As sad as John's passing was to our community, he did an excellent job of passing the torch on before he left us. There was only one unresolved pull request from him (we are still working on it, actually), and he selected an excellent person with almost as many commits as him to take over. Michael Drottenboom has been doing an excellent job, and our developer base has actually grown a bit. Of course, we would love to have some more people involved, but there is absolutely no uncertainty in our community with regards to the future of matplotlib. Have you tried out the experimental WebAgg feature? Pure awesomness.
Heh, try being a meteorologist (not even a climate scientist), and those people come out of woodworks. I had one guy trying to argue against it based on (his understanding of) the laws of thermodynamics. Another trying to claim that because it couldn't accurately forecast the temperature outside his house, it must be wrong.
No LOL... you claimed that I said that there were so many problems that I wouldn't know where to start. That is not what I said, and I even provided a starting point. I pointed out a problem with your dependence upon using the press as the bona fide source of scientific consensus. Others have pointed out errors in other statements you made. Furthermore, you still fail to understand the distinction between a press release from a single scientist or scientific entity (be it a journal article or an article in a newspaper) as opposed to true scientific consensus. Just because it was published doesn't make it a part of the scientific consensus. As I stated, subsequent vetting of some of those ideas have resulted in finding flaws in the research, but you almost never hear of those articles in the press. Meanwhile, the vetting of other articles have yet to find significant flaws and the information has been subsequently been used in other research and proved valuable.
Of course, just because someone publishes an article claiming to find a flaw in someone else's research does not necessarially mean that the original research was flawed, either. That article has to be vetted as well. Science is slow, tedious, and a lot more ambiguous than the media has made it out to be.
There was a time when, based on their observations, scientists thought there were canals on Mars. The reception of that news was probably mostly positive too.
Actually, that was a result of a misunderstanding of the Italian word "canali" that resulted in a translation into English as canals. *Some* English-reading scientists then made the logical leap that the canals must be made by intelligent life. As soon as better telescopes became available, it was found that the original observed canali were an optical illusion, and the scientific community as a whole dropped the false canals idea.
Then there's the fact that global warming causes *everything*. Warm winter? Global warming. Terrible winter with lots of snow? Global warming. Bad hurricane? Global warming. Few hurricanes during the season? Global warming.
Every single thing in that list has been attributed to global warming in the press.
Emphasis mine. There are a bunch of other issues with what you have said, but I wish to focus on this: "in the press".
Academic discourse does not take place in the press. Just because a researcher publishes a single article in a scientific journal does not make it automatically a part of the consensus. It takes years of subsequent vetting to verify or refute the claims made in the article. I will tell you that in the current scientific discourse, we have found several of these claims to be bogus or unsubstantiated, but other claims have so far stood the test of scrutiny.
Actually, he is. These sort of large-scale projects are funded through authorizations by Congress. He has to work with the budget he is given, and when an authorization bill says that such-and-such will be purchased, he can't go ahead and say no. Specific details are often left up to the Executive branch, but the president can not unilaterally decide to build a hundred datacenters without having the money approved by Congress.
By and large, most of the active scientists and researchers directly in the climate field and those in the periphery (like myself) are like this (including Dr. Mann). We often have to call out BS publications (on both sides of the argument) that uses shoddy statistics and methods. However, because most of the scientific discourse is within the community, the few things that catches the attention of the general public and "armchair scientists" provides a highly skewed picture of the active debate. Add in that the media loves a good drama, and things go hell in a handbasket.
For the raw data that was freely (as in gratis and libre) available already, several other research groups have taken their published methods for quality-control and duplicated their results for that data. For the data that was not freely available, there were some groups that purchased the data themselves (much of this data was always available for purchase) and reproduced and published results as well.
On top of that, there were other research groups that performed "quality-control and analysis" on completely different sets of data, and their results agree well with results published by others. Note that I said the results "agree well" with each other. They are not perfect matches, and where there are differences, subsequent research and analyses have yielded refined methods and results. Think of it as a large bootstrapping problem.
Now, you ask that how do we know that the analysis was done in a fair and objective manner in all places? Well, we could never be 100% sure until each and every single datapoint has been vetted and doing this is now easier than before (not that it was impossible to do before). However, analyses and research on the published datasets have not revealed any such tampering so far, therefore *I* am fairly confident that it didn't happen. If you are not convinced, then feel free to take these datasets and others and perform the analysis yourself. Just remember to publish your findings whether they are for good or naught.
That is a separate discussion. This data release is about weather station data. This was something I am much more familiar with. How the tree ring data was collected and used is outside my field of expertise. If the data was strictly from a single tree, then that would be a severe problem. However, since I generally work from scientific publications and correspondance and not "The Telegraph", I hope you would excuse me from immediately vilifying Dr. Mann and his associates.
I usually don't reply to AC, but what the heck. All of the published methods were reproducible with established datasets, and the "massaging" process was also reproducible. The data being directly massaged into climate data was available (just not "freely" available -- as in gratis). You would have had to pay money to get at that data, just as CRU did for many of them. People did not want to do the legwork that CRU had to do. CRU was more than happy to release the data, but they were contractually bound not to. But when the same people kept on insisting that CRU break the contractual obligations, that is when they got testy.
Right... so, half the energy goes up into space (assuming the simple RTE model) and half goes down to the earth's surface. Let's consider that energy that went up to space as "lost". What about the half that went down to the Earth's surface? Well, some gets reflected, and most gets absorbed. Then, what happens to that absorbed energy? It gets radiated back out to the atmosphere. Some of which passes right through, some of it gets reflected down to the surface (top of the loop again), and some of it gets absorbed (back at the beginning).
This is taught in undergraduate meteorology courses. Graduate-level courses use even more intricate models that account for far more. Were you under the assumption that climate scientists were not "considering both sides of the molecule"?
Yes and no. The data that was already released was the "reanalysis" data which is the culmination of many, many, many observations from all around the world. These observations were all done at different time intervals, with different methods and different instruments. The raw data is nearly useless as it contains faulty data, biases and other effects that have to be accounted for. The work of those at CRU and other places have been to meticulously quality-control and analyze the raw observations down to a uniform grid (spatially and temporally).
In addition to the reanalysis data that was already fully released, much (but admittedly not all) of the raw observational data used to generate the reanalysis data was also already released. The data that was not already released was being withheld by the various organizations that accrued that data (some European countries and such). CRU was not allowed to release that data that they were given access to -- until now.
Personally, I think all data should always be available and most scientists and research groups do abide by this tenet. However, I can't bring myself to hold it against a research unit for being able to obtain some proprietary data and publish results on that information. When I was an undergraduate student, I had the opportunity to work on an analysis of snow storms/ice storms using an insurance company's accident dataset. That is highly proprietary information, and we were very lucky to even get a glimpse of a small subset of this information. If companies thought that one day down the road, some government would come along and force their proprietary datasets to be opened up just because part of it got shared with a public university, then we would never get access to such data and be able to publish useful research based on it. Heck, researchers within various companies would never publish their works either because of that looming threat.
Again, I repeat, I personally believe that all that data should be open anyway, but as a pragmatist, I would rather have some of the proprietary data rather than none.
Actually, if anything, I have always thought that with the way Canoncial was doing global menus, it was actually helping to phase them out. Quite honestly, how often does anybody use the menus in many of the apps? I think LibreOffice is the only application where I regularly use the menu. By moving menus to a global location, and even doing the hiding of it with the window's title really pushes the menu further and further into irrelevance -- which I agree with 100%.
Maybe now, apps won't need to shoehorn in a menu, just because all other applications have them too.
From that, he drew the logical conclusion that if his theory was correct, then increasing CO2 would increase surface temperatures.
That's an assertion, not a fact.
I never claimed it was a fact. Actually, I only claimed it was a corollary that was entirely dependent upon the general radiative transfer theory being correct
Since obviously there are more players in the general greenhouse theory than simply CO2 (cloud albedo, for example), you can only really say "increasing CO2 would increase surface temperature, *all other things being kept exactly the same*". Since we know the climate system, both terrestrial and solar does not stay the same, this is hardly a useful general theory.
Of course there are more players, but that's why Arrhenius's theory calls CO2's impact as an "augmentation of temperature". He didn''t say that the theory absolutely predicts with absolute certainty that the global temperature will rise. He said that CO2 will have a warming forcing upon the surface temperature of the Earth. Indeed, if all else is kept equal, then that will mean an overall warming, but this was climate science at its infancy, and they couldn't have possibly imagine all of the interesting dynamic feedback mechanisms that we have since learned.
Arrhenius's statement of "if the quantity of carbonic acid increases in geometric progression, the augmentation of temperature will increase in nearly in arithmetic progression" is merely a corollary to the mathematical formulation he used for his theory.
Again, I think you're glossing over the "all other things being kept exactly the same".
And you would be wrong. You simply fail to understand the context that the theory is used in modern day climate science. It by itself does not explain everything, and no climate scientist ever would claim that it does.
Now, what particular component of influences CO2 may have may certainly be open to discussion, but the blunt assertion that CO2, in any quantity, will overwhelm all other drivers is obviously inane.
I am sorry, but those last two sentences do not make any sense. At first, you seem to concede that CO2 might have some influence, and that the amount of influence is up for debate (a debate you are about 100 years late for), and then you proceed to then claim that CO2 could never play a dominate role in the temperature regulation of a planet (which is patently false due to the plain evidence of Venus).
Actually, it wouldn't be that hard. Depending on what your tolerance is, it is pretty much the same as any other day. Also, keep in mind that most of the time, climate scientists are speaking of average temperature deviation. Areas of cold are typically balanced out by areas of warm.
Ok, I think I see the confusion here. The theory that I am talking about was the general greenhouse effect theory that Arrhenius constructed and used to explain the atmosphere's impact on a planet's surface temperature. From that, he drew the logical conclusion that if his theory was correct, then increasing CO2 would increase surface temperatures.
A theory for each planet and moon is not necessary, as Arrhenius's theory has the conditions of a planetary body as parameters to the theory. As for planets like Mars and Venus, we do have surface temperature measures, albeit not long-term measurements. However, because Arrhenius's greenhouse effect theory was not addressing how the surface temperature will change over time (it was a 1-dimensional, steady-state model), short-term observations would be all that was needed to support or disprove his theory. The moons and Mercury do not need in-situ temperature measurements because their surface temperatures can be measured from their brightness temperatures (they do not have much of an atmosphere). Bodies with and without atmospheres provides the means to test for the greenhouse effect.
keep in mind that his theory was only meant to explain the first-order effects of the atmosphere to the surface temperature. In other words, in the presence of an atmosphere, the average surface temperature is significantly warmer than what the steady-state, thermodynamic equilibrium would allow without an atmsphere. Furthermore, his theory stated that different gases at different concentrations had more or less warming of the surface. Arrhenius's statement of "if the quantity of carbonic acid increases in geometric progression, the augmentation of temperature will increase in nearly in arithmetic progression" is merely a corollary to the mathematical formulation he used for his theory. One way to disprove the statement is to disprove the greenhouse effect (by any gas, not just CO2). Another way to disprove it is to find that the temperature augmentation does not follow this formula in lab experiments.
Why is it that the scientists can detect an ozone hole, provide a fix, show that the fix solved the problem
It's worth noting that the complete sequence described above hasn't actually happened. Sure, an ozone hole was detected, but we don't know that human activities have played a significant role in its existence, that is, it may something that occurs anyway without human interference and hence, we are at best very limited in our ability to fix it without some large scale geoengineering project.
True, but given that the CFCs-Deplete-Ozone-Over-Antarctic theory has a well-explained mechanism that has been thoroughly tested in the lab and match well with observations, it has become widely accepted as the explanation. Therefore, the hypothesis that the ozone hole is naturally occurring (to this extent, that is) will require an explanation of the mechanisms that could account for the observations we have. Note that there are ozone observations in the antarctic from before CFCs, so differences in ozone observations before and after CFCs were introduced would need to be addressed.
Then the final claim in the sequence that the "fix solved the problem" is based on nothing but wishful thinking. Here's an alternate scenario. Ozone holes form frequently over Antarctica. We just happened to start observing when an ozone hole had formed. Now that the phenomenon is starting to close up, temporarily, we're attributing that change to our actions which didn't have an effect.
You are right that it is too early to tell for certain that the ozone hole has "recovered". But, do keep in mind that this is slashdot and not your local news channel. This is a first observation, and more are needed over the next few years to even know for sure that that first observation was even right. But it still doesn't diminish the fact that this is an observation. Nothing more, nothing less. Even more obs will be needed over several years to even be sure that it is permanent, but the scientists never claimed it was permanent.
This sort of thing is very relevant because we might see the ozone hole reestablish itself in a few years. This incidentally is what I consider an important observation. If ozone holes periodically return, then that indicates that maybe there's something wrong with the current understanding of ozone depletion models. If it never comes back, that's a solid win for the CFCs-caused-the-ozone-hole theory.
Actually, you have it reversed. The CFCs will eventually break down. They are extremely inert at surface pressures and temperatures (which is why it was ideal for use without health effects). However, at the pressures and temperatures of the ozone layer, and with the level of ultraviolet radiation up there, CFCs do break down. Therefore, a re-established ozone layer is evidence towards CFCs causing ozone depletion, but an ozone layer that does not re-establish itself is evidence that something else caused the depletion. However, even then it would never be 100% for sure, because *maybe* it was a natural oscillation and this was just a coincidence (if it re-establishes itself), or maybe some other agent causes a continued depression of ozone (if it never comes back).
Well, of course we can't just deplete the Earth of its atmosphere in order to satisfy your whims (because that would be the most direct way to support or falsify the theory), but we don't need to. There are several planetary bodies in this solar system with and without atmospheres, and those with atmospheres have different compositions. The temperatures of those planets and moons all match well to the theory put forth by Arrhenius. We have yet to observe a situation where the theory did not hold true. Until that happens, his theory is sound.
Slashdot Mirror
As sad as John's passing was to our community, he did an excellent job of passing the torch on before he left us. There was only one unresolved pull request from him (we are still working on it, actually), and he selected an excellent person with almost as many commits as him to take over. Michael Drottenboom has been doing an excellent job, and our developer base has actually grown a bit. Of course, we would love to have some more people involved, but there is absolutely no uncertainty in our community with regards to the future of matplotlib. Have you tried out the experimental WebAgg feature? Pure awesomness.
My kingdom for a +1 Insightful!
Heh, try being a meteorologist (not even a climate scientist), and those people come out of woodworks. I had one guy trying to argue against it based on (his understanding of) the laws of thermodynamics. Another trying to claim that because it couldn't accurately forecast the temperature outside his house, it must be wrong.
No LOL... you claimed that I said that there were so many problems that I wouldn't know where to start. That is not what I said, and I even provided a starting point. I pointed out a problem with your dependence upon using the press as the bona fide source of scientific consensus. Others have pointed out errors in other statements you made. Furthermore, you still fail to understand the distinction between a press release from a single scientist or scientific entity (be it a journal article or an article in a newspaper) as opposed to true scientific consensus. Just because it was published doesn't make it a part of the scientific consensus. As I stated, subsequent vetting of some of those ideas have resulted in finding flaws in the research, but you almost never hear of those articles in the press. Meanwhile, the vetting of other articles have yet to find significant flaws and the information has been subsequently been used in other research and proved valuable.
Of course, just because someone publishes an article claiming to find a flaw in someone else's research does not necessarially mean that the original research was flawed, either. That article has to be vetted as well. Science is slow, tedious, and a lot more ambiguous than the media has made it out to be.
Were you quoting me? To what are you referring?
There was a time when, based on their observations, scientists thought there were canals on Mars. The reception of that news was probably mostly positive too.
Actually, that was a result of a misunderstanding of the Italian word "canali" that resulted in a translation into English as canals. *Some* English-reading scientists then made the logical leap that the canals must be made by intelligent life. As soon as better telescopes became available, it was found that the original observed canali were an optical illusion, and the scientific community as a whole dropped the false canals idea.
Then there's the fact that global warming causes *everything*. Warm winter? Global warming. Terrible winter with lots of snow? Global warming. Bad hurricane? Global warming. Few hurricanes during the season? Global warming.
Every single thing in that list has been attributed to global warming in the press.
Emphasis mine. There are a bunch of other issues with what you have said, but I wish to focus on this: "in the press".
Academic discourse does not take place in the press. Just because a researcher publishes a single article in a scientific journal does not make it automatically a part of the consensus. It takes years of subsequent vetting to verify or refute the claims made in the article. I will tell you that in the current scientific discourse, we have found several of these claims to be bogus or unsubstantiated, but other claims have so far stood the test of scrutiny.
Huh? Ctrl+g in Firefox means "Find Next", because 'g' was "next to" 'find'.
I totally agree with you about the Damocles sword over NASA's budget, but the one thing that needs to be pointed out is that NASA had nothing to do with this study: http://paleblueblog.org/post/9110304050/some-important-points-of-clarification
The Guardian got it *very* wrong. NASA had nothing to do with this study: http://paleblueblog.org/post/9110304050/some-important-points-of-clarification
Actually, he is. These sort of large-scale projects are funded through authorizations by Congress. He has to work with the budget he is given, and when an authorization bill says that such-and-such will be purchased, he can't go ahead and say no. Specific details are often left up to the Executive branch, but the president can not unilaterally decide to build a hundred datacenters without having the money approved by Congress.
By and large, most of the active scientists and researchers directly in the climate field and those in the periphery (like myself) are like this (including Dr. Mann). We often have to call out BS publications (on both sides of the argument) that uses shoddy statistics and methods. However, because most of the scientific discourse is within the community, the few things that catches the attention of the general public and "armchair scientists" provides a highly skewed picture of the active debate. Add in that the media loves a good drama, and things go hell in a handbasket.
For the raw data that was freely (as in gratis and libre) available already, several other research groups have taken their published methods for quality-control and duplicated their results for that data. For the data that was not freely available, there were some groups that purchased the data themselves (much of this data was always available for purchase) and reproduced and published results as well.
On top of that, there were other research groups that performed "quality-control and analysis" on completely different sets of data, and their results agree well with results published by others. Note that I said the results "agree well" with each other. They are not perfect matches, and where there are differences, subsequent research and analyses have yielded refined methods and results. Think of it as a large bootstrapping problem.
Now, you ask that how do we know that the analysis was done in a fair and objective manner in all places? Well, we could never be 100% sure until each and every single datapoint has been vetted and doing this is now easier than before (not that it was impossible to do before). However, analyses and research on the published datasets have not revealed any such tampering so far, therefore *I* am fairly confident that it didn't happen. If you are not convinced, then feel free to take these datasets and others and perform the analysis yourself. Just remember to publish your findings whether they are for good or naught.
That is a separate discussion. This data release is about weather station data. This was something I am much more familiar with. How the tree ring data was collected and used is outside my field of expertise. If the data was strictly from a single tree, then that would be a severe problem. However, since I generally work from scientific publications and correspondance and not "The Telegraph", I hope you would excuse me from immediately vilifying Dr. Mann and his associates.
I usually don't reply to AC, but what the heck. All of the published methods were reproducible with established datasets, and the "massaging" process was also reproducible. The data being directly massaged into climate data was available (just not "freely" available -- as in gratis). You would have had to pay money to get at that data, just as CRU did for many of them. People did not want to do the legwork that CRU had to do. CRU was more than happy to release the data, but they were contractually bound not to. But when the same people kept on insisting that CRU break the contractual obligations, that is when they got testy.
This is taught in undergraduate meteorology courses. Graduate-level courses use even more intricate models that account for far more. Were you under the assumption that climate scientists were not "considering both sides of the molecule"?
In addition to the reanalysis data that was already fully released, much (but admittedly not all) of the raw observational data used to generate the reanalysis data was also already released. The data that was not already released was being withheld by the various organizations that accrued that data (some European countries and such). CRU was not allowed to release that data that they were given access to -- until now.
Personally, I think all data should always be available and most scientists and research groups do abide by this tenet. However, I can't bring myself to hold it against a research unit for being able to obtain some proprietary data and publish results on that information. When I was an undergraduate student, I had the opportunity to work on an analysis of snow storms/ice storms using an insurance company's accident dataset. That is highly proprietary information, and we were very lucky to even get a glimpse of a small subset of this information. If companies thought that one day down the road, some government would come along and force their proprietary datasets to be opened up just because part of it got shared with a public university, then we would never get access to such data and be able to publish useful research based on it. Heck, researchers within various companies would never publish their works either because of that looming threat.
Again, I repeat, I personally believe that all that data should be open anyway, but as a pragmatist, I would rather have some of the proprietary data rather than none.
Thanks for the Airplane 2 reference.
Actually, if anything, I have always thought that with the way Canoncial was doing global menus, it was actually helping to phase them out. Quite honestly, how often does anybody use the menus in many of the apps? I think LibreOffice is the only application where I regularly use the menu. By moving menus to a global location, and even doing the hiding of it with the window's title really pushes the menu further and further into irrelevance -- which I agree with 100%.
Maybe now, apps won't need to shoehorn in a menu, just because all other applications have them too.
That's an assertion, not a fact.
I never claimed it was a fact. Actually, I only claimed it was a corollary that was entirely dependent upon the general radiative transfer theory being correct
Since obviously there are more players in the general greenhouse theory than simply CO2 (cloud albedo, for example), you can only really say "increasing CO2 would increase surface temperature, *all other things being kept exactly the same*". Since we know the climate system, both terrestrial and solar does not stay the same, this is hardly a useful general theory.
Of course there are more players, but that's why Arrhenius's theory calls CO2's impact as an "augmentation of temperature". He didn''t say that the theory absolutely predicts with absolute certainty that the global temperature will rise. He said that CO2 will have a warming forcing upon the surface temperature of the Earth. Indeed, if all else is kept equal, then that will mean an overall warming, but this was climate science at its infancy, and they couldn't have possibly imagine all of the interesting dynamic feedback mechanisms that we have since learned.
Again, I think you're glossing over the "all other things being kept exactly the same".
And you would be wrong. You simply fail to understand the context that the theory is used in modern day climate science. It by itself does not explain everything, and no climate scientist ever would claim that it does.
Now, what particular component of influences CO2 may have may certainly be open to discussion, but the blunt assertion that CO2, in any quantity, will overwhelm all other drivers is obviously inane.
I am sorry, but those last two sentences do not make any sense. At first, you seem to concede that CO2 might have some influence, and that the amount of influence is up for debate (a debate you are about 100 years late for), and then you proceed to then claim that CO2 could never play a dominate role in the temperature regulation of a planet (which is patently false due to the plain evidence of Venus).
Actually, it wouldn't be that hard. Depending on what your tolerance is, it is pretty much the same as any other day. Also, keep in mind that most of the time, climate scientists are speaking of average temperature deviation. Areas of cold are typically balanced out by areas of warm.
Ok, I think I see the confusion here. The theory that I am talking about was the general greenhouse effect theory that Arrhenius constructed and used to explain the atmosphere's impact on a planet's surface temperature. From that, he drew the logical conclusion that if his theory was correct, then increasing CO2 would increase surface temperatures.
A theory for each planet and moon is not necessary, as Arrhenius's theory has the conditions of a planetary body as parameters to the theory. As for planets like Mars and Venus, we do have surface temperature measures, albeit not long-term measurements. However, because Arrhenius's greenhouse effect theory was not addressing how the surface temperature will change over time (it was a 1-dimensional, steady-state model), short-term observations would be all that was needed to support or disprove his theory. The moons and Mercury do not need in-situ temperature measurements because their surface temperatures can be measured from their brightness temperatures (they do not have much of an atmosphere). Bodies with and without atmospheres provides the means to test for the greenhouse effect.
keep in mind that his theory was only meant to explain the first-order effects of the atmosphere to the surface temperature. In other words, in the presence of an atmosphere, the average surface temperature is significantly warmer than what the steady-state, thermodynamic equilibrium would allow without an atmsphere. Furthermore, his theory stated that different gases at different concentrations had more or less warming of the surface. Arrhenius's statement of "if the quantity of carbonic acid increases in geometric progression, the augmentation of temperature will increase in nearly in arithmetic progression" is merely a corollary to the mathematical formulation he used for his theory. One way to disprove the statement is to disprove the greenhouse effect (by any gas, not just CO2). Another way to disprove it is to find that the temperature augmentation does not follow this formula in lab experiments.
Why is it that the scientists can detect an ozone hole, provide a fix, show that the fix solved the problem
It's worth noting that the complete sequence described above hasn't actually happened. Sure, an ozone hole was detected, but we don't know that human activities have played a significant role in its existence, that is, it may something that occurs anyway without human interference and hence, we are at best very limited in our ability to fix it without some large scale geoengineering project.
True, but given that the CFCs-Deplete-Ozone-Over-Antarctic theory has a well-explained mechanism that has been thoroughly tested in the lab and match well with observations, it has become widely accepted as the explanation. Therefore, the hypothesis that the ozone hole is naturally occurring (to this extent, that is) will require an explanation of the mechanisms that could account for the observations we have. Note that there are ozone observations in the antarctic from before CFCs, so differences in ozone observations before and after CFCs were introduced would need to be addressed.
Then the final claim in the sequence that the "fix solved the problem" is based on nothing but wishful thinking. Here's an alternate scenario. Ozone holes form frequently over Antarctica. We just happened to start observing when an ozone hole had formed. Now that the phenomenon is starting to close up, temporarily, we're attributing that change to our actions which didn't have an effect.
You are right that it is too early to tell for certain that the ozone hole has "recovered". But, do keep in mind that this is slashdot and not your local news channel. This is a first observation, and more are needed over the next few years to even know for sure that that first observation was even right. But it still doesn't diminish the fact that this is an observation. Nothing more, nothing less. Even more obs will be needed over several years to even be sure that it is permanent, but the scientists never claimed it was permanent.
This sort of thing is very relevant because we might see the ozone hole reestablish itself in a few years. This incidentally is what I consider an important observation. If ozone holes periodically return, then that indicates that maybe there's something wrong with the current understanding of ozone depletion models. If it never comes back, that's a solid win for the CFCs-caused-the-ozone-hole theory.
Actually, you have it reversed. The CFCs will eventually break down. They are extremely inert at surface pressures and temperatures (which is why it was ideal for use without health effects). However, at the pressures and temperatures of the ozone layer, and with the level of ultraviolet radiation up there, CFCs do break down. Therefore, a re-established ozone layer is evidence towards CFCs causing ozone depletion, but an ozone layer that does not re-establish itself is evidence that something else caused the depletion. However, even then it would never be 100% for sure, because *maybe* it was a natural oscillation and this was just a coincidence (if it re-establishes itself), or maybe some other agent causes a continued depression of ozone (if it never comes back).
Well, of course we can't just deplete the Earth of its atmosphere in order to satisfy your whims (because that would be the most direct way to support or falsify the theory), but we don't need to. There are several planetary bodies in this solar system with and without atmospheres, and those with atmospheres have different compositions. The temperatures of those planets and moons all match well to the theory put forth by Arrhenius. We have yet to observe a situation where the theory did not hold true. Until that happens, his theory is sound.
Heh, must be a bug in slashdot... your post ended up with the wrong article...