A consensus is usually established when one explanation is more convincing than alternative accounts, convincing the majority. This is also true in science. However, science-based knowledge is also our best description of our world because it is built on testing hypotheses that are independently reexamined by colleagues.
It is also typical that there are a few stubborn people who think they know better than the rest. When it comes to climate science, there is a small group of people who refuse to acknowledge the facts that have convinced almost the entire scientific community. Most of these contrarians are not even scientists.
But there are also about 500 scholars who recently have come forward and signed a declaration at odds with the scientific consensus, claiming “there is no climate emergency”. They represent a tiny fraction of the scholar community dismissing man-made climate change – by comparison, there is about 20,000 participants on the annual meetings of the American Geophysical Union.
A press conferences has been scheduled on Friday October 18th in Brussels, Rome and Oslo in order to promote the declaration. The intention behind the declaration is to influence the EU and the UN.
Most of the academics who signed the petition have no or little experience within climate research (check Google Scholar). Some of the signatures also have connections with political think tanks.
The message of the declaration is the same that the contrarians have repeated over and over again – but repeating it doesn’t make it more true.
I and some colleagues have examined the most common contrarian papers on climate change and have found that all of them were based on flawed methods/analysis (see previous post Let’s learn from mistakes). Some of the people who signed this petition have demonstrated their incompetence – the proof is in the papers that I and my colleagues reexamined in that study.
We cannot expect every scientist to have the same understanding, especially when it comes to scientific disciplines other than those in which they have professional experience. When they dismiss evidence on matters in an unfamiliar discipline without a convincing explanation, then they demonstrate a lack of respect for both science and the wider public.
They obviously don’t care whether people get true facts of false ideas. Below, I’ll try to explain why their arguments still do not convince.
The following statement is misleading:
“The geological archive reveals that Earth’s climate has varied as long as the planet has existed, with natural cold and warm phases. The Little Ice Age ended as recently as 1850. Therefore, it is no surprise that we now are experiencing a period of warming. Only very few peer-reviewed papers even go so far as to say that recent warming is chiefly anthropogenic”
It is true that Earth’s climate has changed over the past, but such changes have had specific physical causes, which are reasonably well understood.
There have been changes in the shape of the continents, formation of mountain ranges, changes in atmospheric composition, changes in Earth’s orbit around the sun (the Milankovitch cycles), changes in the sun, volcanic activity, and changes in ocean currents, all of which have influenced Earth’s climate.
As for the “Little Ice Age”, it was very different to the present global warming. It had a more regional character and was not as synchronised on a global scale as the ongoing climate change.
The scientific documentation of past changes in climate is one of the ways that we know that that the climate is sensitive to changed conditions. The Earth has never been as closely monitored as today, especially with the help of satellites and advanced modern instruments, giving unprecedented amounts of high-quality data.
This monitoring shows that the conditions that caused climate change in the past are absent today, except for the increases in greenhouse gases. The IPCC reports provide lists of peer reviewed papers on the global warming.
The following statement is incorrect:
“The world has warmed at less than half the originally-predicted rate, and at less than half the rate to be expected on the basis of net anthropogenic forcing and radiative imbalance. It tells us that we are far from understanding climate change.”
Indeed, comparisons between simulated and observed global mean surface temperatures indicate a good correspondence.
I can believe that the people who signed the petition don’t understand climate change, but they should speak for themselves. The rest of the science community has a fairly good understanding.
The fact that we can write computer code based on the fundamental laws of physics that is able to reproduce phenomena we observe on Earth, indicates that we do understand the climate system. See the description of climate models on both Carbonbrief.org and TED.com.
The following statement is incorrect:
“Climate models have many shortcomings and are not remotely plausible as policy tools. Moreover, they most likely exaggerate the effect of greenhouse gases such as CO2. In addition, they ignore the fact that enriching the atmosphere with CO2 is beneficial.”
The scientific knowledge underpinning climate policies is established both from observations as well as the laws of physics and climate models.
The global climate models share common description of the atmosphere with weather forecast models used on a daily basis to provide operational weather warnings.
All climate models have been evaluated and tested, and they do reproduce the observed global warming as seen with the observations.
The concentration of greenhouse gases in the atmosphere is increasing. Their physical properties can be established accurately through lab studies.
Carbon Dioxide (CO2) is a greenhouse gas which is a byproduct from the consumption of fossil energy, and the increase in the atmospheric CO2 concentrations represents approximately 40% of the total amount produced from the exploitation of fossil fuels.
The CO2 bears a fingerprint that connects the increased amount to coal, oil and gas, in terms of the isotopes carbon-13 and carbon-14, as well as the comparable concentrations of oxygen and nitrogen and ocean acidification.
The climate models reproduce the observed sensitivity, as shown in Benestad and Schmidt (2009) and the figure below.
The following statement is irrelevant:
“CO2 is not a pollutant. It is essential to all life on Earth. Photosynthesis is a blessing. More CO2 is beneficial for nature, greening the Earth: additional CO2 in the air has promoted growth in global plant biomass. It is also good for agriculture, increasing the yields of crops worldwide”
Water too is essential to all life on Earth. Too much is not good, such as flooding or drowning.
The following statement is incorrect:
“There is no statistical evidence that global warming is intensifying hurricanes, floods, droughts and such like natural disasters, or making them more frequent. However, CO2-mitigation measures are as damaging as they are costly. For instance, wind turbines kill birds and insects, and palm-oil plantations destroy the biodiversity of the rainforests.”
CO2 has an indirect effect on extreme weather conditions through increasing the greenhouse effect and changing Earth’s hydrological cycle. It is well-established that increased surface temperatures lead to increased evaporation and water vapour in the atmosphere.
Water vapour is the main fuel for weather phenomena such as storms and rainfall. Global warming is also accompanied by changes to the large-scale circulation pattern, such as the Hadley cell, affecting both extreme rainfall in the tropics and drought conditions in the sub-tropics.
The observed number of record-breaking temperatures and rainfall provide statistical evidence for the weather becoming more extreme. One example is the increased probability of heavy precipitation.
The following statement is misguided:
“There is no climate emergency. Therefore, there is no cause for panic and alarm. We strongly oppose the harmful and unrealistic net-zero CO2 policy proposed for 2050. If better approaches emerge, we will have ample time to reflect and adapt. The aim of international policy should be to provide reliable and affordable energy at all times, and throughout the world.”
There is ample evidence of changing risks connected to weather, with more heatwaves and more extreme rainfall.
The global mean sea-level is rising and coral reefs are dying. Glaciers providing predictable water supply are melting, such as in the Himalayas. The consequences for ecosystems and agriculture are dire.
The insurance sector is already affected, and the consequences from climate change will increasingly disrupt new sectors such as agriculture, water management, transport, tourism, and trade.
There will be regions where people no longer will be able to reside and there will be increased levels of migration and conflicts connected to climate change.
Rather than pushing a petition, the contrarians should present scientific evidence for their view. If such evidence exists, it needs to be transparent so that others can reexamine it and get swayed by the information. So far, the typical contrarians (and one of the signatures) have preferred not to disclose their work.
There have already been some reactions to this petition, e.g. on Climatefeedback.org. It was also preceded by a similar Italian “pro-fake-news” petition (signed by more or less the same Italian contrarians as this version) that prompted a response from Italian scientists.
The claims presented in the petition signed by 500 contrarians is the strongest case the contrarians can muster against climate science. In other words, the best shot from the majority of world’s supposedly prominent academics known to have an alternative opinion (i.e. the majority of a tiny minority).
Obviously, there is not much convincing evidence against anthropogenic climate change.
–>
References
- R.E. Benestad, and G.A. Schmidt, "Solar trends and global warming", Journal of Geophysical Research: Atmospheres, vol. 114, 2009. http://dx.doi.org/10.1029/2008JD011639
MA R@148. I do see the distinction you are making, but I still do not agree. The processes are not well understood. Let me just quote just a few:-
“neither the mechanism through which ice house conditions were initiated, nor the mechanism whereby the 100 kyr cycle has come to dominate glacial oscillations are understood” Olsen 2009
“Milankovitch forcing (i.e., variations in orbital parameters and their effect on the insolation at the top of the atmosphere) plays a role in glacial cycle dynamics. However, precisely what that role is, and what is meant by “Milankovitch theories” remains unclear despite decades of work on the subject” Tziperman 2006
“Although the importance of insolation as the ultimate driver is now appreciated, the mechanism what determines timing and strength of terminations are far from clearly understood” Ouchi 2015.
There are hundreds of papers that say the same thing. I think it is clear that the process that completely dominates recent (a few million years) significant climate change is not well understood.
Keith Woollard @152,
Firstly may I provide proper reference to your citations.
[1] Olsen & Whiteside (2009) ‘Pre-Quaternary Milankovitch Cycles and Climate Variability’ in Gornitz (2008) ‘Encyclopedia of Paeleoclimatology & Ancient Environments’ pp826-35.
[2] Tziperman et al (2006) ‘Consequences of pacing the Pleistocene 100 kyr ice ages by nonlinear phase locking to Milankovitch forcing’.
[3] Abe-Ouchi et al (2015) ‘How and when to terminate the Pleistocene ice ages?’[ABSTRACT].
These three references and, as you state, many others describe how the mechanisms, these “specific physical causes,” which came together to create the ice age cycles of the Pleistocene … to be exact … do so in a process which is still poorly understood. The problem faced by paleoclimatology is the remarkable level of instability within the ice age system and the number of mechanisms involved in the ice age cycles which still manage to bash out a regular ice age every 40ky then 100ky.
Now, we could argue over the symantics here. Is it the process that is poorly understood? Or is it perhaps the mechanisms, perhaps the role of the different mechanisms, that is poorly understood? Or, just for completeness, we could argue over the possibility that there are “specific physical causes” yet to be recruited into this ice age cycle process or, even in the extreme and utterly controversially, some process that has yet to be identified as even existing, ice age or no.
However, is there any need to be so pedantic?
Bar the utterly controversial idea that there exists some crucial yet-to-be-identified climatological mechanism, we can say that the many mechansms that combine to create the ice age cycles of the Pleistocene, or to quote the OP, these particular “conditions that caused climate change in the past are absent today” in the late-20th/early-21st century.
Romain,
“oxymoronanity…”
Oh, aren’t you adorable, bless your little heart.
Dude, it is called science. If you have an alternative theory, publish it, or at least state it. Any fricking imbecile can criticize the existing theory. Be smarter.
KW, #152–
It strikes me that “well understood” is not well defined, as (I believe) nigel already pointed out.
However, if we’re talking about ‘understanding’ past climate states, then we have at least two components of the problem: 1) ‘understanding’ mechanisms of change, and 2) correctly characterizing the relevant parameters. Seems to me that component #1 is indeed pretty well-understood, whereas in general #2 is less so, due to the difficulty of finding proxies that are as reliable, comprehensive and precise as one would wish.
Unfortunately for the argument in 152, it is component #1 that is relevant for diagnosing *current* climate change.
Keith Woollard,
Yes, there are uncertainties having to do with the paleoclimate, but they have precisely diddly and squat to do with the current situation. The energy inputs and outputs for the current climate are measured. We know how much the planet is warming. We know how much sunlight is coming in. We know that the oceans are heating up, not cooling down. We know the troposphere is heating up. We know the stratosphere is cooling down.
So, two questions:
1) Why do you assume that if there is any uncertainty that it will magically benefit your side of the argument?
2) Given 1) above, can we get together sometime and play poker?
You should listen to you guys. Am I right in believing that you are trying to say the mechanism is not understood but the process is? Really? Call it what you like. Come up with a bogus rating of understanding from zero to eight out of ten, but trying to defend Rasmus’ take down is simply not possible.
What you really need to focus on is Ray’s two questions. Why are they there? They are there simply because the tribal mentality here is that if anyone questions anything that said by one of the elite then they must be a heretic and everything they say is wrong.
There was no “my side of the argument” I am not saying current GW is all natural but every time you dismiss legitimate concerns you weaken your position as authorities.
There are huge unknowns in palaeoclimatology. Everyone knows that and to dismiss those by blithely saying they are “reasonably well understood” is not what science is about. You can admit mistakes without throwing the game
Be the bigger man Rasmus
Keith Woolard,
Understanding uncertainties is important. However, just as important is understanding whether the uncertainties have significance to the problem at hand.
The importance of the uncertainty in Young’s modulus of aluminum pales in comparison to the trajectory of the airplane towards the cliff face. Or more to the point, the physical properties of the Aluminum used in planes that have crashed in the past may be unimportant if I know with high precision the properties of the aluminum used for the plane I am flying on.
Now, to my point with respect to the questions I asked above:
First, the GCMs for Earth’s climate actually have quite a good record of predictive success. However, if they did not, why in the hell would you think that this benefits the case of denialists like you? That climate change presents a credible threat is absolutely, 100% beyond dispute. The temperature record, the increase in impulsive precipitation events, droughts…(and precisely where the climate models predict them) all support that we are affecting the climate. The science supports that conclusion.
So, given that we have a credible threat, I would have thought that climate denialists ought to be praying to whatever deities they believe in that the climate models could limit the severity of the threat. If they cannot, given that we have only one planet capable of supporting life, then what choice would we have but to slam on the brakes to ensure things don’t go Venus-shaped?
Keith Woollard @158,
You ask “Am I right in believing that you are trying to say the mechanism is not understood but the process is? Really?” And the very obvious answer is “No, you are not right!!”
Ray Ladbury,
No, what you and others are doing, by not accepting the “we don’t know” answer, is politics, not science. It’s even close to religious talks.
Dude, be humble for once.
Keith Woollard @158
“Come up with a bogus rating of understanding from zero to eight out of ten,”
It’s not a bogus rating. It should be self evident that there are several different levels of understanding and a scale from 1 – 10 just formalises this. Its just a case of pinning down our level of understanding of past climate change and what drives it. There are certainly more levels of understanding than good and poor. Or are you saying there aren’t?
In fact I tend to agree with you to the extent that the article was over confident on this issue, but I would dispute that we have a poor understanding of past climate change. We have a reasonable understanding boringly in the middle! In fact MAR sounds like he’s on the right track.
You have also picked just a couple of sceptical sounding papers, and with all due respect you can’t possibly have read all the papers on the subject because there are thousands. It would be interesting to know what the consensus view is on past climate change and the level of understanding, but the IPCC appears to imply we have at least a passable understanding.
“There was no “my side of the argument” I am not saying current GW is all natural but every time you dismiss legitimate concerns you weaken your position as authorities.”
I agree with you there’s a tendency to sometimes be defensive of the warming consensus etcetera, and we need healthy scepticism, but the defensiveness is because so much of the scepticism is crazy scepticism. Not saying yours is necessarily. MAR is a bit sceptical at times of some of the more skyrockety claims, and gets labeled a luke warmer and closet denialist, which is quite absurd imho, but its how some people react. But both you guys might help yourself by stating your general view on agw etc clearly and unequivocally in your main posts. I know its tiresome to have to do this, but it might help.
Romain @162 what you and KW appear to be doing is claiming that because something is not really well understood that it is only very poorly understood. I will never buy that because its ridiculous, a false dichotomy. There is obviously a middle ground. Our understanding of the past climates would be reasonable.
To claim holding a more optimistic view of understanding of the past is politics does not follow. It could simply be defensiveness when constantly attacked by ignoramuses.
Romain,
You know, somehow I think the National Academies–and every other relevant, legitimate organization of scientists on the planet for that matter–have a better understanding of what science is than you do. Then there’s the fact that I’ve been doing physics myself for over 30 years. So, I hope you’ll forgive me if I don’t take the opinion of a politically motivated troll on the Intertubes very seriously.
Keith Woollard and all the other science illiterates:
We have zero understanding of how the wave function in quantum mechanics collapses during measurement. Do you think that means that we should abandon all research into quantum computing?
OK Ray@#166 – you have gone full loony here.
“We have zero understanding of how the wave function in quantum mechanics collapses during measurement. Do you think that means that we should abandon all research into quantum computing?”
What an absolute load of tripe! I have never suggested anything about reducing any sort of research ever, in fact the reverse. Anything we don’t understand warrants further research. Just don’t say we understand it when we don’t. It’s pretty simple
Good grief – there is a world of difference between an unconstrained problem – common in geology – where there are multiple possible solutions and insuffient data to determine them; and a problem where there are no satisfactory solutions.
This is a facile attempt to discredit science that is unappealling. Who do you think you are fooling?
Keith Woollard@167,
Once again, my projectile scatters off a surface at a very obtuse angle. It would seem to me that if you were to apply your criteria for climate science to quantum computing that you would insist that understanding the collapse of the wave function was essential before proceeding with the application thereof.
And yet…
Ray Ladbury: It would seem to me that if you were to apply your criteria for climate science to quantum computing that you would insist that understanding the collapse of the wave function was essential before proceeding with the application thereof.
AB: Ahh, but methinks KW isn’t interested in truth, but in “winning”. And to “win” one simply parses one’s opponent’s statements for potential gotchas. Your analogy talked of stopping research into how to design and build quantum computers until after the collapse of the wave function was understood, an excellent analogy for KW’s stance that we must avoid working on solutions for climate change until after the science of climate change has reached uh, “some impossible-to-achieve level of understanding(?)”. KW swapped that with “stopping research into the collapse of the wave function” and viola! You’re an instant “loser” and KW takes a victory lap.
Either that or he’s incapable of understanding the difference between fundamental physics and building a machine.
MA Rodger: The problem faced by paleoclimatology is the remarkable level of instability within the ice age system and
AB: Keith Woollard teaches us that if you have a life support device that you’ve studied for well over a century and if it fails You Will Die and if it appears that it breaks more easily than your calculations suggest then it is IMPERATIVE that you whack the device harder and harder because you don’t have a complete understanding about how it breaks.
AB, #170–
Oh, I’m pretty sure our Keith would be fine with continuing climate research, too–just so long as no action is taken based on the results. #171 was pretty apposite to that, I thought, as well as hilarious–in a very dark way, of course.
“Precautionary principle! Absolutely! Who knows what terrible things might happen if we reduce our reliance on fossil energy!”
Makes me wonder if some folks are just addicted to the smell of burnt hydrocarbons.
Kevin McKinney: Makes me wonder if some folks are just addicted to the smell of burnt hydrocarbons.
AB: Obviously the result of lighting matches and candles to cover up their farts.
And yes, Ray made an inferior word choice (“research” instead of “building”). Not even a blip to mention but that didn’t prevent KW from, well, anyone got a match?
Kevin McKinney: “Precautionary principle! Absolutely! Who knows what terrible things might happen if we reduce our reliance on fossil energy!”
AB, jumping up and down with hand in air: I know! Charles Koch will die with fewer significant digits in his bank account. The HORROR, eh?
Listening to the dorky and stupid goop that comes out of GOPpers’ mouths I find it hard to believe that the rich are soooooo superior that they deserve all increases in productivity (as they’ve scarfed since the 1970s). Seriously, if they all retired and put their fortunes in blind trusts do you think the world’s productivity would be significantly reduced? Naw, their game is all about gaming the system. About scarfing up inventors’, artists’, engineers’, and others’ productivity. So as to be excessively fair I’ll say that’s worth about a negative nickel.
I am recently retired Physicist after 49 years at a major University.
I am definitely not a climate scientist, however, given retirement and intellectual curiosity I reviewed some global warming literature. In particular the Mauna Loa atmospheric data, https://www.esrl.noaa.gov/gmd/ccgg/trends/ ,shows a continuous, almost exponential, rise in CO2. However, the Berkeley Earth, http://berkeleyearth.org/summary-of-findings/ ,shows a warming “pause”. The obvious interpretations, to me, are:
The current insensitivity of Average Annual Global Temperature Anomaly (AAGTA) to CO2 indicates that CO2 longer is a factor in Global Warming, and suggests that CO2 might never have been a factor for AAGTA and the inferred CO2 Sensitivity is an artifact of un-modelled underlying processes.
Alternately, CO2 may be a factor but its warming effect saturates at atmospheric CO2 levels above 360 ppm.
From my professional experience the latter is more likely since saturation is the most common non-linear effect encountered in the physical world.
Regards, John
Wow! This is someone very arrogant! Only this writer knows everything. Shall I note that scientists have been wrong in the past.
JW 175: The current insensitivity of Average Annual Global Temperature Anomaly (AAGTA) to CO2
BPL: Doesn’t exist. You need 30 years to show a temperature trend. The correlation between CO2 and temperature anomalies from 1850 to 2018 is r = 0.92.
#175, JDW–
After 49 years of service anywhere, it’s fantastic to be able to wave one’s hands so fast.
John the PhD at a MAJOR university,
Those who barely graduate high school often parrot dorky pontifications while claiming vague alleged credentials.
Quinton,
Wow. Two within 14 minutes. Deja doofus?
Science is about constantly getting closer to “truth”. Climate scientists are doing just that. Since the ” answer” has consistently drifted towards “it’s worse than we thought” it is screamingly obvious that you’ve invested fewer than three neuron-seconds in analysis.
Thank you, John Walter, PhD and Quinton for your utterly ignorant opinions. We will certainly give them the consideration they deserve–as soon as we can figure out how to print them out on toilet paper.
“BPL: Doesn’t exist. You need 30 years to show a temperature trend. The correlation between CO2 and temperature anomalies from 1850 to 2018 is r = 0.92.”
Does your comment “Doesn’t exist.” refer to the “Pause” as discussed here: http://berkeleyearth.org/global-warming-pause/ by Zeke Hausfather and Richard Muller?
The pause appears to be about 20 years, where is the reference to a required 30 years, please.
Your comment about “correlation between CO2 and temperature anomalies from 1850 to 2018 is r = 0.92 is not relevant.” You are confusing correlation with causation. The difference is discussed here: http://www.differencebetween.net/science/difference-between-causation-and-correlation/ .
Thanks for your reply, Regards, John
John Walter, the article referring to the pause came from 2013. There was a big warming spike afterward. Berkeley Earth later concluded that the warmest four years on record came from 2015-18. In addition, that’s only surface temperature. The ocean was gaining a large amount of heat during the supposed hiatus in surface temperature, released some of it during the early phase of the warm spike in surface temperature, and has since accumulated even more heat. https://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/
If a major heat sink in a system is accumulating energy, that system is out of equilibrium, not saturated. The cause of the heat accumulation is greenhouse gas forced warming, since there are no other major energy sources that explain the trend.
John Walter, PhD @175 — I recommend that you study “Principles of Planetary Climate” by Ray Pierrehumbert before attempting to comment further.
John Walter,
You appear to have missed the past 6 years, since you see fit to cite an op ed from 2013. Let me fill you in. 2014 was a record or near-record year. So were 2015 and 2016, and every subsequent year since 2013 has been warmer than any year prior. Pretty odd definition of “pause”.
And even the previous decade was pretty much a fizzle as a pause. The oceans continued to warm apace. We still had record or near-record years (2005 and 2010), and 10 years is way too short to achieve statistical significance.
Dude, if you are a physicist, your understanding of data sure is pathetic.
Finally, while it is true that correlation does not equate to causation, correlation consistent with a particular mechanism known to be extant is pretty much about as close to proof of causation as you are going to get.
Please, don’t be pathetic.
JW 182: The 30-year standard was decided on by the World Meteorological Organization in 1935. Here’s an essay as to why:
http://bartonlevenson.com/30Years.html
It’s my belief, and that of statistician Grant Foster (“tamino”) that the pause didn’t exist. It was pure noise.
For those responding to “John Walter”, and John Walter,It is possible that this person is in fact as described…do a little search and you will see; the name is modified a bit. But of course it might be some high school kid or college freshman using the name. If not, it’s probably the emeritus thing.
For JW himself. If you are the real person, then you shouldn’t be making silly Denialist high-school level statements about correlation and causality. In physics, we work from the theoretical basis to make predictions. With your background, you should be able to enlighten us as to what exactly is incorrect about that basis with respect to CO2 absorption of radiation.
If you don’t disagree with the underlying physics, which tells us the increase in CO2 results in an increase in energy in the climate system, then your statements make no sense. Nothing about the variations in rate of GMST increase is inconsistent with the nature of the system under consideration.
Your exposition is eagerly awaited.
@182 “You are confusing correlation with causation.”
Possibly. Any 2 trend lines with the exception of 2 precisely flat lines exactly pi radians out of phase will exhibit at least some correlation.
However YOU Sir Arrogant Physicist from a MAJOR university are confusing is signal and noise.
Statistically in a long term series where the noise is a goodly multiple of the standard error of the trend–as the various canonical temp series are–will have completely expectable, that is nonsignificant, “pauses”. What YOU need to read is about statistical power of a test. Here is one basic source from a well known, well published statistician: https://tamino.wordpress.com/2018/01/25/how-to-fake-a-pause-in-global-warming/
BPL and John Pollack:
BPL and John Pollack
Thanks for your helpful updates. The 2018 http://berkeleyearth.org/2018-temperatures/ update paints a different picture.
What is the current view of Michael Mann’s hockey stick prediction?
Thanks, John
Whoops…Stated that wrong. Meant to say two random sets of data where each has no trend at all.
John Walter @175 I clicked on your name and got “Site cant be reached”. Is the site a fiction like your other comments?
JW 190: What is the current view of Michael Mann’s hockey stick prediction?
BPL: What prediction? The “hockey stick” papers were paleoclimatology.
John Walter:
“What is the current view of Michael Mann’s hockey stick prediction?”
Even a retired physicist should understand the difference between a reconstruction of past temperatures (Mann’s “hockey stick”) and a prediction.
John Walter says:
“BPL and John Pollack
Thanks for your helpful updates. The 2018 http://berkeleyearth.org/2018-temperatures/ update paints a different picture.”
In response to John Pollock’s stating that “John Walter, the article referring to the pause came from 2013. There was a big warming spike afterward. Berkeley Earth later concluded that the warmest four years on record came from 2015-18.”
Well, John, the Berkeley Earth post you linked to says “We conclude that 2018 was likely the fourth warmest year on Earth since 1850. Global mean temperature in 2018 was colder than 2015, 2016, and 2017, but warmer than every previously observed year prior to 2015.”
In other words, 2015-2018 were the fourth warmest years on record. Just as John Pollock said.
The four warmest years on record, that is …
JW (@190) The “Hockey Stick” analysis was not a prediction. It was a reconstruction of historical temperatures. It has been confirmed by numerous subsequent studies.
#190, JW–
There is literally no such thing as a “Michael Mann hockey stick prediction;” the so-called hockey-stick graph was and is purely a reconstruction of *past* mean global qtemperatures. Google “Mann Bradley Hughes 1990.”
John Walter,
Are you even bothering to read the posts you cite, because they are certainly a whole helluva lot more consistent with John Pollack’s characterization than they are with yours?
You aren’t exactly wowing us with your powers of observation and judgment. In fact, as a physicist, I would say that if you are a physicist, then my posterior chews gum.
The word “emergency” is not concrete enough to be useful.
Ray Ladbury: In fact, as a physicist, I would say that if you are a physicist, then my posterior chews gum.
AB: Ray? A small request. Please fart.
https://www.desmog.co.uk/2019/11/18/3-climategate-myths-have-not-aged-well
Looks like Mann was right about the MWP: “The most recent and robust such reconstruction (of the MWP) was completed by a team of over 5,000 scientists from more than 100 countries contributing to the Past Global Changes (PAGES) 2k network, which produced the following chart of global temperatures over the past 2,000 years. It shows temperatures today rapidly rising above the historical record like the blade of a hockey stick.”