How many scientists really dispute global warming?

[droskill]

Quote from CaptainObvious:

Rejected by who, the cultists? It may not be the primary source, but it absolutely plays a role, and that's what's being ignored. The possibility that anything other than evil humans, especially Americans, could even remotely be the cause of any climate shift. It simply must be human activity and nothing else for the cult to survive.
Hell, a contributing source could be gamma rays from starbursts throughout the universe. Taken from a science article:
"There is also speculation that waves of cosmic rays streaming down the spiral arms of the galaxy could have contributed to past episodes of mass extinction on earth".
You want the link? OK! Why embarrass you later.
http://www.sciencedaily.com/releases/2007/03/070319174510.htm
Of course you say it's out of context and absurd. Blah, blah, blah. You cultists have a political agenda, nothing more, nothing less. Anything other than the evils of mankind just won't do.

What makes you think sunspot activity is being ignored? It has been extensively studied and the output of the sun is incorporated into the IPCC models.

"Many climate scientists agree that sunspots and solar wind could be playing a role in climate change, but the vast majority view it as very minimal and attribute Earth’s warming primarily to emissions from industrial activity—and they have thousands of peer-reviewed studies available to back up that claim.

Peter Foukal of the Massachusetts-based firm Heliophysics, Inc., who has tracked sunspot intensities from different spots around the globe dating back four centuries, also concludes that such solar disturbances have little or no impact on global warming. Nevertheless, he adds, most up-to-date climate models—including those used by the United Nations’ prestigious Intergovernmental Panel on Climate Change (IPCC)—incorporate the effects of the sun’s variable degree of brightness in their overall calculations."

http://www.scientificamerican.com/article.cfm?id=sun-spots-and-climate-change

 

[PiggyBank]

Quote from dcraig:

1) The civil engineering example is interesting because civil or mechanical engineers do NOT have complete knowledge of their designs in the sense that a set of equations can be written down and solved analytically. It is just not possible. They use approximations through modeling that is based on physical principles and the supporting mathematics. One example is finite element analysis which is somewhat like climate modeling in that the system is broken down into a (large but finite) number of pieces and their interactions calculated based on physical principles. It cannot be 100% correct, but it is in general very successful in predicting the future of the structure if properly used. Which is one of the reasons for safety factors.

Making this a bit more abstract, it is true that most of science and engineering relies on incomplete models that are not "100%" correct. Here is a very simple example. In a vacuum, if you drop something then you can solve the equation of motion analytically. But moving onto something just a little more complicated (though seemingly simple) and it can't be done. The famous three body problem - sun, earth and moon. Nobody has been able to provide a general analytic solution to the equations of motion. If you want to find out where they are sometime in the future you need a model which will give you an approximation. The model will not be 100% correct but some models will be better than others as I proved conclusively by my feeble attempt as a physics student trying to write a FORTRAN program for a such a model.

The point of this is that most of nature can only be modeled. And a lot of science is modeling.



2a) First of all predictions do not need 100% certainty to be useful, and models do not need complete knowledge to provide useful approximations. 2b) Any individual climate model is certainly fair game as a subject for criticism but the assertion that climate cannot be modeled to produce useful forecasts is wholly unsubstantiated. The analogy with predicting price in financial markets is misplaced because we really have very few (if any) well know quantifiable principles to base models on. A bit of hand waving about supply and demand doesn't really cut it. On the other hand there is a lot of physical principles known to a large degree of certainty that are used in formulating climate models.

3) In the absence of mathematical proofs, the weight of evidence supports AGW. It is a fact that temperature is rising. So what has changed? What is causing the change? Solar irradience change - no. Cosmic rays?- no? CO2 change? - yes. Could CO2 have this effect - yes. That CO2 is a greenhouse gas is as certain as that gravity is a force of nature. Could there be other factors ( some strong negative feedback) that counteracts the warming effect of CO2? It seems possible that there might be. So how do we investigate - we build climate models based on physical principles to better understand the changes. What do they tell us - there are feedbacks both positive and negative, but the best science available suggests on balance positive. As far as we can test these models they do quite well. Do observations support the CO2 hypothesis? yes - there is currently a measured inbalance between energy received from the sun and energy radiated off into space and an enhanced green house effect is by far the best explanation. There really is an awful lot of evidence for AGW. And weight of evidence is the only sensible thing to base a judgement on.



You can find a brief and informative discussion about CO2 lag/lead temperature here:

http://www.skepticalscience.com/Why-does-CO2-lag-temperature.html

As a general comment, I would add that there is no basic physical principle that says CO2 leads or lags temperature. If there were, then it would be a powerful argument -but there isn't. Detailed research is needed as to the current factors driving climate change. Large scale human activity adds the new factor.

1) I believe you and take your word for it, as it is rational to me. The motion example you gave is also interesting, I didn't know
that.

2a) I agree with this as well.
2b) Disagree here, where is the evidence of useful forecasts? I am completely serious, if they are so accurate then I would like to see the forecasts and the results in order for me to believe in said "usefulness". If these results exist then there could not be any dispute whatsoever, which is why I doubt their existence. Also, that same model would have to remain unaltered, otherwise well... I'm sure u can see the problems that would arise if it were to change (something like curve fitting comes to mind).

3) I am not denying anything in this argument. I do have a major problem however; "In the absence of mathematical proofs" is an issue for me. Basing models on assumptions... is flawed, at least flawed enough for anyone rational to not believe in the model's predictions without question. Basing predictions on the weight of evidence is fine and logical, but let's not pretend it is anywhere close to accurate. I believe the market analogy is much more relevant this time around, for example most people knew the real estate market was overvalued (in specific areas if u lived there), long (years) before the crash. However very few people predicted it with anything even close to resembling accuracy, including myself.

Another issue is the CO2 lag/lead, even that article does not fully explain it, and admits as much in this sentence "The exact mechanism of how the deep ocean gives up its CO2 is not fully understood but believed to be related to vertical ocean mixing".

I know that u are more knowledgeable than I am on the subject, so I would simply like for u to give me your opinion of the chart posted earlier on the same skeptical science website, of the sun's output. IMO it is extremely flawed and essentially worthless, yet it has been touted as "overwhelming evidence" in this thread.

BTW I agree that the weight of evidence supports global warming. However, I 99% disagree that it can/is being predicted accurately, and most importantly that the consequences of it are as dire as some would have us believe. In other words, I am entirely indifferent to it, and I think that any logical person would never even consider to give up their profession/business/hobby etc, over a prediction of the future. And CaptainObvious articulated why "predicting" day and night is not quite the same as predicting the future, much better than I did.

 

[PiggyBank]

Quote from droskill:

Your second statment "a statement of fact would be that 100 years from now the earth, assuming it still exits, will have a measurable temperature" is just what you say it is - an assumption that is used in constructing an prediction, model or argument. It is not, however, a statement of fact.

Yes it is. It is a fact that the earth has a temp, it is a fact that it always has, and that as long as it exists it will have a temp. Every other body in the universe also has one, with the exception possibly of black holes, which are kinda the opposite of the rest.

 

[droskill]

Quote from PiggyBank:

Yes it is. It is a fact that the earth has a temp, it is a fact that it always has, and that as long as it exists it will have a temp. Every other body in the universe also has one, with the exception possibly of black holes, which are kinda the opposite of the rest.

Quite right - it is not an assumption - I misread the sentence. But if you are going to project that fact into the future, it is a prediction, albeit one with as close to certainty as possible. There have been many facts in the past that have been overturned by new knowledge or new discovery (e.g. the earth is flat). Now do I believe this will be a fact in the future? Absolutely - just as I believe in other core physics.

Does the evidence of global climate change match the probability/confidence of the temp example? Absolutely not. Does it meet a level where I believe it is happening, that we have a decent understanding of what is causing it, and that we believe it will happen in the future (and the consequences of it happening) - yes, I believe we do. But everyone is entitled to their own opinion.

 

[PiggyBank]

Quote from droskill:

Quite right - it is not an assumption - I misread the sentence. But if you are going to project that fact into the future, it is a prediction, albeit one with as close to certainty as possible. There have been many facts in the past that have been overturned by new knowledge or new discovery (e.g. the earth is flat). Now do I believe this will be a fact in the future? Absolutely - just as I believe in other core physics.

Does the evidence of global climate change match the probability/confidence of the temp example? Absolutely not. Does it meet a level where I believe it is happening, that we have a decent understanding of what is causing it, and that we believe it will happen in the future (and the consequences of it happening) - yes, I believe we do. But everyone is entitled to their own opinion.

Ok, that is pretty much splitting hairs though. For example what do we actually KNOW? I know when I am hungry, thirsty etc, aside from that nothing is 100% certain. But the temp example is, as u said, as close to certainty as possible.

This sentence "There have been many facts in the past that have been overturned by new knowledge or new discovery", concisely sums up my argument AGAINST global warming, or more specifically the exact causes and consequences of it. Backed by the very small % of the total data in existence that we actually have (in reference to the history of our climate and the Sun's output.)

I agree with the rest of your post. I would only ask that as a believer in the causes and consequences of AGW, do u believe that we should halt all detrimental activities by force if necessary, to stop it.

 

[droskill]

Quote from PiggyBank:

Ok, that is pretty much splitting hairs though. For example what do we actually KNOW? I know when I am hungry, thirsty etc, aside from that nothing is 100% certain. But the temp example is, as u said, as close to certainty as possible.

This sentence "There have been many facts in the past that have been overturned by new knowledge or new discovery", concisely sums up my argument AGAINST global warming, or more specifically the exact causes and consequences of it. Backed by the very small % of the total data in existence that we actually have (in reference to the history of our climate and the Sun's output.)

I agree with the rest of your post. I would only ask that as a believer in the causes and consequences of AGW, do u believe that we should halt all detrimental activities by force if necessary, to stop it.

Well, take a class is epistemology and then tell me what you know.

Your second point - that there is new information that overturns the global climate change thesis - as far as I can see (in reading major papers), while there are minor squabbles over different aspects of climate change, there is a serious lack of papers that overturn it. There maybe a few here and there, but overall, the literature doesn't have a lot of variation on whether it exists or whether man is causing it - most scientists now understand that as a well understood concept but would change if there was new evidence brought forward that disproves the thesis.

The skeptics have forced more transparency on the science (which is a good thing), but now I put the ball back in the skeptic's camp in my opinion. The skeptics have the data, and the models (GISS models are free for anyone to download) - so let's see some science disproving it. Until I see that, I see no reason to doubt the conclusions.

Now to your final point - what to do about global climate change? It may sound silly based on what I've posted, but I don't think it matters what I think about what to do - the reality of the situation is that the US government is unlikely, under either Democrats or Republicans to do anything terribly meaningful. The US government seems to be almost completely captured by business interests, who, now let loose to spend as much as they want, will take the natural step of just buying the Congress outright, thus stopping any reform possibilities.

And I'm saddened by that - even if you don't believe in global climate change, I think reducing our oil consumption (and thereby reducing our carbon output - taking into account the "moving the tailpipe syndrome) by using other energy products to power our cars is, to me, a national security issue. Who knows if Congress will be able to pass something supporting that outside of the Cap and Trade bill - it will be interesting to watch.

 

[PiggyBank]

Quote from droskill:

Well, take a class is epistemology and then tell me what you know.

Your second point - that there is new information that overturns the global climate change thesis - as far as I can see (in reading major papers), while there are minor squabbles over different aspects of climate change, there is a serious lack of papers that overturn it. There maybe a few here and there, but overall, the literature doesn't have a lot of variation on whether it exists or whether man is causing it - most scientists now understand that as a well understood concept but would change if there was new evidence brought forward that disproves the thesis.

The skeptics have forced more transparency on the science (which is a good thing), but now I put the ball back in the skeptic's camp in my opinion. The skeptics have the data, and the models (GISS models are free for anyone to download) - so let's see some science disproving it. Until I see that, I see no reason to doubt the conclusions.

Now to your final point - what to do about global climate change? It may sound silly based on what I've posted, but I don't think it matters what I think about what to do - the reality of the situation is that the US government is unlikely, under either Democrats or Republicans to do anything terribly meaningful. The US government seems to be almost completely captured by business interests, who, now let loose to spend as much as they want, will take the natural step of just buying the Congress outright, thus stopping any reform possibilities.

And I'm saddened by that - even if you don't believe in global climate change, I think reducing our oil consumption (and thereby reducing our carbon output - taking into account the "moving the tailpipe syndrome) by using other energy products to power our cars is, to me, a national security issue. Who knows if Congress will be able to pass something supporting that outside of the Cap and Trade bill - it will be interesting to watch.

I had to take philosophy in HS and college, and I can't remember much about epistemology... but enough to get your point.

After re-reading my second point I didn't make it clearly. I was not implying that this evidence has already been uncovered, just that it MAY be. Based only on the vast amount of historical data that exists, from which we have very small % of, and that some of the physical principles are not fully understood. Also I didn't know the models were available on the GISS website, since I am bored for the next few days maybe I will check them out.

 

[Haroki]

Quote from bigdavediode:

Actually solar radiation has been extensively researched and analyzed (and rejected as a primary cause of global warming.)

And yet, when it is pointed out to you that the lasr few years have cooled, you and your ilk don't hesitate to point out that solar activity is at a minimum to explain away that cooling.

Sounds like you've just exposed your hypocrisy, Dave.

 

[dcraig]

Quote from Haroki:

And yet, when it is pointed out to you that the lasr few years have cooled, you and your ilk don't hesitate to point out that solar activity is at a minimum to explain away that cooling.

The last few years have NOT cooled - that is a complete fantasy. This is the hottest decade on record. Nobody is explaining it away because of a low in the solar cycle, even though there is a low in the short term solar cycle. GISS temperature record shows 2009 as the second hottest year by a whisker. You are seriously misinformed:

http://www.giss.nasa.gov/research/news/20100121/

 

[dcraig]

Quote from PiggyBank:

Also I didn't know the models were available on the GISS website, since I am bored for the next few days maybe I will check them out.

If you want to look at the models you may also like to have a look here:

http://clearclimatecode.org/

Which is a project to rewrite the GISS models code in Python and to do a general cleanup to make it more understandable and more accessible. They are effectively auditing the GISS code as they go along and have reported a couple of minor bugs to GISS.

Interestingly, their results are in very close agreement with GISS.