We are outside of normal climate patterns in one obvious way, which is the rate of warming. It's easier to adapt to something the more slowly it happens. Also, proto-humans did not have large civilizations which were optimized for specific climate conditions. If it got too hot, or too flooded, or whatever, it wasn't that hard to move. Furthemore, just because we can survive a 5-6C climate change, doesn't mean that we want such a change. As for climate change killing species, don't forget that our other activities are massively destabilizing ecosystems to an extent that has been unprecedented outside of a few mass extinctions (e.g. here. Adding climate change to that isn't going to help. Also don't forget that many species didn't survive climate change in the past.
The only kind of planetary warming that has relevance to Earth is warming due to increase in solar output, because that is the only factor Earth shares in common with other planets.
Solar output has been increasing for some time. However:
1. The warming on Mars is not due to an increase in solar output; solar output actually decreased slightly over the period that its warming was observed. (It's also not global warming, but rather regional warming of Mars's south pole.) See here.
2. According to the article you cite, the warming on Pluto is not due to an increase in solar output. It is due to orbital variations: Pluto recently passed perihelion.
3. According to the article you cite, the warming on Triton is not due to an increase in solar output. It is due to changes in surface albedo (the amount of solar radiation that the planet reflects vs. absorbs).
4. According to the article you cite, the climate changes on Jupiter are not due to an increase in solar output. They are due to changes in atmospheric circulation patterns. (It's also not clear from that article whether the overall effect is global warming; there is warming at the equator and cooling at the poles.)
In short, other planets don't tell us much about global warming on Earth. Even if they were all warming for the same reason, that reason would have to be solar output, and we don't need to study other planets in order to know about that: we can measure solar output directly.
As it turns out, solar output isn't sufficient to explain the observed global warming. It has been increasing overall, but not by very much. It explains a little bit of the warming, but not most of it. See this article for more details (subscription required).
Most current research tends to show that human Co2 has some affect on the climate, but nobody is really sure how. Current research shows that human CO2 has had a large effect on the climate, compared to pre-industrial times, and we know how: the greenhouse effect.
We are less certain about the extent of future climate change, largely because we don't know by exactly how much feedback effects amplify the greenhouse effect, and we don't know what future CO2 emissions will be like: a lot will depend on what we choose to do and when we do it.
The problem is that nobody really knows, any many people aren't willing to make major sacrifices regarding something that we need more information about. [...] Perhaps it would be wiser to make an evolutionary shift in technology and lifestyles, which the global economy can afford...and maybe do it in a manner consistent with our understanding of the phenomena that we're just beginning to understand. Obviously, we are not going to take any action that we cannot afford to take. But it is far from clear that mitigating climate change would require "major sacrifices" (except perhaps to some people who seem to feel that any sacrifice is "major").
Even more uncertainty arises when it comes to predicting the costs of climate change, and the costs of mitigating it. We do know, however, that it's better to start mitigating early and prevent some of that CO2 from entering the atmosphere in the first place. It thus may be better to ramp up mitigation and taper it off if we find that the climate change is less than expected — the "better safe than sorry" approach.
Doing something for the sake of doing something is equally unjustifiable, especially when all sides of the issue are confounded with politically charged BS. That's true, but doing something is almost certainly better than doing nothing, given what we already know, even under the economic uncertainties that are present. It's very difficult to find reasonable combinations of climate change predictions and economic assumptions that lead to "doing nothing" as the best course of action. The question is "how much should we mitigate", not "whether".
If global climate change is based around cyclical patterns that we can't change, there is little point in making drastic, sweeping changes. Global warming is not due to cyclical patterns that we can't change. We know that much.
You are, however, correct in saying that global warming is not a threat to the survival of our species. Its effects will be mostly economic, although at least some deaths will probably result (be it from more extreme weather, droughts, crop failure, spread of disease vectors, etc.)
It's no longer a debate within the climate science community that humans are a significant cause of the increase in temperature; that has been well established by now. See the IPCC SPM for a summary of how much anthropogenic forcings have grown compared to natural forcings, as well as a comparison of how poorly the late-20th century climate is reproduced if you leave out anthropogenic contributions.
The value of mitigating climate change, on the other hand, is vigorously debated, and includes considerations beyond the merely scientific (namely economic, political, social, and moral).
I don't know what experiments you're thinking of, but you can determine the efficiency of CO2 adsorption directly from its adsorption spectrum, at any concentration. You can extrapolate to any other concentration by a simple logarithmic relationship which is easily derivable from physical laws. In fact, CO2's spectrum is measured with a chamber of pure CO2, not an atmospheric mix.
It seems as though some people monitoring the sun do seem to believe (or at least did in 2003) that the solar output has been increasing. Solar output has been increasing. But it has increased by an amount that is much too small to explain the observed warming, particularly the warming in the last 40 years. See the 2006 Foukal et al. review article for a good summary.
Also, it's pretty well known that many simple lab experiments don't generalize well to larger, complex (real-world) systems. That's nice, but it is a basic physical fact that greenhouse gases cause warming. They have to, given the nature of their absorption spectra. It doesn't matter whether they're in a lab chamber or in the atmosphere.
The uncertainty is not about whether CO2 in the real atmosphere causes warming. It's about the warming and cooling contributions from other sources — how much of the total warming can be attributed to each source. (The direct contribution from CO2 can be calculated directly from adsorption physics, but there is uncertainty about how feedback effects amplify its contribution, as well as the contribution of other sources.)
There is not now enough remaining uncertainty to attribute global warming to non-CO2 sources; see the IPCC estimates in Figure SPM-2 of their latest publication.
the problem is that all "data" comes from lab experiments where all variables can be controlled. That's an advantage, not a problem. That's the whole reason why controlled experiments are preferable to uncontrolled observations.
you can't control all the earth's variables and thus the correlation is invalid. You're being ridiculous.
I cool water in a controlled laboratory experiment, and it freezes. Water in the real world... who knows what could happen when it's cooled?? There are so many uncontrolled variables! Maybe it will boil!
There are many variables in the Earth's climate, but none of them change the fact that CO2 and other gases produce a greenhouse effect, and they don't change the magnitude of that greenhouse effect. Those are physical facts.
The uncertainties are not in the greenhouse effect. The uncertainties are: how much warming and cooling is there from other sources, and how much do feedbacks amplify those effects.
the simple fact is that there is no physical proof that we have warmed the earth or that we can alter its course. There is never any "proof" in science. The fact that we have warmed the Earth is, however, supported by evidence at this point that is now beyond reasonable doubt. We have altered the course of its climate. It is also a basic physical fact that we can alter the future course of warming by reducing greenhouse gas emissions. (How much alteration is economically feasible is a different matter.)
there is speculation, lab models, and computer simulations, but nothing conclusive. You are woefully underinformed about the evidence. You can start by reading the IPCC reports.
Wow, another Slashdotter getting modded up for pointing out that correlation != causation.
You know, repating "correlation does not equal causation" is not an excuse to ignore any line of statistical evidence you choose. Correlation doesn't prove causation, but often it is damn suggestive. Most of the evidence linking lung cancer to smoking is "merely" correlation too.
Beside that, experiments do not show merely a "correlation" between CO2 and warming. It is known and very obvious adsorption physics that greater absorption in the IR spectrum than in the visible causes greenhouse warming, when the gas is subjected to visible light and coupled to a heat sink ("the Earth"). The heat sink re-radiates in infrared, and a gas which absorbs more re-radiated heat than incoming visible radiation will inevitably lead to overall warming. As noted by the grandparent, this is easily demonstrated by laboratory experiment.
This is, in fact, the reason why the entire planet is not a frozen iceball: if you leave the greenhouse effect out of the energy balance equations (incoming radiation = outgoing radiation), you'll find that the the temperature of the Earth should be much lower than it actually is. Something is trapping heat, we know for sure. The greenhouse effect is a proven mechanism, and lo, the amount of warming you should get from it is equal to the missing component of the energy balance.
People still debate about global warming, but I can't believe that people are still skeptical of the very existence of the greenhouse effect.
It's reporting on a paper published in the journal Science, one of the top two scientific journals in the world, with something like a 5% acceptance rate for new papers. Don't blame the news editor for thinking it's newsworthy; other Science papers get similar coverage.
Apparently, Purdue refused to state what the exact allegations investigated were, how many inquiries it conducted, or what its conclusions were based on. Hard to tell if the investigation's conclusions were arrived at fairly or were politically motivated. More details in this NYT article which I found from this blog entry.
We don't know what drove these climate changes in the past. That's right. Once again, it is irrelevant to the point that we do know what is driving climate change now.
We know only that the temperature has trended up recently. We know a lot more about the climate than that.
It might be mankind's "carbon footprint". It might be something else that we don't know to look for. Be reasonable. We are not so ignorant about our own climate that there is a totally unknown source of warming capable of raising the planet's temperature to the extent observed. Even if there were, there would also have to be an even bigger totally unknown source of cooling, to explain why our carbon footprint hasn't warmed the planet even more than this unknown source of warming has. And then you would have to explain why the warming of the Earth agreeing in timing, magnitude, and rate with our CO2 emissions is just a coincidence. Put the three together, and it's not credible.
The fact that these changes take place without us and we don't know why is completely relevant to the discussion. No, it isn't. It's like arguing that because we don't know how the first single-celled organisms arose, we can't say anything about how modern-day humans evolved.
The climatic conditions tens of millions of years ago are irrelevant to the attribution of the recent phenomenon of global warming. We can say that the current warming is "primarily due to" mankind's CO2 emissions irrespective of what drove the climate in past ages, purely on the basis of what we know about the recent climate. The fact that the Earth was once warmer, or colder, is not relevant to the fact that actions due to mankind are substantially responsible for the temperature increase that has occurred over the past 150 years.
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Not hardly; it wouldn't even pay for a Mars mission (estimated in excess of $50 billion).
And without a bit of help from mankind and his evil CO2 emissions, it might be pointed out. What's your point? Are you attempting to deny that global warming is primarily due to mankind's CO2 emissions, or are you merely pointing out the irrelevant?
Habitable, perhaps not preferable. That is what self-correcting means. Well duh. Nobody thinks that global warming will wipe out all life on Earth. That's not what the debate is about.
Yes, there are examples like this article of increased temperature. Why the first week of January it was 60 outside here, setting record highs by huge amounts! Of course, last week it was very nearly a record low. If you look at temperature records, we have been breaking record highs more often than we have record lows. Not that extreme temperature records are the best signal of global warming.
On the same note, there are no news stories on the glaciers that are growing. And yea, a surprising number are. More are shrinking, of course, but worldwide the change is *far* less then any single glacier or group of glaciers that makes the news. It's less, since anything that makes the news is necessarily an extreme case. But it's not "far" less; ice loss is one of the most dramatic effects of global warming so far.
I believe that humans are increasing the average temperature of the earth, but I also believe that it would be increasing anyway. Our best temperature reconstructions suggest that the Earth has been slightly cooling for about 8000 years, with small temporary increases now and then like the Medieval Warm Period. Most of the global warming which has taken place over the last 150 years is attributable to human activity. There has been a smaller amount of warming due to natural causes. Human activity will become considerably more significant over the next few hundred years, given the residence time of CO2 in the atmosphere and the rate at which we are still emitting it. The difference between the real global temperature and what it would be without our emissions will continue to diverge at least over the next century, and at an accelerating rate. Even if we cut our emissions to zero right now, the amount of CO2 in the atmosphere right now would likely cause as much warming over the next century as all the global warming we've currently seen to date.
Human influence on the climate is not negligible, and will become even less so in the future.
Ya, I'd say glacial growth is very under estimated. And why do you say that? Do you think glaciologists are unaware of glacial growth, and you are in unique possession of this fact? It's well known that central Greenland's ice is growing. It's just being outweighed by the faster melting of outer Greenland's ice.
Riiiiight... we're going to selectively engineer a global climate when we can't even selectively control other undesirable local weather phenomenon like hurricanes and tornadoes. We've already engineered our global climate with our greenhouse gas, aerosol, and particulate emissions. We just didn't engineer a great climate. Altering our emissions can likewise bring about a more favorable outcome.
Climate is historically self-correcting. I have no reason to believe it is not still so. What does "climate is self-correcting" mean? The world spent millions of years with a tropical climate in the Cretaceous age. Do we want that? I'm not saying that will happen with global warming, but the point is that the climate doesn't necessarily stabilize at conditions that we would find preferable. Global temperatures will not continue to increase until the planet incinerates, but at current CO2 levels, they will continue to increase for some time before negative feedbacks can substantially slow, let alone reverse the warming.
If you read the scholar.google.com papers, 1.1C is caused by increased solar activity. You mean, these papers?
Rahmstorf et al. (2004) Foukal et al. (2006) Stott et al. (2003)
Human activity is responsible for 50% of CO2, the other 50% is volcanic sources. It's been some time since volcanic sources could compete with human activity for CO2 production; current anthropogenic CO2 production is about 100x larger than that of volcanic activity.
That makes human activity culpable for about 0.05C in two hundred years. That is very far from what pretty much every other study ever done in climatology has found.
Also note that even that paper finds that anthropogenic activity competes equally with solar forcing before 1955, and exceeds it after 1955.
Of course this paper attributes global warming to cosmic forces No, it doesn't. It attempts to associate glaciation cycles with cosmic rays. It doesn't say anything about the relatively recent phenomenon of global warming.
We've reached the technological ability to see the change, and like Chicken Little run around declaring the "the sky is falling". Are you denying that climate change, whatever its source, has serious potential impacts that we should be concerned about?
It is likely that orbital variations do affect climate over tens of thousands of years; see the Milankovitch cycles. That said, it's fairly irrelevant to global warming, other than the fact that global warming might not be as much of an issue if we were in an ice age part of the cycle.
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Does anyone think we can afford that? The U.S.'s manned space and Moon/Mars initiative is strangling NASA and forcing it to shut down many of its science programs (here, here, here, here, here). It hasn't even started to get into the real spending for a Moon mission, let alone a Mars mission.
An interstellar mission would cost orders of magnitude more than an interplanetary mission. Who would ever fund it? Even an international collaboration would be hard pressed to put together much more than the currently planned Mars mission. And governments wouldn't be too keen to start a mission that can outlive entire nations before we hear the results.
"Frontier spirit" just doesn't cut it against those scales of money and time.
The only thing that likely could spur a manned interstellar mission, barring drastic improvements in technology, is the impending destruction of human civilization — and who would see that coming in time, with enough certainty, to spur the development of a crash program like that? (Especially given the wars likely to ensue if people are that sure of the annihilation of the human race.)
No, I don't see it happening unless we get much, much better technology. It costs enough just to lift things off Earth, let alone build and launch a working intergenerational starship. (The economics of space development given launch costs and the absence of space industry is an extra can of worms... and I am also not economically optimistic of the development of orbital factories or space elevators or the like.)
Niven wrote about this in A Gift From Earth. In his scenario, there were the "crew" who stayed awake through the voyage, and the "colonists" who stayed asleep. Upon arrival, the crew decided that they should rule by natural right, since they stayed awake, aged, and did the hard work while the others snoozed away. They forced the colonists at gunpoint to sign their rights away, and essentially enslaved them.
It will be less reconizable as the traditional sence goes but even without a god, there will be a ultimate power that dictates quite a few things for them. So far, science seems to be it. Science does not "dictate" anything, and your dichotomy between science and religion is entirely invented. Atheists don't follow "science" any more than religious people do, with the exception of the creationist wingnuts and the like who believe that science conflicts with their religion.
I have noticed this directly when discussing things like Global warming and evolution. The debate usualy goes back to "the consensus says this" so thats how it is, never minding that the scietific process often discusses alternative ideas to come to a different concesus. Consensus on a subject doesn't prove anything, but if a collection of experts have worked on something for decades or centuries and come to some conclusion based on evidence, and have come to a consensus on the matter, that means something. It's not restricted to science, either.
Claiming "scientists can be wrong" is not an argument. Everyone can be wrong. It is up to you to show that they are wrong, despite the evidence to the contrary.
And I believe I addressed that when I made the statement of them being subject to poor choices of their government and parrents. You also said that the problem was because the land they lived on could not sustain them. Just because you said something non-stupid along with something stupid, doesn't mean that you didn't say something stupid, so stop accusing me of putting words in your mouth.
Most prefereble in there back yard. And then to the back yards of the closest place that resembles their climate and political/geographical reagons. Then spread out from there. Sure, very convenient. Let other countries take up the burden.
If it happens to be my back yard then be it. Really? You'll give up some of your land?
Somehow these "solutions" don't seem as preferable when it's you who has to bear the burden. And don't even try to claim that there is unlimited free land for refugees to buy with the cushy new jobs they'll be able to get.
Lol.. You act like that cannot be done. And there being enough jobs is something that will need to be looked at when the movment is happening. I don't know which is more appalling, your economics or your politics. No, the free market will not magically create as many jobs as there are people who need them.
The illegal ones do shit jobs that don't pay but hat is because as illegal aliens they don't have the same amounts of recourse a citizen does. I assure you, if we had as many legal immigrants as there are illegal immigrants, they wouldn't be getting jobs as good as the current average citizen's, particularly if we don't get to pick the ones with the best educations but have to take anybody who needs to be relocated.
This is more because of how france is run then how immigrants are treated. Yeah, as if other countries treat immigrants equally. I hope you are not going to claim that America has.
If you dump tons of new immigrants into any country over a relatively short period of time, you will have social unrest and incomplete assimilation. It's easy to see this in America's own past, and that's when America was relatively eager to accept new immigrants. Which countries do you think are going to be eager to accept large new populations from random, say, African nations? Certainly not other African nations.
If they don't want to move, then let them suffer whatever the problems are. It is that simple. Like I said, a very Stalinist viewpoint. The social consequences of depopulating entire nations are far worse to both them and to the other nations purportedly resettling them, which is why nobody has been stupid enough to try your plan.
But suggesting that others are somehow obligated to support them because they didn't make a sound decision is bullshit. Moving to another country is not always the "sound decision" you think it is, and it is far less expensive to support nations as-is than try to eradicate them in a diaspora and re-establish their people inside other countries.
So, How does my ability to get along with someone effect anything in discusion here? It means that you have a Stalinist viewpoint towards population control, and we all saw how well that worked out. Stalin too tried to redistribute the population within his own country, to poor effect.
And you think living there in those condition is a good idea? It's better than your idea, which is economically, politically, socially, and ethically completely unworkable.
1. I didn't claim a deser wasn't uninhabital. I was making the conection of too many people and not enough food in a desert meand is cannot support the life living there. Starving people in other countries by and large are not living in places where the land cannot support them.
Most starving children aren't actualy starving. All starving children are starving, by definition.
They are also victoms of their parents poor choices and the poor choices of the governments over seeing them. So?
But I wasn't talking about the starving children in non hostile enviroments was I? No. But starving children by and large don't live in places as hostile as deserts, either.
You should move them to non hostile places. Yeah? Where? Your backyard?
And you don't need to "give" them anything. They get temporary housing and find their own jobs, use the public education systems just like the other people and become usefull citizens of the new home. Oh really? Who says that there are enough jobs, homes, etc. in existing countries to meet a huge influx of displaced refugees, considering that they have nonzero unemployment rates even without tons of new immigrants. (You are talking about relocating tens or hundreds of millions of people here, you know. Even the U.S. in its period of unrestricted immigration never dealt with that many.) And which jobs are they going to end up with in this new society? Equal access to employment as native citizens? Witness the fate of Mexican immigrants in the U.S., Muslim immigrants in France, etc. And those are small numbers of immigrants.
Even if it is just to another part of the same country. More then likley it will require somewhat of an education campain to help them adjust and anyone refusing to go should be left to fend for themsleves. It is questionable if the children should be taken against their parrents wishes but if they are so young that they couldn't understand the choice then take them. Yeah, I'm sure you would love a forced relocation program if your government was making you move where it saw fit "for your own good". You are looking less at "fending for themselves" and more at "civil war".
You and Stalin would have gotten along just fine, I think.
In a lot of situations, the problem isn't that the land won't support the life living on it, it is more like the life living on it has outnumbered the ability for the land to support it. It is rarely the case that starvation is due to an intrinsic inability of land to support its population. It has more to do with an economy that can't support modern practices of agriculture and distribution of goods, dictators that don't support their people, and so on.
Ah, the old "well-meaning but naive environmentalists make stupid decisions" meme.
The ban on DDT in the U.S. did not result in 30 million deaths from malaria. There is no international ban on DDT: it is still used in developing countries to combat malaria, and it can only be used up to a point before the mosquitoes start developing immunity to it. (In fact, it is even used in the U.S. occasionally for disease control as a residential insecticide; it is only banned as a general-use agricultural pesticide.)
Slashdot Mirror
We are outside of normal climate patterns in one obvious way, which is the rate of warming. It's easier to adapt to something the more slowly it happens. Also, proto-humans did not have large civilizations which were optimized for specific climate conditions. If it got too hot, or too flooded, or whatever, it wasn't that hard to move. Furthemore, just because we can survive a 5-6C climate change, doesn't mean that we want such a change. As for climate change killing species, don't forget that our other activities are massively destabilizing ecosystems to an extent that has been unprecedented outside of a few mass extinctions (e.g. here. Adding climate change to that isn't going to help. Also don't forget that many species didn't survive climate change in the past.
The only kind of planetary warming that has relevance to Earth is warming due to increase in solar output, because that is the only factor Earth shares in common with other planets.
Solar output has been increasing for some time. However:
1. The warming on Mars is not due to an increase in solar output; solar output actually decreased slightly over the period that its warming was observed. (It's also not global warming, but rather regional warming of Mars's south pole.) See here.
2. According to the article you cite, the warming on Pluto is not due to an increase in solar output. It is due to orbital variations: Pluto recently passed perihelion.
3. According to the article you cite, the warming on Triton is not due to an increase in solar output. It is due to changes in surface albedo (the amount of solar radiation that the planet reflects vs. absorbs).
4. According to the article you cite, the climate changes on Jupiter are not due to an increase in solar output. They are due to changes in atmospheric circulation patterns. (It's also not clear from that article whether the overall effect is global warming; there is warming at the equator and cooling at the poles.)
In short, other planets don't tell us much about global warming on Earth. Even if they were all warming for the same reason, that reason would have to be solar output, and we don't need to study other planets in order to know about that: we can measure solar output directly.
As it turns out, solar output isn't sufficient to explain the observed global warming. It has been increasing overall, but not by very much. It explains a little bit of the warming, but not most of it. See this article for more details (subscription required).
We are less certain about the extent of future climate change, largely because we don't know by exactly how much feedback effects amplify the greenhouse effect, and we don't know what future CO2 emissions will be like: a lot will depend on what we choose to do and when we do it. The problem is that nobody really knows, any many people aren't willing to make major sacrifices regarding something that we need more information about. [...] Perhaps it would be wiser to make an evolutionary shift in technology and lifestyles, which the global economy can afford...and maybe do it in a manner consistent with our understanding of the phenomena that we're just beginning to understand. Obviously, we are not going to take any action that we cannot afford to take. But it is far from clear that mitigating climate change would require "major sacrifices" (except perhaps to some people who seem to feel that any sacrifice is "major").
Even more uncertainty arises when it comes to predicting the costs of climate change, and the costs of mitigating it. We do know, however, that it's better to start mitigating early and prevent some of that CO2 from entering the atmosphere in the first place. It thus may be better to ramp up mitigation and taper it off if we find that the climate change is less than expected — the "better safe than sorry" approach. Doing something for the sake of doing something is equally unjustifiable, especially when all sides of the issue are confounded with politically charged BS. That's true, but doing something is almost certainly better than doing nothing, given what we already know, even under the economic uncertainties that are present. It's very difficult to find reasonable combinations of climate change predictions and economic assumptions that lead to "doing nothing" as the best course of action. The question is "how much should we mitigate", not "whether". If global climate change is based around cyclical patterns that we can't change, there is little point in making drastic, sweeping changes. Global warming is not due to cyclical patterns that we can't change. We know that much.
You are, however, correct in saying that global warming is not a threat to the survival of our species. Its effects will be mostly economic, although at least some deaths will probably result (be it from more extreme weather, droughts, crop failure, spread of disease vectors, etc.)
It's no longer a debate within the climate science community that humans are a significant cause of the increase in temperature; that has been well established by now. See the IPCC SPM for a summary of how much anthropogenic forcings have grown compared to natural forcings, as well as a comparison of how poorly the late-20th century climate is reproduced if you leave out anthropogenic contributions.
The value of mitigating climate change, on the other hand, is vigorously debated, and includes considerations beyond the merely scientific (namely economic, political, social, and moral).
I don't know what experiments you're thinking of, but you can determine the efficiency of CO2 adsorption directly from its adsorption spectrum, at any concentration. You can extrapolate to any other concentration by a simple logarithmic relationship which is easily derivable from physical laws. In fact, CO2's spectrum is measured with a chamber of pure CO2, not an atmospheric mix.
The uncertainty is not about whether CO2 in the real atmosphere causes warming. It's about the warming and cooling contributions from other sources — how much of the total warming can be attributed to each source. (The direct contribution from CO2 can be calculated directly from adsorption physics, but there is uncertainty about how feedback effects amplify its contribution, as well as the contribution of other sources.)
There is not now enough remaining uncertainty to attribute global warming to non-CO2 sources; see the IPCC estimates in Figure SPM-2 of their latest publication.
I cool water in a controlled laboratory experiment, and it freezes. Water in the real world
There are many variables in the Earth's climate, but none of them change the fact that CO2 and other gases produce a greenhouse effect, and they don't change the magnitude of that greenhouse effect. Those are physical facts.
The uncertainties are not in the greenhouse effect. The uncertainties are: how much warming and cooling is there from other sources, and how much do feedbacks amplify those effects. the simple fact is that there is no physical proof that we have warmed the earth or that we can alter its course. There is never any "proof" in science. The fact that we have warmed the Earth is, however, supported by evidence at this point that is now beyond reasonable doubt. We have altered the course of its climate. It is also a basic physical fact that we can alter the future course of warming by reducing greenhouse gas emissions. (How much alteration is economically feasible is a different matter.) there is speculation, lab models, and computer simulations, but nothing conclusive. You are woefully underinformed about the evidence. You can start by reading the IPCC reports.
Wow, another Slashdotter getting modded up for pointing out that correlation != causation.
You know, repating "correlation does not equal causation" is not an excuse to ignore any line of statistical evidence you choose. Correlation doesn't prove causation, but often it is damn suggestive. Most of the evidence linking lung cancer to smoking is "merely" correlation too.
Beside that, experiments do not show merely a "correlation" between CO2 and warming. It is known and very obvious adsorption physics that greater absorption in the IR spectrum than in the visible causes greenhouse warming, when the gas is subjected to visible light and coupled to a heat sink ("the Earth"). The heat sink re-radiates in infrared, and a gas which absorbs more re-radiated heat than incoming visible radiation will inevitably lead to overall warming. As noted by the grandparent, this is easily demonstrated by laboratory experiment.
This is, in fact, the reason why the entire planet is not a frozen iceball: if you leave the greenhouse effect out of the energy balance equations (incoming radiation = outgoing radiation), you'll find that the the temperature of the Earth should be much lower than it actually is. Something is trapping heat, we know for sure. The greenhouse effect is a proven mechanism, and lo, the amount of warming you should get from it is equal to the missing component of the energy balance.
People still debate about global warming, but I can't believe that people are still skeptical of the very existence of the greenhouse effect.
It's reporting on a paper published in the journal Science, one of the top two scientific journals in the world, with something like a 5% acceptance rate for new papers. Don't blame the news editor for thinking it's newsworthy; other Science papers get similar coverage.
Apparently, Purdue refused to state what the exact allegations investigated were, how many inquiries it conducted, or what its conclusions were based on. Hard to tell if the investigation's conclusions were arrived at fairly or were politically motivated. More details in this NYT article which I found from this blog entry.
The climatic conditions tens of millions of years ago are irrelevant to the attribution of the recent phenomenon of global warming. We can say that the current warming is "primarily due to" mankind's CO2 emissions irrespective of what drove the climate in past ages, purely on the basis of what we know about the recent climate. The fact that the Earth was once warmer, or colder, is not relevant to the fact that actions due to mankind are substantially responsible for the temperature increase that has occurred over the past 150 years.
Not hardly; it wouldn't even pay for a Mars mission (estimated in excess of $50 billion).
Human influence on the climate is not negligible, and will become even less so in the future.
Rahmstorf et al. (2004)
Foukal et al. (2006)
Stott et al. (2003) Human activity is responsible for 50% of CO2, the other 50% is volcanic sources. It's been some time since volcanic sources could compete with human activity for CO2 production; current anthropogenic CO2 production is about 100x larger than that of volcanic activity. That makes human activity culpable for about 0.05C in two hundred years. That is very far from what pretty much every other study ever done in climatology has found.
Also note that even that paper finds that anthropogenic activity competes equally with solar forcing before 1955, and exceeds it after 1955. Of course this paper attributes global warming to cosmic forces No, it doesn't. It attempts to associate glaciation cycles with cosmic rays. It doesn't say anything about the relatively recent phenomenon of global warming. We've reached the technological ability to see the change, and like Chicken Little run around declaring the "the sky is falling". Are you denying that climate change, whatever its source, has serious potential impacts that we should be concerned about?
It is likely that orbital variations do affect climate over tens of thousands of years; see the Milankovitch cycles. That said, it's fairly irrelevant to global warming, other than the fact that global warming might not be as much of an issue if we were in an ice age part of the cycle.
Does anyone think we can afford that? The U.S.'s manned space and Moon/Mars initiative is strangling NASA and forcing it to shut down many of its science programs (here, here, here, here, here). It hasn't even started to get into the real spending for a Moon mission, let alone a Mars mission.
An interstellar mission would cost orders of magnitude more than an interplanetary mission. Who would ever fund it? Even an international collaboration would be hard pressed to put together much more than the currently planned Mars mission. And governments wouldn't be too keen to start a mission that can outlive entire nations before we hear the results.
"Frontier spirit" just doesn't cut it against those scales of money and time.
The only thing that likely could spur a manned interstellar mission, barring drastic improvements in technology, is the impending destruction of human civilization — and who would see that coming in time, with enough certainty, to spur the development of a crash program like that? (Especially given the wars likely to ensue if people are that sure of the annihilation of the human race.)
No, I don't see it happening unless we get much, much better technology. It costs enough just to lift things off Earth, let alone build and launch a working intergenerational starship. (The economics of space development given launch costs and the absence of space industry is an extra can of worms... and I am also not economically optimistic of the development of orbital factories or space elevators or the like.)
Niven wrote about this in A Gift From Earth. In his scenario, there were the "crew" who stayed awake through the voyage, and the "colonists" who stayed asleep. Upon arrival, the crew decided that they should rule by natural right, since they stayed awake, aged, and did the hard work while the others snoozed away. They forced the colonists at gunpoint to sign their rights away, and essentially enslaved them.
Claiming "scientists can be wrong" is not an argument. Everyone can be wrong. It is up to you to show that they are wrong, despite the evidence to the contrary.
Somehow these "solutions" don't seem as preferable when it's you who has to bear the burden. And don't even try to claim that there is unlimited free land for refugees to buy with the cushy new jobs they'll be able to get. Lol.. You act like that cannot be done. And there being enough jobs is something that will need to be looked at when the movment is happening. I don't know which is more appalling, your economics or your politics. No, the free market will not magically create as many jobs as there are people who need them. The illegal ones do shit jobs that don't pay but hat is because as illegal aliens they don't have the same amounts of recourse a citizen does. I assure you, if we had as many legal immigrants as there are illegal immigrants, they wouldn't be getting jobs as good as the current average citizen's, particularly if we don't get to pick the ones with the best educations but have to take anybody who needs to be relocated. This is more because of how france is run then how immigrants are treated. Yeah, as if other countries treat immigrants equally. I hope you are not going to claim that America has.
If you dump tons of new immigrants into any country over a relatively short period of time, you will have social unrest and incomplete assimilation. It's easy to see this in America's own past, and that's when America was relatively eager to accept new immigrants. Which countries do you think are going to be eager to accept large new populations from random, say, African nations? Certainly not other African nations. If they don't want to move, then let them suffer whatever the problems are. It is that simple. Like I said, a very Stalinist viewpoint. The social consequences of depopulating entire nations are far worse to both them and to the other nations purportedly resettling them, which is why nobody has been stupid enough to try your plan. But suggesting that others are somehow obligated to support them because they didn't make a sound decision is bullshit. Moving to another country is not always the "sound decision" you think it is, and it is far less expensive to support nations as-is than try to eradicate them in a diaspora and re-establish their people inside other countries. So, How does my ability to get along with someone effect anything in discusion here? It means that you have a Stalinist viewpoint towards population control, and we all saw how well that worked out. Stalin too tried to redistribute the population within his own country, to poor effect. And you think living there in those condition is a good idea? It's better than your idea, which is economically, politically, socially, and ethically completely unworkable.
You and Stalin would have gotten along just fine, I think. In a lot of situations, the problem isn't that the land won't support the life living on it, it is more like the life living on it has outnumbered the ability for the land to support it. It is rarely the case that starvation is due to an intrinsic inability of land to support its population. It has more to do with an economy that can't support modern practices of agriculture and distribution of goods, dictators that don't support their people, and so on.
Ah, the old "well-meaning but naive environmentalists make stupid decisions" meme.
The ban on DDT in the U.S. did not result in 30 million deaths from malaria. There is no international ban on DDT: it is still used in developing countries to combat malaria, and it can only be used up to a point before the mosquitoes start developing immunity to it. (In fact, it is even used in the U.S. occasionally for disease control as a residential insecticide; it is only banned as a general-use agricultural pesticide.)