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Global warming has been a major concern since the 1800s and Svante Arrhenius proved the heat trapping effect of carbon released by burning fossil fuel. Its accumulation as more fossil fuel is burned is well documented in later works by multiple other scientists.

Yes, show me how its all going to be paid for,...

Did you see Trump's budget proposal, released yesterday? He wants to slash the budget for scientific research (among other areas). One target seems to be anything related to energy efficiency, because why would we need that?

If we're working on computer models of climate, how come the first paper on AGW was written in 1896?

Do the world a favor and learn something.

You're a fucking idiot. Go read.

Re: "If he'd just put an ounce of two of that energy into learning science instead of peddling pseudo-science, he probably wouldn't be mocked as much."

Mockery comes with the territory of engaging new ideas in science. I'm not trying to avoid it.

What I do is track scientific controversies. I learn the models, as they've been stated by the theorists. I seek out the critiques of those models, so I can understand what the debate is. I resist the urge to judge the model before I've learned it. I also expose other people to the claims so that I can witness their reactions. I systematically seek out persuasive arguments. And over time, I track whether or not new observations can be interpreted as vindicating this competing model. What I've learned - through practice - is that we can use this process to differentiate legitimate groundbreaking science claims from pseudoscience.

I didn't actually make this process up. It's how universities teach critical thinking in humanities programs. This is what students are every day taught to do in elite schools like Harvard with literature: They read challenging texts, and through discussion, practice interpreting those texts from competing perspectives. The daily practice of tracking scientific controversies takes this same technique - a method which has already been shown to teach complex thought in the humanities for many years now - and applies it to science.

Arp himself has noted this difference in how science and humanities are taught:

The courses at Harvard were divided into two: one was the Humanities, the English, literature and so forth. They tended to be quite challenging and quite stimulating because there were quite a few good people. There was an ambience of intellectual creativity so the science courses were good too, but they were much more cut and dried. You had to bring your own stimulation to those courses. Again, in prep school, high school, no I guess prep school, again the literary ends were quite stimulating and the science courses began around a routine, you know, solid stuff, learning intrinsically, they did not have the same intellectual adventure as the Humanities courses.

The price of overly caring about whether or not people are mocking you is that you are not free to think for yourself. Learning to engage multiple working hypotheses is actually learning to "think like a scientist" - which should not be conflated with learning to "think what scientists think." These are two very different things: The former is a process for asking questions about the world or universe such that the answers are not already known, whereas the latter is simply learning to apply the consensus view models.

The science graduate programs today are not teaching people how to think. They're teaching people to be part of a scientific society. Inclusion into this society is determined not by whether or not you are critically thinking about what you're being taught - but rather to what degree you adhere to claims which are said to be "settled". This is actually what makes Big Science "efficient" - so don't get me wrong: there are actually systems-oriented reasons for why the programs are taught this way. It's helped to create this efficient technological capitalist system we live in.

But, there are both social and personal costs for this "efficient" approach to science: The social cost is that progress on big important questions will sometimes become completely stalled. Innovation always involves somebody diverging from the pack, so if you set the culture of your scientific society such that the independent thinkers are mocked as cultists, then you run the risk of eventually waging an ideological war on the next big idea. The personal cost of efficient schooling in science is that it tends to make the practice of science considerably mo

See also The Discovery of Global Warming, which gives a historical overview of the major papers. Note that AGW was considered entirely disproven for about 50 years: the reasons why should be of considerable interest to true skeptics.

Really? That's like what, your intellectual fig leaf over your ignorance?

This is a good place to start fixing that.

The greenhouse effect is established science. Its basic physics than can be demonstrated in a laboratory. Adding more greenhouse gases to the atmosphere makes the greenhouse effect stronger.

True, but the effects are diminishing with increasing concentrations. That's because CO2 acts like an optical filter, and most of the radiation is already absorbed.

Yes, the effect is logarithmic. This has been known since Arrhenius calculated it in 1896 [ref]. And it is incorporated into every single greenhouse model that is run.

It's why the anthropogenic greenhouse effect-- about 1 degree C so far-- is so vastly smaller than the natural greenhouse effect, about 33 degrees C.[ref].

Really. This is already part of the science. You're not telling us anything that the scientists aren't already incorporating into their models.

So, if that basic physics was all there was to the science, we clearly wouldn't have to worry about carbon emissions at all.

That's not true. Again: all of the current models already incorporate the effect you notice.

In order to conclude that there is any significant danger from greenhouse gases, you have to run climate models that make various assumptions about positive feedback loops;

The main feedback effect is known as "constant humidity." If you want to turn this feedback off, you need to come up with a mechanism that decreases the humidity as the temperature rises. I'm not saying that such a model is impossible... but it's hard to come up with a realistic mechanism.

those feedback loops are not "basic physics",

They most certainly are.

can't be "demonstrated in a laboratory",

Humidity can't be measured in a laboratory? I beg to differ.

and are largely speculative and unproven at this point.

They are not.

You also have to assume that there are no additional negative feedback loops to counteract the effects, again something we don't know.

People have been searching for such a negative feedback loop for several decades. So far all of the ones proposed have been disproven by measurements.

Uh, you do know that people measure the properties of the atmosphere, right? And that climate models are baselined against measured values?

It's dishonest for you and others to conflate the basic physics of the greenhouse effect with the speculative models involving assumptions about feedback that are used to argue for the need to reduce carbon emissions.

Except for the most part these aren't speculative models. They're well-tested models that are checked against measurements. And, there are many thousands of models run-- by independent groups on all five continents-- and cross-checked against each other to see which effects dominate. That's why the climate study outputs have error bars, because one of the things we do know is how much we don't know.

Yes, that's right: the actual science includes error bars. That's one of the ways you can tell the science from the speculation, like yours.

Why don't you start here and let us know where you get hung up. The total energy captured by a century of fossil fuel use is going to have some relatively wide error bars, but it's almost exactly as much as required for the climatic shift you mention. Curiously enough, the relation of CO2 levels to ice ages was exactly the topic of Arrhenius' 1896 paper which originated the Theory of AGW. The exact number has varied slightly, but that a halving or doubling of CO2 levels could cause or reverse an Ice Age is an undisputed result for something more than a century now. If you've gone thus far without reading anything scientific on this matter, Arrhenius isn't a bad place to start. After that I imagine that you will be interested in the many reasons that his work was entirely dismissed for the next five decades, as being the best hopes for actually, say, coming up with a semi-plausible reason why AGW isn't true.

I'm not sure what in particular you're claiming doesn't exist (or is it just a need to be spoon fed?) but the science is most certainly out there. The "back of the envelope" science you're asking for is found in literally the oldest paper on the topic. Consider doing us the favor of reading it.

I cannot believe how freaked out everyone is about carbon, when it is a basic and abundant element of the planet...

People are "freaked out" about carbon-- specifically, carbon dioxide in the atmosphere-- because it is known to absorb outgoing infrared radiation, so the amount of carbon dioxide in the atmosphere affects the temperature balance of the planet. This is an effect that has been known for a very long time (here's a good review from the American Institute of Physics: https://history.aip.org/climate/co2.htm), but only recently has the amount of carbon dioxide put in the atmosphere by humans been enough to make the effect visible.

You're correct that it is "basic and abundant", although I'm not sure why that's relevant

the amount in the atmosphere is minuscule to begin with,

Correct. It was the great discovery of Tyndall in 1859 that extremely small amounts of trace gasses can affect the infrared absorption. https://earthobservatory.nasa....

never mind whatever we are adding in being a tiny fraction of what it is already.

Humans have increased the carbon dioxide content of the atmosphere by about 45% since preindustrial times, most of that in the last century (graph: https://www.esrl.noaa.gov/gmd/...). Depends on whether you call that a "tiny fraction."

But, indeed, the natural greenhouse effect of about 30C (ref) is about much larger than the human contribution. That's one reason we understand the greenhouse effect; it's large enough to be easily measured.

The entire ecosystem of the Earth is built to process carbon, to consume carbon, to use carbon to sustain life.

Correct again. Over a period of few hundred thousand years, this will undoubtably be removed from the biosphere.

It would be lot faster than that, except we're cutting down trees a lot faster than we're growing trees.

It is so sad to see rational people get lost in a death cult that makes absolutely no sense to anyone with a shred of scientific understanding of the climate, or indeed basic material science...

I will assure you that I have a pretty good scientific understanding of climate, and also of basic materials science. This is how we understand the atmospheres of all the planets, not just Earth. The basic physics of the greenhouse effect is quite well understood science, and the absorption coefficients of trace gasses in the infrared are all well measured.

Perhaps you don't remember this far back, but "global cooling" actually was the widely hyped fear back in the 1960s and part of the 1970s.

No, it wasn't. That claim is something deniers say all the time, but it just isn't true. Here, for example, is the American Meteorological Society: http://journals.ametsoc.org/do...

I know a lot of people today (many of whom were born in the 1980s or even the 1990s!) will wrongly claim that it was only "the media" pushing those claims back then, but the media was just reporting on what those in various scientific fields were claiming.

I was born in the 1950s, and you are wrong.

It wasn't until into the 1970s that the "global warming" hype really started up.

Wrong again. Here's the American Institute of Physics's history of Global Warming: https://history.aip.org/climat... -- the effect has been known for well over a century.

I remember the greenhouse effect being discussed in my science classes back in high school. Of course, back then it was "here's an effect that, if we keep on burning fossil fuels, might be measurable sometime by the 1990s or 2000" (which seemed impossibly far in the future back then.) Well, guess what: we kept on burning fossil fuels, the 1990s and then 2000 came, and the effect was measurable.

When it became clear by the late 1990s that we weren't really seeing any significant warming, the name was changed again to the much vaguer "climate change".

Wrong, and wrong. We were seeing significant warming by the late 1990s (check the data), and the name was changed by the Bush administration in order to get people less excited about the effect.

This is convenient, because it allows any normal variation in the Earth's dynamic, chaotic, and unpredictable weather systems to be claimed to be evidence of this alleged "climate change".

Now, on that one I'll agree with you: it annoys me when people attribute weather events to global warming. No single weather event, no hot summer in one location, no warm winter in another location, can be particularly attributed to global warming. Global warming is real, and is well understood-- but it is a long-term, global phenomenon. It is not a local thing.

Of that insignificant portion, anthropogenic gas is an infinitesimally smaller portion

It used to be, yes. Since we started burning a cubic kilometer of oil per year there's quite a bit more than it used to be. I mean, unless you're arguing that the oil we're burning and the excess carbon are completely unrelated.

The real question is, home much of the anthropogenic CO2 is absorbed into the mountaintops consisting of limestone?

Not enough to prevent atmospheric concentrations from rising, clearly.

You haven't asked all the questions that would be required in a court of law to prosecute a case

"But if it is flat, will the King's command make it round? And if it is round, will the King's command flatten it?"

Why don't you convince me, rather than make attempt to make me disprove your religion?

Well, since you don't dispute Tyndall then the next step would be Arrhenius' 1896 paper on the properties of atmospheric carbonic acid. For a more general study of the science, there's always the IPCC reports. And for a historical perspective I would recommend starting here

But yes, you are expected to disprove my 'religion'. Either you can point to a contrary observation or you're blowing smoke. "Why don't you convince me," you ask? Because you can look it up in a textbook, the same as you can with plate tectonics. Either you find that explanation convincing or you can damn well say why not, but the onus is firmly yours to discharge.

What you're seeing there in the 20's/30's is the dust bowl that wreaked havoc on the central US during that time (high heat, vast drought). It is really interesting to see that. But it was a regional effect. Globally the story is different.

Really? I'd love to see that, because, just like this graph from teh American Institute of Physics pretty much all 20th century tempurature records have a big warming throughout the 203s and 30s, then switched to cooling through the 40s to mid 70s.

A related important point was well explained recently by NYT: extreme high temperature events are increasing in frequency.

https://www.nytimes.com/intera...

That is the claim, but the report the NY Times uses states the exact opposite. Look at that "leaked" report, and check page 287. The number of extreme high temperature days has not increased; it's the average lows that have increased. That raises the average, but if anything it points to a lessening of the extremes of tempurature. Lows aren't as low, and highs are slightly less high.

Projection, ad hominem and threats. I suppose I should have expected as much. There are a number of freely available textbooks on earth and atmospheric science, and MIT as well as other institutions have most of their course materials available online. Additionally, the notable primary sources are also typically available online in PDF form. This site provides a basic overview of the chronology of the science, which may better help you understand how we know what we know. If at some point you acquire some foundational knowledge of the subject, I am sure I would be happy to discuss it.

*facepalm* Yes, and I even noticed the error before looking up the date on Tyndall's experiments. You are correct. Full paper is here for anyone who is interested. Further context.

Some where able to think ahead ..

http://history.aip.org/climate...

Actually you are just a moron. Sorry to be the one to let you know. If you were qualified to be "skeptical" you would write a rebuttal paper and submit it for review. That goes double for anything involving modeling.

Why don't you cure your skepticism with some facts.

Nice try at moving the goalposts. Why don't you go read the IPCC report, it has answers to these questions. Kinda what it's for. Alternately, you could read more about the history of the discoveries here.

That you think this facile objection was somehow overlooked by the scientific community heretofore speaks volumes. You've demonstrated that you can read: why don't you apply yourself to some education rather than trying to insist on the validity of your ignorance.

However, to address your specific concern regarding natural warming, it is actually sufficient to demonstrate that there is CO2-induced warming. I don't know why you think postulating additional natural warming helps that situation. If you were going to postulate a natural cooling trend, my comments on negative feedbacks apply.

if you can't explain what's causing it

Bzzzt. It's very well explained.

predict the future by modelling the data

Predicting the future is hard, especially when you have to take into account human reactions to what you're doing. Modeling the entire planet plus whether or not humans take action sounds hard enough to me that I'm willing to cut people a bit of slack. That the warming will happen is driven by fundamental properties of atmospheric gases, and this has been obvious since Tyndall in 1856.

Personally I have little doubt that burning billions of tons of fossil fuels into the atmosphere every year is contributing hugely to global warming, if global warming is indeed real, but I keep an open mind. Personally I don't give a fuck what the current scientific consensus for anything is. Most new scientific discoveries go against the current scientific consensus. Fuck scientific consensus up it's closed minded ass.

Dipshit. Go learn the science then come back and tell us what's wrong with it. We've been trying to falsify this theory for over 100 years. It was considered completely invalidated throughout the entire first half of the 20th Century. The consensus did change. Read about it.

Open minded my ass.

It's cute how you think you have any idea what would make global warming falsifiable. It's cute because you have no idea what the evidence is or how the theory was developed. Global warming is not based on statistics, nor models. Also, when it was proposed initially in 1896 it was immediately discredited, and you can find meteorology textbooks from the 1950s that not only deny that climate changes but explicitly deny anything but the most minor role to carbon dioxide. This is a theory that had to fight for acceptance. Sufficiently good evidence was acquired in the middle of the 20th Century to change that consensus, almost in parallel with Wegener's theory of continental drift. If you don't know why, go look it the fuck up.

He has a job to do with explaining why dumping gigatons of carbon into the atmosphere should result in a cooling trend. Let me take a stab though and assume that you're talking about one David W. Titley, rear admiral USN, professor at Penn State. Let's see what Wikipedia says about him.

He was formerly a climate change skeptic, but later changed his mind after looking at the evidence of what factors influence climate—which are, according to Titley, "what are the larger things doing — what is the ocean doing? What is the sun doing? And what's our atmosphere doing?"[3] Since then, he has described climate change as "one of the driving forces in the 21st century" and said that it contributed to the 2011 Arab Spring.[4]

I guess you two don't keep in touch much. He had the courage to admit he was wrong and to learn the science. Maybe you should too.

If you grab a classic atmospheric physics text from 1950 it will actually tell you that climate doesn't change and CO2 plays little to no role in regulating the Earth's temperature. There's one on Google Scholar, I think by Addison Wesley. It's pretty funny from a certain perspective: the introduction alludes to the science being in an exciting state of flux. However, the CO2-mediated theory of climate change had been proposed in 1896, and although it was initially discredited, by the mid-1950s there were enough warning signs that it was becoming clear that climate did indeed change and that CO2 could not be ruled out as a causative factor, and it was equally obvious from the mid-19th century that many human activities resulted in increased atmospheric carbon. Keeling's observations in 1959 established a global baseline for the CO2 content of the atmosphere, and every subsequent year has seen an increase in that measurement. Although there had been a consensus against both climate change and the CO2-mediated theory of global warming, by the end of the 1960s both ideas had gained broad acceptance, and by the end of the 1970s this was pretty much universal. At no point during this shift of opinion was anyone persecuted or denied funding for picking either side of the debate.

Now, I recognize that someone who prefers "Herp derp! Greenland!" to actually knowing the slightest bit about scientific history is likely beyond help, but for everyone else, this site goes over in considerable depth the history of the discovery and acceptance of AGW.

"I'm not "alleging" a distortion of science. I simply pointed out that climate scientists have strong financial stake in the conclusions they reach, nothing more and nothing less."

So either you're contradicting yourself from one sentence to the next or there is no problem here. The warming will be catastrophic, but you don't care because you think it won't affect you. For the sake of the world at large, you might want to reconsider that one.

And as an aside, the "research papers" I mentioned would obviously be the foundational evidence for the theory. The IPCC is an excellent summary of current understanding, but it's not really possible to discuss the evidence for the theory without some mention of Arrhenius, Callendar, Keeling, Hansen, and various other people who established and defended the theory. I do recommend this site if you haven't approached the subject from a historical perspective. I would also recommend reading Arrhenius 1896 just on its own merits. It's well written, it did get a lot of things mostly right. and yet it was debunked immediately upon publication and didn't return to respectability for 50 years. There are actually few enough papers on the topic before 1950 that one can read them exhaustively in an afternoon or two. The study of the evolution of thought on this issue is at least as interesting to me as the current scientific perspective.

So in the early 19th Century the prevailing wisdom was that the climate did not change. The idea of climate as being the long-term average of weather didn't die until the mid-1950s at the earliest.

Actually no. http://history.aip.org/climate/20ctrend.htm#L_M0465

The head of the U.S. Weather Bureau's Division of Climate and Crop Weather responded in 1934. "With 'Grand-Dad' insisting that the winters were colder and the snows deeper when he was a lad," he said, "...it was decided to make a rather exhaustive study of the question." Averaging results from many stations in the eastern United States and some scattered locations elsewhere around the world, the weather services found that "Grand-Dad" was right: since 1865 average temperatures had risen several degrees Fahrenheit (F) in most regions. Experts thought this was simply one phase of a cycle of rising and falling temperatures that probably ambled along for centuries. As one scientist explained, when he spoke of the current "climate change" he did not mean any permanent shift, but a long-term cyclical change "like all other climate fluctuations."(3)

So 1934's 'Grand-Dad' was able to see a warming that was much less pronounced than the one deniers deny today.

Go on reading, because now comes Callendar: "Callendar's statistics gave him confidence to push ahead with another and more audacious claim. Reviving an old theory that human emissions of carbon dioxide gas (CO2) from burning fuel could cause a "greenhouse effect,""

Classic ignorant denialism. The evidence for AGW has nothing to do with models or the temperature record. It is a straightforward result of the properties of CO2. Straightforward as in, "Some guy in 1896 figured it out using research from 1859". You know this theory is more than 100 years old, right?

It's really irritating to read this. It's one thing to be completely ignorant of a subject -- we all start out that way. It's quite another thing for you to declare your ignorance of the causal chain but insist that other people got it wrong. Yes, you're right, it's hard to draw causal links from statistics, but that's not remotely what has happened, and the idea that you know this and some scientific community might not is breathtakingly stupid. But okay, I'll try to believe that you at least mean well and maybe don't have a lot of time to read about this. I would recommend starting here, and maybe continuing on the section about basic radiation maths. Keep in mind that what we know about Earth's atmosphere we have also been able to apply to extraterrestrial atmospheres, including the Sun. Generally what you're going to find is that warming is a direct result of CO2 trapping heat, and that we've been trying pretty hard to find reasons why raising the partial pressure won't also raise the temperature. There's only so many things that can happen in terms of radiation between the surface of the Earth and outer space, and we've pretty much ruled out anything that could prevent drastic warming. Which, yes, sucks balls. The other interesting thing that you'll find is that there was a scientific consensus *against* the CO2 theory, and you'll have to see why it was overturned.

Whether the Earth will warm is easily proven. The energy imbalance is easy to quantify. The rate of warming is hard, especially because it depends on human interactions. Global climate models have nothing to do with the first two things. AGW was proven decades before digital computers even existed. CO2-induced warming was actually completely discredited up until the mid-1950s. Somehow opinions changed then, but they can't change now because "conspiracy!", even though Roy Spencer is the lead author on segments of the IPCC reports.

Yes, climate change is a difficult topic to study. It's taken most of the last 200 years to figure out that it does change, and that humans could change it. Apparently you've never bothered to learn anything about that, but you're not dead yet, so if you'd like to educate yourself, you can start here.

The global climate models have little or nothing to do with validating or invalidating any particular element of climate science. Similarly, epidemiological models are not evidence for or against the germ theory of disease. Also, you are categorically wrong to conflate weather and climate. The inability to predict weather precisely over long timeframes has nothing to do with the 30-year-average temperature trends; Lorenz did not invalidate statistical analysis nor physics generally. Additionally, weather and water vapor are mostly confined to the troposphere, and the effect of a higher partial pressure of CO2 is actually to push the CO2-rich layer further out into space, so the situation there is much simpler. We would be able to predict warming even if we treated the lower atmosphere as a black box.

The Global Climate Models are an easy target, but this is like the drunk man looking for his keys underneath the lamppost because that is where the light is. The principles of climate change and anthropogenic global warming were laid down decades before the first computer model. Merely advancing this argument betrays a complete lack of understanding of the foundational science of climate change. Please go here and read through the history. You will probably be interested in the period 1900-1950 when CO2-induced warming was considered completely disproven. But either way, you have a spectacularly bad argument. Please continue making it if you would like to further discredit your side. I sort of get the impression that your misunderstanding of its relevance is likely to be motivated reasoning and likely incurable, so I don't expect you to be able to recognize why it's a bad argument, but as said, your ignorance is so profound that it is useful to the opposing side, so there's not really a bad outcome here.

I'm sorry, your argument is completely invalid. Not only has there been significant historical debate over both climate change and AGW, but there are still contrarian researchers publishing in respected journals. The reason that no one takes them seriously is because the foundational science for AGW was done over 100 years ago, and we have tried and failed to rule out alternatives since then.

There are two ways to approach the question, "How do we know x?" Obviously with empirical facts it's a question of what observations were made, but you can either approach it from a perspective of, "What are the current best obvservations?", or you can take the historical approach and ask, "How did we get here?" Did you know that the theory of CO2-induced climate change was considered completely disproven up until the mid 1950s? Ice ages were accepted as having happened historically, but the default position was that the climate did not change, that while it might have warmer or cooler cycles that these would always balance out in the long run. The need to explain ice ages was the driving force for theories of climate change beginning in the late 1850s. Now, Arrhenius did correctly identify CO2 as a potential climactic influence, and his seminal 1896 paper gives a factor of sensitivity that still agrees well with the IPCC estimates.

However, Arrhenius was considered debunked, for a couple of reasons, until the mid 1950s when better analyses of the upper atmosphere were being conducted. Studies like Callendar 1949 "Can Carbon Dioxide Influence Climate? provided a new understanding for the behavior of CO2 in the upper atmosphere, and helped to dispel the idea of a static or cyclical climate. Also another key observation was that the oceans turned over much more slowly than had been suspected. These things led to calls for increased research and eventually the tide of opinion accumulated behind AGW in the space of about fifteen to twenty years. Nobody was fired or lost funding, because then the science wasn't politically useful to anyone. The only thing that universities and funding institutions care about is where the facts lead to. It's also worth noting that internal research by the oil industry in the 1970s reached similar conclusions about the validity of the AGW theory.

You are trying to make this a political subject. You do not know the science in question, you are simply saying it is wrong, and wrong because of some political reason. You need a scientific argument. Your political argument is also bankrupt, because not only do we have legitimately conducted and published contrarian research, but Dr Roy Spencer, frequent contributor to WUWT and perhaps the most notable contrarian, was lead author on sections of the IPCC reports. That's not exactly what I would call silencing dissent.

The evidence available in the 19th Century was sufficient to advance a theory of CO2-induced climate change. The evidence gathered over the intervening years has been conclusive. If you would like some exposure to what exactly has happened in climate science in the last century, you might start here, or just get on Google Scholar and start going through the publications. There's only a handful of papers published before 1950 so it's not like you have to go poring through a lot of articles. Armed with the evidence, you might then be able to suggest defects in it, and gather counterevidence. As things stand, that would basically require radically new physics, but that's science for you. You can put what buildings you like to the torch, but you can't burn down a scientific institution without doing better science.

I'm sorry, your argument is completely invalid. Not only has there been significant historical debate over both climate change and AGW, but there are still contrarian researchers publishing in respected journals. The reason that no one takes them seriously is because the foundational science for AGW was done over 100 years ago, and we have tried and failed to rule out alternatives since then.

There are two ways to approach the question, "How do we know x?" Obviously with empirical facts it's a question of what observations were made, but you can either approach it from a perspective of, "What are the current best obvservations?", or you can take the historical approach and ask, "How did we get here?" Did you know that the theory of CO2-induced climate change was considered completely disproven up until the mid 1950s? Ice ages were accepted as having happened historically, but the default position was that the climate did not change, that while it might have warmer or cooler cycles that these would always balance out in the long run. The need to explain ice ages was the driving force for theories of climate change beginning in the late 1850s. Now, Arrhenius did correctly identify CO2 as a potential climactic influence, and his seminal 1896 paper gives a factor of sensitivity that still agrees well with the IPCC estimates.

However, Arrhenius was considered debunked, for a couple of reasons, until the mid 1950s when better analyses of the upper atmosphere were being conducted. Studies like Callendar 1949 "Can Carbon Dioxide Influence Climate? provided a new understanding for the behavior of CO2 in the upper atmosphere, and helped to dispel the idea of a static or cyclical climate. Also another key observation was that the oceans turned over much more slowly than had been suspected. These things led to calls for increased research and eventually the tide of opinion accumulated behind AGW in the space of about fifteen to twenty years. Nobody was fired or lost funding, because then the science wasn't politically useful to anyone. The only thing that universities and funding institutions care about is where the facts lead to. It's also worth noting that internal research by the oil industry in the 1970s reached similar conclusions about the validity of the AGW theory.

You are trying to make this a political subject. You do not know the science in question, you are simply saying it is wrong, and wrong because of some political reason. You need a scientific argument. Your political argument is also bankrupt, because not only do we have legitimately conducted and published contrarian research, but Dr Roy Spencer, frequent contributor to WUWT and perhaps the most notable contrarian, was lead author on sections of the IPCC reports. That's not exactly what I would call silencing dissent.

The evidence available in the 19th Century was sufficient to advance a theory of CO2-induced climate change. The evidence gathered over the intervening years has been conclusive. If you would like some exposure to what exactly has happened in climate science in the last century, you might start here, or just get on Google Scholar and start going through the publications. There's only a handful of papers published before 1950 so it's not like you have to go poring through a lot of articles. Armed with the evidence, you might then be able to suggest defects in it, and gather counterevidence. As things stand, that would basically require radically new physics, but that's science for you. You can put what buildings you like to the torch, but you can't burn down a scientific institution without doing better science.

This would be a skeptical perspective, there are various other wrong arguments. As it happens it's one of the better wrong arguments available, but still insufficient. Links are likely to be first resource available rather than an authoritative source; the nice thing about empiricism is that it's consistent.

Doubling the concentration of CO2 in the atmosphere increases global surface temperatures by 1.16 K.

Yes, that's a reasonable figure.

we are not far off the conditions of CO2 starvation for plants where all plant life dies, since they evolved in an atmosphere of 2000 ppmV CO2

Carbon dioxide levels have not been at that level for since, what, the mid-Cretaceous? Tens of millions of years at any rate. For most crops the saturation point will be reached at about 1,000—1,300 ppm under ideal circumstances., higher levels inhibit growth. There are any number of studies which bear these figures out, but as it happens I have also personally experimented with gardening with supplemental CO2, and with my hydroponic setup anything higher than 1500 ppm produced noticeably less healthy plants.

...[plants] rapidly absorb human-emitted CO2..."

If plants were starved for CO2, we would not be seeing the global concentration rising. This also misses a much better argument. In the first decades of the 20th Century, AGW was discredited for a number of reasons, the relevant one being that it was thought that the oceans would be able to absorb and buffer any increase of CO2. There is 50 times the amount of dissolved carbon in the oceans than there is in the atmosphere, and it seemed obvious that anything happening to the atmosphere would necessarily be minor. That turned out not to be the case.

the lifetime is certainly under 10 years and possibly as short as 10 months

This is an extraordinary claim. I would ask you to provide a citation from a reputable journal, but I cannot imagine that a claim so blatantly unphysical would ever be accepted into a reputable journal. However, it's clear that the excess carbon is not being sequestered; however long it stays in the atmosphere is irrelevant to whether it is increasing.

The debate is entirely about what the effect of water vapor (clouds have) on these sensitivities.

Clouds are not water vapor, actually, they're condensed water. Water vapor is the stuff that's not visible. The Earth is actually opaque to IR. Water vapor and CO2 in the laboratory have a very strong feedback effect. Clouds do not cover 100% of the Earth's surface, but water vapor does, so we should intuitively expect that clouds should not have a greater effect than water vapor. Also, since it is undisputed that clouds also contribute to warming, the required negative feedback would need to be that much greater. Given that the positive feedbacks are as you say of alarming magnitude, this negative feedback should be fairly obvious. And yet no skeptic has been able to propose a mechanism. Sufficient evidence has not been presented to overturn the IPCC results.

Meanwhile the skeptics believe the IPCC computer models are wrong

Of course they are, "all models are wrong, some are useful". Modeling that atmosphere in two dimensions or as a column of gases is a very easy way to demonstrate the warming effect. But having an accurate or inaccurate model is irrelevant to whether the observations that it's built on are correct. You need the observat

So which part of the history I wrote was false, then? Before you answer you may want do do some research here. It's well cited and I am sure that I can find some other citations if necessary. I'm really not sure what you're alleging, but your flat denial of verifiable scientific history is appalling.

Spending all this effort to accurately measure the thrust is an utter waste of time if the moment you start to investigate the cause you find it is simply due to electron emission.

http://scitation.aip.org/conte...

It seems to me they ARE looking into causes. I mean, if it were something obvious that we already knew about they'd have found it already.

still have not seen any evidence that the feedbacks are positive, and I have looked...

You can do an experiment to prove the relationship in your basement. It's not like CO2 and H2O are hard to come by.

The main problem with the argument for positive feedbacks is if they were correct then at several times in the past the planet would have gone hot and killed off life...

Apparently you haven't bothered to look at why the Earth isn't at risk of runaway warming for the next billion years.

Models are shit, and only tell you what you have programmed into them, if you presume you must have positive feed back for certain values, you will set them like that and the model will tell you what you wanted to occur, caused by setting the parameters wrong.

You have no idea what you're talking about. The models are based on the laws of physics. Are they inaccurate? Of course, all models are -- even Relativity. All scientific knowledge is inaccurate. Does that mean we don't understand the laws of physics? If your measurement of your cannon's arc doesn't match the Newtonian projection, are you going to blame Newton or your measurement?

You don't seem to have a clue about much of anything, but maybe reading about simple climate models would help you be not as much a waste of oxygen.

Now follow that out to its logical conclusion. Your statistical model is easy to conceive and pretty accurate. Using more advanced statistical methods should yield a more accurate estimation. Clearly that's not what they did.

This is not a statistical model. It works because physics. Get a clue

http://descanso.jpl.nasa.gov/S... is as good a summary as any about NASA's current ion engines, while the APL paper by Neumann, Bilek and McKenzie for the http://scitation.aip.org/conte... has information about the Neumann Drive.

Short version is that xenon drives vary in specific impulse and power efficiency depending on the power levels, while Neumann Drives vary in specific impulse and power efficiency depending on the fuel used, while the power level affects how many pulses per seconds. Higher power levels appear to cause faster wear of the grid in Gridded Ion Thrusters, or the chamber in the case of Hall Effect Thrusters, as well as needing more investment in Power Processing Units and so on. Additionally, there is the issue of tankage, regulators and so on for dealing with the xenon itself, which means it's not a straight 1:1 comparison. That said ...

TLDR : Magnesium in a Neumann Drive runs about 9 uN/watt and 11 000s specific impulse. A NSTAR running at ~1000 watts input has about 32 uN/watt and 2850s of specific impulse.

Hi,

I'm Ian Whitchurch, the CEO of Neumann Space.

First of all, if you want more technical information about the Neumann Drive, there's an article in Applied Physics Letters. It may be available here

http://scitation.aip.org/conte...

If that isnt working, then you might know someone with an APL subscription, or it might be somewhere on the internets under "A centre-triggered magnesium fuelled cathodic arc thruster uses sublimation to deliver a record high specific impulse Patrick R. C. Neumann, Marcela Bilek and David R. McKenzie".

Secondly, it's not just the Neumann Drive that's going up to the Bartolomeo platform on the ISS. We're planning on taking a bunch of other peoples small projects, which deserve to go into space, but cant by themselves get a ride into orbit, or an easy method to get power, heating, cooling and communications once they are there. If you're interested, you might want a look at this fine Airbus DS press release.

https://airbusdefenceandspace....

There is also information available about the Facility for Australian Space Tests on our website, at http://neumannspace.com/fast/

Thirdly, Im happy to answer further questions people might have.

Finally, our poor, poor website. Also, the original post lacks a poll, which itself lacks a Cmdr Taco option. What the heck am I supposed to vote for ?

A better solution is to cover the blue LED with special phosphor that can absorb the blue light and re-emit the energy as some other color, like yellow. Here's a link about that.

You'd think professional journalists would properly cite even link to the original publication.

Oussama Mhibik, Sebastien Chenais, Sebastien Forget, Christophe Defranoux and Sebastien Sanaur: Inkjet-printed vertically emitting solid-state organic lasers, J. Appl. Phys. 119, 173101 (2016).

http://scitation.aip.org/conte...

Successful predictions include surface warming and stratospheric cooling coincident with a rise in CO2 levels, and stronger warming effects at the poles. Are you under the misapprehension that producing fine-grained projections of global temperature is the only thing that climate scientists do?

The challenge I put forth asked for correctness of just 80% for any cited prediction

Studies usually already include their error margins. If a prediction comes in within its own error margin, that is a successful test. Surely you don't apply your own arbitrary standards to other physical sciences? As it happens, results within the error margins of prediction are true for Hansen et all (1988), linked previously, for Plass (1956), Arrhenius (linked previously), and most accurately by Sawyer (1972), who managed to get both the magnitude of increased emissions and the resulting temperature increase exactly correct. I apparently wasn't clear when I gave you the temperature predictions earlier for Sawyer, Plass, and Hansen. I assumed that you would be able to find a graph of global temperatures for the 20th Century. Here's a graph for you, which corroborates their findings. I hope it's not too much trouble to be able to look at my previous posts for the numbers.

Also, Arrhenius (1896) and Callendar (30s-40s) were confirmed in the mid-50s with CO2 and temperature measurements. You could also consider Plass and Kaplan (1952) to be confirmation of the previous work on the matter. Also, you will note that Hansen's spacial distribution of the temperature anomaly was very accurate. Looking at graphs in the 1995 IPCC report their prediction (p40) of the warming trend matches the observed warming through to the present quite well.

We see scary predictions published — even on Slashdot — about once a week.

If you're getting your scientific information from the popular press, you're probably being misinformed in some manner. In my experience newspaper articles are rarely peer reviewed, and I don't think I've seen very many cited, or that have citations. As it happens, I believe most of the articles on Slashdot are concerned with weather events and annual records.

does this mean, you admit, no predictions I seek have been made until "just recently"?

What you want isn't actually a test of the science in the way you think it is. Global climate models cannot be used to disprove AGW any more than epidemiological models can be used to disprove the germ theory of disease, and Kerbal Space Program is similarly not a test of relativity. Economists can construct models to show that rapid expansions of the monetary supply cause harmful inflation, and there is empirical evidence to support this idea. Constructing a model to predict the exact effects of the Fed's Quantitative Easing program would be something of a challenge. Failure to model something accurately means that your model is inaccurate, not that the theory is wrong. Are climate models inaccurate? Of course they are! Every model is inaccurate. All of science is inaccurate, it's inherent to empirical observation. The question is to what degree they are useful, and to begin to be able to answer that, I would suggest you start here or

An impossible task since there wasn't any one paper that convinced me AGW is real. It's a subject I've been following since the late 1980s. At first I was skeptical but over time the pieces started fitting together into a coherent whole so overwhelming evidence works for me.

You might try Spencer Weart's "The Discovery of Global Warming" for starters. I also recommend the papers cited in the IPCC WG1 report (look for the "All Citations" link). If you're worried about computer models you can download the GISS ModelE code and tell me how it's "cooked". There is code for other models available as well.

The models are one thing. Even the temperature record is not necessarily critical to the theory. For AGW to be conclusively disproven, there would have to be at least one of the following discoveries: [a] a new way for large amounts of heat to be transferred to space, or [b] a feedback loop that cancels out the (strongly positive) H2O-CO2 forcing.

Both of these ideas have issues. The first one is almost too fanciful to even mention, but suffice to say we would expect to see this effect in extraterrestrial atmospheres as well. The second hypothetical has seen some investigation and was a favorite of anti-AGW researchers for a while, but so far all proposed mechanisms fall seriously short of negating the known positive feedbacks. It's not enough to say "the data sucks" or "the models suck", you need to have some sort of replacement hypothesis which explains why, all else being equal, an increase in atmospheric carbon does not lead to increased temperatures. We've eliminated a lot of false candidates over the last 100 years, and if there is some sort of force that would prevent a carbon catastrophe, we could sure use one now. It's pretty slim pickings at this point though.

Ignore the temperature data. That is to say, what the planet is doing at any given moment is less important than the underlying physics, and unfortunately we have a very good idea of what the underlying physics say. We know from very basic atmospheric physics/thermodynamics that the Earth must be warming. You should also completely ignore what any bloggers say about temperature trends; if they had valid critique they could get published, or at the very least they could get the original articles retracted. There's also no such thing as a replacement hypothesis from the denier camp: if increased CO2 and H2O are not warming the planet, why not? And if there is some mechanism that removes the excess heat, why do we not observe it in other atmospheres?

My advice is to start with the basics: The History of Global Warming. We've been trying to prove AGW wrong for over a hundred years already, and the history of these experiments and discoveries should answer many questions you have about what is happening and why.

I could be reading this article wrong - I'm only looking at one of the graphs but I'm reading the temperature as warmer today than 50,000 years ago. By my reading you need to go back about 125,000 years to get a warmer temp. https://www.aip.org/history/cl... - graph link http://www.aip.org/history/cli...

I could be reading this article wrong - I'm only looking at one of the graphs but I'm reading the temperature as warmer today than 50,000 years ago. By my reading you need to go back about 125,000 years to get a warmer temp. https://www.aip.org/history/cl... - graph link http://www.aip.org/history/cli...

Doh. Broken link.

Seems they have been doing predictions for a while, and the time frame is set: Transitions between glacial and warm climates — and back again — might come in a matter of only a few centuries if not faster. So as you can see we have not even approached a single test's time frame, although the effects of the predictions appear to be happening more or less.

Oh, now I understand what you mean. If I am discovered, you will of course stop communicating. The next time you try to communicate, I might have discovered a way around your nifty attack-detector-thing. Or I might not. The point is that you can not guarantee that I won't attack your system unless you correct the flaws in the security proof. All of this is in the paper, but Makarov has an excellent write-up to your very question: http://scitation.aip.org/conte...

For those who avoid Googling, this thought experiment is by Galileo Galilei.

Something not entirely different: in Otto Frisch's delightful memoir "What Little I Remember" he relates a story about Niels Bohr and him, which can also be read here (search on the page for "thought experiments" or - even better - just read the whole transcript); in "The Making of the Atomic Bomb" by Richard Rhodes this is told as follows:

He [Bohr] was traveling through Germany to determine who needed help. [This was in the 1930s.] "To me it was a great experience," Frisch writes, "to be suddenly confronted with Niels Bohr - an almost legendary name for me - and to see him smile at me like a kindly father; he took me by my waistcoat button and said: 'I hope you will come and work with us sometime; we like people who can carry out "thought experiments"!'" (Frisch had recently verified the prediction of quantum theory that an atom recoils when it emits a photon, a movement previously considered too slight to meaasure.)

His aunt was Lise Meitner, and together they gave a correct interpretation of experiment by Otto Hahn: "We [Frisch and Lise Meitner] walked up and down in the snow, I on skis and she on foot (she said and proved that she could get along just as fast that way), and gradually the idea took shape that this was no chipping or cracking of the nucleus but rather a process to be explained by Bohr's idea that the nucleus was like a liquid drop; such a drop might elongate and divide itself."

I highly recommend Frisch's memoir. From it another Bohr story. Frisch was invited to Bohr's home, and on seeing a horseshoe hanging above the door and said to Bohr: "Surely you don't believe in that?"; Bohr's reply: "Of course not, but I'm told it works even if you don't believe in it!"

A quote by Frisch: "Scientists have one thing in common with children: curiosity. To be a good scientist you must have kept this trait of childhood, and perhaps it is not easy to retain just one trait. A scientist has to be curious like a child; perhaps one can understand that there are other childish features he hasn't grown out of."

OK - my maths was out by 3 orders of magnitude. A 500km long 70mm^2 Carbon nanotube rope would have a mass of about 50 tonnes, not 50kg.

Even with 3.6GPa ultimate tensile strength (2.75x10^6 N.m/kg specific strength) of carbon nanotube ropes, it won't work.

Assuming a 2 tonne craft (as specified in the article), assuming 100% loading:

• cross-sectional area: 10^5N / 3.6x10^9N/m^2 = 2.77x10^-5m^2 = 27.7mm^2
• mass assuming 1000km rope: 10^6m x 2.77x10^-5m^2 x 1300kg/m^3 = 3.6x10^5kg = 36 tonnes of rope for a 2 tonne vessel.

Required specific strength, assuming a rope with a mass of 2 tonnes, giving a total mass of 4 tonnes: (10^6m x 2x10^5N) / 2x10^3kg = 1x10^8 N.m/kg