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scaddenp at 11:18 AM on 16 July 2017Models are unreliable
NorrisM,
To me the issue of how close the models match observations over whatever necessary period (20 years?) is critical.
as a lawyer then, perhaps I could ask you whether a person should be judged on the basis of what they have clearly stated (and is recorded), or on the basis of what someone else has reinterpretated them to say?
What climate science expects, is that surface temperature will evolve as a very wiggly line that mostly lies within the range of the multiple model runs ( the grey area in the model projection maps).
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Tom Curtis at 10:20 AM on 16 July 2017Water vapor is the most powerful greenhouse gas
JeffDylan @283, first, even absent any water vapour feedback (but including the albedo feedback), my analysis shows a drop on GMST from the removal of all CO2 in the order of 17oC, ie, a drop to a GMST of -3oC. That in itself shows your claim of a drop of "a few degrees C" to be nonsense. Indeed, even the no feedback drop of 13oC demonstrates that.
Second, my analysis does not assume water vapour is a feedback on CO2, but on temperature, as formalized by the Clausius-Claperyon relation, which is basic laboratory physics. It is also demonstrated in the atmosphere by the relation of the total column water vapour to latitude:
Or the change in relative humidity over land over time in recent decades, plotted as a scatterplot against global land surface temperature:
(Black is observations (HadISDh), pink a reanalysis product (ERA-40), with the other three being model ensembles for historical greenhouse gas forcings (yellow), historical natural forcings (green), and all historical forcings (purple).)
You may want to assume total column water vapour is constant regardless of GMST, but when you do you render your views no more interesting, or realistic, than those of flat earthers.
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factotum at 10:20 AM on 16 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
Skeptical Science asks that you review the comments policy. Thank you.
It occurs to me that given the degree to which our current political system is messed up / disconnected from "reality"
1.) the degree to which our current political system is messed up / disconnected from "reality"
2. That scientists are still among the most prestegious / respected groups in the country,
3. Many, if not most of our founding fathers had a scientific mind set. This objective mindset in dealing with the real physical world being necessary to be successful when you are in intimate contact with the physical world
then I would like to propose that a new political party be created. Viz. the party of science. One of its first goals would be a constitutional amendment that any candidate for public office be required to take and pass an upper division science course, and a year of calculus.
And that science course would be hard science as in biology, physics, or chemestry. Maybe a few others. But not psychology, or other "soft" sciences that have little, if any, mathematical foundations.
https://en.wikipedia.org/wiki/Hard_and_soft_science
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Eclectic at 09:49 AM on 16 July 2017Water vapor is the most powerful greenhouse gas
Tom Dayton @285 ,
I hope you are not intending a disparagement of Trump University.
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One Planet Only Forever at 09:14 AM on 16 July 20172017 SkS Weekly Climate Change & Global Warming News Roundup #28
nigelj@2,
SInce the baseline global average is warming due to increasing GHG (primarily CO2) and strong El Nino events are typically the most significant temporary warming bumps above the average it is to be expected that many of the "warmest" years are the "Warmer than average" El Nino years.
Jan Nul's Webpage of ENSO events is a helpful presentation of the magnitude of the NOAA ENSO evaluations. The big El Nino events do appear to be getting bigger in that presentation.
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Tom Dayton at 07:36 AM on 16 July 2017Water vapor is the most powerful greenhouse gas
JeffDylan, which university gave you your doctorate in physics, along the way teaching you atmospheric physics while claiming the very concept of relative humidity is a fraud invented by the United Nations and the IPCC in the 1700s through early 1800s, and promulgated ever since by everyone including your local meteorologist?
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nigelj at 07:35 AM on 16 July 2017Models are unreliable
Regarding modelling. Even if you forget models, just for one minute, and just project the last 30 years trends forward as a linear trend to end of century, you get very significant warming.
However it will then only take a quite small acceleration to this recent trend, due to constant ramping up of emissions combined with proven positive feedbacks, to cause more warming of about roughly 4 degrees. (Sort of like compound interest). This is what people need to get their heads around.
The Red Blue team court room concept is not the appropriate mechanism to decide science. Courts are already having huge problems making sense of complex financial cases, that are beyond judges, juries and lawyers. Repeating this exercise for science is verging on insanity.
You would be deciding the fate of the planet on who is the best dressed most articulate, and possibly devious speaker and gut reactions of people to all this. Its better to leave such decisions to the people at the IPCC and their more measured processes.
The Europeans grasp this problem and have more of an "Inquisitorial" legal system for complex cases. The IPCC system that we already use is essentially an inquisitorial system!
Honestly I cannot believe the absurd lenths the Republican Party are going to try to deny the climate problem. If only they could see themselves from the outside looking in, and how absurd and desperate they look.
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nigelj at 06:23 AM on 16 July 20172017 SkS Weekly Climate Change & Global Warming News Roundup #28
The "Ten Hottest Years" graph in the first article shows a bit of an ominous looking curve / acceleration. Quite a few of those years look like el nino years, so does this mean el ninos are becoming more powerful over time, possibly due to agw influences?
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nigelj at 06:04 AM on 16 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
Chriskoz @6
Yes political donations from industry should be banned or capped. But ironically this will probably only happen if the voting public "lobby politicians" more effectively to try to get them to amend the relevant law. So we are back to what I was saying. Politiicans wont do it willingly, they will have to be pushed hard by the public.
There's another problem in America. The Democrats already tried to limit / cap election donations, but it was struck down by the courts as "unconstitutional" as below.
Regarding other countries, I would ideally like to see election campaigns funded out of taxation. That way private money and influence is removed. It won't be easy of course, because people react negatively to taxes spent on politicians in any way, but I think we would all be better off for it.
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KR at 06:03 AM on 16 July 2017Water vapor is the most powerful greenhouse gas
JeffDylan - I'm afraid that your personal incredulity is not a argument; CO2 as the control knob of global temperature is quite frankly as well established as the existence of gravity. Non-condensible gases set the thermal equilibrium, condensible gases (water vapor) can only act as feedback because they respond so quickly to a temperature change, even if their overall effect is quite large.
Again, your claim of disbelief in the science carries no weight by itself - try the peer-reviewed science, such as Lacis et al 2010, for actual discussions of the evidence.
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JeffDylan at 05:39 AM on 16 July 2017Water vapor is the most powerful greenhouse gas
Tom Curtis @281
Your analysis presumes the concept of H2O as only a feedback to the CO2 forcing, which no one has proven (even though climate "experts" use it all of the time), and I believe is false. Also, nothing coming from the IPCC or the United Nations in general carries any credibility with me. I'm afraid that unless you can come up with no arm-waving proof that CO2 is the "control knob" for the greenhouse effect (even though the greenhouse contribution from H2O vapor is mathematically much larger), there is really nothing further to discuss. You are only building castles on quicksand in your postings.
Moderator Response:[JH] Antagonisitic and baseless sloganeering snipped.
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ubrew12 at 04:30 AM on 16 July 20172017 SkS Weekly Climate Change & Global Warming News Roundup #28
The reason Scott Pruitt wants a televised red team/blue team debate on Climate Change is because the blue team will be composed of actual climate scientists, uncomfortable in the spotlight and unpracticed at debate. They will be right but will look wrong: and television is all about appearances.
Meanwhile, the fossil-funded red team will be composed of good-looking lawyers trained in winning debates, and having memorized their talking points. They also will have a distinct advantage: to win the debate they only have to spread doubt. They don't have to provide climate answers, just paint the answers the other side gives with cynicism. Keep in mind: these will be trained experts in planting doubt and cynicism in the public's mind.
A few years ago, Bill Nye (the Science guy) debated climate change with GOP Rep. Marsha Blackburn on 'Meet the Press'. She easily held her own, because she's trained in debate and had memorized her talking points, and because Nye is a 'science communicator' who, as scientists rarely do, doesn't react well to hearing someone speak with a forked tongue with such apparent ease. It's difficult but instructive to watch Blackburn toss off climate myths one after another with such cheery authority. No wonder Scott Pruitt wants to 'go there'.
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Doug_C at 02:10 AM on 16 July 2017Conservatives are again denying the very existence of global warming
nigelj, I hadn't thought of the addiction aspects of fossil fuels but that does seem to fit. George W. Bush in a rare moment of honesty and clarity a decade ago talked of Americans being addicted oil, but that probably applies to many places and is spreading as the growth of person autmobiles in the most populated nations rapidly increases.
Billions of Chinese and Indians may also eventually share this addiction.
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Eclectic at 01:49 AM on 16 July 2017It's too hard
Carn @67 ,
you seem to be very enthusiastic for a big increase in nuclear generation of electricity, but at the same time strongly opposed to government subsidies (i.e. the hand in the taxpayer pocket).
Yet nuclear power dies without subsidy.
And even with a big building program, the OECD and World Nuclear Association expect that they would achieve a "too little, too late" result by 2050 (in reducing world CO2 emissions). And it all needs government money, anyway.
There is the problem of up-front costs (and slow build rates, despite cutting regulations) plus de-commissioning costs. And many other aspects, of course. And after the severe financial embarrassments of the latest Finnish power plant (at Olkiluoto-3), it has come down to a reliance on government money (some from Finland, some from the Russian government) to get things done.
Private company investors are running for cover, when it comes to the suggestion of financing nuclear power plants. (And even with government money, it "just ain't gonna happen" in most of the tropical and near-tropic countries of the world.)
My own money, for instance, is invested in a spread of things giving a good return — not in the low-return / very-high-risk area of nuclear plants. And fund managers everywhere have much the same idea.
# Big new hydro schemes are mostly just not on : because there's really not much scope for expansion there nowadays. Even recent ones such as the Three Gorges scheme, come from [Chinese] government money — and may be embarrassed, some decades in the future, by water-flow alterations consequent on effects from the ongoing global warming. However, as you say, there is room for numerous tiny pumped-hydro plants, to supply electricity overnight where originally generated from solar & wind. And some of these could draw on seawater as their fluid.
Wind power is cheap enough nowadays for private companies to be willing to invest in, even without subsidy. And similarly with large-scale solar plants. And solar power is cheap enough now for private individuals to install their own roof panels — again without subsidy. So I don't know why you are so "down" on solar.
# If you are ideologically opposed to any subsidies, then you should be strongly opposed to the direct & indirect subsidies given to coal-fired plants and indeed also to most other fossil-fuel usage [not only because of CO2 emissions] where there are large taxpayer subsidies — some open and obvious, some hidden or indirect/external.
One guy I know says (only half-jokingly) that the entire costs of the USN Fifth Fleet over past decades should have been added to the per-gallon price of gasoline.
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One Planet Only Forever at 01:27 AM on 16 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
JWRebel@8,
The 'Good Intentions to Improve the future for all of humanity driven by rational consideration of all available information' that you have so generously offered as an explanation of the behaviour of rich and powerful people only applies to 'Some of the rich and powerful people'.
It is possible to test whether a rich and powerful person is deserving of that respect, or deserves ridicule. One of the most comprehensive tests is to:
- compare the claims made by them against all available information
- Seeing how they respond to skeptical questioning about whether their claims are supportable based on all available information
- validating that their actions support the achievement of the Sustainable Development Goals
- Seeing how they respond to skeptical questioning regarding the likely result of their actions, do they deliver Good Reason or Poor Excuses (or try to distract).
The SDGs were only published in 2015, but the 1972 Stockholm Conference included the understanding that fossil fuel burning had to end before the freedom of people to believe what they wished and do as they please (the marketplace) would end it. Climate impacts and all of the other SDGs have been developed since 1972 through coordinated cooperative international effort by 'people who actually do understand what is required, do know better'.
Based on that evaluation there is no doubt that many wealthy powerful people do not deserve to have Won Leadership positions (in business or government) and actually understand that they only have Poor Excuses for their chosen claim-making and desired action plans. And one of the poorest excuses is the claims that they 'pursue a broad support base' when what they really do is try to encourage people to be Greedier and Less Tolerant and gang up to Win undeservingly (undeserving if Winners are supposed to have proven by Good Reason that they help lead humanity to a sustainable better future - deserving in their minds if the measure of Winning is Winning whatever game has been made-up by getting away with behaving less acceptably/less justifiably than their competition).
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ralbin at 01:20 AM on 16 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
This piece and this research is based on a misunderstanding. The key constituency for Republican politicians isn't voters, it's their wealthy conservative donors. The fact that American politicians, Republican politicians in particular, don't reflect the views and interests of voters is well established in the political science literature. As for the final question of this piece, there is no single answer but a large part of the explanation is that the Republican Party apparatus is largely under the control of the clients of wealthy conservatives.
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Daniel Bailey at 00:18 AM on 16 July 2017Water vapor is the most powerful greenhouse gas
Your utter lack of actual analysis is duly noted. FYI: arguments from your personal incredulity carry no weight in a science-based venue, such as this.
As Tom Curtis notes, bring actual credible evidence for support of your claims. And remember to construct your comments in compliance with this venue's Comments Policy...
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Tom Curtis at 23:59 PM on 15 July 2017Water vapor is the most powerful greenhouse gas
JeffDylan @280, CO2 is responsible for approximately 20% of the Total Greenhouse Effect (TGE), ie, Total upward IR radiation at the surface minus total upward IR radiation at the top of the atmosphere. Based on IPCC AR5, the TGE is 159 W/m^2. Therefore removing the CO2 completely would increase upward IR radiation at the TOA by 31.8 W/m^2. With no feedbacks, that would result in a temperature decline of 8.9oC to Global Mean Surface Temperature (GMST). That decline in temperature would result in a fall in total column water vapour, which in turn would increase the lapse rate (a negative feedback) and reduce the contribution of water vapour to the greenhouse effect (a positive feedback). Combined, the two feedbacks have a feedback factor of +1.1 (+0.9 to +1.3) )W/m^2)/oC. That results in a further drop in GMST of 4oC, for a total of 12.9oC.
That is, eliminating all CO2 from the atmosphere, and with the combined WV/Lapse Rate feedback, the GMST would drop from 14oC to 1oC. That is from two to three times the reduction in GMST of the Last Glacial Maximum relative to the Holocene. Naturally, it will result in increased sea ice exent. Indeed, it would push the sea ice extent significantly south of the southern tip of the United Kingdom (its extent in the LGM):
That increased sea ice extent would result in a significant increase in the Earth's albedo. Based on Lacis et al (2010), it would increase it from 0.3 to 0.4 (second diagram in DB's post). Using that figure, that would result in a fall of 34 W/m^2 in the net incoming Short Wave radiation. From that we can expect a further fall of >13oC in GMST from the increase in albedo plus the effect of the WV&Lapse Rate combined feedback.
All up, we are looking at a >26oC drop in GMST just from those two feedbacks. That is less than that shown by Lacis et al, but their model was not restricted to just two feedbacks (although it did exclude very slow feedbacks, such as the formation and growth of ice sheets). >26oC is not "a few degrees C". In fact, the suggestion of a drop of just a few degrees C from the removal of all CO2 is absurd even for just the 9oC Planck responce, let alone once any feedbacks are taken into account. Given this, I suggest you reconsider your position carefully. If you want to insist on your absurdly low estimate, you at least owe us an explanation of how it was calculated (I know how deniers typically mispresent the science in calculating these values, but you may have simply assumed a low value without calculation, or be making a different mistake, so I will ask you to describe the calculation in your own words.)
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JeffDylan at 23:11 PM on 15 July 2017Water vapor is the most powerful greenhouse gas
Daniel Bailey @278
I'm not sure what you mean by a "real scientist", but I do have a doctorate degree in physics which includes some course background in atmospheric physics including the greenhouse effect. Also, I have tried for over ten years to sort out what the "experts" are saying about climate change and anthropogenic global warming (AGW). Therefore, I feel I should be at least qualified to comment on the claims made by these experts.
Do you actually believe the statement you quoted from Lacis et. al. 2010
Without the radiative forcing supplied by CO2 and the other non-condensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state.
So if we take the earth and atmosphere as is, and remove the atmospheric CO2, the earth would lose its entire greenhouse effect despite the fact that the H2O vapor caused about 95 percent of the greenhouse heating — I don't think so. The laws of physics say that no matter how we label H2O vapor (forcing, feedback, both, or neither), those molecules are going to continue capturing and re-emitting IR photons for as long as they stay up there. Furthermore, all H2O molecules that we lose from the atmosphere through condensation or precipitation we gain through evaporation. Therefore, we will still have most of the greenhouse heating that we had before we removed the CO2. Temperatures would likely drop a few degrees C, but we won't see that "frozen world" resulting from a total shutdown of the greenhouse effect. That's absurd!
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JWRebel at 20:06 PM on 15 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
Politicians pay only scant notice to polls. They assume other people (their constituents) are like them, as do most human beings. Americans go to Iraq, Afghanistan, or Bosnia and think well-meaning people there, being like them, will welcome efforts to bring democracy and to be able to act more like Americans.
Rich people (in Congress) also think that they are acting benevolently for the others in society, noblesse oblige, and often assume they know better what the interest of other people are than do those people themselves. Many are not actually cynical, just other-worldly. It is a smugness that only wears off when events conspire against them and they land up swapping their social position. One of the flaws in human beings are that they are naturally poor in putting themselves in others' shoes; only suffering breaks down people's "character" enough to be susceptible to "truth" [compassion].
An example: During the Great Financial Crisis in '08, millions of messages came to Congress members, skewed more than 99% against bailing out the banks. They did it anyway, not only because they are whores to money interests and campaign finance, but because they thought they knew better what was at stake.
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BBHY at 18:05 PM on 15 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
I would like to see 10% of congress be ordinary people, chosen by random lottery. They would only serve one term, then go back to their regular lives.
IMHO, that would be enough to break up the hold of career politicians, beholden to the rich, on our government.
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Eclectic at 17:25 PM on 15 July 2017Models are unreliable
Correction : that should be addressed to NorrisM @1063.
My apologies for that typo.
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chriskoz at 17:24 PM on 15 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
I don't think increased lobbying by voters will change politician's mind.
Just like they deny science, they also deny reality in broader sense, the same mechanism of cognitive bias aply here. T-man is a prime example.
Rather than increased citizen's lobbying, other measures, that would remove the incentives for cognitive bias, will be more effective: e.g. to start with, ban all political donations by industries (FF industry in particular) and over small limit. Then they would not be as encumbered by e.g. Koch bros as they are right now.
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Eclectic at 17:20 PM on 15 July 2017Models are unreliable
NorrisM @1061 , several points :-
1. Yes, you are beyond even the most extreme naivety, if you feel there's a chance that the political extremists [= Republicans, in this case] would come to any "acceptance" of what the climate science is telling us. And I'm sure that you, as a man of the world, are aware of the situation. It doesn't matter how many hearings occur, at ever higher levels of review and appeal, all the way up to the Supreme Court or beyond . . . . . the extremists will reject authoritative judgment (even if it were issued by the Archangel Gabriel).
2. The Global Warming issue has already already been "Red-Teamed and Blue-Teamed" extensively, for many years — and the result is as you know, a unanimous decision by the only court truly competent to make the judgment (i.e. by the scientists who have the technical knowledge to make the properly-informed decision). Yes, not quite strictly unanimous : there is a minuscule group of "dissenter" climate scientists [ well under 1% ] but their decisions are incompetent owing to the incoherent and mutually contradictory assertions they make. (And a realistic cynic would regard these "few" as composed of crackpots and/or shills for vested interests).
3. The politicians who reject & deny the plain scientific truth, will only change their viewpoint if it seems imminent that they will be voted out by a "fed-up" public — or if their major donors die off or themselves succumb to public pressure (e.g. to shareholder revolt). It is the long-running propaganda campaign of denial, which is the actual influencer or "hamperer" of public opinion : and not any judicial decision or series of judicial decisions.
4. NorrisM, let us be realistic : the question of virtuosity of "models" is unnecessary to the scientific case. The real physical world has already given us the decision, by means of obvious and incontrovertible evidence — sea levels have risen and are rising ever faster; planetary temperature has already risen 1 degreeC above the previous [downward] trend; glaciers and polar ice and permafrost are disappearing at a rapid & increasing rate; the oceans have warmed & acidified; plants and animals have changed their traditional pattern of activity.
Crackpots & shills try to delude themselves and deceive us with graphs which are downright economical with the truth [to use that ironically polite phrase!!]. But in summary :- the world is clearly rising significantly higher in temperature, and with no sign of slowing down any time soon — so to that extent "models" are unnecessary for responsible policymakers (and for us ordinary citizens, too).
Reckless foolhardiness & negligence are the traits of the "deniers".
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NorrisM at 15:20 PM on 15 July 2017Models are unreliable
Thanks everyone above.
Nigelj, I have to admit that 1054-1059 are challenging for a lawyer. I have not had time to go to realclimate.org but I will after we return from holidays. On our sailboat and hoping for wind but I have to admit, I do turn the diesel engine on when there is no wind!
To me the issue of how close the models match observations over whatever necessary period (20 years?) is critical. The "other side" says that there are large discrepancies (I believe that is what they say). If anything, a Red Team Blue Team approach would be the opportunity to show the other side what the models can and cannot do over specified periods of time and how accurate they are. As I noted elsewhere, Santer and Held had the chance to make this point at the APS panel and now have Koonin questioning the models because they did not adequately defend them.
My simplistic understanding of the scientific method is that one comes up with a theory and tests it to see if it is borne out by the tests. Or the model makes predictions and one looks back to see if the models were correct.
If the models cannot show that they are accurate over a 10 year period, then it does get problematic because how are public officials expected to commit massive amounts of funds until the models have shown that it is reasonable to assume they are right on, for example, a 3C rise by 2100 assuming that it is "business as usual"? When I use "predict", I mean a model projection which assumes that no mitigation is taken.
One last point before I head off. I do not think we can rely on "hind casting" to prove that the models can closely match reality because there are too many "fudge" factors used to make the models "fit" the actual history. There is no way of knowing if the same fudge factors work for the future. This is not original, I know. I think this is Freeman Dyson's comment at the beginning of this thread.
i will certainly spend more time on this when I get back. Perhaps by then we will have heard what the Trump administration has decided to do. If all we get is a TV debate as suggested by Scott Pruitt then all we will get is a gong show.
I truly think that a scientific debate along the lines of a legal hearing with both sides going at each other with an independent panel coming to a decision (with dissenting opinions) would be the best way to achieve some form of acceptance by the Republican party. I know this sounds naive but I have to admit I would like to see it!
Moderator: Sorry, just a little "off topic" at the last. Sometimes it does not make sense to fully "stream" these thoughts.
I am very much still a "fence sitter" on this issue because it is so technical and you have intelligent human beings on both sides of this debate saying different things. It is very frustrating. You would think that everyone could at least agree on the facts. Perhaps the Red Team Blue Team traditional approach could achieve some agreement on at least how far apart the models are from observations. That is why I so much trust our adversarial system of justice in Canada and the US compared to the European system. Let each side go at it and have an independent judge or judges render their decision AND provide their reasons for their decision. If there is disagreement amongst the panel, then dissenting opinions are also given.
Moderator Response:[DB] "If the models cannot show that they are accurate over a 10 year period"
As Tom Dayton notes, you continue to ignore the explanation he gave you even earlier. You also continue to not investigate the links you were given. You instead resort to sloganeering (repeating claims already invalidated). In a judicial trial, a judge would warn you for this behaviour. In this venue, there is a similar reproach.
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Eclectic at 11:34 AM on 15 July 2017Water vapor is the most powerful greenhouse gas
Thanks DB. I particularly like your first chart, which presents a "balanced" argument ;-) ..... though at the most elementary level [suited to my mind!!] it doesn't make the important distinction between "feedback" and "forcing".
JeffDylan @277 , we arrive at the frozen world scenario (discussed earlier) because there is a huge difference between CO2 and H2O as GreenHouse gasses.
At first glance , you might think there is not much difference — because under present-day Earth conditions, CO2 contributes [IIRC] roughly 30 watts/squ.meter of GreenHouse warming and H2O (vapor) roughly 70 watts/squ.meter of GH warming. But there is a huge difference in negative feedback once you "perturb" things toward lower levels of GH gasses. The essential cause of the difference is that at habitable temperatures, H2O transforms between ice / water / vapor over a very narrow temperature range (while CO2 remains as a gas, and exerting its usual GH effect).
How this difference works out "so differently" — is through the albedo effect. Currently the Earth has an albedo of about 0.3 , so roughly 30% of the sun's heat (predominantly as light) is reflected away, and 70% is absorbed by the planetary "surface". Yet snow/ice has an albedo of about 0.9 — so as a greater percentage of the planet gets covered in ice, there's a vast reduction in absorption of the sun's heat. It is a very strong feedback, since cooler air loses H2O vapor which is precipitated as snow and frost (and more extensive sea-ice) and more ice leads to even colder conditions. And so it goes. And hence the (hypothetical) fully frozen world, which stays frozen [if without CO2].
You can see a more graduated (and fortunately limited!!) effect occurring in the real planet Earth. So the scientists are well-justified in calling CO2 the "control knob" and describing H2O vapor as the tail on the dog [metaphorically speaking].
Yes, the dog's H2O tail is bigger than the CO2 dog [at present temperatures] -— but it is the dog which controls where it goes!!
And hence the emphasis on the vital importance of reducing atmospheric CO2.
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Daniel Bailey at 09:39 AM on 15 July 2017Water vapor is the most powerful greenhouse gas
"If we take the earth and atmosphere as is, and made every atmospheric CO2 molecule vanish, we would certainly lose the greenhouse effect contribution from CO2, but remember that H2O is the stronger and more abundant greenhouse gas. Therefore, we would expect a small reduction in greenhouse heating possibly causing temperatures to drop by a few degrees C, but not at all like the "frozen world" you describe."
Real scientists have examined exactly that. FYI, Water vapor is a condensible GHG. As such, and by definition, it cannot be a driver of temperature changes but can only serve as a feedback to them.
Carbon dioxide, on the other hand, is the most important temperature control knob on the planetary thermostat.
"Ample physical evidence shows that carbon dioxide (CO2) is the single most important climate-relevant greenhouse gas in Earth's atmosphere. This is because CO2, like ozone, N2O, CH4, and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can, and does.
Non-condensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapor and clouds via feedback processes that account for the remaining 75% of the greenhouse effect.
Without the radiative forcing supplied by CO2 and the other non-condensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state."
"The climate system of the Earth is endowed with a moderately strong greenhouse effect that is characterized by non-condensing greenhouse gases (GHGs) that provide the core radiative forcing. Of these, the most important is atmospheric CO2. There is a strong feedback contribution to the greenhouse effect by water vapor and clouds that is unique in the solar system, exceeding the core radiative forcing due to the non-condensing GHGs by a factor of three. The significance of the non-condensing GHGs is that once they have been injected into the atmosphere, they remain there virtually indefinitely because they do not condense and precipitate from the atmosphere, their chemical removal time ranging from decades to millennia. Water vapor and clouds have only a short lifespan, with their distribution determined by the locally prevailing meteorological conditions, subject to Clausius-Clapeyron constraint.
Although solar irradiance is the ultimate energy source that powers the terrestrial greenhouse effect, there has been no discernible long-term trend in solar irradiance since precise monitoring began in the late 1970s. This leaves atmospheric CO2 as the effective control knob driving the current global warming trend.
Over geologic time scales, volcanoes are the principal source of atmospheric CO2, and the weathering of rocks is the principal sink, with the biosphere participating as both a source and a sink. The problem at hand is that human industrial activity is causing atmospheric CO2 to increase by 2 ppm/yr, whereas the interglacial rate has been 0.005 ppm/yr. This is a geologically unprecedented rate to turn the CO2 climate control knob. This is causing the global warming that threatens the global environment."
And:"If there had been no increase in the amounts of non-condensable greenhouse gases, the amount of water vapor in the atmosphere would not have changed with all other variables remaining the same.
The addition of the non-condensable gases causes the temperature to increase and this leads to an increase in water vapor that further increases the temperature.
This is an example of a positive feedback effect. The warming due to increasing non-condensable gases causes more water vapor to enter the atmosphere, which adds to the effect of the non-condensables."
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JeffDylan at 09:10 AM on 15 July 2017Water vapor is the most powerful greenhouse gas
Eclectic — I'm not sure I understand how we arrive at the frozen world scenerio you described in 268. If we take the earth and atmosphere as is, and made every atmospheric CO2 molecule vanish, we would certainly lose the greenhouse effect contribution from CO2, but remember that H2O is the stronger and more abundant greenhouse gas. Therefore, we would expect a small reduction in greenhouse heating possibly causing temperatures to drop by a few degrees C, but not at all like the "frozen world" you describe.
Remember that the earth, atmosphere, and solar radiation as they are today must share an energy balance relation. That is, whatever energy the earth and atmosphere absorb from the solar radiation must be re-radiated from the earth and atmosphere, at least in the long term. Since CO2 has only a minor impact on the greenhouse effect, I would not expect the temperatures after CO2 removal to be much different from what they are now in order to maintain energy balance.
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bjchip at 08:20 AM on 15 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
Darn it... I keep forgetting the link thing.
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bjchip at 08:19 AM on 15 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
So maybe liberals vote but their votes aren't counted?
Maybe they don't pay attention in the local elections that ultimately determine the lines drawn for the larger issues?
http://athensforeveryone.com/gerrymandering-fairness-and-you/
Maybe there is a reason we are governed by a minority?
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nigelj at 08:01 AM on 15 July 2017Planet Hacks: Food
John Wise @6, I do accept there seems some inconsistency in the two links on the total emissions from agriculture. The second is most accurate. If you want a more authoritative analysis of fundamental sources of emissions try the American EPA as below. They discuss all sources and agriculture is 24% similar to my second link:
www.epa.gov/ghgemissions/global-greenhouse-gas-emissions-data#Sector
However your question related to carbon footprints of different types of foods, and I responded to that. As you can see two different sources gave similar results, which gives some credibility to the numbers. I have no reason to doubt the basic percentage differences between the foods, and you haven't given me any. You have basically changed the subject and shifted the goal posts.
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nigelj at 07:22 AM on 15 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
"American politicians perceive their constituents’ positions as more conservative than they are."
This comes as no surprise to me. Perhaps politicians just hear what they want to hear.
Polls by organisations like Pew consistently show the majority of Americans want action on climate change, in stark contrast to the views of Congress.
As you say perhaps conservatives lobby more. Here is another possibility that may explain part of this issues. I listen to talkback radio sometimes (not hugely, it can get a bit mind numbing at times, the ignorance is astounding) but one thing comes across clearly. It's the conservative leaning callers that dominate, and are the loudest and most direct and blunt in their views. Liberal leaning callers are fewer in number, and tend to be more laid back, nuanced and complex in their views. It creates an impression that conservative views are more numerous, when they clearly actually aren't.
This conservative dominance is possibly because liberals promote tolerance as a key value, so dont want to be too blunt. They end up holding back just a little too much at times.
I find both conservative and liberal views interesting and am not saying one side is always right, because that's just not the case in my view. But the way views are put has a difference.
However for some reason liberals and conservatives seem equally loud in internet forums, but politicians still probably look a lot at traditional media like radio, given their age group.
The views of people are complex and confused as well and this is what politicians are listening to. The Economist.com July edition did an interesting, excellent and relevant article called America Divided. It would be on their website if you are a subscriber and you can get a few articles for free. Briefly they interviewed people living in small town america and discussed political views, occupations, and voting habits etc.
They identified some partisan divisions between conservative / liberal and occupational groups particularly. They identified partisan divisions between republican and democrat, but not as large as anticipated. They found many people were not too clear on what the parties even stood for, and voting was often out of habit, peer group leanings, and personalities rather than policies.
Some voted for Trump because he "spoke like them" or said he cared, even although they admitted his policies didn't make a lot of sense. However democrat and liberal leaning people tended to look a little more at policies than personality. Personally I think its policies that count for most.
You therefore have a very complex, confused voter base feeding information back to elected representatives. With so much poor quality understaanding of policies the end result is not going to be good. In such an environment it will also be the loud groups with vested business interests that dominate, and get through to politicians and articlulate views most cogently, for good or bad.
The other obvious dynamic is politiicans are funded by various groups including fossil fuel lobbies, and are therefore probably susceptible to the wishes of those groups. But that's another separate issue.
I agree if people want Congress to reflect their views they need to engage politicians directly. This overcomes many issues. People also need to state their views more firmly. Being tolerant and open minded should not have to mean being too reticent or wooly thinking or holding back.
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John Wise at 06:55 AM on 15 July 2017Planet Hacks: Food
nigelj
Thanks for the links. They contain similar information to others I have read. They are all over the place. The first(greeneatz) suggests that as much as 50% of emissions are due to agriculture,mainly from livestock. The second(U. of Michigan) states in the text that over 20% are from agriculture. Then,in the graph further in the MIchigan article,it breaks down U.S. emissions as follows: transportation 27%,energy 32%,other fuel 11%,manufacturing 12%,fugitive emissions 4%,industrial processes 5%,waste 2%,and agriculture 8%.
So,we have 8% to 50% of emissions from agriculture? I realize that the other categories include transportation,food processing etc.,but 50% seems pretty high.
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BBHY at 06:50 AM on 15 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
I saw an article on Grist yesterday about the actions people can take on climate change, but voting wasn't included.
I think voting may be the most important step people can take. Changing your lightbulbs and not bothering to vote against climate denier politicians is a failed strategy.
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BBHY at 06:47 AM on 15 July 2017Study: On climate change and elsewhere, politicians more conservative than citizens
Many liberals don't vote, often because they don't have candidates that represent their values. In many districts, the Dems even allow the R candidate to run unchallenged.
This is wrong. If a football coach said the team was only going to try to win the easiest games, he would be fired immediately.
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nigelj at 06:25 AM on 15 July 2017Conservatives are again denying the very existence of global warming
Doug_C, yes well said. The manufacturers of tobacco and oil / coal etc have a lot in common, including huge vested interests, and a historical tendency to deny the science, and blatantly misslead people. Both groups knew about the problem, and knew it was real, much earlier than they admitted.The book "Merchants of Doubt" documents some of this.
I have also often wondered if the users fossil fuel use also have a sort of addiction, or at least an ingrained habit and of course that includes many of us. In my view theres no real hard line defining what substances can form addictions, or when an addiction becomes a habit. I think it's all just matter of degree to some extent, and more a question of whether the addiction is causing more harm than good.
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nigelj at 06:11 AM on 15 July 2017Planet Hacks: Food
John Wise @4
Here is a quick comparison of carbon footprint of meat versus various lentils and vegetables. I assume its full life cycle:
www.greeneatz.com/foods-carbon-footprint.html
Here is a more detailed comparison and explanation:
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carn at 01:33 AM on 15 July 2017It's too hard
@ Eclectic
"Yes Carn, that outcome is quite understandable — if we deliberately do nothing more than sit on our bums."
No, this is not only a "function" of our efforts, but also depend upon laws of nature and what they allow for and what they do not allow for. Science and research is not some 'work hard and you get what you want'; its 'work hard and maybe nature is nice, maybe it isn't; and maybe one day it falls into your lap without effort; and maybe you will achieve it never'.
"Please show some Can-Do attitude"
Its just the "Can-Do attitude" by some ecos that gives me the chills; they claim that something is possible via R&D at some date; then laws are passed towards that; and nobody ever caring whether it is realistic or not; leading to all kinds of problems and maybe not even helping in regard to GW.
"and express your own ideas of how best to tackle the AGW problem"
Change rules for building permits, safety regulations and police laws such, that nuclear power can be ramped up by at least 50% per decade. Especially weaken the insanely low concentration limits for radiation and the insane differntiation between "natural" and "artificial" radiation. Cut all funding for all eco groups having the slightest problem with that and use all legally avaible means to utterly bankrupt, destroy, dissolve such groups.
Cut subsidies for solar power and electric cars to such an extent that devlopment continues but building lots of ecologically inefficient solar power plants/cars is avoided.
Subsidies for wind power can to some extent remain (wind power is lot more ecologically efficient than solar).
Also change building permit rules, ecological protection laws, etc. that the scenario "there is enough water flow for a hydro power plant" results in 75%+ of all cases within 15 years into "there is a hydro power plant"; hydro power is the most ecologically efficient stuff out there and can serve as near perfect storage for compensating changing wind power output. If any eco cries about some poor endangered species living in the area effected by a dam, directly kill some of the creeps so the ecos understand no one cares about animals (which we do not need), since the issue is saving human lives.
Develop the technology for using nuclear power plants to create hydrogen, so nuclear plants can operate either in elcetric production more, when wind output is low, or in hydrogen production mode, when output is high.
But it seems to me, that many people will disagree with my suggestions; some for good reasons, but many due to simply not thinking but letting their emotions think.
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John Wise at 01:05 AM on 15 July 2017Planet Hacks: Food
Can anyone direct me to a study showing the full lifecycle carbon footprint of ruminant meat/dairy production on pasture vs. plant protein production such as beans or lentils?
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Doug_C at 01:03 AM on 15 July 2017Conservatives are again denying the very existence of global warming
I live in BC, the forcast today is sunny with smoke from the wildfires that are all across this Canadian province, it has been this way for a week and is forecast for days to come.
NASA is detecting the smoke from the worst wildfires in Siberia in 10,000 years.
There are so many indicators like this that the climate in many places has been altered significantly already with more to come that denying human forced climate change is purely an exercise in marketing, not even marginal science. People make a living selling fossil fuels indirectly by denying the negative impacts in almost exactly the same way they sold so many cigarettes for so long long by concealing how dangerous they are.
Big tobacco and climate change denial
It's basically lying for a living in the interests of a product that is eventually going to kill off not just billions of people if left un-mitigated, it will take out a huge swack of the entire biosphere just like any carbon dioxide driven extinction event in the past. The tobacco industry used denial of the science to "recruit" replacement smokers for the ones their products killed.
We don't have a replacement Earth.
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Eclectic at 17:00 PM on 14 July 2017Water vapor is the most powerful greenhouse gas
JeffDylan @273 , I hope you found TD's and Scaddenp's posts helpful.
The hypothetical fully frozen world is locked in stable equilibrium (since it lacks CO2 in its atmosphere) but of course it is only an illustrative example of how CO2 or H2O greenhouse effect works.
The real physical world is the one we are interested in. And in the real world, it is largely CO2 which works as the "control knob". Real-world perturbations (e.g. your "forest fires, volcanoes, lightning, or even a solar flare") are brief and relatively small, compared with the decades/centuries-long cumulative effects of CO2 planetwide.
You might also be interested to look at the (intermediate) "CO2 Lags Temperature" [Climate Myth Number 12, via the Home Page] where the Milankovitch cycles are mentioned. The biggest take-home message there, is that subtle alterations in albedo (Northern Hemisphere ice cover & vegetation changes) connected with summer/winter axial tilt, being enormously amplified in effect by consequent outgassing (or the opposite) of CO2 from the oceans. Hence the lag effect, mentioned.
Climate science is like a 1000-piece jigsaw puzzle where all of the pieces fit together nicely to produce a portrait. Even with a piece or two missing, the portrait still presents a clear and unmistakable picture (and does not produce "alternative" pictures). JeffDylan, I sense you feel that [so to speak] one of the pieces is upside down or in the wrong place. If that is so, then please clarify your thoughts on the matter (but I strongly suspect the overall picture will remain the same — and that your unease stems from a semantics problem, not a physical-reality problem).
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Tom Dayton at 15:03 PM on 14 July 2017Water vapor is the most powerful greenhouse gas
JeffDylan, if the instability of the sensitivity you described existed, it would exist for all configurations of the Earth, not just frozen Earths. Think about it--all of them. Empirically that simply is not the case. Please read the "runaway" post I pointed you to.
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scaddenp at 14:57 PM on 14 July 2017Water vapor is the most powerful greenhouse gas
As per Tom Dayton - "unstable" implies feedback with gain > 1.0. Maybe there is a some configuration with this level of unstability but I am unaware of any evidence from observation or models for such a strong gain. Certainly in the modern climate, water feedback gain is small (0.3-0.4 from memory).
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JeffDylan at 14:35 PM on 14 July 2017Water vapor is the most powerful greenhouse gas
By "perturbation", I mean any event that releases heat into the atmosphere. It could be forest fires, volcanoes, lightning, or even a solar flare. The purpose of part (b) of my posting @270 is to show that the "frozen world" scenerio described by Eclectic @268 is not stable even though it is an equilibrium, and to analyze stability of a system in equilibrium, we ask the general question "Will some small deviation (or perturbation) in the system from equilibrium grow?". In this case, the answer is "yes". As I argued in 270, a tiny amount of heat applied to the ice leads to big changes in the greenhouse heating which means the system is unstable. Therefore, we really can't use this frozen world scenerio to conclude anything.
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nigelj at 13:40 PM on 14 July 2017Planet Hacks: Food
Just adding to OPOF's list of cultural reasons for meat eating. According to this psychologist American meat eating is related to validating and celebrating manhood.
www.nbcnews.com/id/49920136/ns/health/t/why-real-men-eat-meat-it-makes-them-feel-manly/#.WWg4-4SGPIU
In my view it probably goes right back to stone age men killing wooly mammoths etc, and roasting them over the fire. It may have become a cultural meme / memory. This probably explains why we love barbecues.
You have other cultural meat issues. Sharks and rhino's are also killed for perceived therapeutic properties of the fins, and horns, despite a total lack of supporting scientific evidence. Whale meat remains a cultural delicacy in certain countries, despite dwindling numbers of whales. While cultural differences are worthy of respect, hunting species to extinction or very low numbers raises its own series of concerns.
Soils and plants have potential as carbon sinks if properly managed, as is well known. Intensive cattle farming and / or poorly managed farming can strip grasslands bare or reduce grass root bundles, and thus reduce potential carbon stores.
en.wikipedia.org/wiki/Carbon_sink
All things taken together suggest high meat consumption has a range of problems.
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Tom Dayton at 12:41 PM on 14 July 2017Water vapor is the most powerful greenhouse gas
JeffDylan: Positive feedback whose gain is less than one converges (peters out). The smaller the gain, the faster it converges. See the post about runaway (though I understand you did not claim it would run away). Note there are Basic, Intermediate, and Advanced tabbed panes.
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Eclectic at 12:28 PM on 14 July 2017Water vapor is the most powerful greenhouse gas
JeffDylan @270 ,
we should await better brains than mine, to give some quantification to the scenario you have proposed!!
As I picture it, a minor perturbation (in the warming direction) would only release a tiny amount of H2O vapor, which would promptly fall back as snow & frost — i.e. it would not meet the threshold to achieve current ambient temperatures (to maintain enough vapor to give positive feedback).
I am not sure of what cause of perturbation you were thinking about. If it was of ("Milankovitch") alterations of planetary tilt or orbital shape, then these would produce only very tiny changes in solar heat flow into the planet. Volcanoes? — they would produce both a "sooty" coating to surface ice [positive] and atmospheric reflective particles/aerosols [negative] : but their real cumulative warming effect would come from the CO2 emitted. Which brings our discussion back full circle!
Without CO2, it is difficult for a fully frozen world to "escape".
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JeffDylan at 11:46 AM on 14 July 2017Water vapor is the most powerful greenhouse gas
Eclectic @268 — Thanks for your response. Understand however that the "answers" I get about the dominant greenhouse gas are generally incomplete or don't make sense at some point.
I did some pondering on your thought experiment, and I believe your prediction in part (a) is correct. Since energy balance is maintained in the long term and the supply of liquid H2O for water vapor is virtually limitless, it makes sense that the earth would tend to return to that state if the atmospheric H2O vapor is somehow removed.
In part (b), however, I believe your prediction is erroneous. The "frozen world" you mention is an unstable equibrium. Although there is no greenhouse effect due to the fact that the CO2 was removed and H2O exists as a solid instead a gas, any minor perturbation of the system that causes some heating will drive H2O molecules from the ice to the atmosphere, thereby causing greenhouse heating which in turn causes more H2O molecules to leave the ice and enter the atmosphere, which causes more greenhouse heating. In this manner, the H2O content of the atmosphere increases until a new equilibrium/energy balance state is obtained. This new state may be somewhat cooler than the old state that included CO2, but it certainly would not be a long-term frozen world.
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Eclectic at 10:44 AM on 14 July 2017Water vapor is the most powerful greenhouse gas
Yes, my apologies TD.
I spoke with clumsy brevity, and was thinking of the H2O's interchange between vaporous and droplet form while remaining in the atmosphere.
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Bob Loblaw at 10:27 AM on 14 July 2017Models are unreliable
Also following along the question of removing El NIno effects from the observational record, a simper appraoch is to look at only the years with El Nino, only the years with La Nina, and the remaining "neutral" years as different data sets. Examining the trend in each set individually will help separate the effects in a much simpler manner than the multiple regression or modelling techniques. The simplicity may make it easier to understand.
This has been done by John Nielsen-Gammon, and SkS posted on this in this discussion:
https://skepticalscience.com/john-nielsen-gammon-commentson-on-continued-global-warming.html
Short story: all three sets show basically the same trend.
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