Hmm, Now I am wondering why the increases COsub2 FOLLOWED the periods of global warming in the past according to the ice core samples. There is a mutual positive feedback between temperature and CO2 over time scales of about a millennium. In hundreds of years we will probably see a lagged non-anthropogenic CO2 rise resulting from our current global warming, by similar mechanisms. See more here.
But when you come here, that is, interface with the public, there is post after post explaining how the human race is going to drown, and "we have to do something", and so on and so forth. [...] And of course the government uses it as a means to keep the citizens focused on anything but the reaming they're getting from the legislature, along with the other big three scare tactics, terrorism, pedophilia, and immigration. I don't know what countries you may be referring to, but if you think that the current U.S. administration has been drumming up "the human race is doomed" global warming hysteria, you might want to recheck your facts.
Exactly - it is an isolated system, except it has the sun in common. That's your "diddly." This is wrong for many reasons, which were explained in the links I gave, if you had bothered to read them.
The warming on Mars does not correlate with any change in solar intensity. In fact, Mars has warmed while solar intensity dropped. If that weren't enough, the change in intensity of the Sun is nowhere near large enough to produce the observed temperature changes on Mars.
The links I gave describe theories of Martian warming that are actually plausible.
Furthermore, the change in intensity of the Sun has not corresponded in either timing, rate, or magnitude with the warming on Earth. (See here.) Even if solar output were responsible for the warming on Mars, it's not responsible for the warming on Earth.
The idea that Martian warming tells us something about the Earth's climate is, in short, completely retarded and only promulgated by people who don't know anything about either planet. Seriously, if you want to argue against anthropogenic global warming, you can use arguments that are much less embarrassing to your side. Heck, I could argue your side better than you have.
It means that using historical CO2 increases as flags for impending warming is an intellectually bankrupt technique. Of course it means no such thing. Historical CO2 increases did cause substantial warming.
The assertion that CO2 is forcing our current very, very minor temperature change The current temperature change is not "minor" when compared to the last thousand years, its rate is much greater than anything we have seen in the past, and it will continue to accelerate over this century.
may or may not be true to some unknown extent, It is true to a rather known extent, your denial notwithstanding.
however, we know that CO2 hasn't done any such thing in the past despite being quite high in post-warming periods, On the contrary, CO2 is responsible for most of the warming in the ice age cycle; the deglaciation persists for far longer than the Sun's forcing in the Milankovitch cycles, due to the increased CO2 liberated by the initial deglaciation. Which was also explained in the references you didn't bother to read.
In other words, as the surface warms for any reason, the water vapor cycle increases the amount of cooling. This establishes a negative feedback, countering warming trends. Actually, the net effect of water vapor feedback does to climate is exactly the opposite, because you have neglected the greenhouse effect of the water vapor, which is quite large and in fact at least doubles the amount of warming due to CO2's greenhouse effect alone.
Perhaps if you read a basic undergraduate textbook on climate science, you would understand this. I recommend David Archer's book.
Those seem like interesting charts. What is the source study? The page doesn't say, See section 9.4 of the IPCC 4th Assessment Report (Working Group 1).
Most climate predictions I have seen have failed miserably at any edge cases, such as in the arctic and with regard to predicting sea level rise, melt in Greenland, and so on. The Arctic is ok with temperature, but so-so with precipitation, and the current GCMs don't have fully dynamical ice sheet models integrated into them yet. Dynamical ice and aerosol/cloud feedbacks are the big frontiers right now. Sea level rise is not bad but has been somewhat underestimated so far.
Take volcano eruptions. One nice big one and this whole global warming trend could be set back 100 years. No. The particulate matter and aerosols from even a huge volcanic eruption drop out of the atmosphere within a few years.
You'll note the dead silence at the news that Mars is warming just as fast (or faster), and by just as much, as the Earth is. Which has diddly squat to do with global warming on Earth (here and here).
You'll note that on earth, historically speaking, CO2 rises lag warm periods, not lead them. Which has diddly squat to do with the fact that CO2 is now forcing the temperature change due, instead of vice versa (here).
You'll also note that the evaporative cooling cycle - water vapor, rain, etc . - runs at many times the speed of the CO2 warming cycle and is temperature sensitive so that a warmer environment will make it run even faster. I have no idea what you are trying to imply by that.
And of course, it is important to observe that the predictions of the climate models have been very, very poor, even completely failing in some regions. In point of fact, climate model predictions of things like global temperatures are not at all bad (here).
If you'd like to discuss mitigation, feel free to start a thread on that. In the meantime, the fact that such obviously wrong arguments such as stonecypher's keep getting modded up shows that there is much more work to be done educating people on attribution/causation. You can't get people to the table on solutions when they won't even admit there's a problem.
One appropriate one would do. Foukal et al. also found no evidence for any non-brightening solar effects on climate, you know.
Also, it'd be nice if you'd defend the claims you're being asked to defend, instead of the ones you feel comfortable hiding behind. I did defend them. You, by contrast, have not even cited any peer reviewed literature supporting your claim, despite insisting on such citations from everyone else in this thread. It's really rather pathetic.
And before you waste your time ranting, please remember that what I was talking about was the Sun's magnetic field, not its luminosity. I cannot "remember" that you were talking about the Sun's magnetic field, because you said nothing about the Sun's magnetic field. You said only, "I do also believe that our "Global Warming" is just another planetary cycle of which has been occurring for million/billions of years prior to the existence of the first human. Actually, it's primarily solar." Perhaps you may have mentioned the Sun's magnetic field somewhere else in the thread, but it's not my responsibility to read every post you've ever written in order to to read between the lines of your missing justifications.
But now that you bring it up, there is no evidence for any "planetary cycle" involving the Sun's magnetic field which has been occurring for million/billions of years. At best, there is the 11-year solar cycle, which not even contrarians claim is what is responsible for global warming.
I challenge you to produce published data supporting the existence of such a cycle.
The magnetic field determines the solar wind, which in turn governs cloud cover through the suppression of cosmic rays. Cloud cover comes into solar heating a hell of a long time beore greenhouse gasses do. I challenge you to produce published data supporting the existence of any declining trend in cosmic ray incidence that corresponds in timing, rate, and magnitude with the trend of global temperatures over the last 40 years.
There is no evidence that cosmic rays have any significant influence on cloud cover, let alone on climate. If you're tempted to cite a certain author featured in the Global Warming Swindle documentary you seem to take on faith, please note that (a) he did not actually show a correlation between cosmic rays and climate, and (b) then read Damon and Laut (2004). I could point you to many other criticisms on RealClimate, but since you seem to feel that publication is more important than the actual scientific arguments involved, I won't bother.
Er. That review agrees with me. Have you even read it? Yes. Have you? The very abstract states,
"The variations measured from spacecraft since 1978 are too small to have contributed appreciably to accelerated global warming over the past 30 years. In this Review, we show that detailed analysis of these small output variations has greatly advanced our understanding of solar luminosity change, and this new understanding indicates that brightening of the Sun is unlikely to have had a significant influence on global warming since the seventeenth century."
Please stop saying things like "massive amounts of blah blah." Either cite it or it doesn't exist. No, I am not going to cite every climate paper that exists. I already referred you to the most comprehensive review on the subject, which does NOT agree with you. Furthermore, the RealClimate links have plenty of references as well that you are welcome to read.
and it becomes clear from your reference to RealClimate that you confuse the personal blogs of individuals with actual science. It is quite clear that you would like to forget that the RealClimate authors are scientists and, if you bother to read them, back up their claims with the citations you so desperately crave.
I note, of course, that you have not cited any evidence of YOUR claims.
All you have discovered is that CO2 is going up. That it happened while we were in the industrial growth phase does not mean that we created it. The fact that we can see the isotopic signature of fossil fuel burning in the atmospheric CO2, in quantities that correspond well with the actual increase in CO2, is a pretty obvious clue. RealClimate has a whole series of essays on this topic, you could try searching their site for "CO2" and "attribution" or something like that.
You'll find for example that the vast bulk of those increases occur after Mount Saint Helens, Mount Pinatubo, Cerro Hudson, El Chichon, Ksudach or Novarupta. I can't believe that you get modded up when you make ridiculous claims like this. Volcanic emissions of CO2 are directly measurable and tiny (and do not contain that telltale isotopic signature that we see in the atmosphere).
Besides, why are you even arguing about what's responsible for CO2 levels? I thought It's All the Sun.
We've had several volcanoes commit a tremendous amount of CO2 to the atmosphere lately, as I've now mentioned several times in several places. I challenge you to justify that claim with published data.
The total CO2 output of all the volcanoes in the world in any given year is still less than 2% of annual anthropogenic emissions.
You are probably getting CO2 confused with aerosol precursors.
There are more than a dozen things on this planet that regularly put out more CO2 than we do. That's kind of a red herring, just like the wingnuts who like to point out that more of the greenhouse effect is due to water vapor than CO2.
As the previous poster pointed out, there are large non-anthropogenic sources of CO2, but until recently they have been essentially balanced by non-anthropogenic sinks of CO2, so that net CO2 concentrations remained pretty much constant on timescales of millennia. We are now sourcing CO2 at a much greater rate than it can be sunk, leading to a rapid rate of accumulation.
Out of curiosity, what do you believe is responsible for the current rapid increase in CO2 concentrations?
They were until 1983, and our CO2 output has not increased much since then (sure we're growing, but we're also becoming more efficient.) I challenge you to justify that claim with published data.
Not only is that not true, it's also not as relevant as you would have it appear: even if our CO2 output leveled off (which it most definitely has not), it would still continue accumulate in the atmosphere because we would still be sourcing it faster than it can be sunk. (Unless we go in for sequestration in a big way.)
Incidentally, you say:
Most climatologists believe that humanity has a net decrease on global CO2 creation, because industry generates less CO2 per acre than biota do. I challenge you to justify that claim with published data. It certainly disagrees with every land use CO2 estimate I've seen (e.g., Jain, Houghton,...), and with, well, pretty much every paper I've ever read. "Most climatologists"?? Come on.
That the CO2 rates follow the temperature rates for six hundred million years, You probably mean six hundred thousand years. There are a lot of anomalies between temperature and CO2 when you go back to hundred million year timescales.
and that our current CO2 and temperature rates fit that model perfectly, should be all the evidence you need. I don't know what "model" you're referring to. Certainly no coupled T/CO2 model of the ice age cycle predicts the current temperature or CO2 increase.
Find me some compelling reason to believe 40 years over 600,000,000 years, which isn't "omg our machines put out almost half the CO2 of a single large volcano, that's completely changing the entire planet." That's utter B.S. A single large volcano doesn't come anywhere close to our CO2 output. Look at, say, Pinatubo. It put out about 40 megatons of CO2 (there's a report by Gerlach et al. on this somewhere). Anthropogenic emissions in one year are on the order of 7 GIGAtons.
Furthermore, the paleo T/CO2 record does not contradict anthropogenic global warming, nor does it explain the current temperature or CO2 trends.
but I do also believe that our "Global Warming" is just another planetary cycle of which has been occurring for million/billions of years prior to the existence of the first human.Actually, it's primarily solar. Massive amounts of scientific evidence disagree with that claim. In addition to any number of RealClimate links refuting specific aspects of this "it's all solar" nonsense, I refer you to the 2006 comprehensive review of Foukal et al. in Nature.
In the event of a 3 degree average increase, which is almost three times the current estimate by 2100, Africa in all areas except the very southern portion of the continent is predicted to receive substantially more and more consistent percipitation. Upon what science is that statement based?
See, for instance, Figure SPM.7 of the Summary for Policymakers of the 2007 IPCC 4th Assessment Report.
That figure gives a >20% precipitation decrease for northern Africa in 2090-2099 (relative to 1980-1999 levels). It gives a similar decrease for southern Africa in the summers. For central-east Africa it gives a precipitation increase in the winters, and finds the predictions are unreliable for central Africa in the summers. Those precipitation decreases are larger than anywhere else in the world, except for the subtropical eastern Pacific ocean. This is for about 3 C of warming under the A1B SRES scenario.
In short, the Intergovernmental Panel on Climate Change comes to a conclusion exactly the opposite of you for much of Africa: Somalia, Ethiopia, and Kenya might be better off, but most of the rest of Africa is predicted to be hit with substantial drought worse than anywhere else in the world.
Humans don't have any fundamental data on the subject, so human nature takes over: we fear change. The whole global warming scare across the world smacks of a very human fear of change. Most people don't even realize that the temperature on Earth now is, as far as we can tell, below the lifetime average for Earth, and below the lifetime median as well. While there is much hysteria about global warming, there is good reason to be conservative: it's often better to stay where you are, in a regime that you know about, than gamble on making things better when there is a substantial risk of making them worse, unless you're very sure that "better" is much more likely than "worse". Humans are risk averse decision makers, and this is not irrational.
On top of that, our current civilization is adapted to a particular type of climate, and there will be at least short term costs which result from changes in any direction. Furthermore, the faster the change, the greater the damages, because adaptation takes time.
While the Earth's climate has been warmer in the past, our civilization and to a certain extent our species itself is evolved for temperatures closer to today or even cooler (we have spent much of the last few million years in ice ages). The mere fact that the climate has been different in the past says little about the benefits or costs of change, as viewed by the human species and their currently preferred ways of living.
If you would benefit from warmer weather or being closer to the beach, move to San Diego. That's a voluntary choice you can make which improves your local climate — by changing localities — and affects no one else. Your proposed alternative is to change everybody's climate and force many of those who like their local climate to move involuntarily just because you don't like your climate.
The same models of climate which predict increased global temperatures also predict increased precipitation in mid-latitudes but decreased precipitation in the subtropics. That being said, the models are less reliable at predicting precipitation than temperature.
Here's a little quiz: Take any point in history. Now, what are the odds that the world's climate on that day will be exactly the same as it is 100 years later? It's a red herring. Sure, the climate varies naturally, and sure, that has resulted in negative impacts for various cities. The fact that it happens naturally, however, doesn't mean that it's desirable for us to add to it, at an accelerated rate.
Dark matter can't be "Matrioshka Brains" or anything else made out of ordinary baryonic matter. That ideas has already been tried, in the form of Massive Compact Halo Objects (MACHOs), which could be brown dwarfs or any other dark lump of matter floating around, including a Dyson sphere. Such kinds of dark matter can't be responsible for most of the dark matter in the universe: they don't cluster gravitationally in the right way, they don't seed galaxy formation correctly (and if they were Dyson spheres, probably wouldn't even exist when galaxy-seeding is going on), etc.
If dark matter reacts gravitationally with ordinary matter, shouldn't we find the two combined within some sort of object?
Not necessarily. Only if (a) there is enough of it around our part of the galaxy to detect, (b) it's possible to detect directly, and (c) it tends to stay around inside objects. Most dark matter would have to be in a spherical halo surrounding our galaxy, not in its disk. It doesn't interact strongly with other matter, so it would tend to pass right through instead of getting stuck inside a rock or something, and similarly passes right through detectors easily without triggering them. (Think of neutrinos and how hard they are to detect.) There might be some trapped gravitationally at the center of the Sun, but for obvious reasons it's hard to check. Nevertheless, there are experiments which attempt to detect dark matter (or its decay products) directly. They might turn up something, but they might not — even if dark matter exists, there are many reasons to believe that it should be very hard to detect.
Why would there be "stars" made entirely of dark matter, anyway? What keeps ordinary matter from falling in?
There probably would be some ordinary matter, but they would form from regions of space that primarily consist of dark matter.
Under present models, dark matter isn't matter at all!
Of course it is. You just have a restricted definition of "matter" which excludes, for instance, neutrinos. Neutrinos are massive fermions and deserve the label "matter" just as much as electrons do.
Under present models, dark matter exists only as a mathematical fudge.
It's not a mathematical fudge. There are a number of theories which naturally contain dark matter-like particles, completely apart from any motivation to explain the astrophysical observations. For instance, the Standard Model itself may well have to contain as-yet unobserved axions which are prime dark matter candidates, in order to resolve the strong CP problem. Also, there are a number of motivations coming from the Standard Model hierarchy problem and grand unification which suggest the existence of supersymmetry, which would provide other prime dark matter candidates. Neither of those motivations have anything to do with intentionally "fudging" the particle content of the theory to make astrophysics work out right.
Simply put, if there is so much dark matter in the universe, why can't we find some? Statistically speaking, there should be some right here on Earth!
Not if it's neutrino-like. Then it's hard to detect (extremely low interaction cross section) and doesn't tend to stick around in one place. Also, while most "regular" matter is confined to the galactic disk, dark matter is likely distributed throughout a spherical halo, meaning not too much of it happens to intersect the galactic disk (where we are). There are direct dark matter searches, but it's very far from a foregone conclusion that they will be able to detect dark matter. Simply put, just because it's abundant doesn't mean that it's easy to find.
It makes almost as much sense to say that there is a parallel material universe, slightly overlapping our own, that only interacts with our universe on a gravitational level.
Actually, that idea has been proposed, but there is much less motivation for it than there is for dark matter, as dark matter candidate particles exist quite naturally in the Standard Model and the most plausible extensions thereof. Also, the "parallel material universe" idea isn't really a substitute for dark matter (it was proposed for other reasons), since a "parallel universe" with "normal" matter in it doesn't behave like dark matter does!
Why shouldn't we believe "the astrophysicists"? Did they lie to you? Gore your ox? Steal your candy? Pee in your breakfast cereal?
After 70 years of computer simulations and observations they failed to predict this new kind of supernova.
Yeah, so? There are infinitely many things that are true which scientists have yet to predict. Why are you under the impression that scientists are supposed to know everything? Even if they did know all the physics involved, you can still only make finitely many predictions in finite time.
Its interesting to read speculations about degenerate lepton gases, but arent they just hand-waving again?
"Again"? When were they "hand-waving" before? About what?
Just goes to show you the arrogance of physicists- they claim answers and grandiose Standard Theories, but are frequently revising them because they mis things like accelerating expansion and 150SM supernova.
That's a feature, not a bug. It's how science works! Physicists claim answers because they have answers. That doesn't mean they have ALL the answers, or they're always right. This is no different in astrophysics than in any other field of physics, or any other science, or in any other field of study, period. People know some things, they can predict some things, and sometimes they miss something or get something wrong. That doesn't mean that nobody knows anything or that experts have nothing useful to say.
(By the way, accelerating expansion was in Einstein's theory from the start, but he took it out because there wasn't any evidence for it at the time.)
I seriously don't understand your point of view, unless (as is likely) it's just flamebait. Every time something new is discovered, do you seriously run around disparaging whole fields of science just because the new thing wasn't predicted ahead of time? Or do you just have some bug up your nose about astrophysicists? It's not like they were even wrong about normal supernovae, they just didn't predict this new kind.
The paper. (TFA has a link to the ApJ version, but it tells me that I have an institutional subscription, which presumably means that those outside of academia do not.)
The Big Bang does involve spacetime: it is a singularity which is essentially a boundary of spacetime ("the creation of the universe"). It's just not an "expansion of spacetime". Big Bang cosmology in general (not just the Big Bang itself) involves a curved spacetime with expanding space. (Space itself may be flat.)
I was not agruing for any particular idea, mearly pointing out that these ideas are not testable, they are conjecture and will remain so unless we work out a way to cross the information boundry. We can't know for sure what goes on inside a black hole without going there, but I maintain that we justifiably have a good idea of what goes on there (other than at the singularity itself), because we have good experimental reasons to be confident in the predictions of general relativity.
Slashdot Mirror
The warming on Mars does not correlate with any change in solar intensity. In fact, Mars has warmed while solar intensity dropped. If that weren't enough, the change in intensity of the Sun is nowhere near large enough to produce the observed temperature changes on Mars.
The links I gave describe theories of Martian warming that are actually plausible.
Furthermore, the change in intensity of the Sun has not corresponded in either timing, rate, or magnitude with the warming on Earth. (See here.) Even if solar output were responsible for the warming on Mars, it's not responsible for the warming on Earth.
The idea that Martian warming tells us something about the Earth's climate is, in short, completely retarded and only promulgated by people who don't know anything about either planet. Seriously, if you want to argue against anthropogenic global warming, you can use arguments that are much less embarrassing to your side. Heck, I could argue your side better than you have. It means that using historical CO2 increases as flags for impending warming is an intellectually bankrupt technique. Of course it means no such thing. Historical CO2 increases did cause substantial warming. The assertion that CO2 is forcing our current very, very minor temperature change The current temperature change is not "minor" when compared to the last thousand years, its rate is much greater than anything we have seen in the past, and it will continue to accelerate over this century. may or may not be true to some unknown extent, It is true to a rather known extent, your denial notwithstanding. however, we know that CO2 hasn't done any such thing in the past despite being quite high in post-warming periods, On the contrary, CO2 is responsible for most of the warming in the ice age cycle; the deglaciation persists for far longer than the Sun's forcing in the Milankovitch cycles, due to the increased CO2 liberated by the initial deglaciation. Which was also explained in the references you didn't bother to read. In other words, as the surface warms for any reason, the water vapor cycle increases the amount of cooling. This establishes a negative feedback, countering warming trends. Actually, the net effect of water vapor feedback does to climate is exactly the opposite, because you have neglected the greenhouse effect of the water vapor, which is quite large and in fact at least doubles the amount of warming due to CO2's greenhouse effect alone.
Perhaps if you read a basic undergraduate textbook on climate science, you would understand this. I recommend David Archer's book. Those seem like interesting charts. What is the source study? The page doesn't say, See section 9.4 of the IPCC 4th Assessment Report (Working Group 1). Most climate predictions I have seen have failed miserably at any edge cases, such as in the arctic and with regard to predicting sea level rise, melt in Greenland, and so on. The Arctic is ok with temperature, but so-so with precipitation, and the current GCMs don't have fully dynamical ice sheet models integrated into them yet. Dynamical ice and aerosol/cloud feedbacks are the big frontiers right now. Sea level rise is not bad but has been somewhat underestimated so far.
You can't refute the science, so you resort to trying to tar it as ideology. Pathetic.
If you'd like to discuss mitigation, feel free to start a thread on that. In the meantime, the fact that such obviously wrong arguments such as stonecypher's keep getting modded up shows that there is much more work to be done educating people on attribution/causation. You can't get people to the table on solutions when they won't even admit there's a problem.
But now that you bring it up, there is no evidence for any "planetary cycle" involving the Sun's magnetic field which has been occurring for million/billions of years. At best, there is the 11-year solar cycle, which not even contrarians claim is what is responsible for global warming.
I challenge you to produce published data supporting the existence of such a cycle. The magnetic field determines the solar wind, which in turn governs cloud cover through the suppression of cosmic rays. Cloud cover comes into solar heating a hell of a long time beore greenhouse gasses do. I challenge you to produce published data supporting the existence of any declining trend in cosmic ray incidence that corresponds in timing, rate, and magnitude with the trend of global temperatures over the last 40 years.
There is no evidence that cosmic rays have any significant influence on cloud cover, let alone on climate. If you're tempted to cite a certain author featured in the Global Warming Swindle documentary you seem to take on faith, please note that (a) he did not actually show a correlation between cosmic rays and climate, and (b) then read Damon and Laut (2004). I could point you to many other criticisms on RealClimate, but since you seem to feel that publication is more important than the actual scientific arguments involved, I won't bother.
"The variations measured from spacecraft since 1978 are too small to have contributed appreciably to accelerated global warming over the past 30 years. In this Review, we show that detailed analysis of these small output variations has greatly advanced our understanding of solar luminosity change, and this new understanding indicates that brightening of the Sun is unlikely to have had a significant influence on global warming since the seventeenth century." Please stop saying things like "massive amounts of blah blah." Either cite it or it doesn't exist. No, I am not going to cite every climate paper that exists. I already referred you to the most comprehensive review on the subject, which does NOT agree with you. Furthermore, the RealClimate links have plenty of references as well that you are welcome to read. and it becomes clear from your reference to RealClimate that you confuse the personal blogs of individuals with actual science. It is quite clear that you would like to forget that the RealClimate authors are scientists and, if you bother to read them, back up their claims with the citations you so desperately crave.
I note, of course, that you have not cited any evidence of YOUR claims.
Besides, why are you even arguing about what's responsible for CO2 levels? I thought It's All the Sun.
The total CO2 output of all the volcanoes in the world in any given year is still less than 2% of annual anthropogenic emissions.
You are probably getting CO2 confused with aerosol precursors. There are more than a dozen things on this planet that regularly put out more CO2 than we do. That's kind of a red herring, just like the wingnuts who like to point out that more of the greenhouse effect is due to water vapor than CO2.
As the previous poster pointed out, there are large non-anthropogenic sources of CO2, but until recently they have been essentially balanced by non-anthropogenic sinks of CO2, so that net CO2 concentrations remained pretty much constant on timescales of millennia. We are now sourcing CO2 at a much greater rate than it can be sunk, leading to a rapid rate of accumulation.
Out of curiosity, what do you believe is responsible for the current rapid increase in CO2 concentrations? They were until 1983, and our CO2 output has not increased much since then (sure we're growing, but we're also becoming more efficient.) I challenge you to justify that claim with published data.
Not only is that not true, it's also not as relevant as you would have it appear: even if our CO2 output leveled off (which it most definitely has not), it would still continue accumulate in the atmosphere because we would still be sourcing it faster than it can be sunk. (Unless we go in for sequestration in a big way.)
Incidentally, you say: Most climatologists believe that humanity has a net decrease on global CO2 creation, because industry generates less CO2 per acre than biota do. I challenge you to justify that claim with published data. It certainly disagrees with every land use CO2 estimate I've seen (e.g., Jain, Houghton,
Furthermore, the paleo T/CO2 record does not contradict anthropogenic global warming, nor does it explain the current temperature or CO2 trends.
See, for instance, Figure SPM.7 of the Summary for Policymakers of the 2007 IPCC 4th Assessment Report.
That figure gives a >20% precipitation decrease for northern Africa in 2090-2099 (relative to 1980-1999 levels). It gives a similar decrease for southern Africa in the summers. For central-east Africa it gives a precipitation increase in the winters, and finds the predictions are unreliable for central Africa in the summers. Those precipitation decreases are larger than anywhere else in the world, except for the subtropical eastern Pacific ocean. This is for about 3 C of warming under the A1B SRES scenario.
In short, the Intergovernmental Panel on Climate Change comes to a conclusion exactly the opposite of you for much of Africa: Somalia, Ethiopia, and Kenya might be better off, but most of the rest of Africa is predicted to be hit with substantial drought worse than anywhere else in the world. Humans don't have any fundamental data on the subject, so human nature takes over: we fear change. The whole global warming scare across the world smacks of a very human fear of change. Most people don't even realize that the temperature on Earth now is, as far as we can tell, below the lifetime average for Earth, and below the lifetime median as well. While there is much hysteria about global warming, there is good reason to be conservative: it's often better to stay where you are, in a regime that you know about, than gamble on making things better when there is a substantial risk of making them worse, unless you're very sure that "better" is much more likely than "worse". Humans are risk averse decision makers, and this is not irrational.
On top of that, our current civilization is adapted to a particular type of climate, and there will be at least short term costs which result from changes in any direction. Furthermore, the faster the change, the greater the damages, because adaptation takes time.
While the Earth's climate has been warmer in the past, our civilization and to a certain extent our species itself is evolved for temperatures closer to today or even cooler (we have spent much of the last few million years in ice ages). The mere fact that the climate has been different in the past says little about the benefits or costs of change, as viewed by the human species and their currently preferred ways of living.
Some might suggest your position is unethical.
If you would benefit from warmer weather or being closer to the beach, move to San Diego. That's a voluntary choice you can make which improves your local climate — by changing localities — and affects no one else. Your proposed alternative is to change everybody's climate and force many of those who like their local climate to move involuntarily just because you don't like your climate.
The same models of climate which predict increased global temperatures also predict increased precipitation in mid-latitudes but decreased precipitation in the subtropics. That being said, the models are less reliable at predicting precipitation than temperature.
Take any point in history.
Now, what are the odds that the world's climate on that day will be exactly the same as it is 100 years later? It's a red herring. Sure, the climate varies naturally, and sure, that has resulted in negative impacts for various cities. The fact that it happens naturally, however, doesn't mean that it's desirable for us to add to it, at an accelerated rate.
Dark matter can't be "Matrioshka Brains" or anything else made out of ordinary baryonic matter. That ideas has already been tried, in the form of Massive Compact Halo Objects (MACHOs), which could be brown dwarfs or any other dark lump of matter floating around, including a Dyson sphere. Such kinds of dark matter can't be responsible for most of the dark matter in the universe: they don't cluster gravitationally in the right way, they don't seed galaxy formation correctly (and if they were Dyson spheres, probably wouldn't even exist when galaxy-seeding is going on), etc.
If dark matter reacts gravitationally with ordinary matter, shouldn't we find the two combined within some sort of object?
Not necessarily. Only if (a) there is enough of it around our part of the galaxy to detect, (b) it's possible to detect directly, and (c) it tends to stay around inside objects. Most dark matter would have to be in a spherical halo surrounding our galaxy, not in its disk. It doesn't interact strongly with other matter, so it would tend to pass right through instead of getting stuck inside a rock or something, and similarly passes right through detectors easily without triggering them. (Think of neutrinos and how hard they are to detect.) There might be some trapped gravitationally at the center of the Sun, but for obvious reasons it's hard to check. Nevertheless, there are experiments which attempt to detect dark matter (or its decay products) directly. They might turn up something, but they might not — even if dark matter exists, there are many reasons to believe that it should be very hard to detect.
Why would there be "stars" made entirely of dark matter, anyway? What keeps ordinary matter from falling in?
There probably would be some ordinary matter, but they would form from regions of space that primarily consist of dark matter.
Under present models, dark matter isn't matter at all!
Of course it is. You just have a restricted definition of "matter" which excludes, for instance, neutrinos. Neutrinos are massive fermions and deserve the label "matter" just as much as electrons do.
Under present models, dark matter exists only as a mathematical fudge.
It's not a mathematical fudge. There are a number of theories which naturally contain dark matter-like particles, completely apart from any motivation to explain the astrophysical observations. For instance, the Standard Model itself may well have to contain as-yet unobserved axions which are prime dark matter candidates, in order to resolve the strong CP problem. Also, there are a number of motivations coming from the Standard Model hierarchy problem and grand unification which suggest the existence of supersymmetry, which would provide other prime dark matter candidates. Neither of those motivations have anything to do with intentionally "fudging" the particle content of the theory to make astrophysics work out right.
Simply put, if there is so much dark matter in the universe, why can't we find some? Statistically speaking, there should be some right here on Earth!
Not if it's neutrino-like. Then it's hard to detect (extremely low interaction cross section) and doesn't tend to stick around in one place. Also, while most "regular" matter is confined to the galactic disk, dark matter is likely distributed throughout a spherical halo, meaning not too much of it happens to intersect the galactic disk (where we are). There are direct dark matter searches, but it's very far from a foregone conclusion that they will be able to detect dark matter. Simply put, just because it's abundant doesn't mean that it's easy to find.
It makes almost as much sense to say that there is a parallel material universe, slightly overlapping our own, that only interacts with our universe on a gravitational level.
Actually, that idea has been proposed, but there is much less motivation for it than there is for dark matter, as dark matter candidate particles exist quite naturally in the Standard Model and the most plausible extensions thereof. Also, the "parallel material universe" idea isn't really a substitute for dark matter (it was proposed for other reasons), since a "parallel universe" with "normal" matter in it doesn't behave like dark matter does!
Why shouldn't we believe "the astrophysicists"? Did they lie to you? Gore your ox? Steal your candy? Pee in your breakfast cereal?
After 70 years of computer simulations and observations they failed to predict this new kind of supernova.
Yeah, so? There are infinitely many things that are true which scientists have yet to predict. Why are you under the impression that scientists are supposed to know everything? Even if they did know all the physics involved, you can still only make finitely many predictions in finite time.
Its interesting to read speculations about degenerate lepton gases, but arent they just hand-waving again?
"Again"? When were they "hand-waving" before? About what?
Just goes to show you the arrogance of physicists- they claim answers and grandiose Standard Theories, but are frequently revising them because they mis things like accelerating expansion and 150SM supernova.
That's a feature, not a bug. It's how science works! Physicists claim answers because they have answers. That doesn't mean they have ALL the answers, or they're always right. This is no different in astrophysics than in any other field of physics, or any other science, or in any other field of study, period. People know some things, they can predict some things, and sometimes they miss something or get something wrong. That doesn't mean that nobody knows anything or that experts have nothing useful to say.
(By the way, accelerating expansion was in Einstein's theory from the start, but he took it out because there wasn't any evidence for it at the time.)
I seriously don't understand your point of view, unless (as is likely) it's just flamebait. Every time something new is discovered, do you seriously run around disparaging whole fields of science just because the new thing wasn't predicted ahead of time? Or do you just have some bug up your nose about astrophysicists? It's not like they were even wrong about normal supernovae, they just didn't predict this new kind.
Oops, somehow I managed to overlook this comment.
The paper. (TFA has a link to the ApJ version, but it tells me that I have an institutional subscription, which presumably means that those outside of academia do not.)
The Big Bang does involve spacetime: it is a singularity which is essentially a boundary of spacetime ("the creation of the universe"). It's just not an "expansion of spacetime". Big Bang cosmology in general (not just the Big Bang itself) involves a curved spacetime with expanding space. (Space itself may be flat.)