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U.S. Climate Has Already Changed, Study Finds
Cerberus.Pleebo
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By Cerberus.Pleebo 2014-05-09 04:19:19
Their rationale: Quote: Many of the graphs in this report illustrate historical changes and future trends in climate compared to some reference
period, with the choice of this period determined by the purpose of the graph and the availability of data. The
great majority of graphs are based on one of two reference periods. The period 1901-1960 is used for graphs that
illustrate past changes in climate conditions, whether in observations or in model simulations. The choice of 1960 as
the ending date of this period was based on past changes in human influences on the climate system. Human-induced
forcing exhibited a slow rise during the early part of the last century but then accelerated after 1960.2 Thus, these
graphs highlight observed changes in climate during the period of rapid increase in human-caused forcing and also
reveal how well climate models simulate these observed changes. The beginning date of 1901 was chosen because
earlier historical observations are less reliable and because many climate model simulations begin in 1900 or 1901.
The other commonly used reference period is 1971-2000, which is consistent with the World Meteorological Organization’s
recommended use of 30-year periods for climate statistics. This is used for graphs that illustrate projected
future changes simulated by climate models. The purpose of these graphs is to show projected changes compared to
a period that people have recently experienced and can remember; thus, the most recent available 30-year period was
chosen (the historical period simulated by the CMIP3 models ends in 1999 or 2000). Basically, the choice of intervals is ultimately arbitrary but is structured around the data sets themselves. The starting point (1900) is where direct observations are most reliable (however, I would assert that indirect observations have a comparable level of reliability prior to that period, as well) and the end point (1960) is where climate "stability" was most notably disrupted. By comparing that particular reference period with a relatively recent time interval, it draws attention to the distinct difference between what we ourselves have experienced in the immediate past and what was historically recorded before most of us were probably born.
It's just one of many ways to convey the basic message that average temperatures have increased over a relatively short period of time. It's not meant to trick you into believing something that isn't demonstrably true but rather meant to communicate a comprehensive set of observations in a terse, relatable (and media-friendly) way.
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Bahamut.Kara
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By Bahamut.Kara 2014-05-09 04:57:29
This is why statistics should be more widely taught, starting in high school or earlier. All you really need is an understanding of algebra.
Regression testing is very common. Creating a data baseline to compare if something is statistically significant is done all the time. OLS, the workhorse of so many industries.
As Raveal pointed out hypothesis testing can be done incorrectly; methodologies could be crap, underlying assumptions could skew results, data could be sampled/cleaned incorrectly, etc.
I think the more people who have had to actually setup an experiment and write a paper explaining their data and methodolgy sections, we might have less stupid arguments. Not less arguments, just more informed ones.
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Gilgamesh.Schmule
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By Gilgamesh.Schmule 2014-05-09 05:34:40
Must be true. They have graphs and everything.
Bahamut.Ravael
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By Bahamut.Ravael 2014-05-09 05:55:11
This is why statistics should be more widely taught, starting in high school or earlier. All you really need is an understanding of algebra.
Well, algebra is all you need for basic statistics at least. I think a statistics class should be required in high school, but I'm a tad biased.
Quote: Regression testing is very common. Creating a data baseline to compare if something is statistically significant is done all the time. OLS, the workhorse of so many industries.
As Raveal pointed out hypothesis testing can be done incorrectly; methodologies could be crap, underlying assumptions could skew results, data could be sampled/cleaned incorrectly, etc.
I think the more people who have had to actually setup an experiment and write a paper explaining their data and methodolgy sections, we might have less stupid arguments. Not less arguments, just more informed ones.
Holy crap yes. On top of that, I think one of the most important things that can be taught early on in school is just general skepticism. Not outright doubt, but skepticism. Towards everything. It doesn't matter if your mom said it, your teacher said it, some doctor said it, or the smartest guy you know said it. I had several friends who would cling to false information no matter what contrary evidence was shown to them, simply because someone they trusted told them otherwise and "Why would they lie?" And I'm not talking specifically about politics either. I have a friend whose dad sunk all 15 billiard balls on a single break. Yup, screw the laws of physics and probability, that really happened because his dad said so.
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Serveur: Shiva
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By Shiva.Onorgul 2014-05-09 07:11:18
So is global warming real or not?
Depends on how you define the issue.
Is the planet getting hotter? Undeniably.
Is it a Significant Threat? To Some, not to others.
Is it Accelerated by Mankind to a significant degree? Data Insufficient. None of these are as important as the big question:
Can we do anything about it?
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By Asura.Kingnobody 2014-05-09 07:13:02
So, when is the planet going to explode again?
And do we blame Bush for it?
VIP
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By Odin.Jassik 2014-05-09 07:33:54
lol, I have no idea where that first link got that 31,487 number since it's completely uncited. For all I know, they made it up.
ffs dude why are you totally ignoring the fact that 1901-1960 and 1991-2012 will have a different avg. no matter what! When you avg. out 59yrs your gonna have a more reliable avg. from what you get when you avg. out 11yrs. IF they was BOTH the same MAYBE we wouldn't be having this discussion. All that and they still only have a 2 degree difference its surprising its not more if the earth is really warming so much. This is what hypothesis testing is designed for - to test if two (or more) values, in this case average temperature, are actually (that is, statistically) different from each other and provide an estimate of how reliable those results are.
2 degrees on average across an entire country is a big difference. This isn't like setting your thermostat from 70 to 72. I don't know how else to explain this.
Why not just take 1902-1942 and 1972-2012 and leave out the Assumption.
that's not how an average works...
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By Asura.Kingnobody 2014-05-09 08:16:23
lol, I have no idea where that first link got that 31,487 number since it's completely uncited. For all I know, they made it up.
ffs dude why are you totally ignoring the fact that 1901-1960 and 1991-2012 will have a different avg. no matter what! When you avg. out 59yrs your gonna have a more reliable avg. from what you get when you avg. out 11yrs. IF they was BOTH the same MAYBE we wouldn't be having this discussion. All that and they still only have a 2 degree difference its surprising its not more if the earth is really warming so much. This is what hypothesis testing is designed for - to test if two (or more) values, in this case average temperature, are actually (that is, statistically) different from each other and provide an estimate of how reliable those results are.
2 degrees on average across an entire country is a big difference. This isn't like setting your thermostat from 70 to 72. I don't know how else to explain this.
Why not just take 1902-1942 and 1972-2012 and leave out the Assumption.
that's not how a selective average works... ftfy
Leviathan.Chaosx
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By Leviathan.Chaosx 2014-05-09 08:37:48
So, when is the planet going to explode again?
And do we blame Bush for it? Wait for Jeb to take office first.
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By fonewear 2014-05-09 08:38:43
It is going to be 82 today is that enough climate change for a Friday or does it have to hit 84 ?
Breaking news today Tom: The temperate in Chicago is going to reach 212 we caution you to wear a light jacket. And to drink water at least once in a while.
By fonewear 2014-05-09 08:41:21
So, when is the planet going to explode again?
And do we blame Bush for it?
Bush was around when the Earth was just forming getting ready to invade what would soon become Iraq.
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VIP
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By Odin.Jassik 2014-05-09 08:49:05
lol, I have no idea where that first link got that 31,487 number since it's completely uncited. For all I know, they made it up.
ffs dude why are you totally ignoring the fact that 1901-1960 and 1991-2012 will have a different avg. no matter what! When you avg. out 59yrs your gonna have a more reliable avg. from what you get when you avg. out 11yrs. IF they was BOTH the same MAYBE we wouldn't be having this discussion. All that and they still only have a 2 degree difference its surprising its not more if the earth is really warming so much. This is what hypothesis testing is designed for - to test if two (or more) values, in this case average temperature, are actually (that is, statistically) different from each other and provide an estimate of how reliable those results are.
2 degrees on average across an entire country is a big difference. This isn't like setting your thermostat from 70 to 72. I don't know how else to explain this.
Why not just take 1902-1942 and 1972-2012 and leave out the Assumption.
that's not how a selective average works... ftfy
no, averages are a way to compare different volumes of data, you can choose any year range, and the data is available. he's arguing that the difference in sample size instantly makes the average different, which is a fundamental misunderstanding of math.
don't misquote me again.
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Serveur: Shiva
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By Shiva.Nikolce 2014-05-09 08:51:06
On behalf of the entire north coast of the united states, I move to stall any action on global warming until the winters near lakes erie and michigan suck about 65%-75% less... and if it costs us florida in the process, you won't hear any complaining from us...
thank you.
Bismarck.Magnuss
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By Bismarck.Magnuss 2014-05-09 08:53:31
Nothing's going to happen legislatively, so let's all just sit back, relax and wait for the impending armageddon.
"It's snowing in winter; global warming is debunked!"
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Serveur: Asura
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Posts: 34187
By Asura.Kingnobody 2014-05-09 08:54:21
lol, I have no idea where that first link got that 31,487 number since it's completely uncited. For all I know, they made it up.
ffs dude why are you totally ignoring the fact that 1901-1960 and 1991-2012 will have a different avg. no matter what! When you avg. out 59yrs your gonna have a more reliable avg. from what you get when you avg. out 11yrs. IF they was BOTH the same MAYBE we wouldn't be having this discussion. All that and they still only have a 2 degree difference its surprising its not more if the earth is really warming so much. This is what hypothesis testing is designed for - to test if two (or more) values, in this case average temperature, are actually (that is, statistically) different from each other and provide an estimate of how reliable those results are.
2 degrees on average across an entire country is a big difference. This isn't like setting your thermostat from 70 to 72. I don't know how else to explain this.
Why not just take 1902-1942 and 1972-2012 and leave out the Assumption.
that's not how a selective average works... ftfy
no, averages are a way to compare different volumes of data, you can choose any year range, and the data is available. he's arguing that the difference in sample size instantly makes the average different, which is a fundamental misunderstanding of math. But if you really want to get the truth of a set of averages, you would compare not only the same timeframe, but different sets of timeframes right next to each other. If you are going to take the average of the temperature of the world between 1999-2012, then you would want to compare it to the average of the temperatures of the world between 1985-1998, 1971-1984, 1957-1970....see my point?
Not only did they skew the timeframe by increasing the number of years by the "control" average, but there was a large gap between the "control" average and the "testing" average. Therefor, the results will be skewed for it.
please continue to correct me if I make a mistake. Sure.
Fenrir.Atheryn
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By Fenrir.Atheryn 2014-05-09 08:56:22
no, averages are a way to compare different volumes of data, you can choose any year range, and the data is available. he's arguing that the difference in sample size instantly makes the average different, which is a fundamental misunderstanding of math.
True, but by the same token, you could say that the average temperature of 1312-1948 is less than the average temperature of 2012. The statement might be correct, but it isn't a fair comparison of sample sizes.
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By fonewear 2014-05-09 08:59:29
Nothing's going to happen legislatively, so let's all just sit back, relax and wait for the impending armageddon.
"It's snowing in winter; global warming is debunked!"
Armageddon that was a terrible film.
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By Asura.Kingnobody 2014-05-09 09:00:23
On behalf of the entire north coast of the united states, I move to stall any action on global warming until the winters near lakes erie and michigan suck about 65%-75% less... and if it costs us florida in the process, you won't hear any complaining from us...
thank you. Wait until Florida is destroyed until AFTER my big road trip please.
No weather controlling devices or death-rays yet please Nik.
Bahamut.Kara
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By Bahamut.Kara 2014-05-09 09:00:57
"Control" is not there to "control" you.
They used 59 years as a baseline. They have stated why they used it as a baseline. The 30 years they chose to show they also stated why.
Then they they regressed it to check for statistical significance.
This is simple statistics. (Not the regression they did, but the basic processes)
Fenrir.Atheryn
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By Fenrir.Atheryn 2014-05-09 09:01:01
On a side note, I always have to question the data when they compare periods of different length. Why compare the average of a 60 year period against the average of a 20 year period?
Either they don't have enough data to compare two 60 year periods, or they do, but doing so would disprove their argument.
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Bismarck.Magnuss
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By Bismarck.Magnuss 2014-05-09 09:01:24
Nothing's going to happen legislatively, so let's all just sit back, relax and wait for the impending armageddon.
"It's snowing in winter; global warming is debunked!"
Armageddon that was a terrible film. I don't wanna close my eyes... I don't wanna faaaaaaaaall asleep, 'cause I miss you, baby; and I don't wanna miss a thang!
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Bahamut.Kara
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By Bahamut.Kara 2014-05-09 09:05:25
On a side note, I always have to question the data when they compare periods of different length. Why compare the average of a 60 year period against the average of a 20 year period?
Either they don't have enough data to compare two 60 year periods, or they do, but doing so would disprove their argument. Pleebo already gave their reasoning. First post on this page.
I'd also recommend you review time series regression for any time period analysis questions
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By Asura.Kingnobody 2014-05-09 09:10:45
"Control" is not there to "control" you.
They used 59 years as a baseline. They have stated why they used it as a baseline. The 30 years they chose to show they also stated why.
Then they they regressed it to check for statistical significance.
This is simple statistics. (Not the regression they did, but the basic processes) Wait, since when did I say that the baseline was there to control you?
Maybe I used the word wrong?
Edit: Doesn't look like it
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By Asura.Kingnobody 2014-05-09 09:12:04
Pleebo already gave their reasoning. First post on this page. What, their BS reasoning to start with the best numbers to suit their hypothesis?
Heck, even I could see the BS for what it is, and I'm not a climate scientist.
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Lakshmi.Zerowone
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By Lakshmi.Zerowone 2014-05-09 09:12:24
On a side note, I always have to question the data when they compare periods of different length. Why compare the average of a 60 year period against the average of a 20 year period?
Either they don't have enough data to compare two 60 year periods, or they do, but doing so would disprove their argument. Pleebo already gave their reasoning. First post on this page.
I'd also recommend you review time series regression for any time period analysis questions
I'd rather just kick them a clue: The Petrol-Industrial Revolution is only 75yrs old. Let them figure it out from there.
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By Asura.Kingnobody 2014-05-09 09:14:35
Why not just say "It's Bush's fault" and get it over with and move on?
Lakshmi.Zerowone
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By Lakshmi.Zerowone 2014-05-09 09:16:28
Why not just say "It's Bush's fault" and get it over with and move on?
Because you would cry, that all we ever do is blame Bush.
Bismarck.Bloodrose
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By Bismarck.Bloodrose 2014-05-09 09:19:02
I blame Al Gore. Because Man-Bear-Pig. And he created the environment.
And he's super cereal.
And needs a friend.
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Bismarck.Magnuss
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By Bismarck.Magnuss 2014-05-09 09:20:10
Why not just say "It's Bush's fault" and get it over with and move on?
Because you would cry, that all we ever do is blame Bush. Even though it pretty much is his fault.
No, I can't make that claim. Bush was just the puppet; Cheney was the nightmarish fiend pulling the strings.
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By Shiva.Onorgul 2014-05-09 09:21:40
Why not just say "It's Bush's fault" and get it over with and move on? Because it is more likely Nixon's fault? With few exceptions, we're all far, far too young to properly appreciate how much Richard Nixon's administration doomed the world. Dubya (since I assume you don't mean the competent, rational, and level-headed Bush, Sr.) was largely impotent and the legacy of his puppetmasters is economic ruin far more than environmental.
http://www.nytimes.com/2014/05/07/science/earth/climate-change-report.html?_r=3
A very extensive report, known as the National Climate Assessment, was released earlier this week. Nothing in the report is particularly surprising, but its presentation for the general public, here, is incredibly impressive. (Not all government website releases are a disaster!)
If hardcore technical reports aren't your thing, the highlights portion of the site breaks each section down as plainly as possible, is extensively cited, and makes no secret the level of uncertainty inherent in current findings. The site is really quite fantastic, and I would encourage anyone with genuine interest, skepticism, and/or curiosity in U.S. climate change to fuck around in it for a while. (Of course, if well-substantiated, easily digestible scientific communications aren't your thing, there's always this.)
Perhaps, the most poignant message arising from the report is summarized in this quote from the article:
Quote: The report pointed out that while the country as a whole still had no comprehensive climate legislation, many states and cities had begun to take steps to limit emissions and to adapt to climatic changes that can no longer be avoided. But the report found that these efforts were inadequate. I don't really consider myself a policy person so... what do?
Edit: Also of note is the high diversity of those involved. Largely scientists, of course, but representative of a wide swath of interests, including some oil companies.
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