The hurricane season has been rather quiet this year, especially in the Atlantic, so, of the course the Warmists are back to their “rare but stronger meme”
How Climate Change Is Creating A New Breed Of Hurricane
Climate change is warming our oceans, and that thermal energy is fueling stronger hurricanes.
A Category 3 hurricane is currently barrelling across the Pacific toward the Hawaiian islands. The storm, known as hurricane Lane, is expected to batter the Hawaiian islands with 120 mile-per-hour winds and enough rain to trigger flash floods and landslides. In both the Atlantic and Pacific oceans, hurricanes are becoming more intense as a result of climate change. Hurricanes are fueled by warm water, which is becoming more widespread as greenhouse gasses continue to trap heat in the atmosphere.
Both hurricane strength and average sea surface temperature have increased significantly over the last century. Although hurricanes can be influenced by wind, humidity and other factors, the majority of scientists agree that warming oceans are the primary cause of the rise in hurricane strength.
Hurricanes form when evaporating sea water transfers thermal energy from the ocean’s surface to the upper atmosphere. The upward movement of warm, moist air creates a pressure vacuum that fuels strong circular winds. When that warm air reaches the atmosphere it condenses, forming storm clouds.
As climate change increases global sea surface temperatures, the strength of seasonal hurricanes is expected to increase. This means more catastrophic hurricanes may soon be on the
horizon.
Aaaaaaand, that’s it. That’s the whole argument for a “new breed of hurricane” at a website called “Inside Science.” First off, they can’t really prove that the current warming is mostly/solely caused by Mankind. Second, hurricanes are not becoming more intense. Third, the overall surface temperature has only gone up 1.5F since 1850. That’s not significant. Fourth, there’s no true way to know that sea temperatures and hurricane strength have increased significantly, because the further back you go in the 20th Century the fewer the data points. Prior to the satellite area, if no one saw it, it really didn’t exist, nor did the temps get measure all over.
Finally, these people are just fearmongering, because that’s what they do. Then they congratulate themselves for Being Brave in writing this, say How Proud They Are Of Themselves for speaking truth to power, then jump in their fossil fueled vehicles to go get a burger. And this was all brought on for writer Annie Roth because a hurricane was barreling towards Hawaii, something that seems to happen every 30 years or so.
What more evidence do you need? What would you accept as “proof”?
Ever hear of “the burden of proof”?
You don’t get it, Formwiz.
The angry little black fella wants YOU to prove his claim for him.
formwiz: Ever hear of “the burden of proof�
Jeffery referred to “other evidence”, presumably on other threads.
For a start, we have the basic physics of greenhouse warming. See, for instance: Arrhenius, On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground, London, Philosophical Magazine and Journal of Science 1896.
Then we have the instrumental record compared to what would be expected without anthropogenic emissions.
To echo Jeffery’s questions: What more evidence do you need? What would you accept as “proofâ€?
Oh goody, let’s have a discussion on basic physics.
Do you kiddiez still believe your fallacious claim?
Liljeffyatemypuppy: Do you kiddiez still believe your fallacious claim?
Well, there is the occasional cometary impact, but generally, the Earth can only gain or lose heat radiatively. How else does the Earth gain or lose heat?
Y’all claimed as a fact according to the basic physics of heat flow the Earth could only gain or lose heat radiatively.
Do you still stand by your claim or not?
Maybe you kiddiez should look up the basic physics of heat flow before making your stupid comments.
Liljeffyatemypuppy: Y’all claimed as a fact according to the basic physics of heat flow the Earth could only gain or lose heat radiatively.
Other than cometary impacts and the like, that is correct. But you never answered. How else does the Earth gain or lose heat?
Tired of toying with you kiddiez.
Try reading up on convection and conduction.
Also the 1st and 2nd Laws of Thermodynamics.
tRump-like, he inexplicably declared victory and dramatically flounced out!
Don’t know what you mean, little fella.
I’m still here waiting to hear an explanation from the kiddiez concerning their fallacious comment.
I even pointed them in the right direction.
Maybe you can explain why their claim is incorrect. Wanna try?
Liljeffyatemypuppy: Try reading up on convection and conduction.
Also the 1st and 2nd Laws of Thermodynamics.
Okay. Done that. Convection and conduction do not transfer energy to space. Anything else?
Rather than playing childish games, what if you use your superior brain and actually express what you believe to be incorrect?
I do recall years ago pseudoscientific skeptics thinking they had discovered that climate scientists missed a basic consideration of the 2nd Law of Thermodynamics. Is that what you are dancing around?
Oh, now y’all are claing something about heat transfer to space.
That wasn’t in your original false claim.
Wanna move those goalposts again, kiddiez?
Another guessing game? Splendid.
What is your complaint again?
You keep doing kabuki theater, we assume because your thoughts on the topic are not quite sorted out.
Anyway, I’m open to learning. Please share your thoughts on warming.
How are things on planet Galera, little guy?
Liljeffyatemypuppy: Oh, now y’all are claing something about heat transfer to space. That wasn’t in your original false claim.
Claim: according to the basic physics of heat flow the Earth can only gain or lose heat radiatively.
The Earth receives radiant energy from the sun. How other than the sink of space does the Earth lose heat?
Convective heat transfer.
Liljeffyatemypuppy: Convective heat transfer.
There is no convection where there is no atmosphere.
Convection moves warm air to the upper atmosphere, as well as redistribute water vapor. This can change the radiative characteristics of the Earth’s upper atmosphere. Regardless, for the Earth to lose heat, the heat has to be radiated into space.
Moving the goalposts one more time, hey, kiddiez?
When precipitation (either rain or snow) occurs is there no loss of heat?
This is convective heat transfer.
Claim: according to the basic physics of heat flow the Earth can only gain or lose heat radiatively.
Liljeffyatemypuppy: When precipitation (either rain or snow) occurs is there no loss of heat?
The Earth does not gain or lose heat when it snows. However, water vapor releases heat locally to form snow crystals, with the heat primarily removed through evaporation.
So you think the heat removed from the lower atmosphere when water evaporates leaves the Earth? How does that happen?
Did say it. Didn’t imply it, little guy.
Oh, and you’really incredibly stupid too.
Liljeffyatemypuppy: Did say it.
In any case, the Earth is surrounded by the vacuum of space. Consequently, the only way for the Earth to gain or lose heat is radiatively (other than the occasional cometary impact or such).
Here’s an informal discussion of the basic physics…
https://www.physicsforums.com/threads/physics-of-global-warming.294362/
Well, the little fella is actually contributing to the discussion.
At least it covers what I’ve been saying. Also, convection is the mechanism that distributes heating and cooling around the world, i.e. ocean currents, wind, clouds, rain, snow, thunderstorms…etc.
The interesting and educational parts are in the comments, at least considering most are from 2009.
Watts covered a lot of this in the cite above.
https://www.physicsforums.com/threads/physics-of-global-warming.294362/
No one with a modicum of knowledge of Earth science would deny that convection is important in the atmosphere. If that’s what you meant you should have said so much earlier. But the Earth does not lose heat to space by convection.
We’re impressed you read the physics discussion.
If you found something of interest in the discussion, why not relate it directly rather than play more games?
Many ‘skeptics’ are not actually interested in a scientific discussion but only want to sow doubt in the scientific conclusions. Is that why you allude to physical principles without further explanation, to make people think there exists a physical or thermodynamic flaw in the theory of greenhouse gas global-warming?
Lijeffyatemypuppy: convection is the mechanism that distributes heating and cooling around the world, i.e. ocean currents, wind, clouds, rain, snow, thunderstorms…etc.
That’s right. Convection distributes heat within the Earth’s climate system, but — and this was the point you argued against — heat only escapes the Earth through radiation into the heat sink of space.
Didn’t claim that.
And I even gave you a compliment.
Oh well.
Then you added:
Do you now understand that the Earth gains and loses heat radiatively and not by convection or conduction? If so, then good.
Why did you bring up convection, conduction and thermodynamics?
The original quote with the parts you left out.
The basic physics of heat flow deal with radiation, convection, and conduction.
If you now understand that the Earth gains and loses heat radiatively, good!
We shouldn’t have argue about it again.
Glad that you agree that their quote in it’s entirety was indeed fallacious.
Liljeffyatemypuppy: The basic physics of heat flow deal with radiation, convection, and conduction.
That’s right. But of those mechanisms, only radiation can cause the Earth to lose heat. That’s because the Earth is suspended in the vacuum of space, so like an ideal vacuum flask, it can only gain or lose heat radiatively.
Still there, kiddiez?
Just because y’all made another untruthful and unscientific claim doesn’t mean y’all have to run away and hide.
Kiddiez?
Liljeffyatemypuppy: Just because y’all made another untruthful and unscientific claim
Actually, we cited two published scientific studies, one from more than a century ago.
Y’all cited two studies that do not verify your claim.
Liljeffyatemypuppy: Y’all cited two studies that do not verify your claim.
Saying “Is not” is not much of an argument, or even interesting. Why is Arrhenius wrong? And why is Meehle wrong? A scientific citation would be appropriate here.
Might want to re-read my comment again.
Never said the studies were ‘wrong”.
Just that they did not back up y’alls fallacious claim.
You made it up.
Liljeffyatemypuppy: Never said the studies were ‘wrongâ€.
The question is whether anthropogenic emissions are causing warming. Arrhenius provides the physical basis, including an estimate of climate sensitivity. Meehle compares warming with and without anthropogenic emissions to show that current warming is due to anthropogenic emissions. So yes, the studies do support the claim.
Wrong. Anyone can read the claim y’all posted stating that the Earth could only gain or lose heat radiatively according to the basic physics of heat flow.
Y’all left out convection and conduction.
Stop with your lying, kiddiez, y’all are wrong, again.
Guess y’all come back with your “handwaving” and “is not” bullshit, again..
Liljeffyatemypuppy: Anyone can read the claim y’all posted stating that the Earth could only gain or lose heat radiatively according to the basic physics of heat flow. Y’all left out convection and conduction.
The Earth can’t lose heat through convection or conduction because the Earth is surrounded by space that is almost completely devoid of matter. The Earth receives radiant energy from the sun, then reflects or re-radiates energy to space.
Notably, you ignored our response concerning the scientific studies Arrhenius 1896 and Meehle 2004.
http://www.applet-magic.com/arrhenius.htm
https://wattsupwiththat.com/2012/01/06/what-we-dont-know-about-energy-flow/
Liljeffyatemypuppy: Arrhenius gave a revised estimate of the effect of a doubling of CO2 being 1.2°C directly and 2.1°C with the water vapor feedback effect included.
Which is right in line with modern estimates of 2-4°C per doubling of CO2. Arrhenius didn’t include a positive albedo feedback, which is why his revised figure is on the low end of the range.
So y’all admit Arrhenius was in error.
Good.
https://wattsupwiththat.com/2012/01/06/what-we-dont-know-about-energy-flow/
Liljeffyatemypuppy: Until all of the physics is known …
Nothing can be known.
In fact, we have more than sufficient knowledge of the physics involved, which are quite basic. Particular mechanisms, on the other hand, such as fluctuations in ocean currents, can be quite intractable. However, the overall heat equations are sufficiently well-known as to know that increasing the greenhouse effect will raise surface temperatures by 2-4°C per doubling of CO2, though the upper limit is less certain.
Liljeffyatemypuppy: What is the temperature that it would be outside right now, if CO_2 were still at its pre-industrial level?
Meehle 2004
Liljeffyatemypuppy: So y’all admit Arrhenius was in error.
Well, Arrhenius’ original estimate was reasonably close, but not perfectly accurate. That’s the nature of estimates. The primary problem was overestimating the effect of CO2.
Liljeffyatemypuppy: “Finally, we don’t know how to build a faithful global climate model, in part because we need answers to many of these questions before we can do so!”
Handwaving. We have reasonably good answers to most of the questions, or they are not directly relevant. The easiest way to see this is to start by calculating the graybody temperature of the Earth, then compare it to the Earth’s actual surface temperature.
Ah, the “handwaving” gambit.
Can the “is not” isn’t an argument be far behind, kiddiez?
Liljeffyatemypuppy: Ah, the “handwaving†gambit. Can the “is not†isn’t an argument be far behind
The way to avoid that is to not use handwaving and bald denials in lieu of argument.
Then stop adding qualifiers to your original post.
Liljeffyatemypuppy: Then stop adding qualifiers to your original post.
Our original on this sub-thread concerned two scientific papers about the greenhouse effect. However, you are probably referring to this statement: “The Earth can only gain or lose heat radiatively.” We have shown why the statement is correct, and we have shown why your objections are not valid.
Begging the question
Another logical fallacy used by the little guy.
Liljeffyatemypuppy: The angry little black fella wants YOU to prove his claim for him.
A logical fallacy used by Liljeffyatemypuppy.
Thought y’all didn’t respond to my comments anymore.
Silly little kiddiez.
Liljeffyatemypuppy: Thought y’all didn’t respond to my comments anymore.
Hmm. Liljeffyatemypuppy is not on our troll list. Are you a troll?
Y’all and the angry little black fella from st. louis are the only trolls here.
It’s not? On what do you base that statement – your personal beliefs? Climate scientists disagree with your conclusion, but they’re part of the hoax.
Actually, he bases it on what a reasonable increase might be. 40 would be significant, to most rational minds.
Climate scientists disagree with your conclusion, but they’re part of the hoax.
By George, I think he’s got it.
formwiz: Actually, he bases it on what a reasonable increase might be. 40 would be significant, to most rational minds.
40 what? Degrees Fahrenheit? On what “rational” basis?
The difference between the last glacial period and today’s climate is only about 7°F.
As said numerous times, we don’t know if it’s significant. Do you know how much the temp went up during other 150 yr periods in earth’s history using a measuring device that records to a tenth of a degree? No, you don’t
Jl: As said numerous times, we don’t know if it’s significant.
Current warming is certainly having significant effects on climate, but not disastrous, if that is what you mean. The problem is that warming is expected to continue. Warming over 2°C is expected to have profound effects on climate. For comparison, global mean temperatures were about 3-5°C cooler during the last glacial maximum.
Jl: Do you know how much the temp went up during other 150 yr periods in earth’s history using a measuring device that records to a tenth of a degree?
There are a number of proxies that can provide useful information about past climate change.
Which doesn’t answer the question. So in other words, we don’t know. Proxies at best cover several hundred yrs and have no where near the accuracy of thermometers. Ever seen, say, the temp change for the yrs 1000-1250? Or 850-1000 to a tenth of a degree? No.
As far as significant effects on climate, those at this time are simply assertions.
Jl: Proxies at best cover several hundred yrs and have no where near the accuracy of thermometers.
Some proxies can provide year-by-year temperature anomalies, but you are correct that they are subject to much more uncertainty than the modern instrumental record. Nonetheless, they can provide important information. You haven’t explained why we need such fine gradations of temperature to reach some reasonable conclusions about past climate.
Because some of the “hottest years on record†only beat others by sometimes tenths of a degree. Fine graduations of temp can be compared to other….fine graduations of temp, but not to paleo records. Another reason why saying “the fastes rate†is meaningless, because we have no idea how fast the rate was hundreds, or thousands of yrs ago.
Jl: Because some of the “hottest years on record†only beat others by sometimes tenths of a degree.
You do realize that the average over many measurements can be more precise than any individual measurement?
Jl: Fine graduations of temp can be compared to other….fine graduations of temp, but not to paleo records.
Of course they can, as long as the margins of error are included in any comparison.
The slippery eels of climate science keep making up new stuff that is hard to prove like “new breed of hurricane”. What could be a bigger BS statement than that????
Decide for yourself whether you think that “Both hurricane strength and average sea surface temperature have increased significantly over the last century”.
Here is the global hurricane (cyclone) frequency since 1980. This includes a trendline for major hurricane frequency.
http://wx.graphics/tropical/global_major_freq.png
Here is the global accumulated cyclone energy since 1970:
http://wx.graphics/tropical/global_running_ace.png
Here’s the sea surface temperature since 1880.
https://wattsupwiththat.com/2017/01/22/mainstream-media-ignores-new-study-present-sea-surface-temperatures-indistinguishable-from-those-during-last-interglacial/
They won’t read it.
Just wasting your time.
I wish I hadn’t read it.
Mein gott. Tisdale has it bass-ackwards as expected, and buried the lede. The previous interglacial was as warm as now and the sea surface temperature was similar to now. Makes sense, doesn’t it? The scientist authors point out that this is disquieting since the sea levels were 6-9 meters higher then, implying that even if our average temp stays constant for a century or so, the sea levels will get much higher!
Tony Wuwt and his band of misinformers are either dumb or dishonest. You pick ’em. The Trickster is just as bad. Stop reading these hacks and join the reality community. You’re reaching the point where you’ll be compared to the Flat Earth Society or Snake Handlers.
Jl: https://wattsupwiththat.com/2017/01/22/mainstream-media-ignores-new-study-present-sea-surface-temperatures-indistinguishable-from-those-during-last-interglacial/
Sea levels were much higher than today, though temperatures were about the same as they are now. There is a long lag between a rise in temperature and sea level. The study would suggest that even if global temperatures were to stabilize, significant sea level rise is already baked in.
Yes, which means these sea temperatures are not out of the ordinary..
Jl: which means these sea temperatures are not out of the ordinary
The Earth was once a molten mass of rock.
Natural variation over geological periods is much greater than the artificial warming that the Earth is experiencing today. But that is not to say humans should welcome avoidable warming which may be catastrophic for human civilization. That life prospered in an ice free world doesn’t mean a sudden shift to such conditions would be salubrious for the human condition.
JGlanton: Here is the global accumulated cyclone energy since 1970
A simple visual inspection shows an increase since 1970.
But what are they “supposed†to do? Without that answer, which we don’t have, it doesn’t mean much
jl: But what are they “supposed†to do?
Generally, we would expect that as the oceans warm that cyclone energy would increase.
Yes, which has probably happened thousands of times in the past.
Jl: Yes, which has probably happened thousands of times in the past.
That life prospered in an ice free world doesn’t mean a sudden shift to such conditions would be salubrious for the human condition.
https://wattsupwiththat.files.wordpress.com/2011/01/global_running_ace1.jpg
J-“the previous interglacial was as warm as nowâ€. So SST are about the same as the past and sea levels were higher. So something other than CO2 causing those highs sea levels. And again, you’ve done nothing to refute what was said in the paper
Jl: So something other than CO2 causing those highs sea levels.
CO2 is a factor in natural climate change, but the triggering event was probably changes in insolation due to orbital variations. Oceanic CO2 acts to amplify the effects of warming and cooling.
“Tony WUWT and his band of misinformers..†More ad hom from J. Anthony Watts had nothing to do with the paper, but nice try at deflection. The paper was written by…the author of the paper. http://science.sciencemag.org/content/355/6322/276
“Independent” researcher, Bob Tisdale, wrote the misleading conclusion of the paper for Tony Wuwt’s site.
The authors of the scientific paper concluded:
This suggests that the longer we keep the avg global temp at this level (or higher) sea level will rise.
What it suggests is that seas rise and fall irrespective of CO2. Sea have been rising for 20,00 yrs, with no appreciable rise in the rate. In other word, natural events.
Jl: What it suggests is that seas rise and fall irrespective of CO2.
What it suggests is that seas rise and fall in response to changes in temperature, but with a long lag time. As climate scientists have discovered, there are many drivers of changes in global temperatures, including solar irradiance, volcanism, orbital variations, continental drift, mountain building, variations in sea currents, changes in greenhouse gases, even cometary impacts.
Yes, temps rise and fall irrespective of CO2
Jl: temps rise and fall irrespective of CO2
That’s right. Earth’s surface temperatures can rise or fall due to a number of mechanisms. Now look at the effect of those mechanisms over the instrumental period, subtracting out the contribution of anthropogenic emissions.
Oh look, another meaningless graph with lots of squiggly lines proving nothing.
Thanks again, kiddiez.
Liljeffyatemypuppy: Oh look, another meaningless graph with lots of squiggly lines proving nothing.
Handwaving. See Meehl, Combinations of Natural and Anthropogenic Forcings in Twentieth-Century Climate, Journal of Climate 2004. If you have specific objections to the methodology, we’d be happy to consider them.
Y’all posted a graph.
A meaningless graph with squiggly lines.
Liljeffyatemypuppy: A meaningless graph with squiggly lines.
We cited a scientific paper. You argue about the paper, you have to actually refer to the paper.
Here’s what I responded to:
https://i1.wp.com/www.skepticalscience.com/pics/meehle_2004.jpg
Y’all posted it.
Silly kiddiez.
Liljeffyatemypuppy: Here’s what I responded to:
To which we responded, “See Meehl, Combinations of Natural and Anthropogenic Forcings in Twentieth-Century Climate, Journal of Climate 2004,” after which you resumed waving your hands, as if waving your hands would chase away those pesky facts buzzing around your head.
The “methodology†is simply speculation, as there’s no definitive way to separate natural from anthropogenic forcings.
If one “tortures” the data long enough you can get it to “say” anything.
Jl: The “methodology†is simply speculation, as there’s no definitive way to separate natural from anthropogenic forcings.
Just another way to say “Is not!” You have to actually refer to the methodology to argue against it.
Funny-read the first line in the abstract. “Ensemble simulations are run with a global coupled climate model…..†In other words, it’s simply computer model simulations.
Jl: In other words, it’s simply computer model simulations.
Newtonian mechanics is a model, so that is not a valid objection. Only by referencing the model can you argue against the model.
Ridiculous-there’s no scientific way to discern when natural warming allegedly stopped and the alleged anthropogenic warming started, hence, no way to tell what “would have happened†by removing one of the variables by computer model simulation. Actually funny, as I said earlier, because we don’t know all the variables and how they react in our climate at this stage of the game. On top of that, the authors start with the false premise that the global temperature record is accurate. All kinds of data to show that’s not true. https://thsresearch.files.wordpress.com/2017/05/ef-gast-data-research-report-062717.pdf
Jl: Ridiculous-there’s no scientific way to discern when natural warming allegedly stopped and the alleged anthropogenic warming started
You apparently didn’t bother to read either paper we cited. The basic physical mechanisms of heat have been known for generations. The mechanisms involved in Earth’s climate are also known to a reasonable degree. Heat doesn’t come and go from nowhere. The Earth receives radiant energy from the Sun, reflects some, absorbs some, warms, and then re-emits radiant energy into space.
You might start by calculating the graybody temperature of the Earth, then compare it to the actual surface temperature. Can you see the difference? Is it consistent with the greenhouse effect? Having done that you can estimate the amount of change due to increases in the greenhouse effect.
Jl: On top of that, the authors start with the false premise that the global temperature record is accurate.
No. They don’t. Climate scientists start with the fact that the historical record is temporally and geographically incomplete and subject to a number of inaccuracies and biases. There are all sorts of scientific studies concerning this. If you get such a fundamental of climate science wrong, don’t you think you should revisit your assumptions?
Actually, it’s the simple “parroting” of the findings of others—the IPCC’s AR3, the climate science paper du jour, etc.—as they relate to a global climate driven by anthropogenic forcings, primarily CO2.
Even Santer, Mann, et.al had to admit later on in 2017 that their computer model simulations were wrong.
liljeffyatemypuppy: Actually, it’s the simple “parroting†of the findings of others—the IPCC’s AR3, the climate science paper du jour, etc.—as they relate to a global climate driven by anthropogenic forcings, primarily CO2.
We read and considered Meehl 2004, finding its conclusions reasonable and supported. The paper was published in a peer reviewed scientific journal. You have yet to cite a study which finds Meehl 2004 in error, or point to any errors that would undermine the findings of the paper.
Z: evidence and argument
lil: {}
liljeffyatemypuppy: Even Santer, Mann, et.al had to admit later on in 2017 that their computer model simulations were wrong.
All models are wrong; some models are useful. — George E. P. Box
You are probably referring to Santer et al. Causes of differences in model and satellite tropospheric warming rates, Nature Geoscience 2017. This paper does not address the conclusions of Meehl 2004. In any case, Santer 2017 concluded that “model overestimation of tropospheric warming in the early twenty-first century is partly due to systematic deficiencies in some of the post-2000 external forcings used in the model simulations,” and “this discussion does not cast doubt on the reality of long-term anthropogenic warming.”
So whose admittedly flawed computer simulations did Meehle use back in 2003?
Liljeffyatemypuppy: So whose admittedly flawed computer simulations did Meehle use back in 2003?
You didn’t read either study, did you? Meehl 2004 concerns surface temperatures. Santer 2017 concerns tropospheric temperatures. Santer 2017 removes effects of internal variability. They find that late 20th century tropospheric warming is well-explained, but that there is still a difference in early 21th century tropospheric warming, and that much of the difference is to due to systematic deficiencies in some of the post-2000 external forcings used in the forecasts (volcanism, solar output, particulate pollution), but not due to errors in climate sensitivity. That means the long-range forecast for global warming is not changed.
Again, flawed because the authors assume things that they don’t know are true. What are the contribution of the various forcings? It’s just an educated guess. As for example, the sensitivity of CO2 is not agreed upon, as this recent paper puts it at 0.4+/-0.1, quite a bit below what the IPCC says. http://iopscience.iop.org/article/10.1088/1361-6463/aabac6/meta
Jl: Again, flawed because the authors assume things that they don’t know are true. What are the contribution of the various forcings? It’s just an educated guess. As for example, the sensitivity of CO2 is not agreed upon
That is incorrect. They didn’t merely assume a level of climate sensitivity, they tested the assumption. A possible error in climate sensitivity did not explain the data.
Jl: It’s just an educated guess.
Climate sensitivity is based on many scientific and empirical studies, including from physical first principles, volcanic eruptions, Earth’s glacial periods, and from measured heat flow.
Jl: this recent paper puts it at 0.4+/-0.1
Uh, no. Even if correct, that’s not actually a paper on climate sensitivity. It only considers CO2, and not feedbacks, such as water vapor.