
Furthermore, accuracy greater than the precision of an individual measurement may be obtained by averaging multiple measurements.
All the tools needed to accurately track temperature existed 120 years ago. For what reasons do you believe that meteorologists did not use the tools available to them?
Furthermore, accuracy greater than the precision of an individual measurement may be obtained by averaging multiple measurements.
All the tools needed to accurately track temperature existed 120 years ago. For what reasons do you believe that meteorologists did not use the tools available to them?
microcolonel(1)
The headline of this post is bullshit. The author of the article doesn't prove "natural cycles" play small role. He claims that the data he analyses points to the conclusion one specific 60-70 year old cycle of oceanic origin has far less impact on climate than commonly accepted. He talks about one mechanism, there are plenty of other natural mechanisms that affect the climate in various ways.
Quoting the article: >This means that ocean cycles on timescales of 60-70 years are unlikely to be a factor in the observed evolution of global temperatures since 1850. Instead, external factors, such as periods of strong volcanic activity and the release of aerosol particles (air pollution), have caused temperatures to fluctuate.
Quoting the article: >This means that ocean cycles on timescales of 60-70 years are unlikely to be a factor in the observed evolution of global temperatures since 1850. Instead, external factors, such as periods of strong volcanic activity and the release of aerosol particles (air pollution), have caused temperatures to fluctuate.
If you look to the paper the article is about - 'A limited role for unforced internal variability in 20th century warming.' - it does seem to demonstrate that natural cycles play small role and the way it is set up it doesn't have to look at all natural cycles to do that.
>Using a two-box impulse response model, we demonstrate that multidecadal ocean variability was unlikely to be the driver of observed changes in global mean surface temperature (GMST) after 1850 A.D. Instead, virtually all (97-98%) of the global low-frequency variability (> 30 years) can be explained by external forcing. We find similarly high percentages of explained variance for inter-hemispheric and land-ocean temperature evolution.
edit - link to paper - https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-18-0555....
>Using a two-box impulse response model, we demonstrate that multidecadal ocean variability was unlikely to be the driver of observed changes in global mean surface temperature (GMST) after 1850 A.D. Instead, virtually all (97-98%) of the global low-frequency variability (> 30 years) can be explained by external forcing. We find similarly high percentages of explained variance for inter-hemispheric and land-ocean temperature evolution.
edit - link to paper - https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-18-0555....
It still seems ass-about to me. The study doesn't show that natural cycles don't do much, it shows that in our models the external forcing they added is sufficient to cause the observed results.
We already know there's more going on than our models account for (consider the post-9/11 discovery of global dimming from airliner exhausts, as one example). There are probably a heap of effects pushing the measured temperatures in each direction that we don't yet know about.
(Note that I'm not saying natural cycles ARE responsible for the bulk of observed warming - just that this research doesn't seem to prove they're NOT.)
We already know there's more going on than our models account for (consider the post-9/11 discovery of global dimming from airliner exhausts, as one example). There are probably a heap of effects pushing the measured temperatures in each direction that we don't yet know about.
(Note that I'm not saying natural cycles ARE responsible for the bulk of observed warming - just that this research doesn't seem to prove they're NOT.)
>(Note that I'm not saying natural cycles ARE responsible for the bulk of observed warming - just that this research doesn't seem to prove they're NOT.)
Well it can't, can it? All it can do is provide evidence one way or another. Now if you think that there is a problem in the model they are using, could you point to it and explain the specific issue? I assume that it is somewhat updated since 9/11 and I also suspect that aerosol effects of airliner exhausts will have been known about to the subject of atmospheric physics, 9/11 will have just given some solid numbers. Which are now presumably in the models.
Well it can't, can it? All it can do is provide evidence one way or another. Now if you think that there is a problem in the model they are using, could you point to it and explain the specific issue? I assume that it is somewhat updated since 9/11 and I also suspect that aerosol effects of airliner exhausts will have been known about to the subject of atmospheric physics, 9/11 will have just given some solid numbers. Which are now presumably in the models.
OK, OK, I was using laymans' terms. If you want to get picky about can't-prove-a-negatives then read it as "this research doesn't seem to provide much evidence that they're NOT."
If you think that there is a problem in the model they are using, could you point to it and explain the specific issue?
It's worth noting that the 9/11 U.S. insolation study showed a human-created mitigating factor, not a causal factor. That is, it showed that high-altitude contrails create clouds high enough to raise the average albedo and reflect solar energy that otherwise would reach the surface. This is, to some extent, "hiding" a portion of the true warming one would expect from the current mix of the atmosphere and solar activity.
That doesn't offer evidence either way for a hypothesis that there are natural processes yet undescribed that could surprise us with their contribution to warming. Discovering one new thing about a complex phenomenon doesn't make it more likely that another new thing is out there to be discovered. If anything, it makes it less likely, on the theory that there are a finite number of factors contributing to a result of given significance in a deterministic system--in this case, global average temperature trend.
And anyway, what we're really worried about is long-term warming, and this paper is not about that. It's about factors that contribute to temperature variance on shorter time scales during the known long-term warming. From the article:
> However, the relative influences of natural drivers of climate change – such as volcanic eruptions, ocean cycles, and the sun – on warmer and cooler phases superimposed on the long-term warming trend is still an area of active research.
There are two levels to the question of global warming. One is the overall, global question--are we making the surface of the Earth warmer by burning fossil fuels? This is a relatively simple question to answer, so simple that it was first proposed over a century ago, basically when thermodynamics was being invented. Very little contemporary research goes toward answering this question; it has basically been answered.
The other level is: can we predict the consequences of this warming at time scales and resolutions relevant to human society? This is an incredibly complex endeavor and where the bulk of contemporary time and resources are spent (including this paper).
That doesn't offer evidence either way for a hypothesis that there are natural processes yet undescribed that could surprise us with their contribution to warming. Discovering one new thing about a complex phenomenon doesn't make it more likely that another new thing is out there to be discovered. If anything, it makes it less likely, on the theory that there are a finite number of factors contributing to a result of given significance in a deterministic system--in this case, global average temperature trend.
And anyway, what we're really worried about is long-term warming, and this paper is not about that. It's about factors that contribute to temperature variance on shorter time scales during the known long-term warming. From the article:
> However, the relative influences of natural drivers of climate change – such as volcanic eruptions, ocean cycles, and the sun – on warmer and cooler phases superimposed on the long-term warming trend is still an area of active research.
There are two levels to the question of global warming. One is the overall, global question--are we making the surface of the Earth warmer by burning fossil fuels? This is a relatively simple question to answer, so simple that it was first proposed over a century ago, basically when thermodynamics was being invented. Very little contemporary research goes toward answering this question; it has basically been answered.
The other level is: can we predict the consequences of this warming at time scales and resolutions relevant to human society? This is an incredibly complex endeavor and where the bulk of contemporary time and resources are spent (including this paper).
I wasn't trying to show that there are specifically natural factors as yet undescribed, just that there was a significant factor that we didn't know about until recently. This indicates that we could easily have missed others (natural or otherwise), and so any argument which assumes that our climate models are complete is flawed from the start.
> what we're really worried about is long-term warming, and this paper is not about that
Well, it sort of is, because it's saying that the argument against long term warming is that our short term observations are being caused by some cyclic behaviour rather than human CO2 emissions. We can't just carve off "long term warming" as a separate already-agreed thing (at least, not using the results in this paper).
> what we're really worried about is long-term warming, and this paper is not about that
Well, it sort of is, because it's saying that the argument against long term warming is that our short term observations are being caused by some cyclic behaviour rather than human CO2 emissions. We can't just carve off "long term warming" as a separate already-agreed thing (at least, not using the results in this paper).
>any argument which assumes that our climate models are complete is flawed from the start.
Could you point me to such an argument? As I don't believe that anyone has made it here.
Could you point me to such an argument? As I don't believe that anyone has made it here.
Yes, the headline is rather self-defeating. I studied persuasion techniques before the Internet got big and one of the trendy manipulation approaches then was to write an article titled "Why XXX" when XXX is some assertion you make, perhaps even with evidence but for which you don't actually offer an explanation (the reader never discovers why XXX, they are only that XXX is true, and why XXX is generally something people would be curious about). This technique naturally has become an arrow in the quiver of click-baiters but with click-bait sooo big now, using such bullshit is more likely to hurt a serious article than help it.
The proper title would be "we show human-generated carbon is sufficient to explain climate for the X many years", a significant claim by itself.
The proper title would be "we show human-generated carbon is sufficient to explain climate for the X many years", a significant claim by itself.
There are other cycles, most of which are right now in a cooling phase, and yet we are warming. So those cycles (i.e. Milankovich cycles) can be written off already
Plate tectonics are another huge factor. When Pangea existed there was just one ocean to distribute heat and no polar continent for glaciers to form on and increase the Earth’s albedo. That meant a much warmer planet.
The Quaternary glaciation is still ongoing because of those tectonic factors.
Another fun fact is that the warmest period in human existence was the Holocene maximum about 8000 years ago[1].
Geology is a fascinating field and thankfully lets us look at climate through a lens that isn’t intensely politicized.
[1] https://en.m.wikipedia.org/wiki/Holocene_climatic_optimum#/m...
The Quaternary glaciation is still ongoing because of those tectonic factors.
Another fun fact is that the warmest period in human existence was the Holocene maximum about 8000 years ago[1].
Geology is a fascinating field and thankfully lets us look at climate through a lens that isn’t intensely politicized.
[1] https://en.m.wikipedia.org/wiki/Holocene_climatic_optimum#/m...
Or, rather than written off, treated as mitigating factors.
From my initial glance at the post and paper, they seem to be claiming that the factors they do look at account for almost all the variation. If this is a correct attribution, then there can't be big role for any other factors, known or unknown.
Now, it's easy to fool oneself in this sort of modelling exercise - by fitting lots of parameters to the data, one can seem to account for lots of variation, without actually capturing the true relationship. I haven't looked at the paper in detail yet, so I can't say whether or not they avoided this pitfall.
Now, it's easy to fool oneself in this sort of modelling exercise - by fitting lots of parameters to the data, one can seem to account for lots of variation, without actually capturing the true relationship. I haven't looked at the paper in detail yet, so I can't say whether or not they avoided this pitfall.
[deleted]
Have been reading the late and great David MacKay's Sustainable Energy - Without the Hot Air lately (completely free on withouthotair.com)
https://www.withouthotair.com/c1/page_5.shtml
>The climate-change motivation is argued in three steps: one: human fossil- fuel burning causes carbon dioxide concentrations to rise; two: carbon dioxide is a greenhouse gas; three: increasing the greenhouse effect in- creases average global temperatures (and has many other effects).
>Fossil fuel burning increases CO2 concentrations significantly. But does it matter? “Carbon is nature!”, the oilspinners remind us, “Carbon is life!” If CO2 had no harmful effects, then indeed carbon emissions would not matter.
>However, carbon dioxide is a greenhouse gas. Not the strongest greenhouse gas, but a significant one nonetheless. Put more of it in the atmosphere, and it does what greenhouse gases do: it absorbs infrared radiation (heat) heading out from the earth and reemits it in a random di- rection; the effect of this random redirection of the atmospheric heat traffic is to impede the flow of heat from the planet, just like a quilt. So carbon dioxide has a warming effect. This fact is based not on complex historical records of global temperatures but on the simple physical properties of CO2 molecules. Greenhouse gases are a quilt, and CO2 is one layer of the quilt.
> One last thing about the climate-change motivation: while a range of human activities cause greenhouse-gas emissions, the biggest cause by far is energy use. Some people justify not doing anything about their energy use by excuses such as “methane from burping cows causes more warming than jet travel.” Yes, agricultural by-products contributed one eighth of greenhouse-gas emissions in the year 2000. But energy-use contributed three quarters (figure 1.9). The climate change problem is principally an energy problem.
Watched Merchants of Doubt recently, point that stuck with me most is that people against global warming are motivated by libertarianism, and anti-communism. lots of the contrarian scientists worked during the cold war. Will be checking out the book version soon
I don't think you even need the climate change motivation to get behind moving off fossil fuels (supply chain security is another huge one, I find climate change deniers often also in the peak oil camp). The way David MacKay presents the numbers allows people to come up with realistic plans to move off fossil fuels on their own instead of reciting someone else's dogma
Teasing out cause and effect is difficult especially with something that we can't perform randomized experiments on. I'd like to read more about counterfactuals and causal analysis of climate change
Judea Pearl has a great little bit about this in The Book of Why
>Until recently, climate scientists have found it very difficult and awkward to answer questions like “Did global warming cause this storm [or this heat wave, or this drought]?” The conventional answer has been that individual weather events cannot be attributed to global climate change. Yet this answer seems rather evasive and may even contribute to public indifference about climate change.
> Counterfactual analysis allows climate scientists to make much more precise and definite statements than before. It requires, however, a slight addition to our everyday vocabulary. It will be helpful to distinguish three different kinds of causation: necessary causation, sufficient causation, and necessary-and-sufficient causation.
> Using these words, a climate scientist can say, “There is a 90 percent probability that man-made climate change was a necessary cause of this heat wave,” or “There is an 80 percent probability that climate change will be sufficient to produce a heat wave this strong at least once every 50 years.” The first sentence has to do with attribution: Who was responsible for the unusual heat? The second has to do with policy. It says that we had better prepare for such heat waves because they are likely to occur sooner or later. Either of these statements is more informative than shrugging our shoulders and saying nothing about the causes of individual weather events
> Climate scientists can get counterfactuals very easily from their computer models: just enter in a new number for the carbon dioxide concentration and let the program run.
and one of my favorite quotes from MacKay:
> Please don't get me wrong: I'm not trying to be pro-nuclear or anti-wind. I'm just pro-arithmetic
https://www.withouthotair.com/c1/page_5.shtml
>The climate-change motivation is argued in three steps: one: human fossil- fuel burning causes carbon dioxide concentrations to rise; two: carbon dioxide is a greenhouse gas; three: increasing the greenhouse effect in- creases average global temperatures (and has many other effects).
>Fossil fuel burning increases CO2 concentrations significantly. But does it matter? “Carbon is nature!”, the oilspinners remind us, “Carbon is life!” If CO2 had no harmful effects, then indeed carbon emissions would not matter.
>However, carbon dioxide is a greenhouse gas. Not the strongest greenhouse gas, but a significant one nonetheless. Put more of it in the atmosphere, and it does what greenhouse gases do: it absorbs infrared radiation (heat) heading out from the earth and reemits it in a random di- rection; the effect of this random redirection of the atmospheric heat traffic is to impede the flow of heat from the planet, just like a quilt. So carbon dioxide has a warming effect. This fact is based not on complex historical records of global temperatures but on the simple physical properties of CO2 molecules. Greenhouse gases are a quilt, and CO2 is one layer of the quilt.
> One last thing about the climate-change motivation: while a range of human activities cause greenhouse-gas emissions, the biggest cause by far is energy use. Some people justify not doing anything about their energy use by excuses such as “methane from burping cows causes more warming than jet travel.” Yes, agricultural by-products contributed one eighth of greenhouse-gas emissions in the year 2000. But energy-use contributed three quarters (figure 1.9). The climate change problem is principally an energy problem.
Watched Merchants of Doubt recently, point that stuck with me most is that people against global warming are motivated by libertarianism, and anti-communism. lots of the contrarian scientists worked during the cold war. Will be checking out the book version soon
I don't think you even need the climate change motivation to get behind moving off fossil fuels (supply chain security is another huge one, I find climate change deniers often also in the peak oil camp). The way David MacKay presents the numbers allows people to come up with realistic plans to move off fossil fuels on their own instead of reciting someone else's dogma
Teasing out cause and effect is difficult especially with something that we can't perform randomized experiments on. I'd like to read more about counterfactuals and causal analysis of climate change
Judea Pearl has a great little bit about this in The Book of Why
>Until recently, climate scientists have found it very difficult and awkward to answer questions like “Did global warming cause this storm [or this heat wave, or this drought]?” The conventional answer has been that individual weather events cannot be attributed to global climate change. Yet this answer seems rather evasive and may even contribute to public indifference about climate change.
> Counterfactual analysis allows climate scientists to make much more precise and definite statements than before. It requires, however, a slight addition to our everyday vocabulary. It will be helpful to distinguish three different kinds of causation: necessary causation, sufficient causation, and necessary-and-sufficient causation.
> Using these words, a climate scientist can say, “There is a 90 percent probability that man-made climate change was a necessary cause of this heat wave,” or “There is an 80 percent probability that climate change will be sufficient to produce a heat wave this strong at least once every 50 years.” The first sentence has to do with attribution: Who was responsible for the unusual heat? The second has to do with policy. It says that we had better prepare for such heat waves because they are likely to occur sooner or later. Either of these statements is more informative than shrugging our shoulders and saying nothing about the causes of individual weather events
> Climate scientists can get counterfactuals very easily from their computer models: just enter in a new number for the carbon dioxide concentration and let the program run.
and one of my favorite quotes from MacKay:
> Please don't get me wrong: I'm not trying to be pro-nuclear or anti-wind. I'm just pro-arithmetic
Why do we continue to debate climate change focusing on centuries old data when the carbon cycle takes hundreds of millions of years? Any data we've collected amounts to less than a rounding error.
This was an interesting article and the author has strong data. I would want to know about the Younger Dryas [1] period though. This is a warming period about 12,000 years ago when some of the most devastating geological events we know of happen. This includes the outburst floods of glaciers holding back bodies of water larger than Lake Erie (Lake Agassiz [2] for example) and a temperature differential in Greenland of 27 degrees Fahrenheit cooler compared to today.
Human being play a huge role in climate change, but I don’t want to also write off the absolute enormous shifts than can occur naturally. We need to take those just as seriously for our own security.
[1] https://en.wikipedia.org/wiki/Younger_Dryas
[2] https://www.dmr.nd.gov/ndgs/ndnotes/agassiz/
Human being play a huge role in climate change, but I don’t want to also write off the absolute enormous shifts than can occur naturally. We need to take those just as seriously for our own security.
[1] https://en.wikipedia.org/wiki/Younger_Dryas
[2] https://www.dmr.nd.gov/ndgs/ndnotes/agassiz/
It was almost certainly caused by one or multiple comet fragment impacts.
Sources: https://scholar.google.fr/scholar?as_ylo=2018&q=hiawatha+cra...
Sources: https://scholar.google.fr/scholar?as_ylo=2018&q=hiawatha+cra...
No, speaking as a former glaciologist, that's not likely to be true. The parent poster is correct. Younger Dryas featured multiple advances and retreats, which is inconsistent with an impact. Multiple impact over many centuries just isn't that statistically likely, and we would see better evidence of it.
Instead, the most probably cause is freshwater pulses coming out of the melting Laurentide ice sheet changing circulation in the Atlantic. This is actually quite well supported.
Younger Dryas was also confined to the parts of the northern hemisphere, mainly in higher latitudes. A large enough impact to significantly alter climate would see the resulting particulates globally mix in the atmosphere, resulting in more uniform cooling.
Instead, the fact that it was confined to parts of the northern hemisphere also supports the freshwater pulse hypothesis, since it is only a change in the transport of heat from the tropics to the pole, not a change in total heat.
The fact that freshwater pulses from the Laurentide ice sheet caused so much cooling is actually a concern with climate change. It's possible that it could happen again with melting of the Greenland Ice Sheet, at least a weakened version of it (the Laurentide Ice Sheet dwarfed the GIS).
Instead, the most probably cause is freshwater pulses coming out of the melting Laurentide ice sheet changing circulation in the Atlantic. This is actually quite well supported.
Younger Dryas was also confined to the parts of the northern hemisphere, mainly in higher latitudes. A large enough impact to significantly alter climate would see the resulting particulates globally mix in the atmosphere, resulting in more uniform cooling.
Instead, the fact that it was confined to parts of the northern hemisphere also supports the freshwater pulse hypothesis, since it is only a change in the transport of heat from the tropics to the pole, not a change in total heat.
The fact that freshwater pulses from the Laurentide ice sheet caused so much cooling is actually a concern with climate change. It's possible that it could happen again with melting of the Greenland Ice Sheet, at least a weakened version of it (the Laurentide Ice Sheet dwarfed the GIS).
A report was published in Nature in spring of this year showing multiple lines of evidence for impact-related effects in the YDB layer in southern Chile:
"In the most extensive investigation south of the equator, we report on a ~12,800-year-old sequence at Pilauco, Chile (~40°S), that exhibits peak YD boundary concentrations of platinum, gold, high-temperature iron- and chromium-rich spherules, and native iron particles rarely found in nature. A major peak in charcoal abundance marks an intense biomass-burning episode, synchronous with dramatic changes in vegetation, including a high-disturbance regime, seasonality in precipitation, and warmer conditions. This is anti-phased with northern-hemispheric cooling at the YD onset, whose rapidity suggests atmospheric linkage. The sudden disappearance of megafaunal remains and dung fungi in the YDB layer at Pilauco correlates with megafaunal extinctions across the Americas. The Pilauco record appears consistent with YDB impact evidence found at sites on four continents."
https://www.nature.com/articles/s41598-018-38089-y
"In the most extensive investigation south of the equator, we report on a ~12,800-year-old sequence at Pilauco, Chile (~40°S), that exhibits peak YD boundary concentrations of platinum, gold, high-temperature iron- and chromium-rich spherules, and native iron particles rarely found in nature. A major peak in charcoal abundance marks an intense biomass-burning episode, synchronous with dramatic changes in vegetation, including a high-disturbance regime, seasonality in precipitation, and warmer conditions. This is anti-phased with northern-hemispheric cooling at the YD onset, whose rapidity suggests atmospheric linkage. The sudden disappearance of megafaunal remains and dung fungi in the YDB layer at Pilauco correlates with megafaunal extinctions across the Americas. The Pilauco record appears consistent with YDB impact evidence found at sites on four continents."
https://www.nature.com/articles/s41598-018-38089-y
That just means that there was an impact at around the same time. There's been numerous impacts like this that have been claimed to be the cause of Younger Dryas in the past. However, just because there was an impact doesn't mean it had anything to do with YD.
The Atlantic meridional overturning current shutdown from a freshwater pulse is much more parsimonious, and is exactly what we would expect from the physics of the Laurentide melt going into the Atlantic.
Impacts still don't explain the multiple advance and retreats during the Laurentide, but it is obvious why that would occur with the AMOC shutdown explanation:
Melting causes the AMOC to shut down, causing nothern hemisphere cooling. The cooling reduces melting, inducing the AMOC to start back up, increasing melting once again.
The Atlantic meridional overturning current shutdown from a freshwater pulse is much more parsimonious, and is exactly what we would expect from the physics of the Laurentide melt going into the Atlantic.
Impacts still don't explain the multiple advance and retreats during the Laurentide, but it is obvious why that would occur with the AMOC shutdown explanation:
Melting causes the AMOC to shut down, causing nothern hemisphere cooling. The cooling reduces melting, inducing the AMOC to start back up, increasing melting once again.
I accept part of what you're saying, which I believe is that the Laurentide melt was probably happening anyways, with the associated effects on the AMOC. Glacial oscillation are their own cycle, clearly.
But the YD impact scenario hardly seems irrelevant to the YD. I'm curious what other impacts you're aware of that you deem irrelevant.
The best candidate I'm aware of for the YD impact would possibly/probably be related to the Hiawatha crater [1], which is 31km after likely boring through a km or so of ice. This puts it amongst the largest impacts on Earth, e.g. since back to the Chesapeake/Siberian impact around 35mya, (if not beyond after the ice impact is taken into account, e.g. to Chicxulub) [2]. It's not solidly dated yet, but according to the authors the evidence at the site is consistent with an impact during the Pleistocene, and they even say it may still be hot, despite being packed in ice!
If we're talking about the same event, with evidence across 24-53 sites on 4 continents that includes continent-wide fires, impact winter and floral and megafaunal extinction, then I'd be hard-pressed to see how this doesn't have to do with the main climate change event of that period; that's the definition of what makes the YD significant: the drastic floral changes (e.g. of Dryas octopetala) at the boundary. The impact seems a more likely candidate cause for the abrupt global changes.
Or put another way, I think the question is back to you of how changes in the AMOC during the YD somehow caused the characteristic extinctions and charcoal residue observed in southern Chile at the YDB.
The contemporaneous, global inferno and impact winter going seems too much to chalk up to coincidence. That's where I see the parsimony breakdown for a simple Laurentide melting/AMOC change being responsible for the YDB.
[1] https://advances.sciencemag.org/content/4/11/eaar8173
[2] https://en.wikipedia.org/wiki/List_of_impact_craters_on_Eart...
But the YD impact scenario hardly seems irrelevant to the YD. I'm curious what other impacts you're aware of that you deem irrelevant.
The best candidate I'm aware of for the YD impact would possibly/probably be related to the Hiawatha crater [1], which is 31km after likely boring through a km or so of ice. This puts it amongst the largest impacts on Earth, e.g. since back to the Chesapeake/Siberian impact around 35mya, (if not beyond after the ice impact is taken into account, e.g. to Chicxulub) [2]. It's not solidly dated yet, but according to the authors the evidence at the site is consistent with an impact during the Pleistocene, and they even say it may still be hot, despite being packed in ice!
If we're talking about the same event, with evidence across 24-53 sites on 4 continents that includes continent-wide fires, impact winter and floral and megafaunal extinction, then I'd be hard-pressed to see how this doesn't have to do with the main climate change event of that period; that's the definition of what makes the YD significant: the drastic floral changes (e.g. of Dryas octopetala) at the boundary. The impact seems a more likely candidate cause for the abrupt global changes.
Or put another way, I think the question is back to you of how changes in the AMOC during the YD somehow caused the characteristic extinctions and charcoal residue observed in southern Chile at the YDB.
The contemporaneous, global inferno and impact winter going seems too much to chalk up to coincidence. That's where I see the parsimony breakdown for a simple Laurentide melting/AMOC change being responsible for the YDB.
[1] https://advances.sciencemag.org/content/4/11/eaar8173
[2] https://en.wikipedia.org/wiki/List_of_impact_craters_on_Eart...
This article's claims fail the smell test. Ultimately we don't know what we don't know & simplistic overarching models are probably missing key components, many of which are non-linear. 200 years is a tiny window when it comes to cosmological time. The methodology of measurement & extrapolation of data also needs public scrutiny. Interpretations of geological events are ridden with conjecture to fit an overarching narrative.
Here's what we have evidence of. Earth receives the majority of it's energy from the Sun. The Sun has significant fluctuations. Earth is affected not only by infrared & visible EM, but also by higher frequencies of EM. Earth is also affected by magnetism from the Sun. Earth's Magnetosphere is affected by the Heliosphere. A weaker Magnetosphere means less protection from Cosmic Rays, Coronal Holes, CMEs, & other space weather. Cosmic Rays perturbs water, seeds clouds, induces volcanic eruptions & earthquakes. Volcanic ash & cloud cover increase albedo, which cools the earth.
The "year without a summer" in 1816 (~200 years ago), was caused by the Mt. Tambora eruption. The Carrington Event happened in 1859.
Here's what we have evidence of. Earth receives the majority of it's energy from the Sun. The Sun has significant fluctuations. Earth is affected not only by infrared & visible EM, but also by higher frequencies of EM. Earth is also affected by magnetism from the Sun. Earth's Magnetosphere is affected by the Heliosphere. A weaker Magnetosphere means less protection from Cosmic Rays, Coronal Holes, CMEs, & other space weather. Cosmic Rays perturbs water, seeds clouds, induces volcanic eruptions & earthquakes. Volcanic ash & cloud cover increase albedo, which cools the earth.
The "year without a summer" in 1816 (~200 years ago), was caused by the Mt. Tambora eruption. The Carrington Event happened in 1859.
The planets been breaking temperature records like hotcakes while solar irradiance has been declining for decades. There is zero evidence for magnetosphere driven climate change. What you've written is just some sciencey sounding BS that rationalizes an irrational position.
If, tomorrow, NASA, NOAA, and the UN IPCC held a joint press conference to announce surprising new evidence which indicated that anthropogenic effects on the climate were minimal, that we could not noticeably affect the climate, regardless of our emissions, and that the climate was essentially out of our control, what would your reaction be? Would that be good news or bad news? Why?
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I suppose it would be nice to know we can worry less about how we impact things, but I don't see what the point is in wishful thinking.
Actually, global cooling & a wet spring means decreased crop yields around the world. This is a serious matter that we need to properly prepare for. Not be distracted by pseudoscience of "Anthropogenic Global Warming".
We are seeing an increase of Earthquakes & Volcanic Eruptions, driven by space weather. We need to prepare accordingly. The next few winters will continue to get colder.
We are seeing an increase of Earthquakes & Volcanic Eruptions, driven by space weather. We need to prepare accordingly. The next few winters will continue to get colder.
Except the records being broken are low temperature records. They aren't actually records in the geological sense, just measurement records in modern times. The "year without a summer" was colder for example.
The magnetosphere does not drive the climate. The magnetosphere protects Earth from space weather, which includes Cosmic radiation, Coronal holes, Coronal mass ejections, etc.
Are you seriously claiming that the sun has no effect on the climate? Are you claiming that the sun does not have cycles? And you call me irrational...
The magnetosphere does not drive the climate. The magnetosphere protects Earth from space weather, which includes Cosmic radiation, Coronal holes, Coronal mass ejections, etc.
Are you seriously claiming that the sun has no effect on the climate? Are you claiming that the sun does not have cycles? And you call me irrational...
>"Except the records being broken are low temperature records. "
The last 5 years are the warmest 5 years in recorded history. Possibly the warmest in 110,000 years. It's also exactly how warm scientists predicted it would be with the emissions scenario that played out. I don't know what stupid blog you get your info from, but you should stop.
>"The magnetosphere protects Earth from space weather, which includes Cosmic radiation, Coronal holes, Coronal mass ejections, etc."
There is no evidence that cosmic or solar rays have any effect on climate. We have a good geologic record of the behavior of the magnetosphere. It doesn't correlate at all with climate data. This is from the psuedoscience blogosphere. Not actual science.
The sun affects climate, but it's variability isn't as strong as the forcing from co2 and none of the warming from the last 30 years can be from the sun since the sun has been in a cooling phase.
The last 5 years are the warmest 5 years in recorded history. Possibly the warmest in 110,000 years. It's also exactly how warm scientists predicted it would be with the emissions scenario that played out. I don't know what stupid blog you get your info from, but you should stop.
>"The magnetosphere protects Earth from space weather, which includes Cosmic radiation, Coronal holes, Coronal mass ejections, etc."
There is no evidence that cosmic or solar rays have any effect on climate. We have a good geologic record of the behavior of the magnetosphere. It doesn't correlate at all with climate data. This is from the psuedoscience blogosphere. Not actual science.
The sun affects climate, but it's variability isn't as strong as the forcing from co2 and none of the warming from the last 30 years can be from the sun since the sun has been in a cooling phase.
It's not the sun: https://climate.nasa.gov/faq/14/is-the-sun-causing-global-wa...
Except that model does not have accurate predictive qualities nor does it account for the other planets in the solar system going through climate change. What about Earth before humans? Here is a model that accurately predicts that solar cycle 24 would be weaker than cycle 23. Only 2 of 150 submitted models got that right.
https://www.researchgate.net/profile/Valentina_Zharkova/publ...
Another thing to consider as that a weakening Heliosphere & weakening Magnetosphere means Earth is more exposed to cosmic radiation. Cosmic radiation seeds clouds, excites water, drives earthquakes & volcanic eruptions. We may have an initial period of warming due to water being excited by cosmic radiation (similar to a microwave oven), but once enough volcanoes erupt, albedo will increase to offset the warming & cause cooling, as demonstrated by the Mt. Tambora eruption in 1816.
https://www.researchgate.net/profile/Valentina_Zharkova/publ...
Another thing to consider as that a weakening Heliosphere & weakening Magnetosphere means Earth is more exposed to cosmic radiation. Cosmic radiation seeds clouds, excites water, drives earthquakes & volcanic eruptions. We may have an initial period of warming due to water being excited by cosmic radiation (similar to a microwave oven), but once enough volcanoes erupt, albedo will increase to offset the warming & cause cooling, as demonstrated by the Mt. Tambora eruption in 1816.
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The climate is changing. The climate is being driven by the sun. Always has & always will. The climate is changing on other planets in the Solar system, being driven by the sun, just like Earth.
This whole "anthropocentric carbon climate change" scheme is a scam to funnel money away from real science & useful tech to special centralization interests that take away freedom of most people in the world. The people behind this scheme are a blight on humanity & should be arrested for fraud. The scale of their operations are orders of magnitude larger & more dangerous than Bernie Madoff.
This whole "anthropocentric carbon climate change" scheme is a scam to funnel money away from real science & useful tech to special centralization interests that take away freedom of most people in the world. The people behind this scheme are a blight on humanity & should be arrested for fraud. The scale of their operations are orders of magnitude larger & more dangerous than Bernie Madoff.
How is it that a graph like this is even acceptable, given the importance of the conclusions? How does this study account for the inevitably poorer precision and accuracy of measurements made over 100 years ago? How are systematic errors (differences in measuring procedure, differences in time of day precision, etc.) accounted for?
A paper from Cowton/Way is available, but it appears to focus on filling in gaps from lack of data at the poles:
https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/qj.22...
Where is the readily-accessible explanation for how the underlying dataset accounts for so many unknown factors?