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Outis
02-14-2014, 11:20 AM
Rule of this thread: No personal attacks. We are discussing the science, and ONLY the science. If you cannot abide by that, please post in the other thread.

Now, it has been asked what would falsify the theory of anthropogenic global warming. The answer is simple, and there's more than one way to do it, but they all boil down to one thing.

Find a significant flaw in the climate models being used.

A significant flaw can (among other possibilities) be a mistake in the models, an error in the data, or a missing factor driving the change. Things like "But it's cold today" are not significant flaws. Things like "They used the word 'trick,' so it's all a hoax" are not significant flaws. Accusations of fraud, conspiracy, hypocrisy on the part of this or that proponent (especially accusations given without evidence) are not serious flaws.

It's that simple.

seer
02-14-2014, 11:42 AM
Rule of this thread: No personal attacks. We are discussing the science, and ONLY the science. If you cannot abide by that, please post in the other thread.

Now, it has been asked what would falsify the theory of anthropogenic global warming. The answer is simple, and there's more than one way to do it, but they all boil down to one thing.

Find a significant flaw in the climate models being used.

A significant flaw can (among other possibilities) be a mistake in the models, an error in the data, or a missing factor driving the change. Things like "But it's cold today" are not significant flaws. Things like "They used the word 'trick,' so it's all a hoax" are not significant flaws. Accusations of fraud, conspiracy, hypocrisy on the part of this or that proponent (especially accusations given without evidence) are not serious flaws.

It's that simple.

How about a 15 year hiatus in warming that no model predicted? Would that qualify?

http://www.seas.harvard.edu/climate/seminars/pdfs/Kosaka_Nature_2013.pdf

Outis
02-14-2014, 11:52 AM
How about a 15 year hiatus in warming that no model predicted? Would that qualify?

http://www.seas.harvard.edu/climate/seminars/pdfs/Kosaka_Nature_2013.pdf

If the 15 year hiatus were actually a hiatus (as opposed to a change in mechanism caused by the warming itself), it would. However, the very article you cite explains why the "hiatus" is occurring, and why it is not actually a "hiatus" in global warming, merely a hiatus in surface temperature rising.

Serious question: Have you read the article?

Also see: http://scholar.google.com/scholar_url?hl=en&q=http://yly-mac.gps.caltech.edu/z_temp/4%2520pdf%2520/ref%2520copy/Meehl_2011%2520s.pdf&sa=X&scisig=AAGBfm1FFKQu_6I1nRVhWKm0afIY6Ey4qw&oi=scholarr

HMS_Beagle
02-14-2014, 11:55 AM
How about a 15 year hiatus in warming that no model predicted? Would that qualify?

http://www.seas.harvard.edu/climate/seminars/pdfs/Kosaka_Nature_2013.pdf

No, it would not.

Here is the second paper referenced by Kosaka / Xie regarding the "hiatus" in the global temperature profile during which the measured small temperature rise was not considered statistically significant.


Is the climate warming or cooling?
Easterling, Wehner (2009),
Geophys. Res. Lett. 36, L08706, doi:10.1029/2009

Abstract: numerous websites, blogs and articles in the media have claimed that the climate is no longer warming, and is now cooling. Here we show that periods of no trend or even cooling of the globally averaged surface air temperature are found in the last 34 years of the observed record, and in climate model simulations of the 20th and 21 st century forced with increasing greenhouse gases. We show that the climate over the 21st century can and likely will produce periods of a decade or two where the globally averaged surface air temperature shows no trend or even slight cooling in the presence of longer-term warming.

whole paper (http://crd.lbl.gov/assets/pubs_presos/grl25859.pdf)

Of particular interest is this passage:


The reality of the climate system is that, due to natural climate variability, it is entirely possible to have a period as long as a decade or two of ‘‘cooling’’ superimposed on the longer-term warming trend due to anthropogenic green-house gas forcing. Climate scientists pay little attention tothese short-term fluctuations as the short term ‘‘cooling trends’’ mentioned above are statistically insignificant and fitting trends to such short periods is not very meaningful in the context of long-term climate change. On the other hand, segments of the general public do pay attention to these fluctuations and some critics cite the most recent period as evidence against anthropogenic-forced climate change. Here we analyze both the observed record and a series of climate model simulations for the occurrence of both positive and negative decadal trends in the globally averaged surface air temperature to show that it is possible, and indeed likely to have a period of as long as a decade or two with no trend in an anthropogenically forced climate.

Basically it's not unusual to have flat or even negative short term runs mixed in with the long term positive trends. It's another example of what mathematicians call regression to the mean.

seer
02-14-2014, 12:13 PM
If the 15 year hiatus were actually a hiatus (as opposed to a change in mechanism caused by the warming itself), it would. However, the very article you cite explains why the "hiatus" is occurring, and why it is not actually a "hiatus" in global warming, merely a hiatus in surface temperature rising.

Serious question: Have you read the article?

Also see: http://scholar.google.com/scholar_url?hl=en&q=http://yly-mac.gps.caltech.edu/z_temp/4%2520pdf%2520/ref%2520copy/Meehl_2011%2520s.pdf&sa=X&scisig=AAGBfm1FFKQu_6I1nRVhWKm0afIY6Ey4qw&oi=scholarr

Yes and like in my thread they blame it on La Nina. And I guess, from what I could understand, the heat was transferred to deep oceans. But again, what computer models predicted this before the fact - not after? The point being, if no models predicted this hiatus then how reliable are our models?

rwatts
02-14-2014, 12:49 PM
How about a 15 year hiatus in warming that no model predicted? Would that qualify?

http://www.seas.harvard.edu/climate/seminars/pdfs/Kosaka_Nature_2013.pdfNot necessarily.

If by "hiatus" you meant that rate of increase has declined - then no.

If by "hiatus" you mean that the increase has stopped, hence it's a false alarm, then not necessarily. If for example, a sink for the heat was found, and by being a sink, more serious problems were being caused elsewhere, then our worries continue.

rwatts
02-14-2014, 12:53 PM
Rule of this thread: No personal attacks. We are discussing the science, and ONLY the science. If you cannot abide by that, please post in the other thread.

Now, it has been asked what would falsify the theory of anthropogenic global warming. The answer is simple, and there's more than one way to do it, but they all boil down to one thing.

Find a significant flaw in the climate models being used.

A significant flaw can (among other possibilities) be a mistake in the models, an error in the data, or a missing factor driving the change. Things like "But it's cold today" are not significant flaws. Things like "They used the word 'trick,' so it's all a hoax" are not significant flaws. Accusations of fraud, conspiracy, hypocrisy on the part of this or that proponent (especially accusations given without evidence) are not serious flaws.

It's that simple.I guess if the increase in CO2 concentrations continued but the increase in temperature rise stopped, and no reason for this could be found, then we would have to begin to wonder.

seer
02-14-2014, 12:55 PM
Not necessarily.

If by "hiatus" you meant that rate of increase has declined - then no.

If by "hiatus" you mean that the increase has stopped, hence it's a false alarm, then not necessarily. If for example, a sink for the heat was found, and by being a sink, more serious problems were being caused elsewhere, then our worries continue.

You know what - in light of the links that have been posted, and from what I can understand, they really don't have a clue what cause this hiatus.

rwatts
02-14-2014, 12:56 PM
You know what - in light of the links that have been posted, and from what I can understand, they really don't have a clue what cause this hiatus.I got an impression that one of the oceans was unexpectedly picking up the heat.

If so, then that can be it's own problem. Rather than atmospheric warming, we now have ocean warming.

HMS_Beagle
02-14-2014, 12:57 PM
Yes and like in my thread they blame it on La Nina. And I guess, from what I could understand, the heat was transferred to deep oceans. But again, what computer models predicted this before the fact - not after? The point being, if no models predicted this hiatus then how reliable are our models?

The real data fell between the estimated error ranges. The error ranges are necessarily wide because we're dealing with a highly chaotic non-linear system that still has unknowns.

Having 20-50 vision may be "poor" but it's a heck of a lot better than being completely blind. Do you know of any models from the AGW denier folks that have made more accurate predictions or have smaller error tolerances? I'd love to see them.

HMS_Beagle
02-14-2014, 01:03 PM
You know what - in light of the links that have been posted, and from what I can understand, they really don't have a clue what cause this hiatus.

That says more about your level of understanding than it does the scientific data. Do we know for a fact what caused the temperature flattening? No. But there is a quite plausible explanation that so far fits the measured data. Researching and continuing to refine the models is a lot more productive than standing on the sidelines flinging stones.

seer
02-14-2014, 01:14 PM
That says more about your level of understanding than it does the scientific data. Do we know for a fact what caused the temperature flattening? No. But there is a quite plausible explanation that so far fits the measured data. Researching and continuing to refine the models is a lot more productive than standing on the sidelines flinging stones.

Ok, that is all I said. And you agree. So why slam me?

HMS_Beagle
02-14-2014, 01:22 PM
Ok, that is all I said. And you agree. So why slam me?

That is not what you said and I didn't argee.

There's a big difference between "really don't have a clue" and "plausible explanation that fits the data". BIG difference.

shunyadragon
02-14-2014, 01:25 PM
How about a 15 year hiatus in warming that no model predicted? Would that qualify?

http://www.seas.harvard.edu/climate/seminars/pdfs/Kosaka_Nature_2013.pdf

No, the time is too short.

seer
02-14-2014, 01:26 PM
That is not what you said and I didn't argee.

There's a big difference between "really don't have a clue" and "plausible explanation that fits the data". BIG difference.

If we don't know for a fact, we don't know. It is supposition.

HMS_Beagle
02-14-2014, 01:31 PM
If we don't know for a fact, we don't know. It is supposition.

That's the stock line we get from Creationists all the time too.

'If we don't know everything then that means we don't know anything!"

I wish you could just for a moment step back and see how silly that sounds.

phank
02-14-2014, 03:21 PM
If we don't know for a fact, we don't know. It is supposition.

You need to be a little more specific about what is known and what is not. I can give you my general layman's understanding, for what it's worth:

1) We know that climate is very complex, and we probably haven't even identified all the important variables yet. Much less the short, medium and long-term dynamics of how they all work together.

2) We can identify and quantify quite a few climate drivers. Those at the top of the list (the sun) and near the top (methane, water vapor), and well down the list (CO2).

3) We can reasonably assume that all of these drivers are in something close to an equilibrium, so that while they all go up and down from time to time, only one is going up only, and steadily. That one is CO2. Human activites add about 15 gigatons of CO2 to the atmosphere each year over and above what is reabsorbed by plants and the ocean. That's only about 3% of the total CO2 in the atmosphere at any one time, and it isn't a particularly strong greenhouse gas, but it is cumulative.

So: If we're steadily adding to the amount of a known greenhouse gas, and nothing else is much off a steady equilibrium, then broadly speaking we can predict warming. Now, how does that warming affect such things as ocean currents, jet streams, trade winds, rainfall patterns, the standard deviation of temperature (that is, more extremes of both hot and cold), and so on? Here seems to be where our knowledge is limited, and our models incomplete.

You can think of all of science as being composed of reasonable suppositions and the base of evidence on which they rest. Some are more reasonable than others, but none are pure guesses.

shunyadragon
02-14-2014, 03:32 PM
How about a 15 year hiatus in warming that no model predicted? Would that qualify?

http://www.seas.harvard.edu/climate/seminars/pdfs/Kosaka_Nature_2013.pdf

I provided the source because it gives the foundation of the different cycles, ie solar radiance, and ocean temperatures, that contribute to the over all ups, downs and plateaus of climate change in a predictive way later models do. It is fundamental to understanding the over all climate cycles in geologic history. Models have both predictive and explanatory abilities. Your example is only ~12 to 15 years, and to short to reflect any thing significant in the long term trends, and yes in different models do take such short term trends into consideration

For a more recent similar use of this showing the ups, downs, checkout David Hone here . . .




About every eight or nine months the MIT Joint Program on the Science and Policy of Global Change holds a forum where it shares its latest research with the program sponsors and invitees from a variety of academic institutions and government. External presenters from similar institutions are also encouraged. The most recent event was in early June and was a hometown event held in Cambridge, Massachusetts.

The forum was excellent and covered a variety of topics, with a particular focus on water and climate, but the opening talk was of particular interest. In the pre-work for the forum the organizers canvass the invitees and ask if there are any particular subjects that should be included (in an otherwise very full agenda). Several responders (including me) had apparently asked for a better explanation than had given at previous forums of the current hiatus in the global temperature trend. Previous explanations largely relied on the fact that the decadal increase in temperatures remains clear (i.e. each decade was higher than the previous). While this remains true, comparing 1980-1989, 1990-1999 and 2000-2009 rather obscures the fact that not a whole lot has happened in the period 1998-2012.

So MIT took up this challenge and organized an opening lecture on this subject. The talk brought together a number of recent peer-reviewed papers that are starting to show what may well be going on. As I discussed in a previous posting on this topic, the likely culprit is the oceans with a particular focus on the role of ENSO (El Nino Southern Oscillation).

With nice graphs of predictions and trends.

Carrikature
02-14-2014, 05:33 PM
You know what - in light of the links that have been posted, and from what I can understand, they really don't have a clue what cause this hiatus.

Everything I've encountered points to the oceans being a much better heat sink than we imagined. That means overall temperature isn't rising as dramatically as expected, but sea life is certainly just as affected.

Outis
02-15-2014, 12:32 AM
Yes and like in my thread they blame it on La Nina. And I guess, from what I could understand, the heat was transferred to deep oceans. But again, what computer models predicted this before the fact - not after? The point being, if no models predicted this hiatus then how reliable are our models?

The models did not predict it. In this, they were incomplete. Once the evidence no longer matched the models, scientists dug into the evidence to find out why the models didn't work.

That's the point, Seer--they didn't just say "See, the model's incorrect, we can all go home now." They looked at the evidence they had, and they saw there was a problem, so they went out in the field to find what the problem was. The correction of the model does not mean the idea as a whole was wrong: it does mean that it was incomplete. Once they found the data they were missing, the variations make sense.

Outis
02-15-2014, 12:33 AM
I guess if the increase in CO2 concentrations continued but the increase in temperature rise stopped, and no reason for this could be found, then we would have to begin to wonder.

We would certainly begin to wonder, but I do not believe the scientists would stop looking.

Outis
02-15-2014, 12:34 AM
You know what - in light of the links that have been posted, and from what I can understand, they really don't have a clue what cause this hiatus.

They didn't when it was first noted. They do now. Why is that a problem?

Outis
02-15-2014, 12:36 AM
That's the stock line we get from Creationists all the time too.

'If we don't know everything then that means we don't know anything!"

I wish you could just for a moment step back and see how silly that sounds.

HMS--that's enough. ANy more, and I will ask the moderators to remove your posts.

firstfloor
02-15-2014, 12:54 AM
How about a 15 year hiatus in warming that no model predicted? Would that qualify?
The currently weak solar maximum might be shielding us from the worst affects of global warming. Some scientists are comparing the lack of sun spot activity to the infamous Maunder Minimum starting about 1645 and lasting until 1715. That might mean that our children and grandchildren will have to face a very steep incline in extreme weather events if the sun is doing something similar now.

Jorge
02-15-2014, 03:21 AM
Rule of this thread: No personal attacks. We are discussing the science, and ONLY the science. If you cannot abide by that, please post in the other thread.

Now, it has been asked what would falsify the theory of anthropogenic global warming. The answer is simple, and there's more than one way to do it, but they all boil down to one thing.

Find a significant flaw in the climate models being used.

A significant flaw can (among other possibilities) be a mistake in the models, an error in the data, or a missing factor driving the change. Things like "But it's cold today" are not significant flaws. Things like "They used the word 'trick,' so it's all a hoax" are not significant flaws. Accusations of fraud, conspiracy, hypocrisy on the part of this or that proponent (especially accusations given without evidence) are not serious flaws.

It's that simple.

The fraud and conspiracy in this matter has been amply proven. Are you not aware of the intercepted messages, fraudulent data and economic/political-agenda-driven interpretations of data that have occurred? If not then you need to do some basic research - it's all out there for anyone to see if they just look. 'Nuff said.

Jorge

phank
02-15-2014, 10:04 AM
The fraud and conspiracy in this matter has been amply proven. Are you not aware of the intercepted messages, fraudulent data and economic/political-agenda-driven interpretations of data that have occurred? If not then you need to do some basic research - it's all out there for anyone to see if they just look. 'Nuff said.

JorgeActually, Jorge is entirely correct in his assertions. The far right-wing denialists have indeed cooked the data, misrepresented the facts, and misinterpreted all the results. Many of them have, not too surprisingly, been funded by the likes to Exxon-Mobile, and others with a strong vested interest in not derailing the gravy train.

Unfortunately, the trends refuse to listen to these people, and instead keep repeating the depressing news that we are polluting our world. Much as most of us would much prefer if Exxon-Mobile's foregone conclusions were correct.

rwatts
02-15-2014, 03:24 PM
We would certainly begin to wonder, but I do not believe the scientists would stop looking.I hope they would not stop looking, either way.

Questions like this are ginormously complex. So a degree of skepticism always needs to be maintained.

I think the whole concept of man made climate change is a valid one to consider and to be worried about given that, in essence, we are digging up a lot of ancient, buried carbon, and pumping it back into the atmosphere. Along with this, we are performing a largish change to the earth's environment via the building of cities, and the altering of forest and grass land for agricultural purposes.

While it's very hard to prove that human activities are to some extent definitely causing global warming, I think the evidence is good enough, but we should nevertheless continue looking, testing and evaluating.

Falsifying it can be a difficult thing to do however. The term "falsification" can be overplayed. It's often stated that if a theory is truly scientific then it has to be falsifiable. Well, just how does one falsify the atomic theory of matter? The time of it being falsifiable has long since passed.

With man made global warming I think it can only be falsified by performing a series of observations which cast legitimate doubt on the idea to the point that, as time goes by, the theory becomes less and less respectable.

Even if that point were reached, I don't think we should ever stop being worried about it though, for the reasons given above.

phank
02-15-2014, 04:48 PM
It's helpful, I think, to regard scientific theories as models, generally fairly complex models. So it's rare if ever than an entire model can be shown to be false. Much more common for a model to be shown to be not very predictive, or unable to account for some set of observations. I think it's rare for any scientific model to be entirely discarded in favor of a totally different model. Instead, models experience steady refinement.

So far, I get the impression that climate models have the dubious advantage of being better than nothing. I hope we see big improvements, because I think modeling the climate well is a worthy goal regardless.

Outis
02-16-2014, 09:29 AM
The fraud and conspiracy in this matter has been amply proven.

I am quite aware of the _assertions_ of fraud and conspiracy. I am also aware that the assertions have been amply demonstrated as false (not to mention the assertions have been traced back to companies and individuals with a vested profit interest in continuing with fossil fuels). Again, I am interested in discussing the science, not the false assertions of the paid shills (a category I do not include you in).

Outis
02-16-2014, 09:34 AM
Falsifying it can be a difficult thing to do however. The term "falsification" can be overplayed. It's often stated that if a theory is truly scientific then it has to be falsifiable. Well, just how does one falsify the atomic theory of matter? The time of it being falsifiable has long since passed.

A valid point. How does one falsify sunrise? I don't think global warming has been established to that level of certainty, but it is more certain than (for instance) quantum gravity or dark energy.

HMS_Beagle
02-16-2014, 10:53 AM
A valid point. How does one falsify sunrise? I don't think global warming has been established to that level of certainty, but it is more certain than (for instance) quantum gravity or dark energy.

Asking what would falsify AGW is somewhat akin to asking what would falsify the theory of evolution. In both cases we have now amassed enough positive evidence for the phenomena that no one observation would overturn the scientific consensus. Basically you'd have to show major long term systematic errors in our understanding of a dozen of different scientific disciplines - physics, chemistry, astronomy, meteorology - just to name a few. Not only that but you'd have to explain why the errors all managed to produce the same consilient results across the board.

When both AGW and evolution were first proposed as hypotheses there were plenty of observations that if made would have falsified them. For AGW finding that temperature increase wasn't correlated with atmospheric GHGs would do it, or finding that humans weren't producing these GHGs. Now with all the supporting evidence they have the job is way tougher. Both hypotheses were quite falsifiable; they just weren't falsified.

Outis
02-16-2014, 11:38 AM
Asking what would falsify AGW is somewhat akin to asking what would falsify the theory of evolution.

Pretty much, and the parallel exists. Evolution (the phenomenon, not the theory) is a fact--it happens. The ToE merely offers an explanation for the mechanics. Global warming is also a fact. AGW merely offers an explanation.