ie. if a photon enters the event horizon at a shallow angle so it has not dropped below the event horizon by very much, then the event horizon is perturbed by a large mass passing close to the black hole, would the photon escape again? And if not, why not? No, it would not escape, because as I said, an event horizon is defined to be a region from which nothing ever escapes. To precisely locate it, you have to know everything about what will happen in the vicinity of the black hole, including everything that will perturb it at any time in the future — only then can you tell which objects will or will not eventually be able to escape.
In many respects, that makes an "event horizon" a very difficult concept to work with, and it means that you can't actually locate an event horizon exactly. There is nothing physically special that happens at an event horizon; it's defined by what may happen infinitely far in the future. For that reason, there are concepts such as "apparent horizons" that are physically possible to locate.
What I'm actually attempting to say is that given a lack of independent confirmation via some other means than gravitional inference, dark matter is on less firm ground than many theories in other areas of physics and astrophysics. I will agree that it's on "less firm ground than many theories in other areas of physics and astrophysics", but I disagree that the evidence for dark matter is weak. It is, by now, quite strong, even if it is indirect.
What would strengthen the case for dark matter is a model in which the gravitationally inferred quantities of dark matter match amounts arrived at by other means, for example. Yes, it would strengthen the case for dark matter even more, but the mere existence of a wide variety of plausible dark matter candidates within frontier particle physics has already strengthened the case for dark matter beyond just astrophysical evidence.
Do you have any evidence to support this supposition? You can't prove it, but it's basically how science works: a theory becomes mainstream when people try to come up with alternatives and fail; eventually, as the body of evidence in favor of the mainstream theory increases, viable alternatives come along less and less frequently.
Back before theories of decoherence were developed (or propagated), you could have said something similar about certain interpretations of QM, and you would have been wrong. That's nonsense. All of the interpretations of QM are physically equivalent to each other, by design; that's why they're interpretations, not theories. (There are a few truly different theories, such as Penrose's objective state reduction, which may be experimentally distinguished from standard QM.) Some interpretations are favored over others in their ease by which they can explain phenomena, but they all make the same predictions. You need a better example than that.
To make my argument more clear. There are many things which control the climate of this planet and many substances which both reflect and absorb infrared radiation other than CO2. Yes, climatologists are aware of this. The carbon cycle, ocean dynamics, solar variation, albedo, greenhouse gases and aerosols, deforestation, and so on. 30 years ago the scientific understanding of these phenomena was uncertain enough (particularly with regard to the GHG/aerosol issue) that scientists couldn't tell whether there was global warming or global cooling. They have better understanding now, and better data. While there is still a great deal of uncertainty, it has now been narrowed down to "warming", or "more warming". And it is also now known that humanity's atmospheric emissions are responsible for the majority (although not all) of the recent warming. But yes, there is still a lot of scientific debate about the severity of the warming, because there is still a lot of uncertainty about how much of it will occur.
My biggest gripes come from the way the data was collected and the amount of thought that went into finding errors or mis-interpretations of the data we gather from tree rings and ice cores. There are wide margins of error in how that data is compiled and interpreted. There are margins of error, but they are quantified and taken into account. You also imply that little thought goes into calculating those errors or interpreting data, which is absurd. There are scientists whose entire careers consist of nothing but calibrating tree ring or ice core data.
This coupled with the fact that our science of climatology is in it's infancy and our computer models are crude at best, I don't think we can 100% rely on computer models and incomplete data to form an opinion. We can't rely on a single prediction of any one model. We can, however, rely reasonably well on the range of outcomes that come out of all the models as their input assumptions are varied over the range of plausible possibilities. This kind of quantification of uncertainty has become possible in the last 5-10 years or so.
Even trying to improve the environment can have unintended consequences and for us to play god with nature right now is folly. A do-nothing argument. Even the very wise cannot see all ends, but that's not an excuse for inaction. You have to do the best you can with the knowledge you have, and skeptics will always claim "unintended consequences" no matter how much information we have.
Incidentally, the decrease in sulfur emissions is not largely responsible for the current warming.
The earth has a way of checking and balancing itself. If the system becomes unstable it self corrects in most cases. We have to get used to the idea of a planet who's climate changes. Another do-nothing argument. Yes, the climate changes, but we don't have to help it change in ways that are detrimental to us.
We are the single most adaptable single species on the planet. We have lived in all environments on this planet even without technology. There is no question we can survive global warming. It's just a matter of what the cost will be, which depends both on the amount of warming, and its rate. The more warming that happens rapidly, the more expensive it is to try to adapt. Our current civilization is optimized for particular conditions, and when those conditions change, there is a cost of readjustment. (e.g., due to relocation of some low-lying populations, or a change in good food-producing regions.)
Water is a buffer. If more ice melts, more water enters the climate and buffers the effects. That's a non sequitur. Nobody claims that the Earth will continue to warm forever, just that it will continue to warm enough to be a concern.
The problems with the "the Sun is globally warming Mars and therefore Earth theory" is twofold:
1. The warming on Mars is regional, not global and 2. As you note, solar irradiance has not increased during this regional warming (it has actually decreased)
I would like to know the mechanism by which "sunspots and solar flares" can significantly warm a planet when the actual energy being received by the Sun does not increase.
But that aside, the regional warming on Mars (near its South Pole) is not due to solar irradiance, and is likely due to the local topography inducing transient climate instabilities. See here for more discussion.
As I said, there is very little you can conclude from the mere observation "temperatures on Earth and Mars are rising", because their climate systems are utterly different. The Earth's climate is modulated by ocean dynamics, greenhouse gases, and all kinds of effects that don't exist on Mars. Those effects can either cause additional warming or cooling, and you have to do careful modeling to tell which is the case.
Further, if you read the link I gave, you would see that Mars has received less solar irradiance during the period that this supposed "Martian global warming" has occurred. Moreover, said "global warming" is actually most likely only a regional warming, and almost certainly unrelated to solar irradiance either increasing or decreasing.
In other words, pretty much every aspect of your Mars argument is wrong.
That being said, solar variations have contributed to global warming over the 20th century; no one has claimed that solar output hasn't produced a temperature increase. The point is, as I said originally, they aren't big enough to be responsible for the majority of the global warming that has taken place since the latter half of that century.
See the 2001 IPCC report on THC changes: "However, even in models where the THC weakens, there is still a warming over Europe. For example, in all AOGCM integrations where the radiative forcing is increasing, the sign of the temperature change over north-west Europe is positive (see Figure 9.10)." (The radiative forcing part refers to an assumption that greenhouse gas concentrations continue to increase.)
Well, let's see. Clicking on the first few links, the first page estimates warming due to solar forcing to be 23% that of GHGs, which is in agreement with the papers I cited. It doesn't give a reference to the any peer reviewed publications, however (although it does cite some generic studies in which that number might be found). The second page cites a non-peer reviewed conference paper by a petroleum geologist with no climatology background, and is published in a book by an association of petroleum geologists. The third page is a web-published analysis by an astronomer. The fourth page has nothing useful. The fifth page states that climate change (of unspecified magnitude) "might result" due to solar variations, but gives no calculation. The sixth page states that while solar variations do alter the climate, GHG emissions are needed to explain global warming in the late 20th century (but no references are given). The seventh page is Wikipedia, which cites both of the papers I mentioned (published in Nature and J. Climate. Its other references also agree with my claims with regard to late-20th century warming. The eighth page cites a 2003 study in Geophysical Research Letters which measures solar variations. The page states that solar variation can be important to climate on century time scales, and quotes the author as claiming it would have a "significant effect" on climate, but it gives no estimate of the effect on climate and neither does the cited paper. The ninth page is a 2002 Science review and concludes nothing about solar variation on global warming. The tenth page, written in 2000, discusses some paleological relationships between solar variation and climate but concludes nothing about global warming.
Could you please cite a paper published in the last 5 years in a climate-related journal (or something non-climate related but respectable, like Nature, Science, PNAS, etc.) which claims that "variation in the sun's energy output has far more impact on our climate than the tiny [sic] increases of various chemicals"?
My point isn't that I blame solar activity for SURE, but that the whole Cause and Effect thing COULD BE still in doubt. All the studies I've seen in the last 5 years have concluded that solar variation is not responsible for modern global warming (the largest figure I've seen attributes at most 1/3 of the warming to solar forcing, and states that the true effect is probably closer to their lower bound of 1/6 of the warming). Earlier than 5 years ago, there wasn't much work on it, and most of the few studies that were done were inconclusive. On what basis are you claiming that "the whole cause and effect thing `could be' still in doubt"? Any scientific claim can be wrong in principle, but the weight of the evidence appears to have turned against your claim, so I would like to know on what basis you insist that it's still up in the air.
I think you need to reconsider that statement in light of the iPhone's price and feature set. It may be good at making phone calls, but it is in the same class of device as smart phones, not regular mobiles.
I would like to see a side by side comparison of the increase in tempature on mars and earth. That wouldn't tell you very much, considering how drastically different the climate systems on the two planets are (see, e.g., here).
I think this paper my seem very weak.. Do you have a scientific reason for thinking that, or is it just because you disagree with its conclusion?
What "other studies" are those, and what is their response to the recent studies which indicate the opposite, such as the one I cited, or this one (PDF link)?
0.4 degrees is a big deal as far as climate is concerned, and it certainly is a significant difference when you consider the rate at which the climate changed in the last 50 years, compared to the rate at which it has changed in the past.
OK, so we all agree that GW is caused by an increase in planetary heat... AND the planet gets its heat from.... the Sun. Believe it or not, climatologists have studied the impact of variations in solar output. They do have some influence in climate, but not enough to explain the global warming trend (PDF link to paper).
These guys really like to ignore the Medieval Warming Period, where temperatures globally were much warmer than they are today. That's not actually true. In the last 50 years, the global mean temperature has surpassed the Medieval Warm Period.
Look closely at Gore's CO2 chart and you'll notice that the CO2 levels can lag the temperature rises. If CO2 was *causing* temperature to rise, CO2 level rises would precede temperature rises. It's a positive feedback cycle. CO2 doesn't start the warming, but if enough warming happens, a bunch of CO2 is liberated from the oceans and amplifies the warming already underway. Warming -> more CO2 -> more warming -> more CO2 ->..., until the system saturates, and other factors stop the warming.
CO2 is a heat trap as your post suggests (known scientific model...) but water vapor beats the hell out of it in that regard. Rising temperatures lead to more water vaporizing. When water vaporizes, it forms clouds which increase the earth's albedo which reduces insolation which reduces temperature. Climate change is a hell of a lot more complicated than "rising CO2 levels equal higher temperatures." You're right about that, but temperatures do rise for quite a bit before reduced insolation can reverse it.
Climatology models run on much longer cycles [than meteorology models] and so get much less feedback as to their accuracy. Moreover, climatologists are building their models on very sparse, inaccurate data. However, climate models are not nearly as sensitive to error as are meteorology models, which is why you can run them longer. Predicting global climate over a span of decades requires less data and less precision than does predicting local weather over a span of days. Both types of models have a prediction horizon beyond which their forecasts are no good; for meteorology models, it's on the order of a week, and for climate models it's on the order of decades to a century.
Climate is not weather.
Despite fewer feedback cycles and lousy data, Climatologists claim to be able to forecast global temperatures to the fraction of a degree. It's nonsense and yet a good number of slashdot denizens seem to believe it. If it's nonsense, you have not presented any argument in support of that claim. To what quantitative extent are the model predictions sensitive to the size of the data set and of the error bars? That is why you have to sit down and crunch numbers, in the form of a sensitivity analysis, which is what climatologists actually do — things like running the models with mock data to simulate plausible observations that we could have gotten. As it turns out, global temperatures can be predicted roughly out to a century — making assumptions, however, about how greenhouse gas emissions will continue — but the forecast accuracy at that time is not "a fraction of a degree", but rather a degree or more. Over shorter time scales, you can get fractional-degree accuracy.
Will someone please explain to me how in the past 30 years we've had a complete 180 on the outlook of the climate? In short: "we" haven't. In the 1970s, climatologists knew that there was a natural cooling trend, but they couldn't estimate the contribution of human activity to tell whether it would offset that trend. At the time, the media hyped it up as "global cooling", despite the fact that climatologists were saying that they didn't have enough data to extrapolate future trends. Over the course of the decade, they continued to gather data, and found that human activity would in fact contribute to an overall warming trend.
Some delving into what scientists and media were actually saying at the time can be found here and here (the latter discusses the Newsweek article).
There may have been individual years warmer than 2006 in the Medieval Warm Period, however there is no record accurate enough to say. What can be said was that the Medieval Warm period was not as warm, as a whole, as the climate has been in the last 50 years.
Of course, "ever" is a ridiculous word to use; temperatures were much warmer back in the Cretaceous. The present climate, however, is overall probably warmer than it has been in about 12,000 years (at the Holocene maximum).
The polar caps have been shrinking overall, if by "shrinking" you mean "occupying fewer cubic meters in volume". Whether they are also shifting is another matter.
As the AC pointed out, both effects happen and enhance each other. Greenhouse CO2 makes the Earth warmer, which releases more CO2 from the ocean, amplifying the warming trend, which in turn releases even more CO2, in addition to the continuing increases in atmospheric CO2 due to human emissions (under business-as-usual scenarios).
The Gulf stream will not stop as a result of global warming; it is wind-driven. The North Atlantic thermohaline circulation (part of the Great Conveyor) may stop, although the odds are thought to be somewhat low (less than 30%). That would cool northern Europe relative to the rest of the world, but in the face of overall global warming, Europe could still end up getting warmer. A shutdown of the THC could have other consequences, however (see the aforementioned Wikipedia articles).
There is a nice recent RealClimate post on the anomalously warm U.S. winter this year, discussing whether it can be attributed to El Nino or to global warming. (The short answer: El Nino plays a large role this year, but global warming is still making winters warmer on average, although you can't really attribute anomalous warmth in any given year to climate change — due to statistical fluctuation, you can only see its definite effect over longer time periods.)
For those who point to the Colorado blizzard as evidence against global warming, they also note that Colorado temperatures have also been warmer than usual. You don't need very cold weather for a blizzard; you just need freezing weather — which will continue to happen even with global warming — and a lot of moisture in the air. Interestingly, warmer air carries more moisture, so some regions may experience more precipitation on average as the Earth continues to warm. However, a particular storm certainly cannot be attributed to global warming.
So one question is whether we can introduce invisible matter into the system in such a way that the theory of gravity in question will work. The fact that the answer seems to turn out "yes" does not in any way demonstrate that the invisible matter actually exists.
It doesn't prove it, but it is strong evidence in its favor, because of the number of independent phenomena that dark matter are able to explain. You continue to dismiss this point as if it is unimportant. There is no reason why introducing dark matter should be consistent with all of those observations.
If a dark matter prediction fails, there's a high probability that it'll be possible to adjust the dark matter distribution to make it succeed.
Dark matter is not as adjustable as you think it is. Humans don't determine how dark matter distributes; it has to distribute in a way that is consistent with the laws of gravity. What we can mostly adjust in theory is how much of it was produced in the Big Bang, and some statistical aspects of how it was distributed at that time. The large-scale structure of galaxies didn't have to be consistent with what the CMBR tells us about dark matter's distribution when it was produced, but it is. The distribution of dark matter within individual galaxies didn't have to be consistent with the distribution necessary to seed the large-scale structure, but it is.
But actually, you're right, but not for the reasons you think. Dark matter is now consistent with a large amount of observational evidence, so there is a high probability it will remain consistent with new evidence simply because some dark matter candidate is likely to be correct. That was once not the case: there are plenty of ways that galaxies could have rotated, or the CMBR spectrum could have fluctuated, that could not have been explained by dark matter. It turns out, however, that they rotated, fluctuated, etc. in ways that are compatible with dark matter.
If the history of science teaches us anything, it's that it's very difficult to judge such things prior to the right discovery being made.
It can be, but on the other hand, historically it's rarely the case that under intensive study, evidence continues to mount for an explanation that ultimately turns out to be largely incorrect. You act as if the evidence counts for nothing.
But there's no independent theory which dictates the quantity and distribution of those particles in a way that supports dark matter, without first assuming dark matter's requirements.
That's wrong. There are a number of such theories which make no assumptions about dark matter's requirements. We don't know which of them may be correct. (We know many that are incorrect.)
If there were, you wouldn't need to point to a whole pantheon of possible particles, and the theory of dark matter would be stronger.
The "pantheon of possible particles" strengthens the case for dark matter, not weakens it. What it tells us is that dark matter candidates are naturally found in most of the most plausible extensions of the Standard Model (as well as one which is found in the Standard Model itself). That is not because they were introduced in order to have any of the requirements for dark matter. The Standard Model axion was introduced to solve the strong-CP problem. The neutralino was introduced along with supersymmetry to help solve the hierarchy and grand unification problems. Kaluza-Klein scalars were introduced with extra dimensions for purposes of unification. Nobody invented any of these to solve any astrophysical problems, yet most of the outstanding problems in particle physics end up implying particles that behave like dark matter. We would thus be led to introduce dark matter even if we hadn't made any astrophysical observations — yet another independent line of argument which leads to dark matter.
Oops, by "Fingers of God" I thought you were referring to a particular filamentary structure that I've heard referred to by that name. You may, however, have been referring to this phenomenon, which also does not imply that we are at the center of the universe (as noted in that article); an observer anywhere in an isotropic universe will observe radial elongation in redshift space towards themselves.
I didn't just rant against the conventional theory without justification. The problem isn't just that the theory is complicated, but that there is a much less complicated theory that explains everything better. Except that there isn't. That's the point. There is no EU/plasma theory of the vast majority of observations that lead to dark matter. Galactic rotation curves are the only phenomena that they even attempt to explain, that is only at a qualitative level, and most importantly, there is no explanation for why we don't observe the fields that they claim exist and are responsible for the observed rotation curves.
How about the fact the Electric/Plasma theory predicts cosmological occurrences better than the traditional one Except that it actually doesn't. It doesn't account for the CMBR anisotropies, it doesn't reproduce the supernova redshift/luminosity relations, it doesn't yield correct nucleosynthesis, it doesn't correctly explain cosmological redshifts, and so on.
Never mind the fact that the current theory isn't even testable through controllable experiments in a lab or even on a computer (excluding self-fulfilling experiments), It is testable both through astrophysical observations and computer simulation, and some models are testable in particle experiments. (Well, all of them are in principle, but only some of them are within reach of current technology.)
The traditional theory doesn't work (even after extensive tweaking) Sure, if by "doesn't work" you mean "passes dozens of experimental tests including galactic rotation curves, the motions of satellite dwarf galaxies, gravitational lensing, measurements of galactic gas temperatures, anisotropies in the CMBR, the rate and structure of large-scale cosmological structure formation, and so on".
so it should be replaced by one that does work (Electrical/Plasma) Sure, if by "working" you mean "making few predictions, most of which are wrong".
And it does so without trying to isolate us from the rest of the universe (no electricity in between celestial bodies), There are plasma currents and such within galaxies, but they do not account for galactic rotation curves.
and also without shitting on Galileo and putting us (as a solar system or galaxy this time) back at the center of the universe (as the current model seems to with its extension 13-odd billion light-years spherically around us and the Fingers of God pointing at us from every direction). The current model does not put us in the center of the universe. In fact, Big Bang cosmology does exactly the opposite.
Incidentally, the "Fingers of God" do not point to us from "every direction", but from two directions, and furthermore, the universe is highly isotropic on scales much larger than those structures.
Slashdot Mirror
In many respects, that makes an "event horizon" a very difficult concept to work with, and it means that you can't actually locate an event horizon exactly. There is nothing physically special that happens at an event horizon; it's defined by what may happen infinitely far in the future. For that reason, there are concepts such as "apparent horizons" that are physically possible to locate.
Incidentally, the decrease in sulfur emissions is not largely responsible for the current warming. The earth has a way of checking and balancing itself. If the system becomes unstable it self corrects in most cases. We have to get used to the idea of a planet who's climate changes. Another do-nothing argument. Yes, the climate changes, but we don't have to help it change in ways that are detrimental to us. We are the single most adaptable single species on the planet. We have lived in all environments on this planet even without technology. There is no question we can survive global warming. It's just a matter of what the cost will be, which depends both on the amount of warming, and its rate. The more warming that happens rapidly, the more expensive it is to try to adapt. Our current civilization is optimized for particular conditions, and when those conditions change, there is a cost of readjustment. (e.g., due to relocation of some low-lying populations, or a change in good food-producing regions.) Water is a buffer. If more ice melts, more water enters the climate and buffers the effects. That's a non sequitur. Nobody claims that the Earth will continue to warm forever, just that it will continue to warm enough to be a concern.
The problems with the "the Sun is globally warming Mars and therefore Earth theory" is twofold:
1. The warming on Mars is regional, not global
and
2. As you note, solar irradiance has not increased during this regional warming (it has actually decreased)
I would like to know the mechanism by which "sunspots and solar flares" can significantly warm a planet when the actual energy being received by the Sun does not increase.
But that aside, the regional warming on Mars (near its South Pole) is not due to solar irradiance, and is likely due to the local topography inducing transient climate instabilities. See here for more discussion.
As I said, there is very little you can conclude from the mere observation "temperatures on Earth and Mars are rising", because their climate systems are utterly different. The Earth's climate is modulated by ocean dynamics, greenhouse gases, and all kinds of effects that don't exist on Mars. Those effects can either cause additional warming or cooling, and you have to do careful modeling to tell which is the case.
Further, if you read the link I gave, you would see that Mars has received less solar irradiance during the period that this supposed "Martian global warming" has occurred. Moreover, said "global warming" is actually most likely only a regional warming, and almost certainly unrelated to solar irradiance either increasing or decreasing.
In other words, pretty much every aspect of your Mars argument is wrong.
That being said, solar variations have contributed to global warming over the 20th century; no one has claimed that solar output hasn't produced a temperature increase. The point is, as I said originally, they aren't big enough to be responsible for the majority of the global warming that has taken place since the latter half of that century.
See the 2001 IPCC report on THC changes: "However, even in models where the THC weakens, there is still a warming over Europe. For example, in all AOGCM integrations where the radiative forcing is increasing, the sign of the temperature change over north-west Europe is positive (see Figure 9.10)." (The radiative forcing part refers to an assumption that greenhouse gas concentrations continue to increase.)
Could you please cite a paper published in the last 5 years in a climate-related journal (or something non-climate related but respectable, like Nature, Science, PNAS, etc.) which claims that "variation in the sun's energy output has far more impact on our climate than the tiny [sic] increases of various chemicals"? My point isn't that I blame solar activity for SURE, but that the whole Cause and Effect thing COULD BE still in doubt. All the studies I've seen in the last 5 years have concluded that solar variation is not responsible for modern global warming (the largest figure I've seen attributes at most 1/3 of the warming to solar forcing, and states that the true effect is probably closer to their lower bound of 1/6 of the warming). Earlier than 5 years ago, there wasn't much work on it, and most of the few studies that were done were inconclusive. On what basis are you claiming that "the whole cause and effect thing `could be' still in doubt"? Any scientific claim can be wrong in principle, but the weight of the evidence appears to have turned against your claim, so I would like to know on what basis you insist that it's still up in the air.
Text input is via a software keyboard. You can see it on Apple's iPhone page in some of the demos.
I think you need to reconsider that statement in light of the iPhone's price and feature set. It may be good at making phone calls, but it is in the same class of device as smart phones, not regular mobiles.
What "other studies" are those, and what is their response to the recent studies which indicate the opposite, such as the one I cited, or this one (PDF link)?
0.4 degrees is a big deal as far as climate is concerned, and it certainly is a significant difference when you consider the rate at which the climate changed in the last 50 years, compared to the rate at which it has changed in the past.
Climate is not weather. Despite fewer feedback cycles and lousy data, Climatologists claim to be able to forecast global temperatures to the fraction of a degree. It's nonsense and yet a good number of slashdot denizens seem to believe it. If it's nonsense, you have not presented any argument in support of that claim. To what quantitative extent are the model predictions sensitive to the size of the data set and of the error bars? That is why you have to sit down and crunch numbers, in the form of a sensitivity analysis, which is what climatologists actually do — things like running the models with mock data to simulate plausible observations that we could have gotten. As it turns out, global temperatures can be
predicted roughly out to a century — making assumptions, however, about how greenhouse gas emissions will continue — but the forecast accuracy at that time is not "a fraction of a degree", but rather a degree or more. Over shorter time scales, you can get fractional-degree accuracy.
Some delving into what scientists and media were actually saying at the time can be found here and here (the latter discusses the Newsweek article).
There may have been individual years warmer than 2006 in the Medieval Warm Period, however there is no record accurate enough to say. What can be said was that the Medieval Warm period was not as warm, as a whole, as the climate has been in the last 50 years.
Of course, "ever" is a ridiculous word to use; temperatures were much warmer back in the Cretaceous. The present climate, however, is overall probably warmer than it has been in about 12,000 years (at the Holocene maximum).
The polar caps have been shrinking overall, if by "shrinking" you mean "occupying fewer cubic meters in volume". Whether they are also shifting is another matter.
As the AC pointed out, both effects happen and enhance each other. Greenhouse CO2 makes the Earth warmer, which releases more CO2 from the ocean, amplifying the warming trend, which in turn releases even more CO2, in addition to the continuing increases in atmospheric CO2 due to human emissions (under business-as-usual scenarios).
The Gulf stream will not stop as a result of global warming; it is wind-driven. The North Atlantic thermohaline circulation (part of the Great Conveyor) may stop, although the odds are thought to be somewhat low (less than 30%). That would cool northern Europe relative to the rest of the world, but in the face of overall global warming, Europe could still end up getting warmer. A shutdown of the THC could have other consequences, however (see the aforementioned Wikipedia articles).
Interestingly, the effect of regional nuclear conflicts in the near future upon the global climate has been studied: see here and here.
There is a nice recent RealClimate post on the anomalously warm U.S. winter this year, discussing whether it can be attributed to El Nino or to global warming. (The short answer: El Nino plays a large role this year, but global warming is still making winters warmer on average, although you can't really attribute anomalous warmth in any given year to climate change — due to statistical fluctuation, you can only see its definite effect over longer time periods.)
For those who point to the Colorado blizzard as evidence against global warming, they also note that Colorado temperatures have also been warmer than usual. You don't need very cold weather for a blizzard; you just need freezing weather — which will continue to happen even with global warming — and a lot of moisture in the air. Interestingly, warmer air carries more moisture, so some regions may experience more precipitation on average as the Earth continues to warm. However, a particular storm certainly cannot be attributed to global warming.
So one question is whether we can introduce invisible matter into the system in such a way that the theory of gravity in question will work. The fact that the answer seems to turn out "yes" does not in any way demonstrate that the invisible matter actually exists.
It doesn't prove it, but it is strong evidence in its favor, because of the number of independent phenomena that dark matter are able to explain. You continue to dismiss this point as if it is unimportant. There is no reason why introducing dark matter should be consistent with all of those observations.
If a dark matter prediction fails, there's a high probability that it'll be possible to adjust the dark matter distribution to make it succeed.
Dark matter is not as adjustable as you think it is. Humans don't determine how dark matter distributes; it has to distribute in a way that is consistent with the laws of gravity. What we can mostly adjust in theory is how much of it was produced in the Big Bang, and some statistical aspects of how it was distributed at that time. The large-scale structure of galaxies didn't have to be consistent with what the CMBR tells us about dark matter's distribution when it was produced, but it is. The distribution of dark matter within individual galaxies didn't have to be consistent with the distribution necessary to seed the large-scale structure, but it is.
But actually, you're right, but not for the reasons you think. Dark matter is now consistent with a large amount of observational evidence, so there is a high probability it will remain consistent with new evidence simply because some dark matter candidate is likely to be correct. That was once not the case: there are plenty of ways that galaxies could have rotated, or the CMBR spectrum could have fluctuated, that could not have been explained by dark matter. It turns out, however, that they rotated, fluctuated, etc. in ways that are compatible with dark matter.
If the history of science teaches us anything, it's that it's very difficult to judge such things prior to the right discovery being made.
It can be, but on the other hand, historically it's rarely the case that under intensive study, evidence continues to mount for an explanation that ultimately turns out to be largely incorrect. You act as if the evidence counts for nothing.
But there's no independent theory which dictates the quantity and distribution of those particles in a way that supports dark matter, without first assuming dark matter's requirements.
That's wrong. There are a number of such theories which make no assumptions about dark matter's requirements. We don't know which of them may be correct. (We know many that are incorrect.)
If there were, you wouldn't need to point to a whole pantheon of possible particles, and the theory of dark matter would be stronger.
The "pantheon of possible particles" strengthens the case for dark matter, not weakens it. What it tells us is that dark matter candidates are naturally found in most of the most plausible extensions of the Standard Model (as well as one which is found in the Standard Model itself). That is not because they were introduced in order to have any of the requirements for dark matter. The Standard Model axion was introduced to solve the strong-CP problem. The neutralino was introduced along with supersymmetry to help solve the hierarchy and grand unification problems. Kaluza-Klein scalars were introduced with extra dimensions for purposes of unification. Nobody invented any of these to solve any astrophysical problems, yet most of the outstanding problems in particle physics end up implying particles that behave like dark matter. We would thus be led to introduce dark matter even if we hadn't made any astrophysical observations — yet another independent line of argument which leads to dark matter.
Dark matter theorie
Oops, by "Fingers of God" I thought you were referring to a particular filamentary structure that I've heard referred to by that name. You may, however, have been referring to this phenomenon, which also does not imply that we are at the center of the universe (as noted in that article); an observer anywhere in an isotropic universe will observe radial elongation in redshift space towards themselves.
Incidentally, the "Fingers of God" do not point to us from "every direction", but from two directions, and furthermore, the universe is highly isotropic on scales much larger than those structures.