Climate Change Politics

@kennethamy,

What question is it you don't feel has been addressed?

@Dave Allen,

Dave Allen;114097 wrote:

What question is it you don't feel has been addressed?

http://upload.wikimedia.org/wikipedia/commons/c/c2/Vostok-ice-core-petit.png

http://upload.wikimedia.org/wikipedia/commons/6/60/Five_Myr_Climate_Change.png
http://upload.wikimedia.org/wikipedia/commons/1/1b/65_Myr_Climate_Change.png

Here's some graphs, the first based on analyzing bubbles in ice cores. The next two suggest changes in glaciation from oxygen isotopes in sediment cores.

Learning about historical geography changed my perspective on time. The whole life span of our species is tiny in geological time. 100 years is practically nothing.

Glaciers melt. Oceans rise. Continents move.

That's why I'm confused about why anybody is focusing on present weather conditions. For a while now, I've been trying to discover the answer to that and the tentative conclusion I've reached is that it's because present weather conditions are palpable. A person has a gut reaction to learning that glaciers are melting. How shocked would they be to find out the Sahara was a prairie 20,000 years ago? Would they try to take responsibility for that? Actually I have no doubt that many would. But I'm open to other reasons for this particular focus. I guess I just need to read more.

Since I first learned about the greenhouse effect several decades ago, I've wished for some kind of reliable prediction. I haven't found it. I favor the direction we're going in: to find alternative fuel sources and reduce consumption. But if it's true that there's reason to fear that the earth's surface doesn't have enough drinkable water to support a population of 10 billion (which appears reachable in this century), then for me, all signs point in the same direction: we need to stop growing. That, along with the price of eggs in China is out of my hands.

1 Reply

@Arjuna,

I think that population growth is the single biggest issue regarding our collective impact on the earth. It probably isn't examined as much as climate change for the simple reason that it carries so many unpalatable associations.

Quote:

That's why I'm confused about why anybody is focusing on present weather conditions.

Because they're happening now, because we, or the generation that follows us, or the generation that follows them, will have to deal with the consequences.

So yes, it was even more extreme in the past, and will be again in the distant future - but we don't have to worry about that.

Whereas dealing with mass migrations of refugees as the result of a flooded Holland or Bangladesh and other low-lying areas is a danger that threatens - and we might be able to prevent it - or at least slow it - by stopping or moderating the production of carbon gasses.

So it would seem anyway.

So the reason people focus on what's happening now is because we're in the now. There were ice ages and floods in the past - but I didn't have to live in them, and I'd rather not live in a dramatically different climate now (or soon) if it can be helped.

Arjuna;114110 wrote:

How shocked would they be to find out the Sahara was a prairie 20,000 years ago? Would they try to take responsibility for that?

No, not unless they were mad.

It was 20,000 years ago.

Sure, it's interesting - but the consequences of a desert being a lush prairie in the distant past don't affect me in the same way as the gulf stream becoming weaker, or a rise in sea level, happening now, or over the next decade, or over the next 50 years.

The past happened - I'm sure climate change in the past was very traumatic for those that lived to see it.

I empathise with that sort of global upheaval and what it does to people - therefore I'd like to see preventable climate change happening now prevented.

1 Reply

@Dave Allen,

Dave Allen;114113 wrote:

Whereas dealing with mass migrations of refugees as the result of a flooded Holland or Bangladesh and other low-lying areas is a danger that threatens - and we might be able to prevent it - or at least slow it - by stopping or moderating the production of carbon gasses.

The heart trumps all human understanding. It will have you giving up freely what an army of millions couldn't take from you.

That's what it is then, isn't it? The prospect of human suffering.

0 Replies

@kennethamy,

Arjuna;114110 wrote:

That's why I'm confused about why anybody is focusing on present weather conditions.

To be sure the focus is on climate and not on weather. It's the unprecedented rapidity of change that is the issue, and that modeling of the simultaneous human activities seems to explain the observations. Of course any model will be biased by your hypothesis, but you have to ask why parallel observations all add up to a rather similar story.

---------- Post added 12-25-2009 at 10:09 AM ----------

Arjuna;114110 wrote:

I favor the direction we're going in: to find alternative fuel sources and reduce consumption. But if it's true that there's reason to fear that the earth's surface doesn't have enough drinkable water to support a population of 10 billion (which appears reachable in this century), then for me, all signs point in the same direction: we need to stop growing. That, along with the price of eggs in China is out of my hands.

We can justify our interventions for climate change in many other ways, such as the contribution of fossil-based pollutants to lung disease, so I think common ground is possible in terms of policy -- whatever one believes about climate change. Climate change is only controversial because it's at the center of a policy debate. If the emphasis were on decreasing dependency on oil, or on decreasing air pollution, then people would generally leave climate change alone. It's mainly angry Republicans and libertarians, people with a vested interest in the petroleum-related industries, and schizoid people who need to find conspiracies everywhere who are the loudest voices of opposition.

1 Reply

@Aedes,

Aedes;114192 wrote:

It's mainly angry Republicans and libertarians, people with a vested interest in the petroleum-related industries, and schizoid people who need to find conspiracies everywhere who are the loudest voices of opposition.

It seems to me that we found a conspiracy at East Anglia University (which feeds data to the UN) because there was a conspiracy there.

1 Reply

@Aedes,

Aedes;114069 wrote:

I haven't been ignoring your question, by the way. I just discovered that my copy of SPSS is not compatible with Windows 7, which I upgraded to last week, so a few hundred bucks out of my pocket and I'll be up and running (which I need for more pressing things anyway).

At any rate, if you take your data set and use a statistical comparison that compares means, like the Student's T-test, you'll get a P-value of 1 because the means are identical. (This is using a 2-tailed test, which is necessary because a temperature can be below 50 or above 80, i.e. you can have variance in either direction -- a 1-tailed test would give you a P-value of 0.5).

And so these two methods tell you what ? p = 1 or p = 0.5.
In the case of 50 + 80, it being equal to 80 + 50, what does that mean in
English, as to the statistical significance ?

Quote:

It's sort of a strange question, though, because embedded in most of these formulae is the assumption of a sort of distribution (i.e. normal or not normal), and it's mathematically impossible to make that determination with only two data points per set.

Given that we cannot "assume" normal distribution or pairing for these samples, I would normally use a Mann-Whitney U test. This I cannot do in Excel, which I incidentally have found rather limited for stats -- better for organizing data than for analyzing it. If I get SPSS up and running next week when I can make it to the bookstore, I'd be happy to run it.

As for the Chi-squared analysis, this was perhaps not the best test to choose because it's really a measurement of distribution and not means (it's also properly speaking a Chi value and not a p-value).

Is this the way that the climate scientists approach the question of statistical significance of temperature readings ?

Quote:

That's the best way I have to answer the question without just throwing out numbers. Obviously having greater sample sizes allows for more robust statistics because the distribution of data becomes more precise and the effect of outliers is minimized. The statistical test you choose depends in part on the question you're asking, the assumptions you make about your data, and parameters like whether they're paired or not and unidirectional or bidirectional.

How would you do it like a climate scientist, using ten thousand readings, from the 2 thermometer stations ?

1 Reply

@memester,

memester;114199 wrote:

And so these two methods tell you what ? p = 1 or p = 0.5.
In the case of 50 + 80, it being equal to 80 + 50, what does that mean in
English, as to the statistical significance ?

It's not so much the method per se, but whether you are using a formula that assumes the variability of interest to be unidirectional or bidirectional. If, for example, you're doing a study of fever, that would (usually) be regarded as a unidirectional variable -- i.e. temperatures above normal, and a temperature below normal would not be allowed to reject the null hypothesis (this depends on what your hypothesis is). So you would use a one-tailed T-test for this. If you can have a bidirectional variable, you'd usually use a two-tailed T-test. The P-value is twice as high for a two-tailed T-test (it's built into the formula and I don't know how the formula is derived), but what that means is it's twice as likely that an observed difference is due to chance.

Two-tailed test - Wikipedia, the free encyclopedia

P = 0.05 literally means that there is a 5% probability that an observed difference is due to chance, and a 95% probability that it was due to a real difference between the groups.

memester;114199 wrote:

Is this the way that the climate scientists approach the question of statistical significance of temperature readings ?
How would you do it like a climate scientist, using ten thousand readings, from the 2 thermometer stations ?

Statistics can be applied to any data set, so it doesn't matter if you're taking 1000 readings each from two weather stations or from two patient groups. Let's assume that study design is uniform (which cannot be completely assumed for a "case-control" design where you're comparing X "now" versus X "then" but you hadn't created a study protocol before X "then" -- and you also don't have a matched control group). But for the sake of simplicity, we assume that the equipment and the method of measurement is uniform, and the measurements are noontime ambient temperature readings at a fixed location every day of July for ten consecutive years -- once from 1900-1909 and once from 2000-2009.

This would generate 300 readings from each period. You could then use something as simple as a T-test to compare means. You need stats, because in all likelihood the "number" is different, i.e. you might get a 17 degrees C from one set and a 20 degrees C from the other set. But is that a REAL difference or can it just be due to chance? The greater your N, the more likely that an observed difference is real. This is intuitive -- if you flip a coin four times and get three heads and one tail, this is not reflecting the true probability -- you need more measurements (which will cause regress to the true mean, which is closer to 50/50).

This effect of sample size is built into the probability equations. Again, I don't know how, it's very complex math that's beyond how I use it. But if you generate a P value of < 0.000001, that means that there is only a 0.0001% probability that the difference is due to chance. If your P value is 0.1, then you have a 10% probability that it was due to chance.

In other words, the P value is simply telling us the confidence with which we can conclude that an observed difference is real. Conventionally a P < 0.05 is considered "significant", though this is arbitrary and people who get a P of 0.053 will often call it a "trend" towards significance.

In the case of 50 + 80 vs 80 + 50, let's say that these are temperature readings done the same way on July 1 and July 10 of 1900 vs 2000. The means are the same, right? It's the commutative property of addition -- 50 + 80 = 80 + 50, and the mean of 80 + 50 is (80 + 50) / 2 = 65.

So if you're doing a test of significance comparing 65 vs 65 (as your means), your P-value will be 1. Why 1? Because there is a 0% probability of there being a true difference between the groups.

1 Reply

@Aedes,

Aedes;114213 wrote:

It's not so much the method per se, but whether you are using a formula that assumes the variability of interest to be unidirectional or bidirectional. If, for example, you're doing a study of fever, that would (usually) be regarded as a unidirectional variable -- i.e. temperatures above normal, and a temperature below normal would not be allowed to reject the null hypothesis (this depends on what your hypothesis is). So you would use a one-tailed T-test for this. If you can have a bidirectional variable, you'd usually use a two-tailed T-test. The P-value is twice as high for a two-tailed T-test (it's built into the formula and I don't know how the formula is derived), but what that means is it's twice as likely that an observed difference is due to chance.

Two-tailed test - Wikipedia, the free encyclopedia

P = 0.05 literally means that there is a 5% probability that an observed difference is due to chance, and a 95% probability that it was due to a real difference between the groups.

Statistics can be applied to any data set, so it doesn't matter if you're taking 1000 readings each from two weather stations or from two patient groups. Let's assume that study design is uniform (which cannot be completely assumed for a "case-control" design where you're comparing X "now" versus X "then" but you hadn't created a study protocol before X "then" -- and you also don't have a matched control group). But for the sake of simplicity, we assume that the equipment and the method of measurement is uniform, and the measurements are noontime ambient temperature readings at a fixed location every day of July for ten consecutive years -- once from 1900-1909 and once from 2000-2009.

This would generate 300 readings from each period. You could then use something as simple as a T-test to compare means. You need stats, because in all likelihood the "number" is different, i.e. you might get a 17 degrees C from one set and a 20 degrees C from the other set. But is that a REAL difference or can it just be due to chance? The greater your N, the more likely that an observed difference is real. This is intuitive -- if you flip a coin four times and get three heads and one tail, this is not reflecting the true probability -- you need more measurements (which will cause regress to the true mean, which is closer to 50/50).

This effect of sample size is built into the probability equations. Again, I don't know how, it's very complex math that's beyond how I use it. But if you generate a P value of < 0.000001, that means that there is only a 0.0001% probability that the difference is due to chance. If your P value is 0.1, then you have a 10% probability that it was due to chance.

In other words, the P value is simply telling us the confidence with which we can conclude that an observed difference is real. Conventionally a P < 0.05 is considered "significant", though this is arbitrary and people who get a P of 0.053 will often call it a "trend" towards significance.

In the case of 50 + 80 vs 80 + 50, let's say that these are temperature readings done the same way on July 1 and July 10 of 1900 vs 2000. The means are the same, right? It's the commutative property of addition -- 50 + 80 = 80 + 50, and the mean of 80 + 50 is (80 + 50) / 2 = 65.

So if you're doing a test of significance comparing 65 vs 65 (as your means), your P-value will be 1. Why 1? Because there is a 0% probability of there being a true difference between the groups.

Right. Now you need more of what might have to be assumptions, filled out with facts. If the readings are from two thermometers in my house, and local temp is manipulated through a program making best randomness in temp, it being read, usually, at 50 or 80, using heaters and coolers with almost instantaneous local temp change, then what ?
It's random, in a way - "by chance" ( whether it will be 50 or 80 at any particular moment ) , - but obviously caused - not "by chance" - in another way.
How do you interpret what "by chance", means, vis a vis statistical significance ?

---------- Post added 12-25-2009 at 02:48 PM ----------

Now suppose we look at some things that xris was yammering about; water pollution, and about acid rain.

These things link into Climate Change hypotheses.

They would be taking results from people like this - the EPA would accept results of study from these people, right ?

Water Quality and Water pH

Ammonia Nitrogen Fish Toxicity Surface Water

1 Reply

@kennethamy,

kennethamy;114196 wrote:

It seems to me that we found a conspiracy at East Anglia University (which feeds data to the UN) because there was a conspiracy there.

What exactly, in your veiw, is/was the conspiracy?

Because when the hacked e-mails are looked at in context - rather than just mined for contentious sounding quotes by news-people without much knowledge of the science under discussion - they don't reveal anything that people weren't being more or less open about anyway.

2 Replies

@Dave Allen,

Dave Allen;114251 wrote:

What exactly, in your veiw, is/was the conspiracy?

Because when the hacked e-mails are looked at in context - rather than just mined for contentious sounding quotes by news-people without much knowledge of the science under discussion - they don't reveal anything that people weren't being more or less open about anyway.

They reveal an attempt to suppress contrary evidence, and to fudge the evidence. Not more, less. A lot less.

0 Replies

@kennethamy,

Can you cite any examples of such things happening?

1 Reply

@Dave Allen,

Dave Allen;114257 wrote:

Can you cite any examples of such things happening?

You can read about it.

1 Reply

@kennethamy,

kennethamy;114258 wrote:

You can read about it.

If you can't do what I challenged you to do then I'd rather you were just big enough to admit it really. Just say "I don't really know Dave, sorry".

That's fine by me.

I've read around the subject pretty widely. I know that - as far as I can tell - each of the e-mails thusfar held up as testament to a conspiracy has been shown - in context of the actual conversations being held - to be far more benign than the initial knee-jerk (with the emphasis on jerk) reaction of Fox News and the like when the story first broke.

I even posted a video all about it earlier in the thread.

Hell, YOU even posted a link to a news story that said pretty much the same thing in this thread - remember?

So I suggest that if you've got something that testifies to it being an honest to god conspiracy then by all means share it.

But don't just say "read about it" - because everything I've read about it is either trumped up hype - or worthy stuff that debunks the trumped up hype.

Have you anything tangible or credible to back up your claim - anything at all?

1 Reply

@Dave Allen,

Dave Allen;114262 wrote:

If you can't do what I challenged you to do then I'd rather you were just big enough to admit it really. Just say "I don't really know Dave, sorry".

That's fine by me.

I've read around the subject pretty widely. I know that - as far as I can tell - each of the e-mails thusfar held up as testament to a conspiracy has been shown - in context of the actual conversations being held - to be far more benign than the initial knee-jerk (with the emphasis on jerk) reaction of Fox News and the like when the story first broke.

I even posted a video all about it earlier in the thread.

Hell, YOU even posted a link to a news story that said pretty much the same thing in this thread - remember?

So I suggest that if you've got something that testifies to it being an honest to god conspiracy then by all means share it.

But don't just say "read about it" - because everything I've read about it is either trumped up hype - or worthy stuff that debunks the trumped up hype.

Have you anything tangible or credible to back up your claim - anything at all?

It must be a conspiracy about a conspiracy. There was obviously nothing to it. Climate change (warming, cooling, whatever it is this week) is God's own truth. No fire. Only smoke.

1 Reply

@kennethamy,

kennethamy;114263 wrote:

It must be a conspiracy about a conspiracy.

If it "MUST" be conspiracy then there "MUST" be something about what has actually been said or done that you can point to to show that, eh?

If it's that apparent?

Do you actually have anything?

Just admit if you don't - it'll be OK.

Quote:

There was obviously nothing to it.

To those of us who actually understand what carbon gasses are, what they do in the atmosphere, how they are produced and reabsorbed in nature, what produces them and how they effect things - there clearly IS something about "it".

Quote:

Climate change (warming, cooling, whatever it is this week) is God's own truth. No fire. Only smoke.

This again eh? As I said when you posted something similar earlier in the thread:

A scientist in the 1970s discovered a cooling trend.

This trend - it is postulated - is a metatrend that will lead to a cooler period in the future of the Earth - thousands of years from now.

The popular press - not scientific journals - leapt on this and you saw headlines like "there's a new ice age on the way!" in Time magazine and so on.

As is so often the case - the perception the popular press created about the science was at odds with reality.

The meta trend is still plausable science - there is likely to be - one day - a cooler earth. These things happen in cycles.

However, all climatologists agree the earth is currently in a state of warming. The evidence points to this trend (within a metatrend, if you like).

There is still some disagreement on what is causing the warming, those skeptics of man made warming are outweighed to an exponential degree by proponents of the idea.

The "Oh my god we're all going to freeze!" panic of the 1970s was a popular press notion - not a scientific one.

"They cannot make up their minds" is a fallacy. A lie.

"They" aren't obliged to agree, for a start, even so they pretty much all agree - we are seeing an abberant rise in temperature which is probably avoidable or could be mitigated if we take action.

This rise is perhaps apart from normal cycles of heating and cooling that will effect the Earth until the sun goes nova.

One of which looks likely to be an ice age thousands of years in the future, which our man made rise of the now will not prevent.

But we could prevent/slow down/restrict the current rise - so why not do so and stop a lot of human suffering?

1 Reply

@Dave Allen,

Emotion is not extricable from this issue. Obviously.

My intuition: current economic conditions are favorable to radical change. Just as the issue of labor dominated the 20th century, our place in nature will dominate this one.

Tune in around a hundred years from now to see. I'm off to learn about CO2 scrubbers!

0 Replies

@Dave Allen,

Dave Allen;114251 wrote:

What exactly, in your veiw, is/was the conspiracy?

Because when the hacked e-mails are looked at in context - rather than just mined for contentious sounding quotes by news-people without much knowledge of the science under discussion - they don't reveal anything that people weren't being more or less open about anyway.

There is a list, but here is a start.

1/ conspiracy to destroy evidence ( seen by Jones as being sought through various freedom of information acts).

You may counter that nothing has gone through court . yawn.

1 Reply

@memester,

In which e-mail (or e-mails) is such a conspiracy laid bare?

What was actually said - and what was the actual context - and is it actually damning?

Or is it just something that can be twisted to look damning if divorced from the actual conversation and touted in and of itself as suspicious looking?

http://www.youtube.com/watch?v=P70SlEqX7oY

http://www.youtube.com/watch?v=eJFZ88EH6i4&feature=related

(Gotta love the fact that Fox News polled 120% of the American population).

As for - yawn - the courts. Well, I don't think any of the people who are screaming about a conspiracy would actually do something credible like levelling an official challenge of fraud against "The Conspirators!!!" - but yeah, the courts would actually look at the details, in context, before damning anyone.

As opposed to a knee jerk decision made based on a few out-of-context quotes.

Trial by court might be a bit "yawn" - but it's usually more thorough than trial by Fox News.

Why isn't anyone following a legal action against these evil people if a conspiracy is so evident? I mean, it would be a huge fraud case if it was actually credible, wouldn't it?

Why not?

Because the charges of conspiracy are a load of heresay, misinformation and/or outright baloney.

1 Reply

@memester,

memester;114215 wrote:

it being read, usually, at 50 or 80, using heaters and coolers with almost instantaneous local temp change, then what ?

Stats determine the likelihood of a real difference, irrespective of whether it came about naturally. It's your job as a scientist to account for significant differences.

memester;114215 wrote:

How do you interpret what "by chance", means, vis a vis statistical significance?

This is not open to my interpretation. It's statistical chance. A coin flip has a (near) 50/50 odds of landing heads or tails. That doesn't mean, though, that for any two throws you'll get one head and one tail. By chance you may get two heads or two tails. THAT is the circumstance referred to by chance -- that from insufficient sampling you might observe a difference that is not actually true.

There is a 25% chance of getting two heads and a 25% chance of getting two tails. So what this means is that if you sample the coin only twice, you have only a 50% chance of demonstrating one heads and one tails. So luck of the draw has a lot to do with it when your sample size is tiny.

On the other hand, flip the coin 10 million times. The odds of you getting 10 million heads and not a single tail would be infinitesimally small. Increasing your sample size decreases the odds that your results are a matter of chance. A good analogy is signal:noise -- by increasing sampling you increase signal and noise correspondingly disappears.

SIGNIFICANCE is simply where the statistical odds of chance are low enough that you are willing to accept the difference as real. This is conventionally set at P < 0.05, i.e. there is a 95% chance that the observed difference is real.

0 Replies

Climate Change Politics

Related Topics

Quick Links

My Account

able2know