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Cedders at 00:05 AM on 29 November 2018Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
I'm not seeing the video on this page, but assume it is:
https://www.youtube.com/watch?v=RhdY-ZezK7w
By the way, I suppose a few things have changed since 2012, in particular understanding how ice sheet melt is likely to accelerate, and recognition of Rignot et al (2011) and Church & White (2011).
I'm trying to recall the two researchers who demonstrated the acceleration in Antarctic melt around 2014. This year web searches find me papers by Konrad et al on Antarctic glacier grounding lines, and by Silvano et al on freshening by glacial meltwater and by IMBIE on tripling of Antarctic ice melt between 1992 and 2017.
Moderator Response:[DB] Updated video link in post. Thanks!
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SirCharles at 23:54 PM on 28 November 2018Why does CO2 cause the Greenhouse Effect?! | Climate Chemistry
I totally agree with nigelj here. I cannot picture kids being overwhelmed by this presentation. Frankly speaking, it's quite boring and not easy to grasp that way.
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Philippe Chantreau at 15:11 PM on 28 November 2018Discussing climate change on the net
Art, that may be so but there is something about expanding effort where it will bring maximal return.
Scaddenp, point taken. Make sure you stay away from the strawberries too... :-)
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JohnStockwell at 14:17 PM on 28 November 2018CO2 lags temperature
The time lag is likely an illusion caused by an age date discrepancy between the ice and the gas trapped in the ice. The ice is snow before it is ice. The atmosphere is free to circulate to the bottom of the snow layer, so the gas is considerably younger than the ice it is imbedded in. Parrenin et al 2013 found that there is no lag between CO2 and the temperature changes when both are put on the same chronology.
Synchronous Change of Atmospheric CO2 and Antarctic Temperature During the Last Deglacial Warming
F. Parrenin et al.
Science 339, 1060 (2013);
DOI: 10.1126/science.1226368 -
Art Vandelay at 11:33 AM on 28 November 2018Discussing climate change on the net
Philippe @ 9: Air travel is not the most urgent emission source to tackle. Getting rid of coal burning and slowing deforestation would achieve far more than reducing air travel.
It's an easy one to target however, given that 78% of air travel is a recreational activity for relatively wealthy individuals. On the other hand, deforestation today is mostly ocurring in developing countries of Asia and South America, as a consequence of economic development.
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Daniel Bailey at 10:18 AM on 28 November 2018Climate science comeback strategies: Al Gore said what?
It's important to remember that the globe is not a homogenous whole, warming or cooling uniformly. And that regional and seasonal differences exist, sometimes opposite in sign, over time. So if the goal is to gain the best understanding of change over time, then I think that most would agree that the imperative is to use as many locations as possible using the most proxy types as possible, with the longest records possible.
With that in mind, we can look at the last 1,700 years, (from the NCA4, Vol 1 from 2017), which covers the specific period in detail, but from a global perspective (and not confined to just winters):
For additional perspective, we can look at global temperatures over the past 22,000 years (from Bruce Railsback's Fundamentals of Quaternary Science):
So as we can see, global proxies offer the best context.
A good summary of the present iteration of warming, from last week's released National Climate Assessment 2018, Vol. 2, from the Trump Administration:
"Scientists have understood the fundamental physics of climate change for almost 200 years. In the 1850s, researchers demonstrated that carbon dioxide and other naturally occurring greenhouse gases in the atmosphere prevent some of the heat radiating from Earth’s surface from escaping to space: this is known as the greenhouse effect.
This natural greenhouse effect warms the planet’s surface about 60°F above what it would be otherwise, creating a habitat suitable for life. Since the late 19th century, however, humans have released an increasing amount of greenhouse gases into the atmosphere through burning fossil fuels and, to a lesser extent, deforestation and land-use change. As a result, the atmospheric concentration of carbon dioxide, the largest contributor to human-caused warming, has increased by about 40% over the industrial era.
This change has intensified the natural greenhouse effect, driving an increase in global surface temperatures and other widespread changes in Earth’s climate that are unprecedented in the history of modern civilization.
Global climate is also influenced by natural factors that determine how much of the sun’s energy enters and leaves Earth’s atmosphere and by natural climate cycles that affect temperatures and weather patterns in the short term, especially regionally.
However, the unambiguous long-term warming trend in global average temperature over the last century cannot be explained by natural factors alone.
Greenhouse gas emissions from human activities are the only factors that can account for the observed warming over the last century; there are no credible alternative human or natural explanations supported by the observational evidence.
Without human activities, the influence of natural factors alone would actually have had a slight cooling effect on global climate over the last 50 years."
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Eclectic at 09:41 AM on 28 November 2018Climate science comeback strategies: Al Gore said what?
JP66 @11 ,
A/ Yes you are quite right, we should assess things coolly and logically, and not be swept away by a few tiny pieces of evidence (like cherry-picking a handful of leaves from a large forest). There is a vast wealth of evidence ~ consilient evidence ~ supporting the mainstream climate science . . . and there is almost none supporting the "denialist" viewpoint. The denialists have rhetoric, and not much else.
B/ As you are already aware, I'm sure, the hugely significant difference between the previous changes in temperature during the Holocene, and the present day global temperature . . . is that of rate of change. At present, the surface temperature is climbing vertically like a Hornet on afterburners (excuse the mild hyperbole!). And it is still climbing rapidly. This is a vastly different situation from the slow & slight changes during the so-called Holocene Optimum and during the 5,000 years since then.
C/ It's a good idea to step back and look at the bigger picture. Coming out of the last glacial stage (and speaking in broad terms) there was a 10,000-year gradual rise of temperature of roughly 5 degreesC (and there was also a 1,000-year wiggle in the middle of that, named the Younger Dryas). Then came a rather flat period of about 5,000 years, which some call the Holocene Optimum. Following that, for 5,000 years has been a slow fall of temperature . . . until now. Just as seen in the level Holocene Optimum, we also see during the declining past 5,000 years ~ various minor bumps and minor troughs (named the Roman Warm Period, the Medieval, the Little Ice Age, etcetera etcetera). These small wiggles are very small, and came and went slowly (and they are so small in amplitude of rise/fall, that is is difficult to exactly define their start and finish).
D/ The more important point is : what caused these previous minor wiggles during the Holocene? There's only a limited number of candidates ~ minor variations in solar output (on a multi-decadal scale); occasional major volcanic activity; long-cycle oceanic overturning currents; etcetera. Climate changes when something causes it to change. It doesn't change for no reason. (And I am sure you also know of the ultra-long cycle of Milankovitch.). This is why the denialists are talking arrant nonsense, when they say that the recent warming [say from 1800 or 1850] is just "a rebound from the Little Ice Age" ~ they seem to forget that there must be an actual cause for change.
JP66 . . . against the overall picture, the overall evidence . . . it is very difficult to find anything to get excited about, in fjord depths. (If I have mis-read that, then I would be grateful if you would explain the significance.)
JP66 , if you wish to question the general world data being correct/incorrect ~ you should read & discuss at a more appropriate thread. [And a Spoiler Alert : the denialists have got that wrong as well!]
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JP66 at 07:36 AM on 28 November 2018Climate science comeback strategies: Al Gore said what?
I am a climate fence sitter. I like to think I read diligently on all sides. Recently I came across a paper listed on a "denier" site and was wondering what the folks here had to say. The conclusion of the study was quite clear:
"The record shows a substantial and long-term warming during the Roman Warm Period (~350 BCE – 450 CE), followed by variable bottom water temperatures during the Dark Ages (~450 – 850 CE). The Viking Age/Medieval Climate Anomaly (~850 – 1350 CE) is also indicated by positive bottom water temperature anomalies, while the Little Ice Age (~1350 – 1850CE) is characterized by a long-term cooling with distinct multidecadal variability. When studying the Gullmar Fjord bottom
water temperature record for the last 2500 years, it is interesting to note that the most recent warming of the 20th century does
not stand out but appears to be comparable to both the Roman Warm Period and the MCA."Tracing winter temperatures over the last two millennia using a NE
Atlantic coastal record
Irina Polovodova Asteman1
, Helena L. Filipsson 2
, Kjell Nordberg 1 5
1 Department of Marine Sciences, University of Gothenburg, Carl Skottbergsgata 22B, 41319 Gothenburg, Sweden
2 Department of Geology, University of Lund, Sölvegatan 12, 22362 Lund, Swedenhttps://www.clim-past-discuss.net/cp-2017-160/cp-2017-160.pdf
I realize the first and foremost rebuttal would be to say the report covers a subset of the globe and not the whole, but similar such studies show the same result in many areas of the globe. Is the data incorrect? Why are global average anomalies better suited to determining whether there is warming?
Thank you for your input.
Joe in NY
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nigelj at 06:51 AM on 28 November 2018Discussing climate change on the net
I listen to talkback radio sometimes (please forgive me) and you hear the same characters phoning in with the same often identical comments in a certain type of style and usually related to climate change denial and small government ideology etcetera. I can't be sure, but it looks like they work for libertarian leaning lobby groups paying them to saturate the media. These people are organised, and to them the means justify the ends and they don't give a damn about standards of ethics, fair play or integrity. Cherrypicking is their middle name.
The book Dark Money is very illuminating.
I'm a free speech advocate, so I dont think climate scepticism should be banned as such, but I think repetitive propoganda, and wild claims should be culled out. Give people are change obviously, a warning, and don't be over zealous either as it alienates people on all sides of the debate and nobody will post comments. Bit of a balancing act I guess.
A certain other climate website (won't name names) has a very slack moderation policy, and their website is a total mess imho full of repetitive denialist propoganda, political rants, and personal insults often among the warmists themselves, which is just embarrassing. It's counter productive, they are shooting themselves in the foot.
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scaddenp at 06:14 AM on 28 November 2018Discussing climate change on the net
Phillipe - that graph needs wider publicity. A lot of deniers see climate action as a threat to their car - justified to some extent - but understanding that coal electricity generation and agricultural are more important is helpful. However, the emission graph depends on your country. Here (NZ) it is roughly 50% transport / 50% agricultural (thermal electricity is a small player). When your economy is based on agriculture (particularly dairy with high methane emissions) and tourism (which needs air and car transport), it can be pretty sobering.
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nigelj at 05:53 AM on 28 November 2018Why does CO2 cause the Greenhouse Effect?! | Climate Chemistry
I hugely respect Climate Adam, and realise hes trying to make science fun, but this video is a trainwreck and just so childish and distracting. A few wiggles of CO2 molecules on a diagram would have been more informative, and taken a fraction of the time. Give them smiley faces, if you want to make it fun.
How do we get from measuring the level of energy absorption by the molecule to calculating a change in global temperature? It would be interesting to see the basic maths and physics but kept at a level the average person in the street can relate to.
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Doug_C at 05:14 AM on 28 November 2018Discussing climate change on the net
"Rebukes that this constitutes censorship or infringement of their rights to free speech can be safely ignored as there are many other websites - perhaps even their very own Facebook page! - where they can post whatever they want. And if they don't get this message, you can always show them the door via XKCD's neat cartoon:"
When you look at the amount of money from individuals like the Koch brothers and corporations like Exxon Mobil, I don't see how climate change denial can be considered free speech in any sense. And more and more this denial is being funded in the same way drug cartels and terrorist groups move money around to avoid discovery.
"Dark Money" Funds Climate Change Denial Effort
"The study, by Drexel University environmental sociologist Robert Brulle, is the first academic effort to probe the organizational underpinnings and funding behind the climate denial movement.
It found that the amount of money flowing through third-party, pass-through foundations like DonorsTrust and Donors Capital, whose funding cannot be traced, has risen dramatically over the past five years.
In all, 140 foundations funneled $558 million to almost 100 climate denial organizations from 2003 to 2010."
Climate change denial has nothing to do with evidence and fair comment, it is essentially deceptive advertizing. And follows on from the same kind of deceptive campaign to prevent action in the public interest that tobacco corporations funded for years.
'So the fight against a ban on passive smoking had to be associated with other people and other issues. Philip Morris, APCO said, needed to create the impression of a "grassroots" movement - one that had been formed spontaneously by concerned citizens to fight "overregulation". It should portray the danger of tobacco smoke as just one "unfounded fear" among others, such as concerns about pesticides and cellphones. APCO proposed to set up "a national coalition intended to educate the media, public officials and the public about the dangers of 'junk science'. Coalition will address credibility of government's scientific studies, risk-assessment techniques and misuse of tax dollars ... Upon formation of Coalition, key leaders will begin media outreach, eg editorial board tours, opinion articles, and brief elected officials in selected states."'
When comments from such sources are removed and people who are quite likely being paid to disseminate false information are banned it is in all our interests.
Climate change is becoming more destructive and deadly every year, the wildfires in California now are just the opening stage of this catastrophic process.
Sites like Skeptical Science and those who are involved in presenting the real story based on clear evidence are working in the interests of our entire species against what is now obviously an existential threat.
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nigelj at 05:10 AM on 28 November 2018Discussing climate change on the net
Art Vandelay @8
Yes effective top down action requires the majority are comfortable with it, however the case of the French protesting against fuel prices is probably not an ideal or representative example. Refer article here. Its due to a combination of higher prices for fuel imports and extra taxes one of them being a carbon tax, so its the combination that has possibly pushed them into protesting. And the French protest about anything, believe me while other countries do not.
The government indeed obviously needs to tread carefully with taxes. It looks like Macron chose the wrong time just when petrol prices are at a peak, which was obviously going to be temporary so he could have waited.
In addition, the french carbon tax is not a tax and dividend scheme, so is quite harsh on consumers. The tax goes into funding a range of things, not just renewable energy.
There's no escaping the need for a top down solution. Individuals cant build electricty grids and individuals are reluctant to reduce carbon footprints, possibly because they dont see many other people doing the same, hence the need for top down solutions of various kinds to get things moving. When people see some action they are likely to be more personally motivated.
Some people might indeed tend to say its governments problem, but I think the vast majority have enough sense to realise mitigation requires both electricity grids and personal changes in behaviour of various types.
Of course its important to show there are several things people can do to make a difference without waiting on governments, and which can only be driven by consumers, like reducing meat consumption and trying to be more economical with energy use. There are multiple benefits in such things as you also alluded to regarding renewable energy. Perhaps this needs to be used more in education campaigns.
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Philippe Chantreau at 05:02 AM on 28 November 2018Discussing climate change on the net
The IPCC attributes 14% of global carbon emissions to transportation.
Among those, all of aviation represents a total of 4% total cumulative greenhouse effect, although the CO2 is only about 2%.
https://en.wikipedia.org/wiki/Environmental_impact_of_aviation#Carbon_dioxide_(CO2)
I'm not saying it's not worth making some effort, but there are lower hanging fruits that are much more juicy, so to speak.
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Philippe Chantreau at 04:50 AM on 28 November 2018Discussing climate change on the net
The problem happening in France has to do with the fact that wages have been stagnant while fixed expenses have been rising. People of modest mens feel that they are being excessively burdened and there is validity in that opinion. Whatever the governemnt there is trying to obtain in revenue could probably be gained by just recovering money fraudulently hidden by the hyper-rich and corporations in tax havens over the course of a year.
Air travel is not the most urgent emission source to tackle. Getting rid of coal burning and slowing deforestation would achieve far more than reducing air travel. Electrifying ground transportation would far exceed any gain achieved by reducing air travel. All these are technically possible to do soon whereas there is not yet a viable way to replace the energy density afforded by hydrocarbons to power heavier than air flight.
Perhaps my background as a pilot and flight instructor makes me biased, but I see that there is far more to gain from phasing out coal and stopping peatland burning than reducing flying. That doesn't mean that we should not be keenly aware of our carbon footprint as individuals.
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Art Vandelay at 23:11 PM on 27 November 2018Discussing climate change on the net
Eclectic @ 6, Unfortunately, fixing the climate problem requires top down action. Even converting half of each national population to a cave-dwelling zero-emission lifestyle (were that even possible) would be quite inadequate for appreciable success
And as we've seen recently on the streets of Paris, it also requires a sufficiently small voter block of persons adversely affected by top-down action. Paradoxically, again, many of the people marching in protest of higher taxes on fuel were the same people marching in September to promote climate change advocacy. The challenge for climate-concerned governments will be to make the hand of government less visible, and to find ways to motivate all citizens, concerned or otherwise, to embrace renewable energy. For some that might be the attraction of a much cleaner and healthier environment and a better quality of life - without harmful toxic air and water pollution, but for the majority it will need to be the potential to save money. Keeping in mind too that climate change advocates are already promoting (often strongly) the lower cost of renewables, so that promise will need to be (or seen to be) delivered at some point - soon.
A side effect of a top-down solution, aside from the often divisive political implications, is that many (climate) advocates will feel that their vote for a climate concerned government is itself a "sufficient" action, effectively outsourcing their responsibilities as individuals.
You're right of course, it doesn't matter who flies more or less or who has the largest pv rooftop installation. Emitting less means more "renewables" and less emissions, and until low or zero emissions air travel is realised, a lot fewer planes and a lot fewer people in the skies.
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Tadaaa at 22:22 PM on 27 November 2018Discussing climate change on the net
@ Harry
I think there have been studies that suggest only 5% of viewers on blogs/comments section etc comment regularly, 10% less so and 80% (odd) lurk and never/rarely post
but purely anecdotedly - I was a lurker on climate blogs (6 odd years ago) and became convinced of the science behind AGW - in part due to the well argued and cogent comments from people such as your good self
so it does work
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Eclectic at 21:43 PM on 27 November 2018Discussing climate change on the net
Art Vandelay, your "question" presents a false dichotomy ~ as I am sure you are aware! (judging by your implicit humorous wording).
But I think there was recently an American survey showing something of that sort, where the "expected" difference was surprisingly small and even slightly reversed in some respects. Yes, a survey difficult to interpret . . . and possibly representing American Exceptionalism a.k.a perversity wrt climate science (I do expect that the rest of the world might show less strangeness, but I haven't seen related surveys which could confirm that).
Unfortunately, fixing the climate problem requires top down action. Even converting half of each national population to a cave-dwelling zero-emission lifestyle (were that even possible) would be quite inadequate for appreciable success.
Success requires political action "at the top" to really speed up the transfer to zero-nett-CO2-emission energy usage. That needs a sufficiently large voter bloc of concerned citizens, to overcome the present denialism and "capture by lobbyists & financial donors", which inhibits sensible statesmanlike activity by politicians.
So in the end, it matters very little who flies more or who has more solar roof panels.
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Art Vandelay at 17:00 PM on 27 November 2018Discussing climate change on the net
It's a paradox but many so-called "deniers" are eager to install the subsidised pv solar systems, so their denial is in words more than actions. On the other hand, lots of so-called activists do lead lifestyles with large carbon footprints.
Which begs the question, is it better to be a climate change denier with pv rooftop and battery storage, or a climate change activist with a large carbon footprint?
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nigelj at 14:03 PM on 27 November 2018Discussing climate change on the net
Free speech is just a shorthand term that means people should be free to hold opinions without fear of state censorship or violence. Free speech is obviously not a licence to say anything in absolutely any context, go way off topic, fill websites with lies and blatant propoganda, and to threaten and insult people. Indeed such bullying speech shuts down free exchange of opinions by intimidating people.
About 90% of the climate denialism seems to be based on logical fallacies rather than factual erros as such, so it makes sense to counter it by explaining the logical fallacies. I dont think this has been done well enough in the past, so its an opportunity for us.
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nigelj at 13:47 PM on 27 November 2018Discussing climate change on the net
I agree with the article on implicatory denial, but we cannot expect individuals to stop using energy, stop eating and to buy electric cars if theres no big efforts towards building a proper renewable energy grid.
We need leadership from government and the corporates to build a 21st century energy grid. They are controlled by money in politics, fear of putting costs on voters, and the profit motive. End result: policy grid lock.
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Trevor_S at 11:30 AM on 27 November 2018Discussing climate change on the net
Similar to anti vax, this article from 2014
Implactory deniers are how ever worse, those who keep emiting vast quantities while saying they acknowledge there is a problem
http://sydney.edu.au/environment-institute/blog/implicatory-denial-sociology-climate-inaction
Moderator Response:[PS] Fixed links. Please learn how to do this yourself in the comments editor.
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Harry Twinotter at 10:34 AM on 27 November 2018Discussing climate change on the net
"As it's very likely that the doubter isn't interested in the answer anyway..."
I agree, Deniers are not usually interested in the answer. This means it is pointless engaging them at all, and might even be counterproductive.
To engage or not for the benefit of the "lurkers" is a bit problematic in my opinion. Because they provide so little feedback, you cannot be sure they even exist! -
michael sweet at 09:06 AM on 27 November 2018Models are unreliable
JoeTP,
Your reference only discusses solar cycles, it does not mention climate. It discusses the magnetic cycles of the sun. It refers to a presentation made at the GWPF, a well known anti-science organization. Can you cite a peer reviewed report to support your wild claims?
Scientists generally have trouble predictinig solar cycles. Claiming to be able to predict solar cycles hundreds of years in the past and future does not seem like a reasonable claim.
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swampfoxh at 08:57 AM on 27 November 20182018 SkS Weekly Climate Change & Global Warming News Roundup #47
Is Animal Agriculture flying below the radar when we look at sources of emissions? The Assessment focus is on fossil fuels, but when one adds deforestation, desertification, eutrophication, acidification of oceans, wild animal habitat loss, outsized water usage, health related problems and the transportation and medical infrastructure to handle Animal Ag, its product distribution and its suspected negative dietary impacts...not to mention freezers with their refrigerants are, for the most part, to store animal flesh...Animal Ag looks like the largest emitter...??? We know what is in our Animal Ag thread here at SkS. Does it need another look?
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JoeThePimpernel at 07:43 AM on 27 November 2018Models are unreliable
The most reliable climate model of all is the solar cycle.
It is 93% accurate when past climate data is used to predict present-day climate.
https://nextgrandminimum.com/2018/11/22/professor-valentina-zharkova-breaks-her-silence-and-confirms-super-grand-solar-minimum/
No computer model comes close to that.
Why do climate scientists refuse to acknowledge the solar cycle as a model for climate change?
Is it because the solar cydle doesn't yield the desired answer?
Moderator Response:[DB] Claims made by skeptic blogs are scarcely credible in this venue. The gold standard is peer-reviewed papers published in credible science journals and primary providers like NOAA or NASA. When Zharkova publishes her research in a credible science journal, it will be properly examined. The blog post you cite contains little actual, verifiable details and is this not credible.
"Why do climate scientists refuse to acknowledge the solar cycle as a model for climate change?"
Scientists use a metric called Total Solar Irradiance (TSI) to measure the changes in output of the energy the Earth receives from the Sun. And TSI, as one would expect given the meaning behind its acronym, incorporates the 11-year solar cycle AND solar flares/storms.
The reality is, over the past 5 decades of significant global warming, the net energy forcing the Earth receives from the Sun had been negative. As in, the Earth should be cooling, not warming, if it was the Sun.
It's not the Sun.
[PS] See also here on effect of grand maximum. Any further discussion should be on this thread. The solar cycle is not a model. If you want to bet on solar, then consider what happened to last solar physicists who were willing to bet (but have refused to pay up).
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william5331 at 05:24 AM on 27 November 20182018 SkS Weekly Climate Change & Global Warming Digest #47
If the world would adopt the so called 'Conservation Agriculture' as espoused in Montgomery's book, Growing a Revolution, it would not only sequester significant amounts of carbon back into the soil but also reduce our output of oxides of Nitrogen. What is really surprising is farmers who have adopted Conservation Agriculture improve their bottom line while becoming the darlings of the ecological movements. Companies supplying various inputs such as fuel and chemical fertilizers are not amused. Less (not none) of their products are needed when using Conservation Agriculture techniques
.https://www.youtube.com/watch?v=c4p-kQ6D8aA
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Eclectic at 22:40 PM on 26 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert @150 ,
again my apologies : your written English is 99+% acceptable. The judgment of "perfect fluency" (in anyone) is difficult to make without extensive verbal conversation ~ and even then it is easy to miss certain lacunae in the communication, and to assume that a full and perfect communication has occurred. My own (native) English is I hope 99.9% acceptable, but is rarely perfect ~ and you will note that I "overread" my own typo ["mount"]. A typo which you and most readers would not notice or would laugh off as a trivial mistake . . . but I ought to proofread my typing more carefully, because just sometimes a typo error might lead a non-native speaker to go off on a tangent, searching for some unexpected meaning (in a complex scientific topic) and thereby waste his time & mental effort. That sort of thing is a discourtesy to the reader.
(Please do not laugh too much, at my ignorance of Dutch ~ I know only the name Zwarte Piet and a handful of words . . . words which are actually Norddeutsch.)
Josbert, in writing your own articles on Greenhouse Effect, it would I suspect be better to avoid mention of Stratospheric Cooling ~ it is a technicality which is not directly relevant to Climate Change and planetary surface warming. Nevertheless, you yourself ought to be familiar with it, because it is one of the "markers" which confirm that the modern Global Warming derives from rising CO2 (and not from increased solar activity or changed cloud patterns or the "natural variability" of multi-decadal oceanic overturning currents, etcetera).
How exactly do molecules convert photonic energy to kinetic energy? I do not know. Somehow the photonic energy is absorbed and changed into rotational or vibrational energy within the molecule (usually a tri-atomic or larger molecule). Some of this extra energy may be imparted to a colliding molecule such as nitrogen oxygen argon H2O etcetera . . . or vice versa. Here we are getting into Quantum Mechanics, where our understanding of reality falls short : where subatomic particles are "twists of nothing", and photons of such-and-such wavelength have zero dimension.
@151 : CBDunkerson's post #110 has the Trenberth basic energy fluxes, but 15-micron figures are complex and also depend on atmospheric altitude and time of day/night.
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Art Vandelay at 21:45 PM on 26 November 20182018 SkS Weekly Climate Change & Global Warming Digest #47
The solar output has been slightly below normal for the past few decades, yet temps on Earth's surface have continued to rise.
The solar cycle has at best a very weak effect on Earth's climate, so any present or future impacts would be well and truly buried in the measurement noise.
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Josbert Lonnee at 19:14 PM on 26 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Somethin I still wonder: CO2 absorbs electromagnetic radiation of some wave lengths, including if 15-micron IR. Now, during day time, with a clear sky, how much of the light of those wave lengths com from the sun w.r.t. that coming from the surface of the earth?
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Josbert Lonnee at 18:26 PM on 26 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Eclectic @ 149
Yes, there is a deficiency of good, neutral articles on the Greenhouse Effect. I am actually trying to write something like that in Dutch. It is here:
https://josbertlonnee.wordpress.com/2018/11/20/het-broeikaseffect/
The stratospheric cooling is not mentioned there (yet). To fascinate a bigger crowd, things shoult get kept simple, but with this kind of subjects that is really hard.
I already started reading more about the IR-spectrum of the earth's atmosphere. I learned you never know enough w.r.t. climate. For instance, how exactly do molecules transfer energy from photons to kinetic energy?
I completely overread your typo. I am quite used to English; not to speaking it. Is my English really that bad?
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scaddenp at 12:52 PM on 26 November 2018CO2 was higher in the past
Norm. First off, no scientist that I am aware of is claiming the putting CO2 into atmosphere could cause a runaway greenhouse. Certainly the consensus opinion is that there is no possibility of a runaway greenhouse. This is a strawman argument. It is best when making a claim that "science is wrong" that you cite science claim that you are disputing. This avoids timewasting with strawman arguments.
Will adding more CO2 increase temperature? Yes, just a plainly as increasing output from the sun would increase temperature. You can measure it directly. However, figuring out how much it will rise depends on feedbacks which are much harder to determine hence the wide error bars on constraining climate sensitivity. See here for more on runaway feedback
Reading the IPCC WG1 report or at least the summary for policy makers would help you in understanding what claims the science is actually making.
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Norm Racherty at 11:49 AM on 26 November 2018CO2 was higher in the past
First of all, I do not believe "CO2 does not drive climate". Beside, the word "drive" is way too vague in this context and can easily be used to smuggle in a whole host of possible interpretations the author possibly didn't have in mind at all.
I prefer classical terms like "correlation" and causation". Let's rephrase the question now:
We know this planet has experienced CO2 concentrations in the past that exceed the current levels by a magnitude without triggering a runaway greenhouse effect. Now you're making 2 claims:
1) those, much smaller concentrations will cause a runaway greenhouse effect, and
2) you can be certain you can understand all the processes and factors involved to such a degree that you can model the mechanism of triggering the runaway effect (I'm not talking about the model predicting the avreage temperatures).
Those are really, really extraordinary claims. I hope you agree with that assessment. And if so, you already know what I will say about proof levels required.
If you say, we can't be certain, but the risks involved are too high, thus worth taking seriously, I have no problem with that... but that's not my question.
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DrivingBy at 11:45 AM on 26 November 2018Did bombing during second world war cool global temperatures?
O/T:
In the first photo, two buildings in the foreground appear to be fully intact. What buildings were those, and how far were they from ground zero?
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Sunspot at 10:48 AM on 26 November 20182018 SkS Weekly Climate Change & Global Warming Digest #47
The warming effect of the excess CO2 in the atmosphere eliminates any possiblilty of an Ice Age anytime soon. The solar output has been slightly below normal for the past few decades, yet temps on Earth's surface have continued to rise. When the sun resumes its normal sunspot cycle in a few more decades or so this will just increase the warming of the Earth. Not that we need any more help...
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Eclectic at 08:56 AM on 26 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert, I am happy to be of help. The so-called Greenhouse Effect is rather counter-intuitive for many people (including me), and I find a deficiency of sites where it is explained completely all in one chapter. In particular, the stratospheric cooling effect is interesting, partly because it demonstrates the falsity of some of the claims of the climate science denialists [the faux-skeptics].
As you are aware, the large majority of 15-micron IR is lost from Earth at the altitude of the upper troposphere, yet a tiny amount is lost from the stratosphere itself, too.
My apologies for my typographical error ["typo"] in my third paragraph of #147, where I wrote "and a smaller mount will escape" ~ the correct word would be amount. This sort of typo must be troublesome and annoying for a reader who is not 100% fluent in English.
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Josbert Lonnee at 01:11 AM on 26 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Eclectic @ 147
What you say is very clear and shows my theory is false.
MA Rodger just kept mentioning the same point and that I do not understand that. My English was to blame.
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michael sweet at 00:06 AM on 26 November 2018Did bombing during second world war cool global temperatures?
Libertador,
The other nuclear explosions that you mention were all performed in remote locations, often underground. That means little smoke from was generated. Since the effect on climate of burning cities mentioned in the OP was small, the effect of other nuclear explosions on climate would be expected to be very small.
We all hope that the effect of nuclear war on climate will never be measured.
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Eclectic at 21:56 PM on 25 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert @145 ,
in your [post #128] scenario, the essential point is that the rate of CO2 molecules emitting IR photons is extremely low in comparison to the rate of collisions, in both the Stratosphere and the Troposphere. In other words, the chance of a photon-emitting relaxation is (very roughly) around 0.01% compared with the chance of an intervening collision (the collision being likely to de-energize the CO2 molecule from its newly-gained photonic packet of energy).
If, owing to different temperatures and densities, that percentage should vary between (very roughly) 0.03% and 0.003% [one order of magnitude] in the two layers of atmosphere . . . then you see that the absolute difference from the [almost 100%] collision chance, remains approximately equal for "S" and "T".
Thus your #128 proposal is barking up the wrong tree. You should focus on the absolute distances ~ the mean travel distance from one "emitting-CO2" to the next "absorbing-CO2". This distance is very short, and (greatly enhanced by the relaxation "delay" period) is the reason why the appropriate IR takes a long time to rise from planetary surface up to the top of the troposphere and eventually make its escape (upwards) from there [and a smaller mount will escape upwards from the stratosphere ~ which is why increased solar irradiation of the stratosphere has a stratosphere-warming effect compared with the stratosphere-cooling effect of increased CO2 concentration [regardless of whether it's a human-caused or natural-caused CO2 increase]).
Josbert, stay on MA Rodger's good side, and he may well provide a much more rigorous explanation than I can !
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MA Rodger at 21:48 PM on 25 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert Lonnee @145,
While you appear to be struggling with the English language, I feel we have reached the end of this interplay. After five attempts to communicate with you regarding a blindingly simple concept, you complain that I understand you "all wrong all the time." If that were true, it is up to you to explain yourself properly. However, I do not consider it true. Your 'theory' set out @128 is nonsense and if you cannot grasp the blindingly simple idea that if CO2 takes longer to travel between collisions then there must be less collisions; if you cannot grasp that obvious truth then there is no point in my responding to you. [Mind, I will likely respond to your comments but not to you.]
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libertador at 21:33 PM on 25 November 2018Did bombing during second world war cool global temperatures?
I have a little question. There have been more bombs dropped, than the ones on Hiroshima and Nagasaki. There has been atomic testing. The number I found in the Bulletin of the Atomic Scientists Mai 1996 is, that 16,000 times the power of the Hiroshima bomb was used in testing in just a 16-month period in 1961/62.
Have these testings be studied? Might these testings give further objects of study?
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Josbert Lonnee at 17:29 PM on 25 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
MA Rodger @ 144
It was already clear to me that you understand me all wrong all the time. With "the theory" I of course mean my theory from @128.
There is no need to repeat your point.
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Synapsid at 08:07 AM on 25 November 2018New research, November 12-18, 2018
Ari,
Thank you again for these summaries, I find them very useful each week.
I am particularly grateful for your posts in palaeoclimatology as that is my primary focus.
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nigelj at 05:07 AM on 25 November 2018The Scientific Consensus on Climate Change
BaerbelW @20, yes I realise the Cook study interpreted abstracts, I was just using a bit of short hand or paraphrasing. Don't have all day to write an essay!
Thank's for the guidlines. This clarifies things, and makes it clear the consensus finding is limited to papers that explicitly or implictly state humans are the main cause of the recent climate change. Your categories on how you categorised papers on this look convincing. The 97% result is a huge, powerful consensus, especially given the nature of the contrarian papers.
It just seemed to me the wording that humans 'contributed' was not specific enough. Maybe I'm nit picking.
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BaerbelW at 20:49 PM on 24 November 2018The Scientific Consensus on Climate Change
nigelj @18 - regarding: "It was really asking people whether they think the greenhouse effect is real and that we are adding to it. I mean its a valid and useful study but rather too general for me"
For one in Cook et al. we didn't ask people what they think but instead interpreted the abstracts of peer-reviewed studies according to defined guidelines for rating abstracts. And, a careful reading of esp. the definitions for the rejection criteria should make it clear that any minimising (< 50%) of human-causation, wouldn't have been counted towards the consensus. Which, to me, makes it quite clear that our paper did in fact restrict the consensus to "mostly human-caused". But then, I'm obviously biased!
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Daniel Bailey at 08:55 AM on 24 November 2018The Scientific Consensus on Climate Change
Interestingly, the 4h National Climate Assessment, Volume 2, was released today. Among many interesting findings, this was prominent:
"Scientists have understood the fundamental physics of climate change for almost 200 years. In the 1850s, researchers demonstrated that carbon dioxide and other naturally occurring greenhouse gases in the atmosphere prevent some of the heat radiating from Earth’s surface from escaping to space: this is known as the greenhouse effect.
This natural greenhouse effect warms the planet’s surface about 60°F above what it would be otherwise, creating a habitat suitable for life. Since the late 19th century, however, humans have released an increasing amount of greenhouse gases into the atmosphere through burning fossil fuels and, to a lesser extent, deforestation and land-use change. As a result, the atmospheric concentration of carbon dioxide, the largest contributor to human-caused warming, has increased by about 40% over the industrial era.
This change has intensified the natural greenhouse effect, driving an increase in global surface temperatures and other widespread changes in Earth’s climate that are unprecedented in the history of modern civilization.
Global climate is also influenced by natural factors that determine how much of the sun’s energy enters and leaves Earth’s atmosphere and by natural climate cycles that affect temperatures and weather patterns in the short term, especially regionally.
However, the unambiguous long-term warming trend in global average temperature over the last century cannot be explained by natural factors alone.
Greenhouse gas emissions from human activities are the only factors that can account for the observed warming over the last century; there are no credible alternative human or natural explanations supported by the observational evidence.
Without human activities, the influence of natural factors alone would actually have had a slight cooling effect on global climate over the last 50 years."
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nigelj at 06:22 AM on 24 November 2018The Scientific Consensus on Climate Change
I may not be be too popular for this, but I like getting to the bottom of things. The John Cook study found that "97.1% endorsed the consensus position that humans are contributing to global warming" which could be interpreted to mean humans are causing all or just some of the recent warming. It was really asking people whether they think the greenhouse effect is real and that we are adding to it. I mean its a valid and useful study but rather too general for me.
Powell 2013, Orekses 2014, and Doran et al 2009 and Stats 2009 asked much the same question about whether humans were a contributory factor, and found a similar result to Cook. Farnsworth and Lichter found a lesser result with 84% believing humans contributed to climate change. So overall all studies do find theres a good consensus that humans at least cause global warming. Anything over 80% seems powerful to me and most studies are well over 90%.
But I think the more important question is whether humans are causing the 'majority' of recent climate change. The study by Verheggen, 2014 finds that 90% of climate scientists agree that greenhouse gases are the main cause of warming. Anderegg et al 2011 also found well over 90% of climate scientists endoresed the IPCC position (which finds humans are the main cause of the recent warming period)
Lefsfrud and Meyer 2012 found no consensus that humans are the main cause of warming, but their study comprised "petroleum geologists" so they have a vested interest in fossil fuel producers.
I think the Verheggen study asked the key question. For me 90% of climate researches concluding humans are the main cause of the recent warming period is a strong finding. Given the fossil fuel industry funds some research and some scientists are just contrarians by nature, or have subconscious biases in a small number of cases, its of no surprise to me that 10% would question how much humans are contributing and could think its largely natural ( a position I personally disagree with). I would have guessed it would be around this number and I recall seeing a list of recent research papers taking contrarian position like climate change is mostly caused by adiabatic processes etc (all very dubious material)
I think what really matters is to get the message across to the public that 1)several studies find over 90% of climate scientists thinks we are the dominant cause of climate change and 2) the contrarian studies are fringe science with a similar range of methodological flaws. The problem is the public believe theres more of a 50 / 50 split. They need correcting on this, but probably won't care so much whether its 90% 0r 92.256% or 97%. If it was less than 80% I think the consensus would be classified as weak.
The bottom line is numerous published and peer reviewed studies do show a strong consensus regarding climate change.
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One Planet Only Forever at 01:35 AM on 24 November 2018The Scientific Consensus on Climate Change
There appears to be confusion due to incorrect conflating of:
- Scientific consensus of understanding (development of an emergent truth that is open to correction if substantive new evidence is contrary to the developing understanding).
- An individual's helpfulness in efforts to improve awareness and understanding: in the field of understanding, among leaders in society, among the general population.
Individuals are not 'part of the 97% or 3%'. The consensus measure is regarding how much of the 'literature that is a legitimate part of the effort to improve the understanding of an area/field of understanding' is aligned with a developing understanding. As the degree of alignment increases it can be understood that an emergent truth is being established (an understanding that is unlikely to be significantly altered by new investigation in that field of learning).
An evaluation of all of an individual's actions is the basis for determining how helpful they are to the improvement of the understanding and to the increased 'correct' awareness and understanding among leaders and the general population.
While the likes of Judith Curry, Roy Spencer and Richard Lindzen may have their names on a specific piece of literature that is included in the 97% side of the climate science consensus evaluation regarding the understanding that human activity is significantly impacting the global climate, that does not make them 'a part of the 97% side'.
Individual merit would be determined by their collective actions regarding the understanding. That evaluation would undeniably indicate that the likes of Judith Curry, Roy Spencer and Richard Lindzen are very unhelpful (harmful) to the improvement of awareness and understanding the understanding that human activity is significantly (and negatively) impacting the global climate that future generations will suffer the consequences of and the challenge of trying to maintain perceptions of prosperity that are the result of a portion of humanity getting away with benefiting from the damaging unsustainable burning of fossil fuels (benefiting in ways that do not develop sustainable improvements for the future of humanity - like perceptions of reduction of poverty that cannot be sustained if the damaging impact creation of fossil fuels is significantly and rapidly curtailed like it has to be in order to minimize the damage done to the future generations of humanity).
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MA Rodger at 00:37 AM on 24 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert Lonnee @142/143,
Correct me if I am wrong. When you talk of "the theory" you are meaning that set out @128 where you describe "my theory." In it you describe a mechanism for a cooling stratosphere and a warming troposphere. You suggest this may be a re-statement of the situation described in the post at the top of this thread [although it is not]. You base your "theory" on the probability of a CO2 molecule emitting a photon following a molecular collision in which it is excited and thus able to emit a photon of IR, a probability which will be greater if this CO2 molecule has longer before it is in another collision. If more photons are emitted by a gas (per molecule), more cooling will occur.
That is what you appear to be saying.
Your suggestion is wrong in a number of ways. The most straightforward error is to consider a higher probability of a CO2 molecule emitting a photon after a collision without considering the lower probability of CO2 molecules being in an appropriate collision. Simplisitically, the two probabilities cancel out. So it is not the case that more photons are emitted from lower pressure air.
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michael sweet at 00:28 AM on 24 November 2018The Scientific Consensus on Climate Change
Art Vandelay,
Richaed Lindzen cannot be considered part of the 97%. He has widely criticized the IPCC. The IPCC report is the basis of the 97% claim. He probably also claims to be part of the consensus to muddy the waters when he speaks.
Many deniers now claim to be part of the 97% to muddy the waters. The mainstream press allows themn to get away with it.
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