Participants is another thing. The quality of the conversation has certainly declined. However, I like to reply to a few of the more arrogantly wrong ones as a public service.
(Not that this applies to this question!)
I'll reply to a well-posed question too in the rare event I come across one. I've seen a couple of other informed posters on these threads as well.
The best climate discussion site these days is realclimate, which is moderated.
Michael Tobis, Ph.D. (Atmospheric and Oceanic Sciences, U. Wisconsin - Madison 1996)
Assuming the ocean stays liquid, there isn't really a "right" temperature for the earth. There is, however, still such a thing as catastrophic climate change. This occurs when climate, er changes, er catastrophically.
Rapid climate change is bad for us and we should do everything in our power not to force the rate of change to get orders of magnitude higher than natural norms.
mt
Just out of curiosity, has anyone bothered to compare the atomic weight of CFC's to say, general atmoshpere of comparitive volume (espcially of the higher O3 areas?). Seems to me it would be mighty diffucult for the CFC's to traverse up that high due to their weight.
The atmosphere is turbulently mixed up to 80 km. This is fortunate, because otherwise the nitrogen would sink below the oxygen and we couldn't breathe.
see this lecture for example. The relevant part is at the end.
Oh, wait a sec! They also only collect AT THE SOUTH POLE. Must like it cold or something.
No, the atmosphere is well-mixed, remember? They only catalyze ozone breakdowns at extremely cold temperatures.
One ought to do some research on the effects of CFC with Ozone (O3).
yes, perhaps one could win a Nobel Prize or something.
[usual paranoid rants about DuPont elided. Let's stipulate that DuPont wanted to make money.]
I agree with an above post. Dissenting voices cause society to label one as a "nutcase" or "extremist" Isn't science all about finding logical explanations to the world around us? I say, follow the money trail, and you'll find who concocted the stories of global warming, global cooling, ozone holes.
Err, yes, I agree. Follow the money is right. I think it might be the case that the tiny little energy corporations are trembling under the onslaught of misinformation from the hugely financed scientific professional organizations and NGOs. But it might be the other way around.
From the BBC article: "New readings from the European satellite Envisat suggest that this year's southern hemisphere ozone hole may be one of the largest on record."
Therefore, no contradiction with "stabilizing", which the BBC article also asserts.
I suppose there's "no such thing as a bad question", but if there were, this would be one. So, bad editing.
I have no trouble accepting that carbon emissions could cause warming, however the evidence isn't there yet.
As usual, let me point out that the evidence is there exactly where you'd look for it.
I doubt you have friends "in climatology" (as opposed to a freshman met survey) who think global warming is not a real problem. Such people are very rare. Shaking youyr head at every "ice age is coming" panic isn;t the same thing as saying the evidence is not there.
The thing is, what happens if (by a miracle) enough nations enact policies that cause lower greenhouse gas emissions and global warming stops? Then who wins?
Unless there's asteroids, huge volcanos or nuclear war, even if net anthropogenic emissions dropped to zero we expect at least twenty or thirty years more warming is already in the pipeline.
Right, fairness should not mean equal time, and even less should it mean taking both sides of a question equally seriously. There is such a thing as being substantively wrong.
A lot of people like to drum up arguments that the world is a few thosand years old. They are wrong. They do not deserve equal time to inflict their superstition on children. They do not deserve their own "research grants".
In the case of climate change, there is a spectrum of scientific opinion, and the exact middle of it is being cast as "one side", while there is a pile of propaganda with a couple of credentialed paid advocates, pretty much outside the spectrum of scientific opinion or at best very much at the fringe (I'm being generous here) that is cast in the press as "the other side".
Whenever people see these as two contending scientific opinions rather than a political opinion arrayed against the great mass of scientific reseach, the propagandists win.
Of course junk science cuts both ways, but in this case the junk is on the side that says there isn't a problem, not on the side that says it is.
That all said, I regret my use of the word "unanimous", and I regret that parent picked up on it. I make no claim that all the membership of the scientific bodies I mentioned supported their positions. Note these are in some cases huge groups, and an occasional bad apple will stray in. The relevant bodies themselves are all agreed (a sort of unanimity), but it goes too far to say or imply that their memberships are *unanimous* about whether IPCC fairly represents the science.
That said, the not-quite-unanimous vast majority of scientists in relevant fields would agree that IPCC does a good job of summarizing the scientific evidence. It is a thorough, disciplined and responsible presentation of the center of informed scientific opinion on these matters.
Even this balanced-seeming 50/50 position is a victory for the propagandists.
In fact, leaving aside the anthropogenic parts of the forcing and just running the models with natural forcing usually shows a slight cooling recently. You could say that the best estimate is that about 110% of the warming is anthropogenic, and negative 10% is natural.
The observed warming in the latter half of the 20th century appears to be inconsistent with natural external (solar and volcanic) forcing of the climate system.
Although there are measurements of these forcings over the last two decades, estimates prior to that are uncertain, as the volcanic forcing is based on limited measurements, and the solar forcing is based entirely on proxy data. However, the overall trend in natural forcing over the last two, and perhaps four, decades of the 20th century is likely to have been small or negative (Chapter 6, Table 6.13) and so is unlikely to explain the increased rate of global warming since the middle of the 20th century.
The fraction of the observed warmng that is caused by humans is almost certainly well over 50 % and may well be over 100%.
It was a nice analogy until you got to the captain part. This boat has no captain, it is run by an unruly committee. Global climate change forcing is a global problem and can't be solved one nation at a time.
The science says NOTHING conclusive concerning what part of global warming is natural and what part is due to human activity. Jury's still out on this one, at least to people who care about empiricism.
This is polemical nonsense. If science says nothing colclusive about this matter it says nothing conclusive about anything.
This is the only planet in the known universe that supports advanced life, not a court of law. Even if the "beyond a reasonable doubt" criterion were not satisfied (a threshhold which was passed some time ago) the criterion is wrong; greenhouse gases are not innocent until proven guilty.
If you must use legalistic arguments, surely the presumption of innocence goes to the undisturbed atmosphere, not to the pollutant.
The best available evidence is overwhelming that most or even all of the observed warming is caused by humans, that most of past warming and cooling episodes were related to natural variation in greenhouse gases, and that the warming will continue to accelerate. The predictions based on this understanding that were made around 1990 are on track.
If you want to call this frenzied hair-pulling, teeth-gnashing, and I-just-pulled-this-out-of-my-ass guesswork I guess you can do that, but I think it's an empirically sound approach to call you uninformed on this matter, to say the least.
Like.. erm.. forming an opinion based on personal morals or political beliefs and then applying for grants to pay for the search to find abberations in nature that support your opinion, while ignoring anything that may or may not be contrary to it?
What makes you think that would be a good way to get grants, anyway? Seriously dishonest people can make a quick buck more easily than by getting doctorates in geophysics and geochemistry and gaming the grants process. Why would someone smart enough and dishonest enough to lie in this way even bother? I'm not saying it never happens, but you are saying it inevitably happens.
You also obvously don't understand how the grants process works, but that's a long story,
I'm not claiming the granting process doesn't distort science; that is an inevitable cost of doing things outside the private sector, and like anything public it requires eternal vigilance. Still, outright fraud of the sort you would like to believe in is rare because it just isn't worth the trouble.
To make matters worse for your point of view, you have to accuse the entire scientific community of complicity for your belief to make sense. The National Academy of Sciences, the American Association for the Advancement of Science, the American Geophysical Union and the American Meteorological Society are not unanimously corrupt on behalf of a small segment of their membership. They wouldn't put the whole scientific enterprise at risk for some superstitious hippie idea.
You need to reconsider who has the preconceived ideas here.
You seem to be confusing "wearing a cheap suit" with "peer review".
As for 60% of the observed warming before 1940, that was a cheap statistical trick back when it was half-true (1940 was an anomalously warm year, and they also chose an anomalously cold start year). Cherry picking the start and end dates rather than doing a proper linear regression made the most of the random fluctuations to assert this misleading point.
However it is no longer a cheap trick. The statement was half-true in the early 90s, but there has been enough warming since then that it is simply wrong.
The 140 M tons is Britain alone, per year. The global total is 6GT, neatly working out to about a ton per person per year. It's unevenly divided, with a few countries having per capita emissions 5 times higher than the average.
High latitude methane may nevertheless work out to be a big deal. Softening the blow a bit is the fact that methane is shorter-lived in the atmosphere than CO2.
Some researchers believe that tundral methane releases play a big role in the termination of the recent glaciations.
The short answer is this. The earth has no proper temperature but it has a proper rate of change of temperature, which it is beginning to exceed, thanks to a huge anthropogenic perturbation.
Read this to see what the dominant opinion is in the relevant scientific communities.
The climate on the planet earth is about five degrees warmer than it was at the peak of the last glaciation twenty thousand years ago. Local temperatures vary much more than the gloabl mean, because the global mean is constrained by an energy balance with incoming solar radiation. That is why a degree in a century is a big deal in itself.
It's a mistake to think of this as a linear trend. It is accelerating; also it takes some decades to warm up to a given forcing. What we see now is the warming we already committed to in 1980. What's more, policies themselves take time to develop and implement, so really what we see now was pretty much the inevitable warming that we had in place by 1960 or so.
In effect, we are already committed to fifty years of more warming. If we don't get a grip on it, there is no reason to expect it won't accelerate, and go on for a very long time. If we do nothing as far as policy is concerned, the science tells us pretty clearly that things will keep getting more out of whack and faster.
The question is, when do we decide to do something about it? Until the coal runs out or we get it into our heads that it is time to act, whatever we see at any given moment will be a small fraction of what we are already committed to.
When I first started studying this matter in 1991, I believed that the world would start taking action by about now, so I did not believe people who saw this as the biggest problem around.
I was wrong.
At this point we are in big trouble and still lots of folks are coming up with irrational arguments for ignoring it.
No, a single eruption, even a gigantic one, is no big deal as far as the total CO2 in the atmosphere/ocean system is concerned. Human activity is already releasing many times more than a large eruption per year.
However, it would take a LOT of CO2 to break out of the snowball state. It looks like the snowball lasted some tens of millions of years. On that time scale, under normal non-snowball conditions CO2 is removed by the reactions involved in erosion of mountain ranges. In the snowball, all that rock is covered up and you have tens of millions of years for the carbon to build up. Then you get a super-greenhouse to get you out of the state that the broken greenhouse got you into.
(Note I am using the "geophysicists second person" grammatical form. We tend to refer to the earth as "you" for some bizarre reason.)
Your prof is worng to say that nobody takes it seriously. We had a couple of lectures at the Univeristy of Chicago Geophysics department on this in the past year. The theory is beyond viable. It currently appears to be winning from what I have seen of late (though it's a bit peripheral to my own expertise.)
The question of how the earth escaped its snowball state, is indeed a good one. The dominant theory is that it was a CO2 buildup from volcanos that was unbalanced by the usual process of rock weathering. Unfortunately, most simulations show that as not quite enough. On the multimillion year time scale though you have enough time for an asteroid hit. One of our profs (not the guy giving the talk) suggested that an asteroid hit in the equatorial region after the CO2 built up, exposing open water. (Geothermal heat along with excellent insulation would have kept the abyss liquid.) This would allow enough of an albedo decrease that along with the CO2 buildup you might trigger the melting. I confess I had the same thought. I'm not sure if anyone has looked into this possibility.
Another good question is how life survived the snowball without having to start entirely over from scratch.
Everyone agrees that (presuming it occurred; I am assured that the geological evidence is compelling) it was a narrow escape.
There is an excellent popuar book on the subject, called "Snowball Earth", by Gabrielle Walker.
You lost me at "this [lack of water vapor] is why it's so cold at the tops of mountains". Wrong in a very elementary sense.
That was long before you completely lost me at "It is my opinion that our global warming folks should take a degree in paleoclimatology and learn what the earth is telling us before they go spouting off. " Oh please, let's do consult the paleoclimatologists. The IPCC, of course, does.
And your mistyped final sentence, which I presume you meant to say there's no water vapor in the IPCC models. First of all, the IPCC has no models; it simply reports on the science other groups do, including running various classes of computer models. Anyway, doesn't the idea that professional climatologists who get articles in Science and Nature have never thought about water vapor strike you as even slightly implausible?
Slashdot Mirror
For one thing the ozone hole was discovered in 1980.
Lots of other nonsense here, probably recycled from a right wing political magazine.
Participants is another thing. The quality of the conversation has certainly declined. However, I like to reply to a few of the more arrogantly wrong ones as a public service. (Not that this applies to this question!)
I'll reply to a well-posed question too in the rare event I come across one. I've seen a couple of other informed posters on these threads as well.
The best climate discussion site these days is realclimate, which is moderated.
Michael Tobis, Ph.D. (Atmospheric and Oceanic Sciences, U. Wisconsin - Madison 1996)
Hmm, the prize said "chemistry" on it, not "junk". Maybe a typo?
Assuming the ocean stays liquid, there isn't really a "right" temperature for the earth. There is, however, still such a thing as catastrophic climate change. This occurs when climate, er changes, er catastrophically. Rapid climate change is bad for us and we should do everything in our power not to force the rate of change to get orders of magnitude higher than natural norms. mt
Just out of curiosity, has anyone bothered to compare the atomic weight of CFC's to say, general atmoshpere of comparitive volume (espcially of the higher O3 areas?). Seems to me it would be mighty diffucult for the CFC's to traverse up that high due to their weight.
The atmosphere is turbulently mixed up to 80 km. This is fortunate, because otherwise the nitrogen would sink below the oxygen and we couldn't breathe.
see this lecture for example. The relevant part is at the end.
Oh, wait a sec! They also only collect AT THE SOUTH POLE. Must like it cold or something.
No, the atmosphere is well-mixed, remember? They only catalyze ozone breakdowns at extremely cold temperatures.
One ought to do some research on the effects of CFC with Ozone (O3).
yes, perhaps one could win a Nobel Prize or something.
[usual paranoid rants about DuPont elided. Let's stipulate that DuPont wanted to make money.]
I agree with an above post. Dissenting voices cause society to label one as a "nutcase" or "extremist" Isn't science all about finding logical explanations to the world around us? I say, follow the money trail, and you'll find who concocted the stories of global warming, global cooling, ozone holes.
Err, yes, I agree. Follow the money is right. I think it might be the case that the tiny little energy corporations are trembling under the onslaught of misinformation from the hugely financed scientific professional organizations and NGOs. But it might be the other way around.
Therefore, no contradiction with "stabilizing", which the BBC article also asserts.
I suppose there's "no such thing as a bad question", but if there were, this would be one. So, bad editing.
As usual, let me point out that the evidence is there exactly where you'd look for it.
I doubt you have friends "in climatology" (as opposed to a freshman met survey) who think global warming is not a real problem. Such people are very rare. Shaking youyr head at every "ice age is coming" panic isn;t the same thing as saying the evidence is not there.
In fact, it's there. Go look.
Unless there's asteroids, huge volcanos or nuclear war, even if net anthropogenic emissions dropped to zero we expect at least twenty or thirty years more warming is already in the pipeline.
A good opportunity here to remind Slashdot of this interesting summary of the state of NASA (a +5 article from not long ago, not one of mine).
A lot of people like to drum up arguments that the world is a few thosand years old. They are wrong. They do not deserve equal time to inflict their superstition on children. They do not deserve their own "research grants".
In the case of climate change, there is a spectrum of scientific opinion, and the exact middle of it is being cast as "one side", while there is a pile of propaganda with a couple of credentialed paid advocates, pretty much outside the spectrum of scientific opinion or at best very much at the fringe (I'm being generous here) that is cast in the press as "the other side".
Whenever people see these as two contending scientific opinions rather than a political opinion arrayed against the great mass of scientific reseach, the propagandists win.
Of course junk science cuts both ways, but in this case the junk is on the side that says there isn't a problem, not on the side that says it is.
That all said, I regret my use of the word "unanimous", and I regret that parent picked up on it. I make no claim that all the membership of the scientific bodies I mentioned supported their positions. Note these are in some cases huge groups, and an occasional bad apple will stray in. The relevant bodies themselves are all agreed (a sort of unanimity), but it goes too far to say or imply that their memberships are *unanimous* about whether IPCC fairly represents the science.
That said, the not-quite-unanimous vast majority of scientists in relevant fields would agree that IPCC does a good job of summarizing the scientific evidence. It is a thorough, disciplined and responsible presentation of the center of informed scientific opinion on these matters.
In fact, leaving aside the anthropogenic parts of the forcing and just running the models with natural forcing usually shows a slight cooling recently. You could say that the best estimate is that about 110% of the warming is anthropogenic, and negative 10% is natural.
see http://www.grida.no/climate/ipcc_tar/wg1/467.htm
The fraction of the observed warmng that is caused by humans is almost certainly well over 50 % and may well be over 100%.
It was a nice analogy until you got to the captain part. This boat has no captain, it is run by an unruly committee. Global climate change forcing is a global problem and can't be solved one nation at a time.
This is polemical nonsense. If science says nothing colclusive about this matter it says nothing conclusive about anything.
This is the only planet in the known universe that supports advanced life, not a court of law. Even if the "beyond a reasonable doubt" criterion were not satisfied (a threshhold which was passed some time ago) the criterion is wrong; greenhouse gases are not innocent until proven guilty.
If you must use legalistic arguments, surely the presumption of innocence goes to the undisturbed atmosphere, not to the pollutant.
The best available evidence is overwhelming that most or even all of the observed warming is caused by humans, that most of past warming and cooling episodes were related to natural variation in greenhouse gases, and that the warming will continue to accelerate. The predictions based on this understanding that were made around 1990 are on track.
If you want to call this frenzied hair-pulling, teeth-gnashing, and I-just-pulled-this-out-of-my-ass guesswork I guess you can do that, but I think it's an empirically sound approach to call you uninformed on this matter, to say the least.
nope.
What makes you think that would be a good way to get grants, anyway? Seriously dishonest people can make a quick buck more easily than by getting doctorates in geophysics and geochemistry and gaming the grants process. Why would someone smart enough and dishonest enough to lie in this way even bother? I'm not saying it never happens, but you are saying it inevitably happens.
You also obvously don't understand how the grants process works, but that's a long story,
I'm not claiming the granting process doesn't distort science; that is an inevitable cost of doing things outside the private sector, and like anything public it requires eternal vigilance. Still, outright fraud of the sort you would like to believe in is rare because it just isn't worth the trouble.
To make matters worse for your point of view, you have to accuse the entire scientific community of complicity for your belief to make sense. The National Academy of Sciences, the American Association for the Advancement of Science, the American Geophysical Union and the American Meteorological Society are not unanimously corrupt on behalf of a small segment of their membership. They wouldn't put the whole scientific enterprise at risk for some superstitious hippie idea.
You need to reconsider who has the preconceived ideas here.
As for 60% of the observed warming before 1940, that was a cheap statistical trick back when it was half-true (1940 was an anomalously warm year, and they also chose an anomalously cold start year). Cherry picking the start and end dates rather than doing a proper linear regression made the most of the random fluctuations to assert this misleading point.
However it is no longer a cheap trick. The statement was half-true in the early 90s, but there has been enough warming since then that it is simply wrong.
High latitude methane may nevertheless work out to be a big deal. Softening the blow a bit is the fact that methane is shorter-lived in the atmosphere than CO2.
Some researchers believe that tundral methane releases play a big role in the termination of the recent glaciations.
I am not assuming anything. Try to understand what the word "science" means.
Applause!
More than a little. http://www.realclimate.org/index.php?p=74 http://www.realclimate.org/index.php?p=76
The short answer is this. The earth has no proper temperature but it has a proper rate of change of temperature, which it is beginning to exceed, thanks to a huge anthropogenic perturbation.
Read this to see what the dominant opinion is in the relevant scientific communities.
It's a mistake to think of this as a linear trend. It is accelerating; also it takes some decades to warm up to a given forcing. What we see now is the warming we already committed to in 1980. What's more, policies themselves take time to develop and implement, so really what we see now was pretty much the inevitable warming that we had in place by 1960 or so.
In effect, we are already committed to fifty years of more warming. If we don't get a grip on it, there is no reason to expect it won't accelerate, and go on for a very long time. If we do nothing as far as policy is concerned, the science tells us pretty clearly that things will keep getting more out of whack and faster.
The question is, when do we decide to do something about it? Until the coal runs out or we get it into our heads that it is time to act, whatever we see at any given moment will be a small fraction of what we are already committed to.
When I first started studying this matter in 1991, I believed that the world would start taking action by about now, so I did not believe people who saw this as the biggest problem around.
I was wrong.
At this point we are in big trouble and still lots of folks are coming up with irrational arguments for ignoring it.
However, it would take a LOT of CO2 to break out of the snowball state. It looks like the snowball lasted some tens of millions of years. On that time scale, under normal non-snowball conditions CO2 is removed by the reactions involved in erosion of mountain ranges. In the snowball, all that rock is covered up and you have tens of millions of years for the carbon to build up. Then you get a super-greenhouse to get you out of the state that the broken greenhouse got you into.
(Note I am using the "geophysicists second person" grammatical form. We tend to refer to the earth as "you" for some bizarre reason.)
The question of how the earth escaped its snowball state, is indeed a good one. The dominant theory is that it was a CO2 buildup from volcanos that was unbalanced by the usual process of rock weathering. Unfortunately, most simulations show that as not quite enough. On the multimillion year time scale though you have enough time for an asteroid hit. One of our profs (not the guy giving the talk) suggested that an asteroid hit in the equatorial region after the CO2 built up, exposing open water. (Geothermal heat along with excellent insulation would have kept the abyss liquid.) This would allow enough of an albedo decrease that along with the CO2 buildup you might trigger the melting. I confess I had the same thought. I'm not sure if anyone has looked into this possibility.
Another good question is how life survived the snowball without having to start entirely over from scratch.
Everyone agrees that (presuming it occurred; I am assured that the geological evidence is compelling) it was a narrow escape.
There is an excellent popuar book on the subject, called "Snowball Earth", by Gabrielle Walker.
Hey editors, Google is your friend!
That was long before you completely lost me at "It is my opinion that our global warming folks should take a degree in paleoclimatology and learn what the earth is telling us before they go spouting off. " Oh please, let's do consult the paleoclimatologists. The IPCC, of course, does.
And your mistyped final sentence, which I presume you meant to say there's no water vapor in the IPCC models. First of all, the IPCC has no models; it simply reports on the science other groups do, including running various classes of computer models. Anyway, doesn't the idea that professional climatologists who get articles in Science and Nature have never thought about water vapor strike you as even slightly implausible?