Climate Change -- conspiracy theory or is it time we all drive a Prius?
Quote: KeyserHow many standard deviations above the mean is the current global warming trend? Anyone?
Which mean are you referring to? Since 1880's?
Quote: KeyserIt's my belief that there simply isn't any real statistical relevance to it.
(I'm not talking about the number of new record highs or lows either.)
A trend doesn't have a statistical relation to a mean. You could compare slopes between two different time periods maybe?
Quote: boymimbo...certainly polar bears have been stressed due to climate change - the quick change in sea ice cover has forced the southern polar bears to have shorter hunting seasons and to adapt. But they are adapting.
The question is, though, can they continue to successfully adapt till the end of the century with continuing global warming as projected? The study I referenced claims they can't.
Also the IPCC report I referenced doesn't even mention polar bears but only talks about the effect on a number of species.
If the standard deviation was statistically significant, then it would be widely published and touted. An increase since 1980 wouldn't be statistically relevant, since it's such a short time period. It would be like examining 34 spins of the roulette wheel in an attempt to find bias.
You wouldn't really even find anything of relevance going back 100 years. For starters, the temperature data collection sites haven't been in static locations, so a great deal of curve fitting and data adjustment has taken place.
The extreme consistency of temperature appears to be more statistically relevant than the small fluctuations.
Quote: paisielloI didn't assume anything. I stated it as an obvious fact because how else do you explain the results of the study which projects a drastic decline in numbers?
Not true. This contradicts the claim of the study I referenced. Also, even if some environmental group is tryng to use it as a poster child, it doesn't change the findings of the study or other studies projecting similar declines in population.
Your own quote contradicts this. Also your claim is contradicted by the referenced study which specifically states that the "projections were instrumental in the decision to list the polar bear as a threatened species under the U.S. Endangered Species Act."
"the study which projects a drastic decline" is not FACT. Sorry you can't understand that considering how obviously simple it is.
Studies are based on assumptions and models. Just because this study makes the claim doesn't make it true yet you apparently accept it without question.
Did you miss the part where Suckling admitted it would be 100 years before polar bears would actually be threatened by climate change? It was a political move nothing more.
Quote: KeyserIf the standard deviation was statistically significant, then it would be widely published and touted. An increase since 1980 wouldn't be statistically relevant, since it's such a short time period. It would be like examining 34 spins of the roulette wheel in an attempt to find bias.
I have never heard of a standard deviation being statistically significant. A standard deviation is used to determine whether a set of data is statistically significant or not.
Quote: KeyserYou wouldn't really even find anything of relevance going back 100 years. For starters, the temperature data collection sites haven't been in static locations, so a great deal of curve fitting and data adjustment has taken place.
I'm not sure that this is true. You can correlate proxies with the land records to get a high level of confidence that your data is statistically significant:
Global warming in an independent record of the last 130 years
Quote: KeyserThe extreme consistency of temperature appears to be more statistically relevant than the small fluctuations.
The IPCC would disagree with you. Their definition of climate change:
Climate change refers to a statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer).
Quote: KeyserIf you believe in man made global warming, then it's interesting to know that we appear to have been warming the other planets, as well, during the same time periods. Blame it on coal!
Source?
What I was saying is that the standard deviation for the temperature rise here on earth wasn't statistically relevant, because there's wasn't enough of a deviation from the norm. Of course standard deviation testing is relevant.
The current supposed rise in temperature is puny.
Furthermore the data collection sites don't really meet the scientific standards required for real testing over a long period of time because they haven't been static. Enviromental conditions at the various locations around the world have changed a great deal.
-Keyser
Quote: PBguy"the study which projects a drastic decline" is not FACT. Sorry you can't understand that considering how obviously simple it is.
I have to assume that what you meant to say is that a projection is not a fact or a guarantee that it will happen. I don't think anyone has said anywhere that any kind of projection whether it be polar bear numbers or global temperature is a 100% guarantee. These are always best estimates based on empirical data and they can only make statements that the projections are "likely" or "not likely" with some statistical significance.
You misunderstood as to what I was saying is a fact. It was not the projections themselves but rather the failure to having time to adapt is true given that the projections are likely. I took this just by definition as to what biologists mean by adapt.
Quote: PBguyStudies are based on assumptions and models. Just because this study makes the claim doesn't make it true yet you apparently accept it without question.
Yes, studies can be and are based on assumptions and models. More importantly, though, they are also based on empirical data which can make the assumptions and models reasonable. If the purpose of a study is to make a projection about future events then this reasonableness is important. Other researchers in the field can come up with other reasonable assumptions and models to make different projections but in this specific instance I am not aware of any such contradicting studies.
Quote: PBguyDid you miss the part where Suckling admitted it would be 100 years before polar bears would actually be threatened by climate change? It was a political move nothing more.
Isn't the end of the 21st century the time frame we have been discussing all along? Sorry if you were somehow mislead into thinking something else.
I have to assume your implying that because politics is involved therefore the science is invalidated? The studies have made projections about the future population levels and these projections are instrumental to a species being placed on the endangered list and labeled as threatened. Just because there might be a formal political process required in order to make this officially happen doesn't invalidate the science.
Your original argument (stated as fact) was that polar bears have survived climate change before and therefore will survive global warming now. I provided evidence that this is not likely.
Quote: Keyserhttp://www.livescience.com/1349-sun-blamed-warming-earth-worlds.html
Your own source contradicts your claim here:
"...the majority of climate scientists and astrophysicists agree that the sun is not to blame for the current and historically sudden uptick in global temperatures on Earth..."
1) You made a claim without citing a source.
2) Your original claim omitted important information that was included by your source that contradicts your claim.
3) Your source is an article from a news website purportedly about science but it is not a professional journal that publishes peer reviewed research.
4) Your source stated the claim from two non-climate scientists who did not publish any of their claims in a professionally peer reviewed journal.
5) The only information published in a peer reviewed journal your source cited actually contradicts your claim.
This is why it is important to always to include a source to back up your claim so that readers can assess the credibility of it. I have attempted to do that here as much as possible to back up my claims. Conversely, I usually have to always ask for the source of others' claims and then, if they bother to do so, I have to explain to the claimant why their source is not credible.
Is it too much to ask that all the posters on this thread adhere to providing credible sources to back up any claims they are making? Unfortunately for some that means you might actually have to read the what the real science is saying rather than what some retired guy with a web blog is posting. You might actually have to drink the kool-aid as it were.
The current supposed warming trend is still statistically insignificant. Any luck on finding how many standard deviations the current warming trend is above the norm?
I didn't think so.
Quote: KeyserThe current supposed warming trend is still statistically insignificant.
Source?
Credible?
I didn't think so.
Quote: KeyserAny luck on finding how many standard deviations the current warming trend is above the norm?
You're still not asking a meaningful question (you ignored my previous response) since for one you haven't defined what period of time you are talking about in regards to the norm. I will, however, provide the following graph which is convincing that the IPCC definition previously stated is correct:
Figure 3.6. Global and hemispheric annual combined land-surface air temperature and SST anomalies (°C) (red) for 1850 to 2006 relative to the 1961 to 1990 mean, along with 5 to 95% error bar ranges, from HadCRUT3 (adapted from Brohan et al., 2006). The smooth blue curves show decadal variations.
The standard deviation from 1850 to 2005 is given as 0.24C (section 3.2.2.6 of the IPCC 2007). Clearly from the graph the average temperature between 1990 and 2005 (looks like about +0.2C) is more than one standard deviation over the average between 1850 and 1961 (about -0.3C).
Quote: paisielloThe standard deviation from 1850 to 2005 is given as 0.24C (section 3.2.2.6 of the IPCC 2007). Clearly from the graph the average temperature between 1990 and 2005 (looks like about +0.2C) is more than one standard deviation over the average between 1850 and 1961 (about -0.3C).
Only one standard deviation? Sorry, but that's not statistically significant. That appears to be just a random spike.
source: http://www.cru.uea.ac.uk/cru/data/temperature/
Quote: KeyserOnly one standard deviation? Sorry, but that's not statistically significant. That appears to be just a random spike.
I did say more than one. The math would work out to:
(+0.2C) - (-0.3C) = +0.5C (this is the approximate difference in anomalies between the averages with respect to the 1961 to 1990 average)
That works out to (+0.5C)/(0.24C) = approximately 2 standard deviations
Usually 2 standard deviations is the accepted definition of statistically significant used in many sciences and confirms the IPCC definition of climate change.
More significant, however, would be to compare the differences between the slopes of different time periods as shown here in this table of the HadCRUT4 global near surface temperature dataset compiled by the Met Office and Climatic Research Unit:
| Time period | Linear trend (°C/decade) | Absolute change in temperature described by linear trend (°C) |
|---|---|---|
| 1880-2011 | 0.062±0.009 | 0.81±0.13 |
| 1900-2011 | 0.074±0.011 | 0.82±0.13 |
| 1950-2011 | 0.106±0.025 | 0.66±0.16 |
| 1970-2011 | 0.166 ± 0.038 | 0.70 ± 0.16 |
Table 1. Trends fitted to monthly global temperature anomalies for HadCRUT4, with uncertainties describing 95% confidence interval bounds for the combination of measurement, sampling and bias uncertainty and uncertainty in the linear trend fitted to the data. The statistical model used allows for persistence in departures using an autoregressive process (ie that an individual value is not independent of the previous one).
The linear trend between the years 1970 - 2011 is 0.166/0.062 = 2.68 times the trend from 1880 - 2011. That works out conservatively to 2.68/0.038 = 70.5 standard deviations!
Quote: PaisielloThat works out to (+0.5C)/(0.24C) = approximately 2 standard deviations
Paisiello,
Two standard deviations still isn't that great, considering the low quality of the data collection, and considering the curve fitting that has already taken place with the data. Furthermore, the test sample is still too small to be considered statistically relevant.
-Keyser
Quote: KeyserPaisiello,
Two standard deviations still isn't that great, considering the low quality of the data collection, and considering the curve fitting that has already taken place with the data. Furthermore, the test sample is still too small to be considered statistically relevant.
-Keyser
S-s-source?
And what does "statistically relevant" mean?
Quote: boymimboJust stop them facts, Paisello!!!! You're bucking the "low-information voter" trend with all of that sciency-facty stuff.
Funny thing is (or maybe it's a sad thing) the polemicists come up with these questions and criticisms completely oblivious to the fact that thousands of professional climate scientists working on this problem for over 50 years have already effectively dealt with these issues.
Here's an interesting program with the late Stephen Schneider in a room full of "sceptics":
The Sceptics
Quote: paisielloS-s-source?
Me. I'm saying that two standard deviations isn't conclusive. It's suspect. Only two standard deviations from the norm over such a short period of time isn't solid evidence, especially since the data collection is suspect. It's weak. Ask any mathematician. Ask the Wizard.
Quote: paisiello
And what does "statistically relevant" mean?
This is a gambling forum, and you don't know what
this means? He's saying it's a blip, it means nothing.
An aberration, mostly because the data collection
is so slipshod and unreliable. Pitiful is more like it,
given that some of the equipment measuring temps
is in the wrong locations and in many cases is decades
old. It's like a science experiment done by 9 year olds.
Furthermore, there really aren't that many REAL scientists involved in climate change. The truth is that the best and the brightest tend to go into more interesting fields of scientific research than just global warming.
(Yes, I know there's the occasional exception, like Dr. Richard Lindzen.)
Quote: KeyserMe. I'm saying that two standard deviations isn't conclusive. It's suspect. Only two standard deviations from the norm over such a short period of time isn't solid evidence, especially since the data collection is suspect. It's weak. Ask any mathematician. Ask the Wizard.
And who are you exactly? I will go out on a limb and guess you're not a mathematician.
Quote: paisielloAnd who are you exactly? I will go out on a limb and guess you're not a mathematician.
Good lord. These are people who believe
in global warming, I rest my case.
Quote: EvenBobThis is a gambling forum, and you don't know what
this means? He's saying it's a blip, it means nothing..
In science it is very important to have definitions otherwise people who practice it professionally will get confused about what you are talking about.
For example, when a scientist claims that something is statistically significant they mean something specific by convention. Otherwise it will mean something different to every person involved. In science you need to be as objective as humanly possible so that professionals can all collaborate and the field can advance beyond one person's experience.
Richard Feynman has an anecdote about how he invented his own trigonometric symbols in high school because he felt the symbols you used weren't important, it was the concepts themselves that were important. But he soon realized he was wrong.
So you have to define what you mean by "statistically relevant". I'll just assume that it was a made up term and not have any useful meaning in this discussion.
Quote: EvenBob...the data collection is so slipshod and unreliable. Pitiful is more like it, given that some of the equipment measuring temps
is in the wrong locations and in many cases is decades old. It's like a science experiment done by 9 year olds.
Do you have a credible source to back up any of these spurious claims?
Quote: Keyser...there really aren't that many REAL scientists involved in climate change. The truth is that the best and the brightest tend to go into more interesting fields of scientific research than just global warming.
(Yes, I know there's the occasional exception, like Dr. Richard Lindzen.)
The thousands of professionals who have devoted their careers to study the earth's climate over their lifetimes would be insulted by this statement. Global warming and climate change is definitely the most significant challenge that human civilization has ever had to face and probably will ever have to face. They are all doing extremely important work.
The fact that you make exceptions only for the scientists that you agree with shows how invalid your statement is.
Quote: EvenBob...I rest my case.
I wasn't aware that you had even attempted to make a credible case.
Quote: PaisielloThe thousands of professionals who have devoted their careers to study the earth's climate over their lifetimes would be insulted by this statement. Global warming and climate change is definitely the most significant challenge that human civilization has ever had to face and probably will ever have to face. They are all doing extremely important work.
Paisiello,
If you say so. I actually believe that much of it is simply hype, eager grad students chasing grant money, and bad politics. Way too much money is being spent on it. Money what could be more wisely spent curing already curable diseases like malaria, and money that could be spend on cancer research.
I'm not going to take the time to teach you about the normal bell curve and how to calculate the z score.
Why don't you ask someone else. Better yet, why don't you start a thread asking how relevant your two standard deviation fluctuation is over the time period that was tested. (You're not going to like the answers)/
-Keyser.
Quote: KeyserMe. I'm saying that two standard deviations isn't conclusive. It's suspect. Only two standard deviations from the norm over such a short period of time isn't solid evidence, especially since the data collection is suspect. It's weak. Ask any mathematician. Ask the Wizard.
2 standard deviations is one of the big delineation marks for acceptable p-values. It corresponds roughly to a p-value of .05 so yes it is statistically significant in most context. If you want a stricter interpretation for statistical significance it is up to you to say what that is.
Quote: KeyserPaisiello,
I'm not going to take the time to teach you about the normal bell curve and how to calculate the z score.
Why don't you ask someone else.
-Keyser.
I didn't ask you to teach me anything just to give me credible source to back up your claims. Since you have failed to do this despite my repeated requests I can dismiss your claims as not being credible and I trust impartial readers will do the same.
Quote: KeyserNO it's most certainly not, given the puny size of the test sample and the suspect data that has been collected.
No source = not credible
Real scientists don't stake their reputations on only a two standard deviation fluctuation. Like I said, if you don't believe me then start a post on the subject.
Quote: KeyserNO it's most certainly not, given the puny size of the test sample and the suspect data that has been collected.
You realize that test sample size changes the size of the standard deviation not how many deviations from standard deviation are needed to say something is statistically significant. So for instance say I wanted to be 95% certain a coin was biased if I flipped it 100 times the mean is 50 and the standard deviation is 5 so if I got less the 40 or more then 60 then I could be 95% certain that the coin is biased so basically if 1 of the sides showed up less then 40% of the time. For 1,000,000 flips mean is 500k and standard deviation is 500 so between 499k and 501k I would be fine so if any face showed up less then 49.9% of the time I could be 95% the coin is biased. In both cases I am 95% sure and am 2 standard deviations away. Doesn't matter that in the first test I only have a hundred flips 2 standard deviations is just as definitive as 1 million flips.
Quote: KeyserPaisiello,
Real scientists don't stake their reputations on only a two standard deviation fluctuation. Like I said, if you don't believe me then start a post on the subject.
Again you need to say what p-score you consider significant since it varies greatly between fields. Saying a p-score of .05 is not significant is wrong since some papers do use that. In fact .05 is the norm to use so if you want to use anything but that norm you need to specify what you mean.
Quote: KeyserPaisiello,
Real scientists don't stake their reputations on only a two standard deviation fluctuation. Like I said, if you don't believe me then start a post on the subject.
I don't believe you but I won't start a post on the subject. Maybe you can start one, though, and stop posting in this one.
I'm sorry if you don't like the facts. If you don't like dissenting views, then perhaps you shouldn't be posting on an open forum.
Quote: KeyserPaisiello,
I'm sorry if you don't like the facts. If you don't like dissenting views, then perhaps you shouldn't be posting on an open forum.
All I have done is provide sources to back up the claims I have made. I am open to dissenting views, I just want some credible evidence to back up your claims which to date you have provided none.
At least PBguy makes some sort of effort.
Yes it's a cartoon but if someone created a cartoon suggesting that climate scientists be murdered there would be an uproar - and rightly so.
Even the use of "denier" for anyone that dares to question the status quo is intentionally pejorative.
Good for him!
Why helping the poor may hurt the climate
Quote: PBguyApparently some people think that "climate change deniers" should be "dispatched" (that would be 'newspeak' for killing):
Yes it's a cartoon but if someone created a cartoon suggesting that climate scientists be murdered there would be an uproar - and rightly so.
Even the use of "denier" for anyone that dares to question the status quo is intentionally pejorative.
Is it a contest? Here's my entry.
http://www.livescience.com/20107-heartland-climate-change-billboards.html
"New Billboards Compare Climate Scientists and Unabomber, Mass Murderers"
Quote: rxwineQuote: PBguyApparently some people think that "climate change deniers" should be "dispatched" (that would be 'newspeak' for killing):
Yes it's a cartoon but if someone created a cartoon suggesting that climate scientists be murdered there would be an uproar - and rightly so.
Even the use of "denier" for anyone that dares to question the status quo is intentionally pejorative.
Is it a contest? Here's my entry.
http://www.livescience.com/20107-heartland-climate-change-billboards.html
"New Billboards Compare Climate Scientists and Unabomber, Mass Murderers"
Climate scientists called those billboards a "heinous action" on the part of Heartland Institute. Do you think they'll react the same way against this cartoon that advocates murdering "dispatching" people for their beliefs?
Quote: paisielloGlobal warming and climate change is definitely the most significant challenge that human civilization has ever had to face and probably will ever have to face.
You can't be serious?
Ice Age
Black Death
Smallpox and other disease
World Wars
Transition to farming from hunter-gathering
Threat of nuclear war
There are dozens of others. And somehow a 1-2C change in temperature which is easily within what the planet has had in the past is a bigger challenge?
So was global cooling 40 years ago...lol
Quote: AZDuffmanYou can't be serious?
Ice Age
Black Death
Smallpox and other disease
World Wars
Transition to farming from hunter-gathering
Threat of nuclear war
There are dozens of others. And somehow a 1-2C change in temperature which is easily within what the planet has had in the past is a bigger challenge?
AZ, I have to agree with you on this one, though the transition from farming to hunter-gathering is quite a stretch. But yeah, curing polio was a pretty big deal, as was defusing some of the nuclear threat in the 80s. I would say that nuclear proliferation is still probably the most significant challgenge out there, followed by global warming.
But global warming is solvable, and I think that in about 20 years when the world gets over the economic bumps they will come together. Some scientific leap will occur (fusion, easy transition to non-fossil fuel without having to replace cars, etc, injecting the atmosphere with some safe global-cooling material, etc) and the problem will be solved.
Certainly to be hoped for. But the development of Tokamak and its descendants has been going on for more than 30 years now.Quote: boymimboI think that in about 20 years when the world gets over the economic bumps they will come together. Some scientific leap will occur (fusion, easy transition to non-fossil fuel without having to replace cars, etc, injecting the atmosphere with some safe global-cooling material, etc) and the problem will be solved.
