Global Warming and all that stuff.

[Texastwister]

I would guess the rest of your commentary is also false, based on that example.

I guess thats the excuse to not answer any of the other points made. Typical

 

[varwoche]

the most confusing part of the whole debate to me is proving that it is human caused. I believe the anti agw people have good points when it comes to that.

Can you cite one good point -- just one -- in the form of recent (say the last 6 six years) peer-reviewed science that counters the body of scientific knowledge showing that AGW is real?

No op-ed pieces or other forms of armchair speculation please.

 

[Earthborn]

6. There is no correlation between local temperature and bristlecone tree growth, so what is it measuring?

Rainfall, mostly. That's actually pretty common knowledge.

The growth of those tree stands in the last 150 years was described as "a mystery" by the people who sampled them.

It would really help if you could come up with actual quotes and names of the people you are refering to. Otherwise people might start to think you're just making stuff up.

 

[Dave1001]

January 2006 was the coldest winter in Siberia in the last fifty years....maybe all those coolers were right in teh 70's??

That type of comment just makes global warming skeptics look silly. A temperature low for one subregion of the planet? Let's try to keep this discussion to the best arguments.

and what are the best arguments? everything people post as sources here seem to be biased....all I know as one who lives and works in Siberia, is that when its unseasonably warm in the states, its unseasonably cold in Siberia.

People repeatedly here say "all credible scientists" say this or that, but I dont believe any of it. The topic of GW (or AGW) has turned so much to the political arena, it can no longer be debated with logical people.

It would be just as silly if someone argued global warming was occuring based solely on one subregion having a temperature high recorded. You are the person introducing these type silly arguments into the thread. I'm quite open to evidence indicating global warming isn't occuring. But, with all respect, an argument as silly as the one you posted is just an insult to the intelligence of most JREF regulars -and it would be no matter which "side" of the discussion posted an argument like that.

 

[Diamond]

http://www.cdc.noaa.gov/people/dezh...olyakov+et+al+(2004)&hl=en&gl=us&ct=clnk&cd=9

I would guess the rest of your commentary is also false, based on that example.

Sorry, this document could not be found. For further information, please contact webmaster.psd@noaa.gov.

Well I'm impressed.

 

[lenny]

People repeatedly here say "all credible scientists" say this or that, but I dont believe any of it.

i don't believe that: WHO said "all credible scientists"? and about what, exactly? just i a few hours ago on this thread:

and noting that consensus is not unanimity, ... .

 

[Diamond]

Polyakov et al (2004) ??

A quick Google found that Polyakov et al (2004) is associated with vast data on the warming of the Arctic and Antarctic. Are you trolling? That is just dumb.

A quick Google showed that you are trolling. Polyakov et al (2004) was quoted correctly - an Arctic warming but nothing unusual or any evidence of a polar amplification. The 1930s were a little warmer than today.

The bulk of Antartica is cooling apart from the Antarctic Peninsula which has warmed rather impressively. That the focus of news items is on the Peninsula shows how well the media reports climate change.

 

[Schneibster]

Well I'm impressed.

I'm not, at least not by your mad skillz on teh internets.

Try this one.

 

[Diamond]

Rainfall, mostly. That's actually pretty common knowledge.

It would really help if you could come up with actual quotes and names of the people you are refering to. Otherwise people might start to think you're just making stuff up.

Oh I'm terribly sorry. The people who took the tree ring cores for the bristlecone proxies were Donald Graybill, Sherwood Idso, Lamarche and Fritts. Hughes and Funkhouser (2003) noted that the growth spurt was "a mystery" while Graybill and Idso (1993) suggested that the growth spurt was due to "carbon dioxide fertilization" of these trees which have a tendency to produce bark in narrow strips.

The common knowledge ain't so common. Why are the bristlecones and foxtails used so universally? Because by chance, their growth correlates with global temperature trends even though they do not correlate with local temperatures - a spurious correlation that translates into a widespread delusion of stable climate prior to the mid-19th century.

 

[Schneibster]

OK, Diamond, here are some questions for you to ponder. Or at least for SOMEONE to ponder, since you disliked my questions so much that you have me on ignore. I'll let everyone else consider what it means that you ignore people whose questions you can't answer. I think the meaning is pretty clear. And I don't think it's a compliment to you.

Q1. The global mean temperature is projected to rise by 1 and 4C by 2050. If every nation on Earth signed to, and kept to the Kyoto Protocol, by how much would this temperature rise be reduced?
A1. 0.07C and that assumes that the sensitivity to carbon dioxide doubling is 3C. Most recent studies suggest the sensitivity is much lower than that. The projected reduction in warming is greater than the oscillation of skin temperature every time your heart beats. It is smaller than any modern measurement of global surface temperature.

So, what you're saying is that we should do nothing? Do you suggest we go to China without doing anything and ask THEM to do something? Or do you suppose they just maybe might IGNORE us if we're not doing anything ourselves, and perhaps even conclude it's all a plot to screw them... AGAIN, like the US and Europe have been doing since the fifteenth century? Hey, here's an idea: let's do all we can ourselves, and then go and tell China, "Hey, we're doing something about it... when are YOU gonna start?" Do you think that might be a MORE SUCCESSFUL strategy?

Q2. The entire nation of the UK decides to abjure all modern technology and return to the Stone Age with immediate effect. How long would it take China to produce all of the carbon dioxide formerly produced by the UK?
A2. 13 months. China is currently commissioning one new coal fired power plant every week.

See above. And think about this: what precisely are you advocating?

Q3. Michael Mann (lead author of the Hockey Stick) wrote of the proxies used in the reconstructions of past climate that:

CFR methods do not require that a proxy indicator used in the reconstruction exhibit any local correlation with the climate field of interest , but instead make use of both local and nonlocal information by relating predictors (i.e., the long-term proxy climate data) to the temporal variations in the large-scale patterns of the spatial field.

Does this mean that proxies can be used even if they don't exhibit any response to local climate conditions so long as they correlate to global temperature change?

A3. Yes. Its like magic. Reference Just in case you think Mann is being misquoted, Wahl and Ammann made this statement regarding Mann's method and similar:

These results enhance the validity of the MBH assumption that proxies used in the reconstruction process do not necessarily need to be closely related to local/regional surface temperatures, as long as they register climatic variations that are linked to the empirical patterns of the global temperature field that the MBH method (and other climate field reconstructions) target.

OK, so what you're saying here (for the rest of everyone who may not know what the upshot of all this is) is that you don't believe that statistics that don't correlate to LOCAL changes should be used, even though they DO (yes, read it again, let me repeat it DO) correlate to GLOBAL changes? So in other words, you prefer to use proxies that DON'T correlate to GLOBAL changes, just because they DO correlate to LOCAL changes??? In other words, you don't accept the statistics because they DO correlate to what we're trying to measure?

Neato. I'll keep that one in mind. Very creative. Also very unconvincing after it's been analyzed properly. I think I prefer the results of the use of proxies that DO correlate to other proxies whose changes have been correlated to GLOBAL changes, since GLOBAL changes are what we're trying to measure.

In addition, it appears (late material) that the correlation of the bristlecone pine data has been reevaluated, and it's a better fit to thermometer data than was previously thought. Details in the Science paper below (sorry, it's pay, this is real data not more reposts from Faux "News.") It appears that the CO2 fertilization problem has been figured out, apropos of your more recent post.

Q4. Michael Mann testified to the NAS Panel this year (2006) that he did not calculate the R2 statistic for his reconstruction, whose zero score showed that his model had no statistical skill. He said calculating the R2 statistic would be a "foolish and incorrect thing to do". Was he telling the truth?

A4. The R2 calculation is in his source code. He lied to the Panel. He did tell them he was "not a statistician" so he's not a complete liar.

You must have neglected to read Mann's response to Senator Joe Barton's committee, a political smear job that (in case you didn't follow what happened after Barton attempted to intimidate a bunch of people he didn't agree with) Barton got castigated for in the scientific press and by his colleagues including another GOP member, Representative Sherwood Boehlert (R-N.Y.), Chairman of the House Science Committee (imagine that! What would HE know???) and also Henry Waxman. Mann's response cites numerous standard textbooks, and previous climate analyses that work with proxy data vs. measurements in the field. Here is the complete answer by Mann to the Barton committee's question on that score:

The Committee inquires about the calculation of the R2 statistic for temperature reconstruction, especially for the 15th Century proxy calculations. In order to answer this question it is important to clarify that I assume that what is meant by the “R2” statistic is the squared Pearson dot-moment correlation, or r2 (i.e., the square of the simple linear correlation coefficient between two time series) over the 1856-1901 “verification” interval for our reconstruction. My colleagues and I did not rely on this statistic in our assessments of “skill” (i.e., the reliability of a statistical model, based on the ability of a statistical model to match data not used in constructing the model) because, in our view, and in the view of other reputable scientists in the field, it is not an adequate measure of “skill.” The statistic used by Mann et al. 1998, the reduction of error, or “RE” statistic, is generally favored by scientists in the field. See, e.g., Luterbacher, J.D., et al., European Seasonal and Annual Temperature Variability, Trends and Extremes Since 1500, Science 303, 1499-1503 (2004).
RE is the preferred measure of statistical skill because it takes into account not only whether a reconstruction is “correlated” with the actual test data, but also whether it can closely reproduce the mean and standard deviation of the test data. If a reconstruction cannot do that, it cannot be considered statistically valid (i.e., useful or meaningful). The linear correlation coefficient (r) is not a sufficient diagnostic of skill, precisely because it cannot measure the ability of a reconstruction to capture changes that occur in either the standard deviation or mean of the series outside the calibration interval. This is well known. See Wilks, D.S., STATISTICAL METHODS IN ATMOSPHERIC SCIENCE, chap. 7 (Academic Press 1995); Cook, et al., Spatial Regression Methods in Dendroclimatology: A Review and Comparison of Two Techniques, International Journal of Climatology, 14, 379-402 (1994). The highest possible attainable value of r2 (i.e., r2 = 1) may result even from a reconstruction that has no statistical skill at all. See, e.g., Rutherford, et al., Proxy-based Northern Hemisphere Surface Temperature Reconstructions: Sensitivity to Methodology, Predictor Network, Target Season and Target Domain, Journal of Climate (2005) (in press, to appear in July issue)(available at: ftp://holocene.evsc.virginia.edu/pub/mann/RuthetalJClimate-inpress05.pdf).
For all of these reasons, we, and other researchers in our field, employ RE and not r2 as the primary measure of reconstructive skill.
As noted above, in contrast to the work of Mann et al. 1998, the results of the McIntyre and McKitrick analyses fail verification tests using the accepted metric RE. This is a key finding of the Wahl and Ammann study cited above. This means that the reconstructions McIntyre and McKitrick produced are statistically inferior to the simplest possible statistical reconstruction: one that simply assigns the mean over the calibration period to all previous reconstructed values. It is for these reasons that Wahl and Ammann have concluded that McIntyre and McKitrick’s results are “without statistical and climatological merit.

If you're going to make a response, you need to respond to this: you are touting a statistical measure that is discredited for the use you are claiming it is the only choice for, and that is not used by the rest of the field according to the papers Mann is citing. Furthermore, Mann is quoting TEXTBOOKS, which I have to assume you have not read being as how you don't mention the material in them. That being the case, where is YOUR proof that R2 is the correct correlation coefficient, and not RE? Do you have one? Have you checked? Or did you just ignore what Mann said because you don't like it, just like you ignore me because you don't like the fact that you don't have any answers for ME, either?

Oh, and by the way, you ARE aware that you HAVE TO HAVE R2 in order to calculate RE, AREN'T YOU, DIAMOND?

Continued.

 

[a_unique_person]

9. None of them. That doesn't stop people from claiming that it could happen. However all of the ice cores show that temperatures fall even as carbon dioxide and methane continue to rise, so the effect is slight, if at all, that greenhouse gases "control" the temperature.

You keep making up strawmen, and shooting them down.

 

[Schneibster]

Q5. There have been eight major reconstructions of past climate using multiple proxies. How many of them used bristlecone pines or foxtails?
A5. All of them. Those that don't use the bristlecones explicitly use the Mann PC1 as a proxy. The Mann PC1 is dominated by the bristlecone pines of the Western US. Some studies use both individual BP sites and the Mann PC1. Double accounting for proxies appears to be a common fault in multiproxy studies (unless you think they're doing it deliberately)

Did you simply FORGET that a statistical test using NONE of the bristlecone pine cores was done, and that it showed less correlation to measurements made with thermometers, using RE to check the correlation (which is the correct measure of the correlation, according to the textbooks on the subject) than the figures obtained WITH the bristlecone pine data? That would be the paper here. Sorry, this is real science, you have to pay to read it. Real statistics, too. According to multiple reviews of the paper, they've done a rigorous statistical analysis, and their results are not only consistent with Mann's hockey stick, but robust under removal of ALL bristlecone pine data.

So much for "all of them." That would be "all of them but the one that doesn't?" Or perhaps "All of them but the one you don't like because it doesn't" would be more accurate?

You might find some interesting insight here, there is a graph that shows their results. It's pretty obvious what it says if you look at it.

Q6. Do the tree rings of bristlecone pines or foxtails correlate to local climate where they grow?
A6. There is no correlation between local temperature and bristlecone tree growth, so what is it measuring? The growth of those tree stands in the last 150 years was described as "a mystery" by the people who sampled them.

First, this is relevant because...? I repeat: the studies are ROBUST UNDER REMOVAL OF ALL THE BRISTLECONE PINE DATA. Second, I also will point out that the Science paper above has done a rigorous statistical analysis and shown that in fact, serious errors were made by the studies (and I'm pretty sure you're citing Soon and Baliunas (2003), but being as how you don't provide sources for what you say, it's just a guess) that purported to show that the bristlecone pine data was no good. Furthermore, that Soon and Baliunas (2003) paper was criticized heavily in the literature, a fact which you ignored in your quest for more cherries to pick.

Q7. Wahl and Ammann produced a study on reconstructions of past climate including the Hockey Stick. What were the R2 results of all of these studies?
A7. All of them were near zero, indicating that they had no more statistical skill for reconstructing past climate than a Magic 8 ball.

You still have not justified the use of R2 as opposed to RE. Since the textbooks say RE is the right measure, you'll pardon me if I believe the textbooks as opposed to, say, some talking head on the 'Net with a political agenda.

Q8. According to Greenhouse theory, the accumulation of greenhouse gases should cause warming in the polar regions. Has any polar amplification of warming been seen in the Arctic? the Antarctic?
A8. None. Polyakov et al (2004) concluded that

In summary, if we accept that long-term SAT trends are a reasonable measure of climate change, then we conclude that the data do not support the hypothesized polar amplification of global warming"

The great bulk of the Antarctic has cooled over the last 50 years and both the East and West Antarctic Ice Sheets are growing, a reversal of a trend of slow melting that has gone on for several thousand years.

So, that would mean that the three ice shelves that just collapsed collapsed because they got colder? Riiiiiiiiiiiight.

And the Northwest Passage opening up this year? Just a fluke, right? Suuuuure.

That would be right up there with the "fluke" that has the Department of the Interior adding polar bears to the Threatened category under the Endangered Species Act, right? Yeahsureyabetcha.

Oh, and by the way, I read that paper. Polyakov ACTUALLY concludes that the reason the polar amplification isn't apparent in SAT measurements is because of other variations in the arctic climate that are swamping the effect. So what he's questioning is not the amplification, but whether SAT is a good measure of what's happening. Which would be relatively obvious to anyone not blinded by ideology, because the fact of the matter is the ice is melting; that would be, you know, why the Northwest Passage is open, and the ice shelves in Antarctica are collapsing?

This is cherry-picking at its worst. You've taken a paper that actually refutes what you're trying to prove, and cherry picked a single sentence from the conclusion that you claim supports your view- and ignored the rest of the paper. This is what I see on all of the global-warming denial sites. You are at least consistent, though I do have to question your ethics.

Q9. How many ice core records show carbon dioxide and methane rise leading temperature rise?
A9. None of them. That doesn't stop people from claiming that it could happen. However all of the ice cores show that temperatures fall even as carbon dioxide and methane continue to rise, so the effect is slight, if at all, that greenhouse gases "control" the temperature.

Oh, really? That's interesting. Perhaps you didn't read this. You know, the part where it says,

Does this prove that CO2 doesn't cause global warming? The answer is no.

The reason has to do with the fact that the warmings take about 5000 years to be complete. The lag is only 800 years. All that the lag shows is that CO2 did not cause the first 800 years of warming, out of the 5000 year trend. The other 4200 years of warming could in fact have been caused by CO2, as far as we can tell from this ice core data.

The 4200 years of warming make up about 5/6 of the total warming. So CO2 could have caused the last 5/6 of the warming, but could not have caused the first 1/6 of the warming.

It comes as no surprise that other factors besides CO2 affect climate. Changes in the amount of summer sunshine, due to changes in the Earth's orbit around the sun that happen every 21,000 years, have long been known to affect the comings and goings of ice ages. Atlantic ocean circulation slowdowns are thought to warm Antarctica, also.

Isn't it amazing what you can find out if you actually bother to do the research? Silly me, I should just be listening to the pundits like you!

Scores:

Heh. Hope you'll allow me a little fun.

7-9 You're actually a skeptic. Wear your badge with pride! You will of course be compared to Holocaust Deniers.

You're a skeptoid, more interested in denying what you don't like than in actually finding out what's going on. You think that it's probably a good idea to avoid doing research because you don't like the answers you find, and you conclude that people ALWAYS lie when they tell you what you don't want to hear.

4-6 You're wondering what's going and so are most of us

You haven't done enough research to have any realistic idea of what's going on. You should consider whether you wish to:
a) spend the time and effort necessary to find out what's going on, or
b) accept the word of someone. (Contra-indicated, since there appears based on the above analysis to be considerable question as to the veracity of the claims being made.)

1-3 You are in a deep sleep. Stay comfortable, and try to stay warm. The nurse will be with you shortly.

You've been paying attention, and are skeptical enough to bother to research the issues before you commit your opinions to paper (or whatever). You are honest, and acknowledge that you don't know all the answers.

0 You are varwoche and I claim my $5

You are a climate scientist.

 

[Diamond]

You keep making up strawmen, and shooting them down.

If you shoot strawmen then they generally remain standing.

On the other hand, you could address the point made that the belief that rises in greenhouse gases causes temperature rise in the Earth's atmosphere is not supported by empirical evidence even if, on a simplistic theoretic level of an equilibrium system, such a result would be expected.

I must admit when I discovered this assumption was not supported by any empirical evidence I was surprised as well. But who do I trust, people who claim confidence or the empirical evidence?

Its a toughie but I'll go with the evidence. I've been burned too many times by people's expressions of confidence based on supposed authority.

 

[politas]

No, I'm not, by you're own measure. Later in your own post you acknowledge (like many climate scientists) that we could be minor contributors to a natural trend.

I was referring to your "cure could be worse than the disease" in relation to halting global warming.

If so, the most draconian measures conceivable to reduce CO2 emissions and other man-made contributors to global warming may do little to halt the global warming trend and its impact on humans. However, it's hard to argue that they wouldn't have a significant impact on economic growth.

So if those measures don't halt global warming, we may need to find some other means.

That's not to say that I think man-made contributions are insignificant, nor that I think we shouldn't try to reduce manmade contributions to global warming. But I do think these various scenarios should be under consideration and studied, to facilitate coming up with the best global policy on how we react as a species to global warming.

How much studying should be done before implementation? At what stage should we say that we need to start acting? How much further does the global climate need to climb before you think we have reached an emergency situation? Bushfire season in south east Australia started at the beginning of spring this year, rather than at the end of summer as it used to. Cyclical patterns account for some of that, but not all.

Right. Nothing I posted denied that potable water, lack of arable land, and mass starvation, including in the 1st world, will all be serious problems.

No, but you made the absolutely fatuous suggestion that air conditioners in some way will help us survive. Global warming isn't about how comfortable we are.

Although I do think 1st world mass starvation is the least plausible of the three (not to say that it's completely implausible).

Lack of potable water and arable land leads to mass starvation.

Because nothing in the known history of the Earth's climate changes seems to present even a strong threat to the survival of the human species as it exists in the year 2006. As a species (as opposed to many individuals) we are about as opposite from being a specialized creature as one can get.

No we aren't. We need quite extensive resources to survive, both food and water. And to provide food, more water is required. As the global climate heats up, the amount of fresh water reduces. We cannot survive without a functional ecosystem. If the climate gets hot enough, the only surviving life will be bacterial. We'd die long before that.

Which is why I think we're in a better spot if the current global warming is part of normal planetary warming and cooling trends, rather than significantly the result of human activity.

As long as the maximum variation isn't sufficient for a mass extinction event, you're probably right. But be certain that we could not survive if the variation goes high enough.

 

[lenny]

citation for "no empirical evidence"

the belief that rises in greenhouse gases causes temperature rise in the Earth's atmosphere is not supported by empirical evidence

could you please give me the citation to a paper that explains this. as it stands it seems an odd claim (unless you are willing to reject alot of day-to-day science as not supported by empirical evidence as well).
sorry if the citation is lower in this thread and i missed it.

 

[CapelDodger]

Do I understand this correctly?

Apparently not.

Britains leading climate scientist is asking skeptics of AGW to prove a negative?

No, he's asking them to defend their claims that global warming is not significantly anthropogenic. There are a number of alternative explanations put forward but they are unsubstantiated. This would be an opportunity to substantiate them.

It would also be an opportunity to explain why increased atmospheric CO2-load isn't leading to global warming when everything we know about CO2's infra-red spectrum indicates that it will.

 

[CapelDodger]

On the other hand, you could address the point made that the belief that rises in greenhouse gases causes temperature rise in the Earth's atmosphere is not supported by empirical evidence even if, on a simplistic theoretic level of an equilibrium system, such a result would be expected.

Of course it's supported by empirical evidence. Where do you get these ideas from? The empirical evidence is all around us. Increased CO2 and a warmer world. Just as expected. Do you claim this is simply a coincidence?

 

[varwoche]

I'm not, at least not by your mad skillz on teh internets. Try this one.

Notice what Diamond's cherry-pick neglected to include:

... our analysis suggests that the Arctic Ocean is in transition towards a new, warmer state with possible implications for already reduced ice cover and potential impacts on processes occurring at lower latitudes

 

[a_unique_person]

If you shoot strawmen then they generally remain standing.

On the other hand, you could address the point made that the belief that rises in greenhouse gases causes temperature rise in the Earth's atmosphere is not supported by empirical evidence even if, on a simplistic theoretic level of an equilibrium system, such a result would be expected.

I must admit when I discovered this assumption was not supported by any empirical evidence I was surprised as well. But who do I trust, people who claim confidence or the empirical evidence?

Its a toughie but I'll go with the evidence. I've been burned too many times by people's expressions of confidence based on supposed authority.

No one has ever claimed that the only driver of climate change is CO2 levels. The world has many components that conrtribute to it's mean temperature, CO2 being one of them. The claim is that the current warming phase is explained by the simple mechanism of a change in CO2 levels, which is kicking off some positive feedback influences.

 

[a_unique_person]

If you shoot strawmen then they generally remain standing.

On the other hand, you could address the point made that the belief that rises in greenhouse gases causes temperature rise in the Earth's atmosphere is not supported by empirical evidence even if, on a simplistic theoretic level of an equilibrium system, such a result would be expected.

I must admit when I discovered this assumption was not supported by any empirical evidence I was surprised as well. But who do I trust, people who claim confidence or the empirical evidence?

Its a toughie but I'll go with the evidence. I've been burned too many times by people's expressions of confidence based on supposed authority.

AUSTRALIANS should not stop being concerned about climate change when the drought eventually breaks, a retired climate scientist has warned.
Barrie Hunt, the former head of the CSIRO's climate modelling program, said there seemed to be widespread confusion about the causes of the drought sapping south-eastern Australia, with some people convinced it was entirely due to global warming.
Using climate models to try to replicate how weather might change over 10,000 years, Mr Hunt has concluded that the drought is part of a naturally occurring cycle of dry and wet periods in Australia.
But he said there were also clear signs that climate change was making the drought worse, with a run of record hot weather in recent years contributing to drier ground and record low run-off of rain.
"The temperature signals we're getting are very clear, distinct greenhouse signals," he said. "The warming over the past 10 years, you can't explain that. There isn't any great variability from year to year; it's going up and up and up. If it was natural variability you would be having years of below-average temperature."
But he said that judging the effects of climate change on rainfall patterns was much more complex. It could take another 20 to 30 years for a clear trend to emerge.
Mr Hunt said if people believed the drought was entirely caused by climate change, they might think it was no longer an issue once better rain returned.
"So it's very important to feed into the public consciousness the fact that there is a lot of climatic variability going on, with which the greenhouse effect is interacting."

Epirical evidence, the current drought in Australia.



http://www.theage.com.au/news/natio...-climate-expert/2006/12/28/1166895421393.html