I thought zm was saying that the oceans were supposed to be keeping all of the accumulated heat due to radiative forcings rather than the land or the atmosphere. This is a slight exaggeration, but only by 25% at most. That's all I meant. Obviously, we're talking about different things so I'm forced to print a retraction for that irrelevant comment of mine.
They don't keep all the accumulated heat. The heat inertia effect is closer to 50%.
Actually...
“The oceans are absorbing more than 80 percent of the heat from global warming,” he says. “If you aren’t measuring heat content in the upper ocean, you aren’t measuring global warming.”[Dr. Josh Willis]
Josh's estimate is plausible because:
Oceans cover 71% of the Earth's surface.
Water's specific heat is over four times greater than that of rock.
Water stores heat using the heat transfer mechanisms present in rock plus convection.
Water is more transparent than rock so visible light warms more than just the very top layer.
But I'm not sure why you're saying that oceans aren't warming.
Nice link, but he's probably referring to a (resolved) problem with the Argo data that's discussed in that same article:
“So the new Argo data were too cold, and the older XBT data were too warm, and together, they made it seem like the ocean had cooled,” says Willis.
For example, what if a male heterosexual soldier discusses his sexual exploits in front of a woman soldier after she has made clear that she doesn't want to hear this, and she then lodges an official complaint?
Rightfully so, but notice that there isn't a law saying that the braggart should be discharged immediately, regardless of the presence or absence of extenuating circumstances.
This is actually quite sensible, as such a betrayal undermines the mutual trust that is an absolute requirement for soldiers who may go into battle.
In exactly the same way asking gay soldiers to hide their identities undermines that trust. In fact, "don't ask, don't tell" makes gay soldiers susceptible to blackmail for that very reason!
If the facts of the case are indeed as they are presented by the blogger that you linked, then I agree that the woman officer's punishment was outrageous and unjust. However, the link from the blog to the original news article is broken, so I'm left in some doubt about what really happened.
MSNBC covered the story, then the ACLU challenged the police department only to receive this reply which makes it clear that the police officer saw the marriage license through the window. Clearly Ms. Newsome's wife needs to answer the charges brought against her (who knows if they're valid?) but as far as I can tell Ms. Newsome didn't ask and didn't tell.
But now as I think about it, I wonder why there should be special rules for homosexuals. I think everyone should be bound by the common rules of courtesy and mutual respect.
EXACTLY.
What I'm afraid of is that the gay rights crowd wants to make homosexuals immune from all rules—perhaps permitting flagrant sexual acts in the barracks, and (oh, the horror) pink underwear. OK, maybe I'm being silly, but the activists don't seem to have made their goals clear.
That silliness is probably a result of the fact that social conservatives routinely say that gays want "special rights". Recently, a friend's younger brother realized he was gay after graduating from college. He's a very committed Republican, and I was horrified to hear him repeat similarly silly notions like "gays already have the right to get married." Later, he claimed that legalizing gay marriage would destabilize society, which seems absurd considering that only ~4% of the population is gay.
By the way, do you mind if I post this conversation to my gay marriage article? That's the place on my website where I'm putting topics like "don't ask, don't tell", and it's refreshing to talk to someone civilized.
When a straight soldier discusses his/her sex life, it's a social faux pas as you say- on the same level as evangelizing co-workers during business hours. But when a gay soldier does the same thing, the consequences are significantly more severe: immediate discharge from the service. Seems like a double standard.
Besides, I've worked with a few homosexuals who eventually trusted me enough to tell me that their "roommate" was actually their partner. I can't imagine what kind of psychological effects are incurred through being forced to pretend their own love lives don't exist. We're not talking about sordid details here (I wouldn't be interested either) but don't you have some vague idea of whether or not your coworkers are married? That's the kind of dishonesty that "don't ask, don't tell" requires: gay people have to pretend their relationships don't even exist. Frankly, that expectation seems incompatible with the code of honor I've come to expect from the military.
And that's even before getting into cases like Jene Newsome who followed the rules only to be discharged because the police ratted her out.
Actually, halving our CO2 output is the consensus view of what we need to do to stabilize temperatures at a reasonable level. [ShakaUVM]
Huh? The IPCC AR4 WG1 says: "For comparison with this constant composition case, it is useful to note that constant emissions would lead to much larger radiative forcing. For example, constant CO2 emissions at year 2000 values would lead to concentrations reaching about 520 ppm by 2100."
Furthermore,"A 50% reduction would stabilise atmospheric CO2, but only for less than a decade. After that, atmospheric CO2 would be expected to rise again as the land and ocean sinks decline owing to well-known chemical and biological adjustments. Complete elimination of CO2 emissions is estimated to lead to a slow decrease in atmospheric CO2 of about 40 ppm over the 21st century."
Notice that reducing emissions by 50% would only stabilize CO2 for less than a decade. It wouldn't stabilize temperatures at all (see "constant emission commitment") because the huge thermal inertia of the oceans causes surface temperatures to lag behind changes in the effective radiating temperature of the Earth brought about by increasing levels of greenhouse gases.
The scientific consensus is actually that the total amount of CO2 emitted is what's important, not the emission rate. Every gigaton of CO2 we emit in 2010 is one less gigaton that our descendents will be able to emit in 2100. Therefore, the person you were lecturing was actually correct about this one point. Scientists wouldn't ever say that we just need to emit 50% less CO2 in order to stabilize temperatures, because that's simply not true.
As usual, I'll have to guess that you're referring to the title of a pop-science article. Next time, read past the title:
"It is wrong to believe that the temperature will remain constant with constant emissions," says Knutti.... The models show that there is a 75 percent probability that global warming will not exceed two degrees if a maximum of 1000 billion tonnes of CO2 are emitted into the atmosphere from 2000 to 2050. This number seems high, but 234 billion tonnes had already been flung into the atmosphere between 2000 and 2006. If the emission remain at this high level, or even increase, the budget would be exhausted before 2030. The results show that time to act is short.... This study also concludes that the total amount of CO2 emissions is crucial in terms of how much the earth warms up. The authors summarise a political interpretation in comments in Nature Reports Climate Change3. According to Knutti, "Every tonne of CO2 is one tonne, whether it is emitted today or in fifty years. This is often lost in the tangle of emission targets, certificates and negotiations. The total quantity is what matters, and must be limited, but short-term goals are necessary to see whether we are on the right track."... The series of studies show that the total quantity of CO2 emission is limited if people want to limit climate change. "With every year of delay, we are using up our quota, losing flexibility, and increasing the probability of dangerous consequences," says Knutti.
Or, look at the picture next to the title. Notice that Knutti's graph of CO2 emissions doesn't just drop in half, because that wouldn't stabilize temperatures. As Knutti stresses, the total amount of CO2 emitted is what's important, which is in this graph is the area under the curve. Knutti's curve has finite area because in hi
Actually, it's because you bore me when you stop talking about physics. Also, you previously seemed to want me to stop copying your statements. But I'm copying all of these right now.
I've fixed the spelling of "viscoscity" and fixed the link in the word "politician" in the permanent version. As I originally intended, it now points to the beginning of the article where last year I said in a popup over the word "politician's": "You have to realize that I view the word 'politician' as a VERY dirty word in order to get the full effect of this sentence".
Light has *momentum*. Technically, it's just p = hf. I'm not sure why you need to reference a textbook, but you seem to go about everything in bizarre and unproductive ways. [ShakaUVM]
Because that's from early 1900's quantum theory, not classical electrodynamics. My point is that even in the 1800's, it should've been clear that light has momentum and thus inertia just by examining Maxwell's equations.
... I only consider objects with mass to have inertia, as a massless object cannot have an inertial reference frame that makes any sense. A number of people agree with me. For example, Greene equates inertia with particles with mass.
That's an interesting definition; I've never heard of it before. Like Einstein, I prefer to call "E/c^2" the "inertia" of light because that's the conceptual breakthrough which resolved the original pesky factor of 4/3 that kept appearing in Lorentz's derivation of "E=mc^2":
And because the em-mass depends on the em-energy, the formula for the energy-mass-relation given by Thomson (1893) and Wien (1900) was m = (4 / 3)E / c2 (Abraham and Lorentz used similar expressions). Wien stated, that if it is assumed that gravitation is an electromagnetic effect too, then there has to be a proportionality between em-energy, inertial mass and gravitational mass. However, it was not recognized that energy can transport inertia from one body to another and that mass can be converted into energy, which was explained by Einstein's mass-energy equivalence.
The idea of an electromagnetic nature of matter had to be given up, however, in the course of the development of relativistic mechanics. Abraham (1904) argued (as described in the preceding section #Lorentz transformation), that non-electrical binding forces were necessary within Lorentz's electrons model. But Abraham also noted that different results occurred, dependent on whether the em-mass is calculated from the energy or from the momentum. To solve those problems, Poincaré in 1905[A 8] and 1906[A 9] introduced some sort of pressure of non-electrical nature, which contributes the amount (1 / 3)E / c2 to the energy of the bodies, and therefore explains the 4/3-factor in the expression for the electromagnetic mass-energy relation.
It also happens to explain the paradox discovered by Poincare regarding conservation of momentum in different frames when using Lorentz transformations to transform between inertial reference frames.
In other words, the reason Einstein is a household name but Lorentz is known only to scientists can be traced back to the fact that Einstein recognized that light has inertia.
You're quite wrong that it was an expected result - read, and look at the number of times they kept trying to get the experiment to "succeed".
First, I just said that as the story goes, Einstein based special relativity on his daydreams and pre-existing problems with the aether. That's the official story, but I find it hard to believe that Einstein really didn't think about the Michelson-Morley experiment during this process. However, that's what Einstein claimed and the story is at least remotely plausible given his stratospheric genius.
Second, I didn't say Michelson and Morley expected it. I just said Einstein claimed to not find it surprising or informative in his development of special relativity, and that aether timeline I linked should provide convincing evidence that the aether had already been shown to be logically inconsistent long before Michelson and Morley started their w
... the study takes into account a rebounding of the Earth's crust called glacial isostatic adjustment, a continuing rise of the crust after being smashed under the weight of the Ice Age. [Slashdot summary]
Here the summary implies that previously published GRACE ice mass balance estimates didn't take GIA into account. At first I assumed this ridiculous implication must have been a mistake on Slashdot's part. Then I read the article:
... according to the new study, published in the September issue of the journal Nature Geoscience, the ice estimates fail to correct for a phenomenon known as glacial isostatic adjustment.... Often ignored or considered a minor factor in previous research, post-glacial rebound turns out to be important, says the paper. [AFP, Sep 8]
Luthcke et al. corrects for GIA using the ICE-5G model which combines many proxies and other empirical evidence regarding ice history since the Last Glacial Maximum, mantle viscosity and the Earth's various Love numbers. Chen et al. used the similar IJ05 model. Velicogna used multiple independent models to estimate uncertainty in the GIA signal. After reading Dr. Wu's paper, it's clear he never claimed that previous research had ignored or failed to correct for GIA.
That would have been a real surprise, because he wouldn't make a claim that can be disproven simply by skimming the papers he referenced. Nor is he rude enough (or at all, for that matter) to imply that the rest of the GRACE community ignored this important issue. Coincidentally, Dr. Wu worked for my advisor as a postdoc in the 1990s, in the same office that I'm currently using. I met him several months ago at the WP-AGU conference in Taiwan, and as far as I can tell he's overwhelmed by the bizarre attention his paper has gotten from the general public:
RUSH: There's a global warming story out. Guess what? Greenland and some of the ice floes, they're only going to melt half as much as originally forecast. So the polar bears are still going to have a place to live. I don't think they're going to melt, period. All of this is a sham.
"Estimates of the rate of ice loss from Greenland and West Antarctica, one of the most worrying questions in the global warming [hoax], should be halved, according to Dutch and US scie
Perhaps you got confused because both of our usernames start with 'S'?... Especially since your ad hominem includes assigning me claims of "gibberish" by linking to posts that aren't even by me. If you want to argue a particular topic, do so - but by this laughably dishonest (did you think that people would just never bother to check your references?) attempt at discrediting someone on the internet, you're just exploding any cachet you had with anyone who cares.
That link defines the word "gibberish" as I mean it in this context:
What you need to understand is that what you said, while sounding philosophical to the uneducated is gibberish. To a scientist what you said sounds something like "What if what I thought was my hand was actually an ardvaark in disguise".
I'll see your Griffiths and raise you a Feynman, Greene, and Gershenfeld.... If your interpretation of your introductory textbook was correct, semiconductors wouldn't work. Read up on them some time.
Sure. Just quote the page numbers and passages (like I did) which support your claim that conservation of energy doesn't apply across very short time scales. Make sure that you're not misinterpreting the concept of quantum foam to support a confused pop-science notion that energy conservation is violated by much slower processes like nuclear decay or anything happening in semiconductors.
The fact that you're taking seriously Penrose's idea means that you have no fucking idea what you're talking about.
I guess I should've mentioned that "I'm heavily skeptical of this claim."
You might want to read up some time on baryogenesis, CP violation, and the big question about why there's more matter in the universe than anti-matter.
Ironically, the reference I gave to Kolb p157 is the first page of chapter 6... which is called "Baryogenesis." I suppose I should've mentioned (twice) that CP violation is considered along with baryon number violation caused by processes like sphalerons.
... Khayman, you've gone completely off the deep end... you sound more like the unibomber than a physicist.... If you want to keep writing these long, unibomber-like screeds... If you're a scientist, as you purport to be, you're a very bad scientist.
There's yet to be any evidence the universe doesn't run on very specific mathematical rules. For example, there's a very good reason for inflation having to do with the 'pressure' at high energy states. [ShakaUVM]
Huh? Your customarily vague but authoritative comment which doesn't include an "IANAP" disclaimer will just reinforce the disturbingly common impression that physicists are bullshitting about concepts like inflation and dark matter.
The cosmology course I've mentioned was taught by Dr. Nanopoulos using Kolb's The Early Universe. He pointed out that physicists have known for decades that something like inflation is required to explain the isotropy of the cosmic microwave background radiation. Kolb disusses these topics in chapter 8, though his overview is somewhat dated now. WMAP has since observed temperature fluctuations on the 10^(-5) level, which matches predictions based on modelling quantum fluctuations in the early universe. More precisely, inflationpredicts that these fluctuations would deviate slightly from the perfect scale invariance expected in a universe without inflation. After 7 years, WMAP can exclude the possibility of a scale invariant spectrum by more than 3 sigma. The WMAP results also show that the universe is perfectly flat, at least to within the limits of measurement. Inflation isn't necessary for the universe to be perfectly flat, but it's sufficient to explain what may seem like "fine-tuning" at first glance.
That's why physicists think inflation happened, but it's an argument based on how relativistic causality affects the large-scale thermodynamics of the universe, not pressure. Pressure is at least tangentially relevant to almost every physics problem imaginable, though, and inflation is no exception. I've explained that dark energy's negative pressure acts as a kind of anti-gravity. Later, Dr. Stoeger (Jesuit priest, astrophysicist working for the Vatican Observatory) observed that "There is, of course, a much deeper connection between inflation and dark energy. The only way we can really conceive of inflation occurring in the early universe is under the influence of a large amount of vacuum energy, which is a type of dark energy. This dark energy must be quickly transformed into the particles and radiation at the end of inflation. So, it's not at all clear if there is a relationship between the dark energy which drove inflation and the dark energy which we have evidence is driving the gentle acceleration of cosmic expansion now. It may be that the dark energy now may be a remnant of the dark energy left over from the very early universe."
Then there's the problem of heavy exotic particles predicted by most GUT's; the only one I'm familiar with is the magnetic monopole. In my senior year, I took electrodynamics using the standard Griffiths 3rd ed. Page 327 shows how symmetric Maxwell's equations appear in the presence of magnetic monopoles, and Griffiths opines that they "beg for magnetic charge to exist." My fondest memory of that class is problem 8.12 on page 362, along with footnotes 11
In this context, error bars aren't simple numbers; they're actually functions of the temporal smoothing applied. If for some reason you decide to smooth the GCM output and sensor data at only 10 years, the error bars will be large. That's why professional climatologists usually smooth data and model output using ~20 year averages.
More fundamentally, falsification requires proper understanding of the dynamical nature of GCMs. This proposed "falsification" is woefully misguided because modern GCMs are dynamical physical models. If GCMs were simply empirical fits to past temperatures (as many seem to think), it would be meaningful to test the model by discussing temperatures alone. But GCMs don't incorporate timeseries of past temperatures, instead they model the climate based on the physics of forcings such as solar output, volcanic activity, aerosols, and human emissions. In other words, scientists don't develop GCMs to predict global temperatures; instead, GCMs are used to constrain a number of parameters such as (for instance) the equilibrium climate sensitivity and the transient climate response to doubling CO2.
All IPCC scenarios explicitly define the forcings that serve as inputs to the GCMs, and the temperature increase is the output. Since physicists are interested in testing physics rather than trying in vain to predict economic activity which could change CO2 emissions, falsification of any parameter constrained by the IPCC GCM ensemble requires comparing the projected forcings to the actual forcings.
You seem to assume that climate models are central to our understanding of the climate's response to rising CO2 levels. In reality, they're just methods of reducing the error bars on (for instance) modern estimates of the equilibrium climate sensitivity. Compared to pre-computer estimates like Hulbert's 1931 estimate of 4C per doubled CO2, computer models have actually reduced the maximum likelihood value to ~3C. They're also backed up by multiple independent experimental constraints on the climate sensitivity, in contexts where I doubt the problems you've been talking about are relevant.
I'm unaware of any model in computational physics (except perhaps lattice QCD?) which can claim to be completely "physical" in the sense that you seem to want. My own research which inverts gravity to solve for ocean tide heights assumes a constant density of water because GRACE measurements are due to changes in mass, not height directly. Not only do I ignore local seasonal fluctuations in temperature (which affects density), I also ignore local seasonal fluctuations in salinity due to calving glaciers (which also affects density).
Of course, my software is an empirical inversion of data rather than a dynamical physical model like a GCM. But in one sense my reason for neglecting salinity fluctuations (and noting it clearly in the upcoming JGR paper) is probably similar; the "unphysicality" is examined and the error estimated. In my case the error introduced by any reasonable density fluctuation is well beneath the noise floor for my desired observable. In a GCM, salinity likely has a negligible effect on global mean temperature which doesn't justify using it as a prognosticating variable. That would increase the degrees of freedom of the model and thus make it harder to test. Any serious effects of any of these examples of empirical "tuning" should have shown up in comparisons of the models to instrumental and proxy records of forcings and temperature. More likely, they play a minor role in the size of the established error bars.
In a completely different sense, long-term integrations of weather models certainly are thrown off by small errors. The "skill" of a weather prediction does indeed fall off exponentially with time because of oversimplified microphysics in addition to errors in measurements of the initial conditions. But the whole point of taking an initial condition ensemble is to average away this noise. By running dozens of simulations and changing the initial conditions each time, it becomes obvious that even though the weather noise is different, the extrema stay in the same "corridor" which we call the climate. The skill of a climate prediction doesn't fall off exponentially with time because the climate is a boundary condition problem, not an initial condition problem. Instead, the skill of a climate prediction depends primarily on taking a long enough temporal average (in addition to specifying the forcings).
For instance, a credible climate prediction would be "If natural forcings remain within established variances and human emissions of CO2 continue to rise at specified rate X, then the global temperature averaged from 2030-2050 will be higher than the equivalent average from 1990-2010.
On the other hand, a bogus climate prediction would be "The global temperature in 2030 will be higher than in 2010." That's bogus primarily because models have precisely the flaws you're talking about, in addition to our insufficient understanding of ENSO, PDO, NAO, etc turbulent heat transfer phenomena, flaws in projections of human and natural forcings, flaws in our understanding of "slow" feedback mechanisms, flaws in models of cloud formation, not to mention our instruments' finite time series, spatial coverage, spatial/temporal density and limited accuracy.
Oops! The "largely due" link should actually point here. This is the main graph from Meehl 2004 as mentioned in the article I'm constantly referencing, which is at the top of my "homepage" as listed here in Slashdot.
Actually, you're both just describing two sides of the same coin (as shown in the second part of my previous comment.) I believe he's comparing our emissions to the annual amplitude, and you're comparing it to the linear trend, which is indeed only influenced by volcanic activity at the 1% level of current human activity as you say.
No time for links, Dr. Jones... but the biosphere actually absorbs ~1/2 of our emissions, based on cross-analyses of Mauna Loa/etc stations, "recent" proxies, tax records on coal/oil/etc, and carbon 12/13 isotope ratios. Whether this absorption will continue at the current percentage is an open question.
Sorry, I need to change "The inefficiency of 1800s era technology merely multiplied the total fossil fuel use by a larger coefficient than today's more efficient tech, but that total fossil fuel use was tiny compared to the demands of the modern world." to "The inefficiency of 1800s era technology just multiplied the total power generation by a larger coefficient than today's (not much) more efficient tech, but the resulting fossil fuel use (and thus corresponding CO2 emissions) were tiny compared to the demands of the modern world."
Neither of you are providing links to peer-reviewed articles, so I won't bother trying to guess what specific event either of you are talking about. But most climate variability pre-1970 can't be "significantly" blamed on anthropogenic CO2 (i.e. "soot") because our population was small and the power generated was miniscule by today's standards. The inefficiency of 1800s era technology merely multiplied the total fossil fuel use by a larger coefficient than today's more efficient tech, but that total fossil fuel use was tiny compared to the demands of the modern world. Various proxies (middle graph) show variability over the last 1000 years, but most of this is explained by natural changes like the solar Maunder Minimum and occasional sustained "statistically significant" changes in volcanic activity (which normally adds aerosols to the atmosphere thus causing a brief "volcanic winter" but the CO2 emitted stays in the atmosphere longer so volcanic activity warms the long term climate). Also, notice that the top graph (the shorter instrumental record) shows no real change from 1800 to 1850, and both absolute temperatures are below the current temperature-- but this is from a period where they don't even bother to provide error bars because there are only a handful of recording stations. If you examine the middle graph (proxy reconstructions) again, you'll note that there's some disagreement about variability on ~30 year timescales, but even the increase around ~1000 CE is consistent among proxy reconstructions, and explained in terms of natural causes.
Remember that climate scientists aren't saying that natural variability doesn't exist. We're just saying that previous and current climate changes have natural causes which are relatively well understood, but the current increase in global average temperature as averaged over ~20 years is at least largely due to anthropogenic causes. Personally, I say this is a good reason to go nuclear. Yesterday.
Slashdot Mirror
I thought zm was saying that the oceans were supposed to be keeping all of the accumulated heat due to radiative forcings rather than the land or the atmosphere. This is a slight exaggeration, but only by 25% at most. That's all I meant. Obviously, we're talking about different things so I'm forced to print a retraction for that irrelevant comment of mine.
Actually...
“The oceans are absorbing more than 80 percent of the heat from global warming,” he says. “If you aren’t measuring heat content in the upper ocean, you aren’t measuring global warming.” [Dr. Josh Willis]
Josh's estimate is plausible because:
Nice link, but he's probably referring to a (resolved) problem with the Argo data that's discussed in that same article:
“So the new Argo data were too cold, and the older XBT data were too warm, and together, they made it seem like the ocean had cooled,” says Willis.
Thanks; if you ever finish it please let me know.
Erm, "wasn't asked, and didn't tell"
Rightfully so, but notice that there isn't a law saying that the braggart should be discharged immediately, regardless of the presence or absence of extenuating circumstances.
In exactly the same way asking gay soldiers to hide their identities undermines that trust. In fact, "don't ask, don't tell" makes gay soldiers susceptible to blackmail for that very reason!
MSNBC covered the story, then the ACLU challenged the police department only to receive this reply which makes it clear that the police officer saw the marriage license through the window. Clearly Ms. Newsome's wife needs to answer the charges brought against her (who knows if they're valid?) but as far as I can tell Ms. Newsome didn't ask and didn't tell.
EXACTLY.
That silliness is probably a result of the fact that social conservatives routinely say that gays want "special rights". Recently, a friend's younger brother realized he was gay after graduating from college. He's a very committed Republican, and I was horrified to hear him repeat similarly silly notions like "gays already have the right to get married." Later, he claimed that legalizing gay marriage would destabilize society, which seems absurd considering that only ~4% of the population is gay.
By the way, do you mind if I post this conversation to my gay marriage article? That's the place on my website where I'm putting topics like "don't ask, don't tell", and it's refreshing to talk to someone civilized.
When a straight soldier discusses his/her sex life, it's a social faux pas as you say- on the same level as evangelizing co-workers during business hours. But when a gay soldier does the same thing, the consequences are significantly more severe: immediate discharge from the service. Seems like a double standard.
Besides, I've worked with a few homosexuals who eventually trusted me enough to tell me that their "roommate" was actually their partner. I can't imagine what kind of psychological effects are incurred through being forced to pretend their own love lives don't exist. We're not talking about sordid details here (I wouldn't be interested either) but don't you have some vague idea of whether or not your coworkers are married? That's the kind of dishonesty that "don't ask, don't tell" requires: gay people have to pretend their relationships don't even exist. Frankly, that expectation seems incompatible with the code of honor I've come to expect from the military.
And that's even before getting into cases like Jene Newsome who followed the rules only to be discharged because the police ratted her out.
Huh? The IPCC AR4 WG1 says: "For comparison with this constant composition case, it is useful to note that constant emissions would lead to much larger radiative forcing. For example, constant CO2 emissions at year 2000 values would lead to concentrations reaching about 520 ppm by 2100."
Furthermore, "A 50% reduction would stabilise atmospheric CO2, but only for less than a decade. After that, atmospheric CO2 would be expected to rise again as the land and ocean sinks decline owing to well-known chemical and biological adjustments. Complete elimination of CO2 emissions is estimated to lead to a slow decrease in atmospheric CO2 of about 40 ppm over the 21st century."
Notice that reducing emissions by 50% would only stabilize CO2 for less than a decade. It wouldn't stabilize temperatures at all (see "constant emission commitment") because the huge thermal inertia of the oceans causes surface temperatures to lag behind changes in the effective radiating temperature of the Earth brought about by increasing levels of greenhouse gases.
The scientific consensus is actually that the total amount of CO2 emitted is what's important, not the emission rate. Every gigaton of CO2 we emit in 2010 is one less gigaton that our descendents will be able to emit in 2100. Therefore, the person you were lecturing was actually correct about this one point. Scientists wouldn't ever say that we just need to emit 50% less CO2 in order to stabilize temperatures, because that's simply not true.
As usual, I'll have to guess that you're referring to the title of a pop-science article. Next time, read past the title:
"It is wrong to believe that the temperature will remain constant with constant emissions," says Knutti. ... The models show that there is a 75 percent probability that global warming will not exceed two degrees if a maximum of 1000 billion tonnes of CO2 are emitted into the atmosphere from 2000 to 2050. This number seems high, but 234 billion tonnes had already been flung into the atmosphere between 2000 and 2006. If the emission remain at this high level, or even increase, the budget would be exhausted before 2030. The results show that time to act is short. ... This study also concludes that the total amount of CO2 emissions is crucial in terms of how much the earth warms up. The authors summarise a political interpretation in comments in Nature Reports Climate Change3. According to Knutti, "Every tonne of CO2 is one tonne, whether it is emitted today or in fifty years. This is often lost in the tangle of emission targets, certificates and negotiations. The total quantity is what matters, and must be limited, but short-term goals are necessary to see whether we are on the right track." ... The series of studies show that the total quantity of CO2 emission is limited if people want to limit climate change. "With every year of delay, we are using up our quota, losing flexibility, and increasing the probability of dangerous consequences," says Knutti.
Or, look at the picture next to the title. Notice that Knutti's graph of CO2 emissions doesn't just drop in half, because that wouldn't stabilize temperatures. As Knutti stresses, the total amount of CO2 emitted is what's important, which is in this graph is the area under the curve. Knutti's curve has finite area because in hi
Actually, it's because you bore me when you stop talking about physics. Also, you previously seemed to want me to stop copying your statements. But I'm copying all of these right now.
Actually, I'm ignoring it on dumbscientist altogether.
I've fixed the spelling of "viscoscity" and fixed the link in the word "politician" in the permanent version. As I originally intended, it now points to the beginning of the article where last year I said in a popup over the word "politician's": "You have to realize that I view the word 'politician' as a VERY dirty word in order to get the full effect of this sentence".
Erm, E=hf.
Also, you mean momentum is p = h/lambda, right? p=hf is the undergraduate notation for energy.
Because that's from early 1900's quantum theory, not classical electrodynamics. My point is that even in the 1800's, it should've been clear that light has momentum and thus inertia just by examining Maxwell's equations.
That's an interesting definition; I've never heard of it before. Like Einstein, I prefer to call "E/c^2" the "inertia" of light because that's the conceptual breakthrough which resolved the original pesky factor of 4/3 that kept appearing in Lorentz's derivation of "E=mc^2":
And because the em-mass depends on the em-energy, the formula for the energy-mass-relation given by Thomson (1893) and Wien (1900) was m = (4 / 3)E / c2 (Abraham and Lorentz used similar expressions). Wien stated, that if it is assumed that gravitation is an electromagnetic effect too, then there has to be a proportionality between em-energy, inertial mass and gravitational mass. However, it was not recognized that energy can transport inertia from one body to another and that mass can be converted into energy, which was explained by Einstein's mass-energy equivalence.
The idea of an electromagnetic nature of matter had to be given up, however, in the course of the development of relativistic mechanics. Abraham (1904) argued (as described in the preceding section #Lorentz transformation), that non-electrical binding forces were necessary within Lorentz's electrons model. But Abraham also noted that different results occurred, dependent on whether the em-mass is calculated from the energy or from the momentum. To solve those problems, Poincaré in 1905[A 8] and 1906[A 9] introduced some sort of pressure of non-electrical nature, which contributes the amount (1 / 3)E / c2 to the energy of the bodies, and therefore explains the 4/3-factor in the expression for the electromagnetic mass-energy relation.
It also happens to explain the paradox discovered by Poincare regarding conservation of momentum in different frames when using Lorentz transformations to transform between inertial reference frames.
In other words, the reason Einstein is a household name but Lorentz is known only to scientists can be traced back to the fact that Einstein recognized that light has inertia.
First, I just said that as the story goes, Einstein based special relativity on his daydreams and pre-existing problems with the aether. That's the official story, but I find it hard to believe that Einstein really didn't think about the Michelson-Morley experiment during this process. However, that's what Einstein claimed and the story is at least remotely plausible given his stratospheric genius.
Second, I didn't say Michelson and Morley expected it. I just said Einstein claimed to not find it surprising or informative in his development of special relativity, and that aether timeline I linked should provide convincing evidence that the aether had already been shown to be logically inconsistent long before Michelson and Morley started their w
Here the summary implies that previously published GRACE ice mass balance estimates didn't take GIA into account. At first I assumed this ridiculous implication must have been a mistake on Slashdot's part. Then I read the article:
No, previous research didn't ignore (see section 2.2.4) GIA/PGR. These news stories are reporting on a paper by Xiaoping Wu et al. (free PDF). In table 2, Dr. Wu shows that his estimates are half as big as those in papers published separately by Velicogna, Chen et al. and Luthcke et al.
Luthcke et al. corrects for GIA using the ICE-5G model which combines many proxies and other empirical evidence regarding ice history since the Last Glacial Maximum, mantle viscosity and the Earth's various Love numbers. Chen et al. used the similar IJ05 model. Velicogna used multiple independent models to estimate uncertainty in the GIA signal. After reading Dr. Wu's paper, it's clear he never claimed that previous research had ignored or failed to correct for GIA.
That would have been a real surprise, because he wouldn't make a claim that can be disproven simply by skimming the papers he referenced. Nor is he rude enough (or at all, for that matter) to imply that the rest of the GRACE community ignored this important issue. Coincidentally, Dr. Wu worked for my advisor as a postdoc in the 1990s, in the same office that I'm currently using. I met him several months ago at the WP-AGU conference in Taiwan, and as far as I can tell he's overwhelmed by the bizarre attention his paper has gotten from the general public:
Nah.
That link defines the word "gibberish" as I mean it in this context:
What you need to understand is that what you said, while sounding philosophical to the uneducated is gibberish. To a scientist what you said sounds something like "What if what I thought was my hand was actually an ardvaark in disguise".
Sure. Just quote the page numbers and passages (like I did) which support your claim that conservation of energy doesn't apply across very short time scales. Make sure that you're not misinterpreting the concept of quantum foam to support a confused pop-science notion that energy conservation is violated by much slower processes like nuclear decay or anything happening in semiconductors.
I guess I should've mentioned that "I'm heavily skeptical of this claim."
Ironically, the reference I gave to Kolb p157 is the first page of chapter 6... which is called "Baryogenesis." I suppose I should've mentioned (twice) that CP violation is considered along with baryon number violation caused by processes like sphalerons.
That's Mr. Unabomber to you.
Huh? Your customarily vague but authoritative comment which doesn't include an "IANAP" disclaimer will just reinforce the disturbingly common impression that physicists are bullshitting about concepts like inflation and dark matter.
The cosmology course I've mentioned was taught by Dr. Nanopoulos using Kolb's The Early Universe. He pointed out that physicists have known for decades that something like inflation is required to explain the isotropy of the cosmic microwave background radiation. Kolb disusses these topics in chapter 8, though his overview is somewhat dated now. WMAP has since observed temperature fluctuations on the 10^(-5) level, which matches predictions based on modelling quantum fluctuations in the early universe. More precisely, inflation predicts that these fluctuations would deviate slightly from the perfect scale invariance expected in a universe without inflation. After 7 years, WMAP can exclude the possibility of a scale invariant spectrum by more than 3 sigma. The WMAP results also show that the universe is perfectly flat, at least to within the limits of measurement. Inflation isn't necessary for the universe to be perfectly flat, but it's sufficient to explain what may seem like "fine-tuning" at first glance.
That's why physicists think inflation happened, but it's an argument based on how relativistic causality affects the large-scale thermodynamics of the universe, not pressure. Pressure is at least tangentially relevant to almost every physics problem imaginable, though, and inflation is no exception. I've explained that dark energy's negative pressure acts as a kind of anti-gravity. Later, Dr. Stoeger (Jesuit priest, astrophysicist working for the Vatican Observatory) observed that "There is, of course, a much deeper connection between inflation and dark energy. The only way we can really conceive of inflation occurring in the early universe is under the influence of a large amount of vacuum energy, which is a type of dark energy. This dark energy must be quickly transformed into the particles and radiation at the end of inflation. So, it's not at all clear if there is a relationship between the dark energy which drove inflation and the dark energy which we have evidence is driving the gentle acceleration of cosmic expansion now. It may be that the dark energy now may be a remnant of the dark energy left over from the very early universe."
Then there's the problem of heavy exotic particles predicted by most GUT's; the only one I'm familiar with is the magnetic monopole. In my senior year, I took electrodynamics using the standard Griffiths 3rd ed. Page 327 shows how symmetric Maxwell's equations appear in the presence of magnetic monopoles, and Griffiths opines that they "beg for magnetic charge to exist." My fondest memory of that class is problem 8.12 on page 362, along with footnotes 11
In this context, error bars aren't simple numbers; they're actually functions of the temporal smoothing applied. If for some reason you decide to smooth the GCM output and sensor data at only 10 years, the error bars will be large. That's why professional climatologists usually smooth data and model output using ~20 year averages.
More fundamentally, falsification requires proper understanding of the dynamical nature of GCMs. This proposed "falsification" is woefully misguided because modern GCMs are dynamical physical models. If GCMs were simply empirical fits to past temperatures (as many seem to think), it would be meaningful to test the model by discussing temperatures alone. But GCMs don't incorporate timeseries of past temperatures, instead they model the climate based on the physics of forcings such as solar output, volcanic activity, aerosols, and human emissions. In other words, scientists don't develop GCMs to predict global temperatures; instead, GCMs are used to constrain a number of parameters such as (for instance) the equilibrium climate sensitivity and the transient climate response to doubling CO2.
All IPCC scenarios explicitly define the forcings that serve as inputs to the GCMs, and the temperature increase is the output. Since physicists are interested in testing physics rather than trying in vain to predict economic activity which could change CO2 emissions, falsification of any parameter constrained by the IPCC GCM ensemble requires comparing the projected forcings to the actual forcings.
You seem to assume that climate models are central to our understanding of the climate's response to rising CO2 levels. In reality, they're just methods of reducing the error bars on (for instance) modern estimates of the equilibrium climate sensitivity. Compared to pre-computer estimates like Hulbert's 1931 estimate of 4C per doubled CO2, computer models have actually reduced the maximum likelihood value to ~3C. They're also backed up by multiple independent experimental constraints on the climate sensitivity, in contexts where I doubt the problems you've been talking about are relevant.
I'm unaware of any model in computational physics (except perhaps lattice QCD?) which can claim to be completely "physical" in the sense that you seem to want. My own research which inverts gravity to solve for ocean tide heights assumes a constant density of water because GRACE measurements are due to changes in mass, not height directly. Not only do I ignore local seasonal fluctuations in temperature (which affects density), I also ignore local seasonal fluctuations in salinity due to calving glaciers (which also affects density).
Of course, my software is an empirical inversion of data rather than a dynamical physical model like a GCM. But in one sense my reason for neglecting salinity fluctuations (and noting it clearly in the upcoming JGR paper) is probably similar; the "unphysicality" is examined and the error estimated. In my case the error introduced by any reasonable density fluctuation is well beneath the noise floor for my desired observable. In a GCM, salinity likely has a negligible effect on global mean temperature which doesn't justify using it as a prognosticating variable. That would increase the degrees of freedom of the model and thus make it harder to test. Any serious effects of any of these examples of empirical "tuning" should have shown up in comparisons of the models to instrumental and proxy records of forcings and temperature. More likely, they play a minor role in the size of the established error bars.
In a completely different sense, long-term integrations of weather models certainly are thrown off by small errors. The "skill" of a weather prediction does indeed fall off exponentially with time because of oversimplified microphysics in addition to errors in measurements of the initial conditions. But the whole point of taking an initial condition ensemble is to average away this noise. By running dozens of simulations and changing the initial conditions each time, it becomes obvious that even though the weather noise is different, the extrema stay in the same "corridor" which we call the climate. The skill of a climate prediction doesn't fall off exponentially with time because the climate is a boundary condition problem, not an initial condition problem. Instead, the skill of a climate prediction depends primarily on taking a long enough temporal average (in addition to specifying the forcings).
For instance, a credible climate prediction would be "If natural forcings remain within established variances and human emissions of CO2 continue to rise at specified rate X, then the global temperature averaged from 2030-2050 will be higher than the equivalent average from 1990-2010.
On the other hand, a bogus climate prediction would be "The global temperature in 2030 will be higher than in 2010." That's bogus primarily because models have precisely the flaws you're talking about, in addition to our insufficient understanding of ENSO, PDO, NAO, etc turbulent heat transfer phenomena, flaws in projections of human and natural forcings, flaws in our understanding of "slow" feedback mechanisms, flaws in models of cloud formation, not to mention our instruments' finite time series, spatial coverage, spatial/temporal density and limited accuracy.
Like this.
Oops! The "largely due" link should actually point here. This is the main graph from Meehl 2004 as mentioned in the article I'm constantly referencing, which is at the top of my "homepage" as listed here in Slashdot.
Actually, you're both just describing two sides of the same coin (as shown in the second part of my previous comment.) I believe he's comparing our emissions to the annual amplitude, and you're comparing it to the linear trend, which is indeed only influenced by volcanic activity at the 1% level of current human activity as you say.
No time for links, Dr. Jones... but the biosphere actually absorbs ~1/2 of our emissions, based on cross-analyses of Mauna Loa/etc stations, "recent" proxies, tax records on coal/oil/etc, and carbon 12/13 isotope ratios. Whether this absorption will continue at the current percentage is an open question.
Sorry, I need to change "The inefficiency of 1800s era technology merely multiplied the total fossil fuel use by a larger coefficient than today's more efficient tech, but that total fossil fuel use was tiny compared to the demands of the modern world." to "The inefficiency of 1800s era technology just multiplied the total power generation by a larger coefficient than today's (not much) more efficient tech, but the resulting fossil fuel use (and thus corresponding CO2 emissions) were tiny compared to the demands of the modern world."
Neither of you are providing links to peer-reviewed articles, so I won't bother trying to guess what specific event either of you are talking about. But most climate variability pre-1970 can't be "significantly" blamed on anthropogenic CO2 (i.e. "soot") because our population was small and the power generated was miniscule by today's standards. The inefficiency of 1800s era technology merely multiplied the total fossil fuel use by a larger coefficient than today's more efficient tech, but that total fossil fuel use was tiny compared to the demands of the modern world. Various proxies (middle graph) show variability over the last 1000 years, but most of this is explained by natural changes like the solar Maunder Minimum and occasional sustained "statistically significant" changes in volcanic activity (which normally adds aerosols to the atmosphere thus causing a brief "volcanic winter" but the CO2 emitted stays in the atmosphere longer so volcanic activity warms the long term climate). Also, notice that the top graph (the shorter instrumental record) shows no real change from 1800 to 1850, and both absolute temperatures are below the current temperature-- but this is from a period where they don't even bother to provide error bars because there are only a handful of recording stations. If you examine the middle graph (proxy reconstructions) again, you'll note that there's some disagreement about variability on ~30 year timescales, but even the increase around ~1000 CE is consistent among proxy reconstructions, and explained in terms of natural causes.
Remember that climate scientists aren't saying that natural variability doesn't exist. We're just saying that previous and current climate changes have natural causes which are relatively well understood, but the current increase in global average temperature as averaged over ~20 years is at least largely due to anthropogenic causes. Personally, I say this is a good reason to go nuclear. Yesterday.
Also, here's a rough approximation of the heat content of the oceans, troposphere, and stratosphere.