The first report of the monthly average Mauna Loa CO2 estimate for July 2008 was lower than expected; the reported value was 384.93 ppmv, with a “seasonally adjusted” value 384.54. In less than a day the figures were revised so that the new reported value is much more in line with the prevailing trend. Anthony Watts noted the change, which caused quite a stir in reader comments. Many (if not most) spouted conspiracy/fraud theories of the first magnitude, even after the reason for the change was explained by the scientist in charge of the data.
Most of the conspiracy theories indicate that commenters don’t really understand what’s been changed. Many involved the fact that data were revised as far back as May of 1974 (I previously mistakenly said June of 1974). Some of them made a big deal out of the fact that the daily data should be available, apparently unaware that the daily data are available through the World Data Center for Greenhouse Gases, but the daily data available online aren’t kept as current as the monthly average data from ESRL. Even so, I managed to retrieve daily data from 1974 through 2004. Generally, Watts’ readers are positively giddy with belief that something underhanded is afoot and ESRL has been “caught in the act.” Watts has shown no sign of discouraging the rampant speculation and accusations.
The explanation is correct, but perhaps not as clear as it could be:
The reason was simply that we had a problem with the equipment for the first half of July, with the result that the earlier monthly average consisted of only the last 10 days. Since CO2 always goes down fast during July the monthly average came out low. I have now changed the program to take this effect into account, and adjusting back to the middle of the month using the multi-year average seasonal cycle. This change also affected the entire record because there are missing days here and there. The other adjustments were minor, typically less than 0.1 ppm.Pieter Tans
It makes perfect sense to me because I’ve seen exactly analogous situations before (I even published a paper about it). So I’d like to explain why the revision was necessary, and what effect it has on the data.
The revision applies only to months for which some days are missing from the data record. Mauna Loa data are only taken under good conditions, and equipment is susceptible to malfunction, so daily data isn’t reported unless it’s considered reliable. So let’s take a month for which I was able to obtain daily data from WDCGG, and for which a number of days’ data are missing, December 1979. Here’s the data:
Data are available for only 24 of 31 days. The original reported value for Dec. 1979 was simply the average of the data for those 24 days, 336.71 ppmv. That value is assigned to December 1979, more specifically to mid-December 1979, i.e., Dec. 16th:
It looks like a good value for mid-December, but is it? We can get a better idea by fitting a trend line to the December data:
Now we can see that the given value isn’t really that good an estimate of the average for all of December; it’s notably below the trend line, and in fact this estimate is too low. It is a good estimate for slightly earlier in December, because most of the data are for earlier in December. The right thing to do with this average is to assign it to the average time of the observations, which is December 14.04:
We can see quite easily that it fits much better with the overall behavior of the December 1979 data, but only if we assign the average value to the average time.
What is a better estimate of the mid-Month (Dec. 16th) value? One considerable improvement is to take the value of the trend line on December 16th:
This gives a value at mid-month of 336.78 ppmv. This isn’t the way ESRL used to compensate for the difference between mid-month and the average time; they used the average rate of change for that month over a number of years to compute the CO2 offset due to time offset, while I’m using the rate of change for the month determined by linear regression. But both methods give good results. And — Lo and Behold! — for December 1979 the revised figure for Mauna Loa CO2 concentration happens to be equal to the value estimated from this linear interpolation: 336.78 ppmv.
The greater the time offset between the average time and the point of mid-month, and the greater the rate of change throughout the month, the greater will be the difference between the simple average of CO2 concentration and the appropriate mid-month estimate. The equipment problem in July 2008 caused the average to be computed from only the last 10 days of the month. Hence the average time was considerably later than mid-month — this is just about a “worst case” — and since CO2 generally declines sharply in July, the error due to time offset was also just about a “worst case,” with the simple average being far too low. That’s what led to the originally reported value being lower than expected, which caused speculation in a number of places around the internet.
The revision is not an attempt to make CO2 concentration fit in with anybody’s theory about what is should be. It’s a straightforward, and very necessary, correction for the difference between the average time of the data and the time for which an estimate is reported. In most cases, the difference is small because the time offset from mid-month is small (for December 1979 the correction is only 0.07 ppmv). But for July 2008 the time offset was large, so the necessary correction was much larger. But it’s still necessary, and frankly, it’s the correct way to do it.
But of course Watts’ readers are taking delight in spawning conspiracy theories. Most of their comments really do reveal how little the commenters understand what the correction is. It says a lot about their proclivity to claim fraud simply because that’s what they want to believe. But is says nothing at all (nothing correct, anyway) about the correctness of the Mauna Loa CO2 data.
Pity.
105 responses so far ↓
David B. Benson // August 6, 2008 at 1:11 am
Clear. Even simple.
Thanks again.
Lee // August 6, 2008 at 1:57 am
Nice explanation.
I posted a similar explanation over at Anthony’s blog earlier - not nearly as elegant as yours, and without the graphics and explanatory analysis, but the same message. Anthony seems not to have felt it was fit for his blog, because he left it trapped in moderation while approving many of those confused conspiracy-theorist screeds.
Gee…
Richard // August 6, 2008 at 2:03 am
In fairnes to Anthony Watts he did seek a verification from NOAA as to why the data had changed. He received a reply from them and says he is satisfied with the answer. So I think the “spawning conspiracy theories” line is a little unkind.
A similar downward adjustment occurred with the daily graph from NDIS that looked suspect. When I queried them about it I recevied a reply that satisfied me that the trend was real.
My point is that one should not just accept a change if there is doubt but should seek clarification. This what Watts and I had done and received satisfactory responses.
[Response: I didn't say that Watts had spawned conspiracy theories, but that his readers had done so in the extreme in comments, and Watts hadn't discouraged that effort. All of which is true.
But it was indeed an act of virtue to seek an explanation from the source, as Watts did. And as I, and Lucia, did also.]
Dano // August 6, 2008 at 2:34 am
Generally, Watts’ readers are positively giddy with belief that something underhanded is afoot and ESRL has been “caught in the act.” Watts has shown no sign of discouraging the rampant speculation and accusations.
Huh. There’s a surprise.
Best,
D
Richard // August 6, 2008 at 3:12 am
My aplogies about the consiracy theory thing. I should read more closely.
nanny_govt_sucks // August 6, 2008 at 5:13 am
But it wasn’t necessary in Dec 1979, apparently. Nor in the months that showed CO2 concentration that were higher than they should have been. Looks like it only became necessary when Anthony’s post got some play.
[Response: Are you trying to embarrass yourself?]
Nils Simon // August 6, 2008 at 6:57 am
Thanks for another great, clear and informative post!
John Mashey // August 6, 2008 at 7:06 am
Thanks for a useful post.
Once again, the old military maxim applies: “The first reports from the front are wrong.”
nanny_govt_sucks // August 6, 2008 at 7:08 am
Perhaps you can address the subject of my post. You said the revision was necessary. OK. But why now and not Dec 1979 where you show above it should have been done?
[Response: It was just as necessary in 1979. But at that time it wasn't noticed, which is a flaw in the computation of monthly averages but not a nefarious scheme to promote false scientific results. Until this July there was no month with such an extreme difference between the average time of observations and the time of mid-month.
But you didn't say, "what boneheads they are not to notice this until, quite by accident, the effect become way larger than ever before!" Instead you implied that it was an attempt to counter criticism from Anthony Watts, which borders on an accusation of a coverup.
You should also note that the error due to failure to compensate for time offset from mid-month is essentially random, so it doesn't invalidate any of the trend analysis of Mauna Loa CO2 data, it only makes it less precise; results with the revised data will be more precise. But that's not what Watts' readers think; they don't just imply, but heap outright accusations of deliberate fraud on the scientists, that they're just trying to cover their asses. Your statement only implies it, but in spite of the evident folly of this attitude, you're pile more on the heap.]
Raven // August 6, 2008 at 7:49 am
Tamino,
I think you don’t give Anthony enough credit since he clearly emphasized that there is no reason to presume that there was anything nefarious going on. I tried to re-enforce that point myself with a comment at the top of thread because I knew there would be a lot of vitriol coming.
That said, you might want to take the time to ask yourself why that vitriol exists and why there are a growing number of people who no longer believe that scientists should be automatically trusted.
My personal opinion is it is the result of too many scientists choosing to become activists pushing specific policy options instead of sticking to the science. This has made it very difficult for the average person to distinguish between between a politician and a lobbyist and a scientist. (e.g. Jim Hansen’s colourful comments may get him media time put they make sound like a political partisan).
This perception will get much worse if (and I realize that it is a big if) this global warming thing ends up being a non-issue. If that happens scientists will likely end sharing the company of lawyers and journalists as the most despised profession.
Now I fully expect you to either delete this post or respond with some comment about it being all the fault of the “denialists”. However, I hope you don’t and do take the time to think about these issues. I don’t think anyone who believes that urgent action on GHGs is required can afford to ignore them.
[Response: And you, too, should seriously consider the possibility that the extreme vitriol is about irrational fears that doing anything about global warming will "destroy our way of life and ruin our prosperity," an idea rooted not in the behavior of scientists but in the propaganda campaign of ultraconservatives and fossil-fuel industry shills. Think about it.]
Bart Verheggen // August 6, 2008 at 12:07 pm
Nice explanation. Just a minor comment: Using the linear trend to estimate the mid-month average requires the assumption that the trend is indeed linear. Now this assumption will in most cases be met (close enough), but it’s not impossible that in some months the rate of change in CO2 concentration changes (eg when the concentration shows an S-shape in time, or is more or less constant for two weeks before rising or dropping sharply). In such cases using the linear trend to estimate the average at mid-month will be slightly off. Using the multi-year trend to do so (as ESRL apparently does) minimizes this potential off set even more of course.
dhogaza // August 6, 2008 at 12:13 pm
The bold bit is perhaps the only honest statement made by Raven here.
J // August 6, 2008 at 1:10 pm
As an interesting thought experiment, consider how Watts would respond if his comment sections were taken over by people spouting a different type of conspiracy theory.
For example, suppose Watts’s posts routinely drew 50-100 comments from people claiming that the Bush administration was behind 9/11, or that the moon landing was faked, or that the Protocols of the Elders of Zion were authentic.
Would Watts adopt the same laissez-faire approach to comments? If not … then why does he tolerate equally bizarre conspiracy theories about climate? I’d gently encourage followers of Watts’s blog to consider that question.
As for Raven’s comment above … Raven appears to be suggesting that climate scientists are to blame for the vitriol directed at them by Watts’s followers (and others). I strongly disagree with that. Rational adults should be held responsible for their own actions. If (as it appears to me) Watts’s site contains little more than a mix of vitriol and conspiracy theories, the blame for that lies squarely with Watts’s commenters, and with Watts himself.
Ray Ladbury // August 6, 2008 at 2:36 pm
Raven,
Let’s think about this. Yes, it is true that scientists do not normally become advocates for policy. Indeed, most of us are more than content to shun the spotlight and let the policy wonks churn out the sausage. Among the reasons why some scientists might not be content to let things play out this way on this issue are the following:
1) In the past, this has led to confused policy that got the science wrong.
2) The risk in this case could range from serious to severe.
3) Despite strong evidence of a serious threat, policy wonks have done bupkis.
4) The science and scientists have been under attack by special interests seeking to undermine both.
Now given that a scientist does not cease to be a citizen with a responsibility to defend civilization, what choice do we have but to try to call attention to this threat. After all, when politicians like Al Gore do it, they are dismissed as political–or worse, demonized as demagogues. So, what, Raven, would you have us do? Our labs will not provide much refuge if human civilization collapses around them.
Ken // August 6, 2008 at 4:14 pm
Those who defend Watts and emphasize the virtue of his contacting ESRL have to acknowledge that his method of writing has created an environment of followers rife with conspiracy theories. When he regularly uses innuendo with phrases like: “Oddly the MLO CO2 dataset available by FTP still shows the timestamp from yesterday”, he’s only feeding the irrational paranoia. Is his post really so urgent that he can’t wait a few hours to see the result of file updates?
Whether it’s 9/11, Area 51, the faked Moon landing, or whatever, people like Watts feed the paranoia and give it a false sense of legitimacy. If Watts wants to analyze data, that’s fine. But if he has any interest in the truth, he needs to drop the innuendo and speculation which only feeds the irrationality on his site.
Aaron Lewis // August 6, 2008 at 4:26 pm
I still wonder if China’s “blue sky” policy for the Olympics in conjuction with the global economic slow down, would have been detectable if we had a full set of data.
My estimate remains - Yes, we really can do something about AGW when we put our mind to it.
pough // August 6, 2008 at 4:51 pm
Is Jim Hansen fat, too? Is that how he gets to be “too many” or is there a League of Activist Scientists I haven’t heard of?
Joseph // August 6, 2008 at 7:17 pm
I would venture a guess that’s because scientists are people who, you know, live in this planet.
Raven // August 6, 2008 at 7:45 pm
Tamino says:
“about irrational fears that doing anything about global warming will “destroy our way of life and ruin our prosperity”
Well part of the problem is there are many different people saying many different things and depending on who you are listening to it is possible to believe that controlling GHGs will lead to economic devastation. For example, Gore’s recent call to eliminate fossil fuels in 10 years was generally dismissed as a practical impossibility, however, I think it is very reasonable for someone to be afraid that some politicians might actually try to accomplish the impossible and destroy the economy in the process.
You can call it the law of equal and opposite rhetoric. If someone insists that the human race will be extinct in 100 years if CO2 emissions aren’t reduced to zero in the next 30 years then someone else will respond with the claim that doing so would cause the economy to collapse.
IOW, the irrational fears about the dangers of AGW are just as unreasonable as the unreasonable fears about the costs of action. If you would like to do something about the latter you need to recognize that it is connected to the former.
Ray Ladbury says:
“Now given that a scientist does not cease to be a citizen with a responsibility to defend civilization, what choice do we have but to try to call attention to this threat.”
The issue is not whether a scientist takes an interest in politics. The issue is whether the scientist tries to use his authority as a scientist to justify particular policy decisions and to denigrate those that have different opinions on the most appropriate policy decisions given the current state of knowledge. For example, Hansen has a big issue with coal and has demanded that governments severely restrict the development of new coal plants. However, that is a specific policy decision that has a wide range of economic implications that Hansen is not really qualified to assess. In fact, a policy maker who does not dispute any of the science of CO2 can reasonably claim that the economic risks associated with a blanket ban on new coal plants are greater than the economic risks of global warming (this is what the policy makers in India and China have said over and over again). Hansen is free to publically disagree but the fact that he is a scientist does not make his opinion on best way to balance the risks any more valid than the opinion of other politicians.
The failure to distinguish between a policy choice and a scientific fact is the reason why the reputation of science and scientists are being hurt by debate on AGW. I realize that not all of this is the fault of scientists because they have often been used as pawns by politicians and activists that seek to promote a certain agenda. However, that does not change the fact that the problem exists and the vitriol that shows up on Anthony’s forum is simply one manifestation of the problem.
Dano // August 6, 2008 at 8:03 pm
So, what, Raven, would you have us do? Our labs will not provide much refuge if human civilization collapses around them.
Silly man! Raven would have corporations - not scientists push their preferred policies.
Will they match up with the science? Who cares? Or corporate benefactors will be making profit, and that’s all that matters anyhoo. And corporate ideals are more in line with certain small-minority ideologies than that pesky ol sciencey stuff, anyways.
That ol’ sciency stuff invalidates too many ideologies (and thus self-identities) for the fringe’s comfort.
Best,
D
Dano // August 6, 2008 at 8:06 pm
The failure to distinguish between a policy choice and a scientific fact is the reason why the reputation of science and scientists are being hurt by debate on AGW. I realize that not all of this is the fault of scientists because they have often been used as pawns by politicians and activists that seek to promote a certain agenda. However, that does not change the fact that the problem exists and the vitriol that shows up on Anthony’s forum is simply one manifestation of the problem.
Wow. Breathtaking in its ignorance, conflation, and projection.
One can’t write parody better than that folks.
Say, lad, shouldn’t you be trying to study up on mountain pine beetles to reply in the other thread? Or have you given that up like so many other topics for which you’ve been exposed as…as…well, the young Raven who can’t speak to so many issues?
Best,
D
J // August 6, 2008 at 8:51 pm
Raven writes: “I realize that not all of this is the fault of scientists because they have often been used as pawns by politicians and activists that seek to promote a certain agenda. However, that does not change the fact that the problem exists and the vitriol that shows up on Anthony’s forum is simply one manifestation of the problem.”
To me, this looks like you’re blaming just about everyone for the vitriol and conspiracy-theorizing on Watts’s site except for the people actually responsible for it: Watts’s commenters, and Watts himself.
I would argue that the commenters on Watts’s site are not puppets; they can and should be held responsible for their own writings. Likewise, “scientists” haven’t forced Watts to turn his blog into a haven for vitriol and paranoia; that’s a choice that’s made (daily) by Watts himself.
Hank Roberts // August 6, 2008 at 8:53 pm
China:
http://environment.newscientist.com/channel/earth/dn14455-could-china-lead-the-green-revolution.html
India:
http://www.talkgreen.ca/india-coal-plant-green-groups-taking-action/
Bradbury:
“People ask me to predict the future, when all I want to do is prevent it.”
http://www.spaceagecity.com/bradbury/quotes.htm
“… unreasonable … irrational … denigrate … pawns … a certain agenda. … vitriol …”
Froth much?
The natural experiment is in progress, brought to you courtesy of the innovative speculative financial instruments currently doing far more to change the global economy than anything ever imagined by the ecologists:
http://www.nytimes.com/2008/08/05/business/worldbusiness/05yuan.html
New orders at Chinese factories plunged last month. Exports are barely growing, …”China has slowed down a lot already, but it’s going to slow down more,” said Hong Liang, the senior China economist at Goldman Sachs…. This slowdown is reflected in the Shanghai SSE composite index that is off about 54% from the peak.
…
http://calculatedrisk.blogspot.com/2008/08/slowdown-in-china.html
Tell us why it’s Hansen you blame.
Rainman // August 6, 2008 at 10:04 pm
I have a question. Can we predict the next Ice Age? That would seem to be the next real threat to mankind. How would we stop it?
David B. Benson // August 6, 2008 at 11:05 pm
Rainman // August 6, 2008 at 10:04 pm — Yes. The next attempt at a stade (massive ice sheets) will not be for about 20,000 years (IPCC states 30,000). This particular4 orbital forcing will be sufficienctly small that the stade may not occur (even without AGW lasting effects). The next, and surely successful attempt is not until about 50,000 years from now.
Hank Roberts // August 6, 2008 at 11:17 pm
> Can we predict the next Ice Age?
Google,
first result pasting in your question:
http://www.whoi.edu/page.do?pid=12455&tid=282&cid=10046
Second result pasting in your question:
http://askville.amazon.com/historians-predict-ice-age/AnswerViewer.do?requestId=429445
And how would we stop it?
There’s good reason to think that we did already once, not all that long ago!
http://scholar.google.com/scholar?q=ruddiman&hl=en&lr=&safe=off&scoring=r&as_ylo=2003
If we’re smart enough not to waste all our fossil carbon, we can again next time:
george // August 6, 2008 at 11:24 pm
Raven
In your dreams.
Scientists — especially James Hansen — enjoy great respect among the general public.
This notwithstanding (rather pathetic) efforts by some to smear scientists with accusations of fraud and innuendo. (”Piltdown Mann” etc)
Sorry, but the only ones who are taking seriously the accusations of fraud and the conspiracy theories are those who are making the accusations and spawning the crackpot theories — ie, those in the echo chamber. The poor dears.
Ray Ladbury // August 7, 2008 at 12:20 am
Raven, The “policy” politicians have opted for would best be termed ignorant complacency, and they usually justified that policy by attacking the science! As someone who deals with risk for a living, I agree that it is not the job of an expert to argue for a particular policy or remedy to a risk. It is my job to ensure that all options are known and the risks are understood. I have yet to hear a responsible, informed argument for using coal without carbon capture and storage. There simply is no way to mitigate the risks of such a strategy, so Hansen is as correct in arguing this as a doctor would be in telling a patient to stop smoking.
I’m all for market-based solutions, minimum intervention, etc. Yet, I mainly hear capitalists attacking science they don’t understand rather than making arguments that address the problem. Is capitalism really so fragile that it can only survive in an era of cheap fossil fuel?
David B. Benson // August 7, 2008 at 12:29 am
David Archer’s papers certainly treat the matter of excess CO2 and the onset of the next stade. HIs papers are avilable on his publication page; I follow his analysis rather than W.F. Ruddiman’s (although his early anthropogene hypothesis has, in the main, surely been confirmed by now).
David Archer has a new (or forthcoming) book with title or subtitle “The Long Thaw”. More details are in the link:
http://www.realclimate.org/index.php/archives/2008/01/our-books/
Raven // August 7, 2008 at 12:36 am
George says:
“Scientists — especially James Hansen — enjoy great respect among the general public.”
From a recent poll of the US electorate:
Is Global Warming caused primarily by human activity or by long term planetary trends?
47% Human activity
34% Long term planetary trends
8% Some other reason
11% Not Sure
I find it hard to believe that people who ‘respected’ scientists would completely repudiate their claims w.r.t. AGW.
I realize that many of you here would like to console yourselves in your own echo chambers by criticizing those stupid and evil people who don’t trust scientists anymore and post vitriolic comments on blogs. However, I think it would be more useful to ask yourselves why they don’t trust scientists - especially if these people are numerous enough to slow down or or block the substantial legislative actions on the problem as you perceive it.
Joseph // August 7, 2008 at 1:48 am
That’s actually a valid point, and it not only happens in this field. For example, in the biological sciences (I deal with this in autism debates all the time) a lot of people have a tendency to trust anecdotal evidence over scientific findings. It’s essentially a human instinct to do that.
Science can be very abstract and inaccessible to the majority. That’s why I think there’s a lot of merit in blogs that scrutinize data directly in a way that can be verified and criticized by readers.
Raven // August 7, 2008 at 1:57 am
Ray Ladbury says:
“The “policy” politicians have opted for would best be termed ignorant complacency, and they usually justified that policy by attacking the science!”
They dispute the science because the science is being used to pressure people to accept specific policy choices. This means people who disagree with the policy choices have no choice but to dispute the science.
If the science was presented seperately from the discussion of policy choices then we could have a debate about the policy choices and we would not get dragged into debates about the science.
For example, we could be 90% certain that we are facing 3 degC of warming but that does not automatically mean that rapid mitigation the best policy approach. The are good arguments that adaption and longer term mitigation would be a better bet because it would likely succeed whereas any ‘rapid mitigation’ policy is doomed to fail.
David B. Benson // August 7, 2008 at 2:40 am
Raven // August 7, 2008 at 1:57 am — Have you read “Six Degrees”? Anyway, here is a starter:
http://www.timesonline.co.uk/tol/news/uk/science/article1480669.ece
The section entitled “BETWEEN TWO AND THREE DEGREES OF WARMING” is bad enough!
Hank Roberts // August 7, 2008 at 2:57 am
> people who disagree with the policy
> choices have no choice but to dispute
> the science.
Your plan is to skip doing science and just make up different facts so you can draw different conclusions?
Have you asked Roger Pielke Jr. about this position? He could give you good advice.
dhogaza // August 7, 2008 at 3:05 am
Bingo! I *love* it when exasperation leads a denialist to make an honest statement.
He’s making it clear that those who don’t care for the policy implications of science HAVE to dispute the science.
Even if they know the science is correct.
THANK YOU, Raven, for admitting the blindingly obvious fact that the ideologues in the denialsphere don’t care a bit about the reality of global warming and the findings of climate science.
In other news, though, Raven misses the obvious:
If the *professional* denialism machine really believed the public doesn’t trust scientists, they wouldn’t spend so much money lying about the fact of a scientific consensus, trotting out lists of “10,000 scientists who don’t believe in global warming”, etc etc.
The denialism machine has successfully clouded the picture for many, convincing them that SCIENTISTS THEMSELVES disagree over whether or not AGW is true.
The fact that polls reflect the success of this effort is not an indicator that people don’t trust scientists, but rather that they trust those who tell them that as many or more scientists don’t believe in AGW as those that do.
Of course, if you’re right, then the denialism machine can quit lying about what science tells us, what science believes, about the scientific consensus, etc, right? I mean, essentially Raven is telling us that these are all wasted effort.
Hank Roberts // August 7, 2008 at 3:06 am
> skip doing the science
Yep! Well at least it’s nice to know you are aware of what you’re doing. I guess.
http://initforthegold.blogspot.com/2008/08/john-holdren-on-climate-skeptics.html
http://www.iht.com/articles/2008/08/04/opinion/edholdren.php?WT.mc_id=newsalert
_____excerpt____
First, they tell you you’re wrong and they can prove it…. … the first is the worst. Their arguments, such as they are, suffer from two huge deficiencies.
First, they have not come up with any plausible alternative culprit for the disruption of global climate that is being observed ….
Second, having not succeeded in finding an alternative, they haven’t even tried to do what would be logically necessary if they had one …
Raven // August 7, 2008 at 3:45 am
dhogaza says:
“He’s making it clear that those who don’t care for the policy implications of science HAVE to dispute the science.”
You are misrepresenting my point. My point is proponents of certain policy positions (i.e. rapid mitigation) have HIJACKED the science are using it as a propoganda tool to push their desired policy options.
This puts people who think different policy choices are appropriate in a difficult position where they end up disputing the science because it has been hijacked by others.
Perhaps the best comparison is the war in Iraq. Many people wanted to oppose the war but the advocates of the war hijacked the concept of national pride which put opponents of the war in a position where opposing it made them appear to be opposing “America”. Various activists are now doing the same with with AGW but they are trying to wrap themselves in the reputation of scientists instead of the american flag.
The bottom line is the science of CO2 is one thing. The appropriate policy response is another. Climate scientists are entitled to their opinion on the policy responses but they have no special expertise or authority that makes their opinion on the appropriate policy response any more valid that other people who participate in the political process.
If you don’t like the fact that the reputation of scientists is questioned as part of the discussion on policy then you should stop trying use the reputation of scientists as a way to push your favoured policy options.
[Response: Perhaps the best comparison is the war in Iraq. Many people wanted to oppose the war but the advocates of the war hijacked the truth by falsifying evidence of weapons of mass destruction and of ties between Saddam Hussein and al-Qaeda.
If you want to argue that adaptation is a better strategy than mitigation, then do so -- but denying the science for ideological reasons is just plain wrong.]
John Mashey // August 7, 2008 at 3:57 am
re: ray
“Yet, I mainly hear capitalists attacking science they don’t understand rather than making arguments that address the problem. Is capitalism really so fragile that it can only survive in an era of cheap fossil fuel?”
I’m sure you don’t mean to over-generalize, but it might read that way.
Of those whose disbelief of AGW is economically motivated, there are:
a) Some of those in the fossil fuel industries whose profits would be directly impacted. I’d put this order as coal, oil, gas.
Coal folks have the most to lose. Oil folks know they’ll sell everything they can ship, and at least some oil folks have pretty rational views, at least from ones I talk to. Gas folks would be happy to see coal whacked. Jeff Goodell’s “Big Coal” is an interesting read; I grew up quite near coal country and what he says fits.
b) Others whose business might be strongly impacted, like car companies, although of course, Peak Oil gets them faster than AGW does. Many car companies have no desire to get away from ICE into BEVPHEV, for the same reason that classic minicomputer companies mostly wanted microprocessors to go away.
c) Others who are nervous, because changes can be threatening.
BUT, there are plenty of capitalists who perfectly well understand AGW, accept the science, and are working hard to create solutions & make money doing so. Around here [Silicon valley], such folks are *pervasive*, among venture capital investors, entrepreneurs, and big-company CEOs.
But there are plenty elsewhere. To pick a few:
Peter Darbee - CEO, Pacific Gas and Electric
Jeff Immelt - CEO, General Electric
Ron Oxburgh - ex-Chairman, Shell UK
Anyway, it is *really* important not to tar all of us with the same brush.
Tim McDermott // August 7, 2008 at 4:32 am
Raven said:
This too, is denialist BS. About 3 years ago I decided to reduce my carbon footprint as opportunity presented itself. So far I’ve had to replace a car, a heat pump, and a hot water heater. The cost of minimal carbon replacements cost me about $18,000. They save me, on average, $200 per month. So my payback time is 7.5 years. Return on investment is 13%.And I’m responsible for about 4 tons carbon per year less than I was 3 years ago.I know that this doesn’t make me carbon neutral. I know that there is are some large capital investments to be made. But next quarter’s financials should not be the only consideration. There are smart investments to be made in renewable energy. It is a shame that our leading “capitalists” are afraid to make them.
Ray Ladbury // August 7, 2008 at 9:03 am
Raven, First, I think that it is unfortunate that your pole did not ask the participants if they thought the science was settled or controversial–most Americans still think there is a credible scientific opposition to the consensus. Second, the “policy” of rapid mitigation is motivated by science. We have a physical system with significant positive feedbacks–not all of which are understood. And while we are confident that CO2 sensitivity is of order 3 degrees per doubling, we cannot preclude much higher values. All of this argues for action now so that technology and appropriate policy can develop–a process that will take much time. Conservation works NOW, and it is feasible. When residents of Juneau, AK suddenly found themselves without hydro-electric power, they managed to quickly and relatively painlessly reduce energy consumption by 33%.
So the arguments of those you term “alarmists” and those of denialists are both motivated by uncertainties in the science. The difference is that the alarmists understand the scientific uncertainties.
Barton Paul Levenson // August 7, 2008 at 11:29 am
Raven writes:
Because there are loud voices out there telling them not to trust scientists. Duh.
Ray Ladbury // August 7, 2008 at 11:57 am
John Mashey, I’ll admit to being more than a little disappointed in even the more responsible voices from the business and ecomomics communities. Despite admitting the cogency of the science and acknowledging the necessity of action, they’ve advanced no concrete proposals that come close to adequacy. Most disturbing has been the reluctance to criticize the denialist fringe of their respective communities.
The most amusing consequence of this is the fact that it has given the bete noire of the right, Al Gore an Oscar and a Nobel Peace Prize–and more important, the moral high ground.
Yes, there are those like you who are exceptions, but the silence I hear as far as true market-based solutions makes me wonder whether climate change is not causing selfdoubt among capitalists. And as we have seen, the political left is not having a similar crisis of confidence.
Craig Allen // August 7, 2008 at 1:14 pm
Raven - Regarding what polls tell us about the science and scientists :
The rest of the western World generally looks on with amazement at the lack of intelligence and insight displayed by the average Joe in the US.
Perhaps it is true that the poll you cite reveals that only 47% of US voters believe that human activity is responsible for climate change. Isn’t that about the same percentage as those who believe the earth was created a few thousand years ago in 6 literal days?
By contrast in Australia where we generally respect scientists and are already suffering severe impacts under global warming:
The latest ‘Newspoll’ survey has confirmed widespread public support for the 2010 implementation of an emissions trading scheme.
- 60 per cent of voters backing the adoption of a scheme “regardless of what other countries do”.
- Another 23 per cent support a scheme if other countries act.
- Only 11 per cent of voters oppose an ETS under any circumstances.
Read more about it here.
Craig Allen // August 7, 2008 at 1:36 pm
PS:
Further down in that article …
“When asked if climate change was caused by human activity, 96 per cent [of Australians] said it was entirely or partly caused by human activity; 84 per cent believed climate change was currently occurring.”
Rainman // August 7, 2008 at 3:39 pm
Tim McDermott: Are you sure you want to throw down the ‘bs’ flag on the statement ‘eliminating fossil fuels in 10 years is a virtual impossibility’?
Seriously, think about it. Replace every fossil fuel power source/engine with something else with a zero or low carbon footprint in 10 years. It boggles the mind…
You reduced your footprint with a couple (expensive) purchases, but you didn’t actually replace what is using fossil fuels.
Rainman // August 7, 2008 at 3:42 pm
Huh… I thought we were close to the end of our current warm period (another 1-3k years) based on prior interglacial (intra?) periods. Guess I have some reading to do.
Raven // August 7, 2008 at 5:58 pm
I don’t put much weight in poll numbers myself. I only posted the ones I did because they illustrated that it is a mistake to assume that the opinion of scientists on AGW is universally accepted. I realize that the political culture of the US is a bit unique because a large segment of the population instinctively dislike government interference in their lives and would oppose anything that sounds like it would increase the amount of government interference so the results in the US are not necessarily reflective of other countries.
That said, I do believe that people believe what they want to believe and that the ‘big oil/coal’ conspiracy theorists on this forum have the cause and effect reversed. i.e. skeptical views exist because people are suspicious of the claims and want to hear the other side. These views would not exist if the AGW advocates had not given people a reason to be suspicious in the first place. I know in my own case that I had no reason be suspicious of the consensus view until I read about the difficulties with the historical temperature reconstructions.
The tendency for people believe what they want to believe is why I think adaptation and long term mitigation is the only strategy that is likely to succeed. Any attempt to impose large amounts of short term pain will inevitably face strong opposition because people will stop believing in AGW as soon as it is no longer in their interest to do so. We are starting to see that in places like the UK where green initiatives have gone from being merely a nuisance to asking people to make some serious sacrifices. I think the same story will play out in every country where the short term public opinion gets folks like Rudd elected but once people realize the implications of the aggressive anti-CO2 policies the opposition starts to grow and skeptical views will proliferate.
This is where linking the science to specific policy choices becomes really problematic because if the scientists succeed in convincing people that the science says that aggressive mitigation is the only option people will end up rejecting the science when they decide that the aggressive mitigation is no longer in their interest. If the scientists made it clear that the choice of policy response is independent of the science then people will be able oppose aggressive mitigation without rejecting the scientific fundamentals. I feel that the latter approach would ensure that progress is made no matter what even if that progress is slower than some would like. Betting everything on the aggressive mitigation strategy could result in a backlash that would halt progress for decades.
Hank Roberts // August 7, 2008 at 6:12 pm
Rainman: here’s a good start:
http://www.sciencemag.org/cgi/content/summary/297/5585/1287
(Don’t rely on PR sites, look with Scholar for peer reviewed journals)
Raven: horseburger.
> choice of policy response is
> independent of the science
The Wile Coyote Theory of Gravity.
Q: You’re in the dark. You have one candle. What is your next move?
Example: Beyond Science into Policy: Gulf of Mexico Hypoxia and the Mississippi River
http://www.bioone.org/perlserv/?request=get-document&doi=10.1641%2F0006-3568(2002)052%5B0129%3ABSIPGO%5D2.0.CO%3B2
NN RABALAIS, RE TURNER, D SCAVIA - BioScience, 2002 - bioone.org
… An independent, unsolicited analysis produced by scientists …continued to strengthen the policy relevance …
http://scholar.google.com/scholar?hl=en&lr=&safe=off&cites=13167393903892687231
J // August 7, 2008 at 6:29 pm
Raven, you persist in ignoring the fact that Watts and his commenters are responsible for the lamentable contents of his blog. Nobody is forcing Watts to use his blog as a vehicle for promoting ignorance and confusion. He chooses to do that himself.
Stop blaming “scientists” for the actions of people who ought to know better.
Hank Roberts // August 7, 2008 at 6:32 pm
It will take a while before the numbers come in, but it will be interesting to speculate ahead of time. Do you think we’re seeing another economic slowdown in fuel use that will show up in the atmosphere, like the pronounced change after the USSR collapsed?
Things to watch for, like this:
http://calculatedrisk.blogspot.com/2008/08/mic-general-aviation-business-travel.html
“… Macquarie Infrastructure Company reported today (page 7) that they saw a 4% decline in fuel volume sold for general aviation….”
————-
The natural experiments being conducted by the political economy are starting to turn up interesting results.
We’ve got the USSR collapse, the 9/11 air travel shutdown, the Beijing Olympics attempts to reduce air pollution, the current fibrillation of the economy.
Gavin's Pussycat // August 7, 2008 at 6:51 pm
Raven:
Yes, you ‘read about’. You were meant to. And it wasn’t the AGW “advocates”‘ fault, as you would know for a fact if you were at home in the science. But we have been over this.
You, and millions of others, are blaming the victims — in this case, of the swiftboating of their scientific competence or even honesty. And there’s nothing that will make you see this for yourselves short of getting a solid education in the relevant sciences. Which is not going to happen for most folks.
You’re a victim too. Angry yet?
Tim McDermott // August 7, 2008 at 6:59 pm
Rainman: You are confusing possible with likely. There is a lot of low-hanging fruit, better insulation, better weatherstripping, keeping tires inflated. Beyond that, the US has repeatedly done amazing things when it had to. My father worked on the Manhatten project, which went from theory to first use of atomic weapons in 3 years and 2 months. The Apollo Project looked virtually impossible when Kennedy committed the country to it. NASA was still having some difficulty with exploding rockets, if I recall correctly. I personally thought JFK was nuts. The task is hard, but that is part of what makes it worth doing. I fear that if you are right it will not be because the a fossil fuel free economy is impossible to achieve, but rather because the US is no longer capable of great things. We appear to prefer to whine about the possibility of any sacrifice. I’m glad I’m getting on in years.
Rainman // August 7, 2008 at 8:32 pm
Tim: It’s not about sacrifice, it’s about reality.
Just think about all the places fossil fuels are used for power generation or vehicular locomotion. Cars, Trucks, Ships, Trains, Airplanes, Construction Equipment, Power Plants, Hand Held Power Tools (Chainsaw, etc), Emergency Power Generators (very important!), etc.
This isn’t a narrow (if rather difficult) task like those you mentioned, this cuts through the heart of our infrastructure. The time and resources just to build a fully electric transportation infrastructure/system (assuming we can develop better batteries) is staggering, never mind what it would take to actually replace every single internal combustion engine in the nation.
And then, you still have to supply this system with electricity. Where does that come from? Wind and Solar only get us so far. HydroElectric is good, but we’ve been taking down dams faster than we build them. Only possiblities are Geothermal and Nuclear. Geothermal can work, but in limited areas, and Nuclear makes people flop and twitch when it’s mentioned. (Having been in the Naval Nuclear Power Program for 9.5 years, I have no issue with nuclear power) Building either of these types of plants will take large amounts of resources as we replace all the coal/fuel oil plants.
Now… I don’t know about you, but I figure my budget is unlikely to be able to handle the massive increases in cost of living due to increases in cost of energy. Just the oil/gas increases over the past couple years have bit into things.
Cheap energy has helped us get by in the past. Expensive energy will likely bury us.
cat black // August 7, 2008 at 10:13 pm
Hank: “…interesting to speculate…”
OK, I’ll bite: the energy density of oil is too great to pass up in an industrial society. What we may be seeing right now is a transition away from “tactical” use of oil to “strategic” use. I’d expect to see recreational uses drop off with the higher price, but expect to see increased use for strategic purposes like military buildup and infrastructure retooling as nations rejigger to fight the resource wars. And, I’d expect the strategic uses to outstrip the tactical ones almost immediately. How much oil did the war in Iraq burn for the purpose of war itself, for example? how much oil will we burn drilling in desperation for the last barrel? And then ironically how much will we burn mitigating climate change? All these together probably represent a vicious death-spiral into oil exhaustion, and I would expect CO2 levels to rocket as a result of the haste to be the last well pumping.
Toward the end, expect to watch humanity run through the last oil fields like crazed maniacs, pumping and drilling and fighting the entire time. I’d give the whole wretched business 15 years tops until it implodes. God help us.
Cthulhu // August 7, 2008 at 10:28 pm
I want to know how Watt’s and his Conspiracy Circle can possibly keep pumping out those Doubts if scientists don’t provide them with daily updates on every climate metric?
Doesn’t ERSL understand the importance of ‘Watt’s Wrong with Watt’ (or whatever the blog is called)? I am not even going to contemplate the possibility that working scientists haven’t heard of Watt’s and his Blog.
On a more (but not entirely) serious note you know what was funny? Someone from the Circle suggested it was rather suspicious that the July co2 figure was updated just as the arctic sea ice anomoly started dropping. As if there was some suspicious connection there..
On an annoying note I just checked-in and I see Watt’s seems to be trying to take credit for “improving” “data reporting” at Mauna Loa. Talk about jumped up self-importance syndrome.
And to think Tans went through all those replies! How patient is he!
george // August 7, 2008 at 10:54 pm
Raven said
That’s funny. I could have sworn you posted the results to that poll to “disprove” my statement that “scientists enjoy great respect among the general public” (which they do, by the way:”Scientist” is consistently among the most trusted/respected professions in poll after poll here in the US.)
You essentially equated the poll result that “34% [attribute warming to] Long term planetary trends” with “34% lack respect for scientists”.
Above, Dhogaza points out the flaw in your logic.
You overlook the very real possibility that (largely due to a disinformation campaign), a large fraction of the American public either does not know that there is a scientific consensus on global warming or does not know what that consensus is.
When large numbers of Americans get their “science” from news outlets like FOX that favor the views of “outlier” scientists (and others) who persistently misrepresent the science, it makes it appear either that no scientific consensus exists or that the consensus is something very different from what it actually is.
You also overlook the possibility that many people are simply voting the party line in this case (most of those making up that 34% are Republican). For some, politics/ideology trumps all else, including respect for scientists.
Nevertheless, I really appreciate your “concern” “that the reputation of science and scientists are being hurt by debate on AGW.”
And with regard to your “concern” about the “people [who] are numerous enough to slow down or or block the substantial legislative actions on the problem as you perceive it”, your “concern” may be set to rest in six months :)
We shall see how effective such people are after the new President (of either party) takes office.
Come January, those people (and you) might have real cause for concern.
Raven // August 7, 2008 at 11:45 pm
Frankly, I have no patience for conspiracy theories whether they are about the CIA blowing up the WTC or the oil/coal companies brainwashing people. People act as individuals based on their personal convictions and self interest. In many cases, their self interest will affect their personal convictions through a phenomena called ‘cognitive dissonance’. The fact that many people share the same self interest/personal convictions can lead to the appearance of a conspiracy when there is none. If you are going to insist that self interest makes some people want to believe that the science is less certain than it is then I will point out that self interest also makes some people want to believe that the science is more certain than it is.
None of these arguments will alter the fact that the science is uncertain and we really have no idea what will happen in the future. Climate models tell us that if we assume that GHGs are the only major driver climate then we can expect about 3 degC of warming. However, everything hinges on the assumption that GHGs are the only major cause of climate change. I realize that posters here will argue that it is a reasonable assumption because the experts have looked at all plausible alternative causes and ruled them out. However, I have an issue with letting the experts assess the probability that they are wrong because experts always believe they are right and that they have taken everything into account – that is why they are the experts. For that reason any prudent person who is being asked to invest huge sums of money on the word of experts needs to independently assess the probability that the experts are wrong.
Unfortunately, too many experts take it personally when someone suggests that they might be wrong. They shouldn’t. It is not personal but a rational response when dealing with unknowns. The insulting, condescending tone taken by many climate activists when faced with this rational criticism makes the problem worse because people intuitively know that arrogant people are blind to their own failings and make mistakes. For me the correctness of the hockey stick is not as important as how the climate science community handled the criticism extremely poorly and unprofessionally.
The contrast with Dr. Tans at MLO is quite striking. In this case he was faced with criticism that was clearly unreasonable yet he responded in a professional manner. You can see the results in the latest post on Anthony’s blog – no vitriol there.
Lee // August 8, 2008 at 2:35 am
Raven:
“Climate models tell us that if we assume that GHGs are the only major driver climate then we can expect about 3 degC of warming. However, everything hinges on the assumption that GHGs are the only major cause of climate change.”
How many errors can one stuff into two sentences?
Climate models do not assume that “GHGs are the only major driver climate.” There are several lines of evidence entirely independent of the models that also tell us that sensitivity to GHGs - as one of many potential drivers of climate change - is about 3C / 2xCO2. Nobody is arguing that GHG’s are the “only major cause” of climate change. Nobody is assuming that, either.
What the models do tell us is that much of THIS bout of warming this century is caused by GHG’s - some of the warming in the early century was caused by changes in insolation, and the models allow s to see that as well, so that pretty much disposes of your ‘they assume its all GHG’ argument. Nealy all the warming since the mid 70’s looks to have been caused by GHG’s - but that statement is NOT the same as saying only GHG’s drive climate. And all fo those results from teh models are consistent with the independently derived sensitivity estimates derived, for example, from glacial-interglacial transitions.
And this is all REALLY BASIC STUFF. Anyone who consistenly repeats arguments that betray they don’t understand this, is betraying a lack of basic knowledge in the field. No, I’m not arguing that if yo disagree with me you are ignorant - far from it. I’m arguing that if you say things like ‘the models assume that GHGs are the only major cause of climate change’ then you just simply don’t know enough about the models to criticize their results.
Joseph // August 8, 2008 at 2:50 am
I suppose it’s possible there are unknown forcings. In that case, though, they would either have to be anthropogenic in nature, or relatively small. Recent temperature increases are certainly anthropogenic to a large degree.
Phil Scadden // August 8, 2008 at 3:12 am
Raven, I think your idea of “bad reaction” comes from exhaustion. Every day, some new person reads some rubbish on a disinformation site, becomes instant expert and challenges the climate scientist with the same old rubbish, time and time again. What’s more the attacker could have easily discovered that it was disinformation with only a modicum of checking. Facing this day in, day out has to be depressing.
Facing genuine new theories or data is different. Scientific debate tends to be pretty robust and scientists are no angels. However, noone makes their mark by following a party line. Thats why I DO trust experts reviewing experts on the whole. You win big time if you can find a better hypothesis. Find a way to explain current climate trends without human GHG and you would be darling of the industrial world and have funding for life. And of course there is no way to completely dispel uncertainity but it doesnt stop me climbing on plane because scientists havent tied down turbulence or that another theory of aerodynamics might come to light.
A do-nothing attitude to AGW because investment might be high is poor risk-assessment in my opinion. Look at the other end of the AGW risks - suppose we UNDERESTIMATE AGW - what costs then?
I am not even sure the projected costs arent disinformation. When I see what US spends in coal and oil subsidies, I wonder what you might achieve by redirecting these. You dont need carbon tax on petrol - static production is achieving the same effect on prices and consumption. Of course this would be BAD for US coal producers especially but for the rest of the planet? Probably bad for me personally too as much of my work is in coal and oil exploration but I am betting its better for my children.
Raven // August 8, 2008 at 5:18 am
Phil Scadden says:
“You win big time if you can find a better hypothesis. Find a way to explain current climate trends without human GHG and you would be darling of the industrial world and have funding for life.”
I don’t buy this argument. It is seems to me that trying to buck the consensus in the current political environment is a losing proposition for any scientist because climate science is a field were theoretical proofs do not really exist and by the time the data is collected to prove them right they will likely be dead. In the meantime they get to be accused of being shills for big oil by numerous activists. Just look at how Spenser and Linzden are treated.
It is also not reasonable to compare models which have been verified in a wind tunnel to climate models. I have a lot of confidence in the models used to design planes because it is possible verify them in a lab before they are ever used to prove the design of plane. We can’t do this for climate models and that has to be taken into account before we can bet trillions on them.
That said, I do not feel that a do nothing policy is useful either. There are a lot of things that we can do that would be useful even if the experts end up being wrong. I see no reason to delay implementation of those policies. For example, we need to start building nuclear plants a lot faster than we do. On the other hand, what if we have underestimated the risk of a quake in California or a large asteroid strike or an alien invasion? Should we invest trillions trying to deal with those risks? Sometimes we just have to cross our fingers and hope for the best. If a problem arises we deal with at that time.
But what I think gets lost in this debate is any rapid mitigation scheme will result in a significant reduction in a standard of living for most people. This will make it politically impossible to sustain this kind of policy over the long run and would ultimately revert to the “do nothing” approach. For that reason alone I think setting more modest objectives is a better strategy because it has a better chance of success.
Petro // August 8, 2008 at 6:25 am
RavenK
Should the policies be baswd on scientific facts?
How scientific facts are achieved?
Who produces scientific facts?
or
Should the policies be based on beliefs?
Whose beliefs?
Gavin's Pussycat // August 8, 2008 at 10:23 am
Raven:
Who is doing the independent assessment? Other experts? (So you trust experts after all? Who decides who are the good and the bad experts? Politicians? You?) Politicians? You?
You see the problem?
(You need to understand recursion in order to understand recursion :-) )
Ray Ladbury // August 8, 2008 at 12:55 pm
Raven says: “It is seems to me that trying to buck the consensus in the current political environment is a losing proposition for any scientist because climate science is a field were theoretical proofs do not really exist and by the time the data is collected to prove them right they will likely be dead. In the meantime they get to be accused of being shills for big oil by numerous activists. Just look at how Spenser and Linzden are treated. ”
Good Lord, man, do you even know any scientists? Do you think that a scientist gets rich and famous (well, famous anyway) by following the crowd? It would appear that much of your opposition is based on your being misinformed. You are wrong about the assumptions in the climate models. You are wrong that the physics in the climate models is unverified. You are wrong. You are wrong about how science is done and about the reward structure in science. You are wrong that “only the experts” have assessed the science in the climate models (every major scientific or honorific (e.g. NAS) society that has looked at the science has endorsed it). BTW, you are also wrong about why Spencer and Lindzen incur the wrath of scientists–it’s because they are more interested in pushing their “science” to nonscientists than to peer-reviewed journals.
Perhaps most significantly, you are wrong in your model of assessing risks. Risk is defined as the probability of a threat being realized times the cost if the threat were realized. You can justify spending any cost up to the value at risk to mitigate the risk–either by lowering the probability of the threat or the cost. Let’s look at the 3 threats you lump together.
A catastrophic earthquake in So. Cal. is a virtual certainty. We cannot prevent it from happening, but we can decrease the cost when it does happen–and the success of this strategy is evident in the reduced fatalities despite the persistent realization of smaller quakes.
An asteroid hitting the Earth is a low-probability event that has severe consequences–as such spending justifiable on this is limited, and it makes much more sense to look at avoiding realization of the threat rather than mitigating consequences, as the consequences are so severe. We probably should be spending more on this one, but only because what we are spending is so pitifully small.
Now climate change. Here the probabilities and the consequences are both somewhat uncertain. If climate sensitivity is high, the consequences are certainly catastrophic, and there is a persistent tail at high sensitivity. However, even at lower sensitivity, we face significant costs from climate change. We probably can’t avoid warming of a few degrees, so it makes to try to mitigate the costs of these changes. However, mitigation will take time, and our chances of success increase greatly if we start NOW and slow the speed at which the climate is changing. This also increases the probability of avoiding catastrophic turning points and limits the portion of the threat probability curve we need to concern ourselves with.
It is also not necessarily true that slowing the speed of change will have disastrous economic consequences. Increased efficiency is a boon to the economy–as would be decreased reliance on a scarce resource found in politically volatile regions. Moreover, technological advances we will need to reduce our carbon emissions will likely also benefit the economy in other areas (just as technologies developed for spaceflight or particle physics have done). Perhaps if you understood the science (and science in general) better, you would be less hostile to the scientists.
Dano // August 8, 2008 at 1:43 pm
After reading the valiant attempts by commenters above, I think the best use of energy and resources wrt certain young, naive, refuse-to-learn and ignorant corvid commenters is:
[killfile]
Or comedy.
You’ll never, ever, ever, ever change the lad’s mind, folks.
Best,
D
caerbannog // August 8, 2008 at 2:55 pm
I wonder if Raven is in favor of shutting down the USA’s nuclear weapons program.
Extremely complex computer models are routinely used at Sandia, Lawrence Livermore, etc. to simulate nuclear explosions and the effects of aging on the safety of our nuclear weapons stockpiles. Since we cannot explode nuclear weapons in a laboratory, and we cannot validate the effects of nuclear decay faster that it actually occurs, it follows that the nuclear modeling software used at our nuclear weapons laboratories is no better validated than is any of NASA’s climate-modeling software.
If Raven does not believe that climate-modeling software can give us valid projections, then it follows that he must feel the same about nuclear-weapons modeling software. So Raven, do you think that we should shut down our nuclear weapons program until we can validate nuclear simulation software by exploding a nuclear weapon in a laboratory?
Joseph // August 8, 2008 at 2:55 pm
I think a detrended cross-correlation is a theoretical proof, or close to it. (This is a technique that is not very well known in most fields of science). Of course, I realize it won’t be taken as such until it’s published in the peer-reviewed literature. If I had a real inclination (or credentials) to publish climate science, I’d do it myself.
Lazar // August 8, 2008 at 2:58 pm
Raven,
Cite please? Numbers? Polls results?
Trust in scientists remains as high as ever in general, on this particular issue also.
That is on the low side.
54% — CNN/Opinion Research Corporation Poll. June 4-5, 2008.
71% — The Harris Poll. Oct. 16-23, 2007
61% — Gallup Poll. March 11-14, 2007
79% — FOX News/Opinion Dynamics Poll. Jan. 30-31, 2007
47% — Los Angeles Times/Bloomberg Poll. July 28-Aug. 1, 2006
They are not.
Newsweek Poll conducted by Princeton Survey Research Associates International. Aug. 1-2, 2007;
“Do you think most climate scientists agree that human activities, such as burning coal and oil, are a major cause of global warming, or do you think there is a lot of disagreement among climate scientists about whether human activities are a major cause?”
47% — Most agree
42% — A lot of disagreement
ABC News/Time/Stanford University Poll. March 9-14, 2006
35% — Most agree
64% — A lot of disagreement
Fossil-fuel sponsorship of FUD is well documented and a primary contributor of public uncertainty.
The best antidote is more scientists like James Hansen making a public stand.
Barton Paul Levenson // August 8, 2008 at 3:06 pm
Rainman writes:
You’re thinking about present-day, site-specific geothermal. There is also “hot dry rock” geothermal which will work pretty much anywhere. I for one think we ought to go into the latter in a big way, if necessary with government subsidies.
Barton Paul Levenson // August 8, 2008 at 3:11 pm
Raven says:
Who says? You? Why should we believe you?
By the way, unchecked global warming will result in a significant reduction in a standard of living for most people. Having world agriculture crash will do that.
dhogaza // August 8, 2008 at 3:39 pm
Just had to correct Raven …
There, that’s better. Yet Raven continues to blame scientists for the fact that people like him are being deceived about reality.
caerbannog // August 8, 2008 at 3:51 pm
Or comedy.
You’ll never, ever, ever, ever change the lad’s mind, folks.
Best…
Oh, I know that I’ll never change Raven’s mind — no amount of evidence will ever do that.
But I *do* hope, in some small way, the material I post might keep other readers from drinking the same stuff that Raven’s been drinking.
Raven // August 8, 2008 at 5:54 pm
Ray Ladbury says
“…You are wrong that the physics in the climate models is unverified….”
You cannot validate a model by taking some historical data of dubious accuracy, fabricating data for processes that weren’t measured and then tweaking the models until they can reproduce the data. You validate models by setting up an experiment, predicting what the outcome would be and then running the experiment as many times as possible and verify that the experimental outcomes matched the model predictions.
It is not possible to validate climate models in the way I described so it is not reasonable to claim that they have been “validated”. The best you can say is they have undergone some sanity checks to ensure they are not completely wrong. This does not mean that the models are useless or that they are necessarily wrong. However, it does mean that we cannot treat the model outputs as gospel and that it is quite possible that they got some basic things very wrong. This possibility needs to be taken into account when developing policy decisions.
I realize that the climate modelers will reject that argument, however, the fact that they reject it simply demonstrates that they do not understand the limitations of their models. The opinions of experts that overstate the reliability of their tools must be treated with extreme caution. This is true of every field – not just climate science.
There are many people who are not involved in climate science who are experts in fields, such as statistics, that are used heavily by climate scientists. These people are more than qualified to review the work done and help policy makers assess the probability that the climate experts are wrong. That said, assessing the probability that the experts are wrong is not a straightforward task but very a necessary one when expensive policy decisions need to be made. The little work that has been done by outside experts does not give me any reason to be confident in the field.
I also realize that we don’t need the climate models to determine that CO2 could be a problem – the basic physics tells us that. This is why I am favour of some action. However, without any reliable information about the possible outcomes we cannot justify many of the ‘rapid mitigation’ policies pushed by AGW activists. The parallel to an earthquake in California is apt. We know an earthquake will happen. We just don’t know when or how big. We respond by building stronger buildings and emergency response systems. We don’t pass a law that forbids people from moving to California or forces the people living there already to move somewhere else. Trying to ban fossil fuels like coal is equivalent to prohibiting people from moving to California – e.g. superficially rational if one looks at the worst case outcomes but impractical and economically unwise.
dhogaza // August 8, 2008 at 6:22 pm
Statements like this are astounding, the equivalent of saying that scientists will reject flat-earth arguments, which just demonstrates the limitations of science…
Hank Roberts // August 8, 2008 at 6:43 pm
It’s always nice to hear from someone who knows it all and isn’t shy about pontificating, eh?
Do you _ever_ cite a source for what you believe? I realize there’ s likely more than one person using userid “Raven” on the range of blogs out there — but I can’t find one who cites sources. Anywhere.
Immense faith, yes. But that’s not science.It’s just coming to science sites to witness for one’s faith in some other source of truth.
Boring, yet intrusive.
Ray Ladbury // August 8, 2008 at 7:06 pm
Raven,
First, you have a really limited view of science if you limit it to only what can be done on a lab bench. The tremendous success of geophysics, astrophysics, ecology, and paleontology demonstrate the falsity of this contention. Second, nature provides experiments all the time–volcanic eruptions, even seasonal and daily variation.
As to outside validation–dude, this has had more outside scrutiny than just about any research in history, and the outside organizations have always agreed with the basics.
One really big difference between the big one in CA and the consequences of climate change: The damage of any earthquake is limited in scale. Assistance can come in from outside. People can leave the affected area. If we trash our ability to grow food to feed 9 billion people, who do we turn to for help?
Rattus Norvegicus // August 8, 2008 at 7:24 pm
>You validate models by setting up an >experiment, predicting what the outcome >would be and then running the experiment as >many times as possible and verify that the >experimental outcomes matched the model >predictions.
Oh like the predictions of what a Pinatubo sized eruption would do?
Petro // August 8, 2008 at 8:02 pm
We are really lucky to have such a genius like Raven among us. Let’s stop doing science and start believing every word of this genius!
Rainman // August 8, 2008 at 8:03 pm
All due respect to those on the site, but my ‘exhaustion’ comes from the laying of any new ‘event’ at the feet of AGW.
Case in point: the short lived (but never should have been mainstreamed) article on how AGW is making earthquakes worse. The media is making a mockery of the science.
Back to reading up on Ice Ages…
Hank Roberts // August 8, 2008 at 8:35 pm
Rainman, you exhaust your own time and energy reading the wrong stuff. Don’t come here complaining and bringing the crap here.
Learn how to learn.
Remember you had this mistaken notion about ice age return? And you discovered you needed to read more science instead of the PR sites?
Same for this story about global warming and earthquakes.
Again, I recommend Google Scholar be compared to Google. The difference is the lesson: what’s science vs. opinion and PR.
Let me use your own example.
I took the phrase from your question, spelled out the acronym, and pasted it into Google Scholar:
http://scholar.google.com/scholar?q=global+warming+making+earthquakes+worse
First hit:
Students’ perceptions of global warming
Int’l Journal of Environmental Studies, 1992
… Poles will melt … there will be more earthquakes …
DOI: 10.1080/00207239208710804
International Journal of Environmental Studies, Vol 42, Issue 4 December 1992 , pages 287 - 300
Abstract
…little is known of the preconceptions and misconceptions of young adults in this area. In this study the ideas of a group of first year undergraduate students about the “Greenhouse Effect” have been studied … misconceptions do persist. … these misconceptions are manifestations of a more general underlying failure to link specific environmental problems with their specific causes and consequences.
—————–
OK, Rainman, if you’ve read this far — the lesson I suggest is NOT to just pick up any tasty tidbit from the PR/denial sites and truck it over here and toss it out.
Look it up for yourself.
Learn how to find answers for yourself
Learn what being skeptical really means by doing the research for yourself.
Learn something. Ask questions that show you’re smart, curious, and able to look for your own answers.
And that you know where to look. Go to your library and ask the Reference Desk librarian for more help.
There’s a world full of people whose idea of entertainment is to take stuff and throw it at the scientists online to distract them, waste their time, and try to piss them off.
Show that you’re interested in learning.
Good advice here, written for software questions but quite appropriate for anyone who wants a scientist to drop what they’re doing and help them understand something:
http://www.catb.org/~esr/faqs/smart-questions.html
Rainman // August 8, 2008 at 9:44 pm
Hank: In all fairness, the last time I did research into Ice Ages (20+ years ago), the information I had was we were close to the end of our current warm period. Info wasn’t as freely available back then (early 80’s). Or at least it wasn’t for a high school student in a small town with no major college within 90 miles. Now here I am reading up on the subject. (Thanks for the pointers on where to look.)
You say I’m talking from denialist sites. Is that what the Associated Press is? They released the story, apparently without due diligence, less than 2 months ago. I will admit to looking at some ’skeptic’ sites to see the other side of the equation. There has to be a way to resolve the dilema without shattering our civilization. Then again… maybe there isn’t, and the question is moot.
Raven // August 9, 2008 at 12:03 am
Ray Ladbury says
“First, you have a really limited view of science if you limit it to only what can be done on a lab bench. The tremendous success of geophysics, astrophysics, ecology, and paleontology demonstrate the falsity of this contention. Second, nature provides experiments all the time–volcanic eruptions, even seasonal and daily variation.”
The reliability of a model is directly linked to amount of validation that is possible. Models that can be tested in the lab are extremely reliable. Models that can only be tested against one set of historical of data can never hope to achieve the same level of reliability. That is why it is extremely deceptive to compare engineering models to climate models. You should also note that I did not say climate models are useless – I only said that any policy decision must take into account the not-insignificant probability that the models are completely wrong.
I have looked into the Pinatubo prediction and I have not found anything that shows it was a prediction rather than hindcast. More importantly, I have not found anything that shows that the distribution of the models was narrow enough to demonstrate they had useful predictive skill. For example, Figure 9.5 in AR4 shows the range of the model ensembles during the eruption. It appears the range covered any response from no cooling at all to a cooling of 0.6 degC. IOW, all plausible cooling responses to the volcano would have been consistent with models. I don’t consider that to be evidence of useful predictive skill.
Hank Roberts // August 9, 2008 at 12:08 am
> Associated Press
Not a science journal (grin). Checking ….
http://www.google.com/search?num=50&q=%22Associated+Press%22+%2B%22next+ice+age%22%2B2008&btnG=Search&aq=f
They’ll quote anybody. Remember, they supply the news — what’s used to fill in the unsold space on each newspaper page after all the advertising’s been laid out. Not reliable, and not a source. Useful as a hint where to look.
If you can pick out the story or find what you’re recalling, check for the name of the scientist, the name of the journal, and the date, and put that into Google Scholar and see what comes up.
I’d bet on Chylek, or William Gray.
Hank Roberts // August 9, 2008 at 12:38 am
> I have not found anything [Raven]
How are you looking? You’re surrounded by information. You can read the original 1988 scenario for yourself and see it includes vulcanism. You can hardly pretend it was written after a comparable volcano erupted. It need not be exactly the same volcano.
Tell us what you’re looking at and we may be able to determine where the blind spot is.
http://www.giss.nasa.gov/research/briefs/hansen_02/
http://scholar.google.com/scholar?num=50&hl=en&lr=&newwindow=1&safe=off&cites=18353513518808259857
There’s also earlier work
http://www.sciencemag.org/cgi/content/abstract/199/4333/1065
David B. Benson // August 9, 2008 at 12:42 am
Rainman // August 8, 2008 at 9:44 pm — Yes, it wasn’t until looking at the Vostok ice core confirmed that the interglacial at MIS 11 (400 kybp) was much longer that the subsequent three completed interglacials that climatologists were in a position to thoroughly understand the effects of orbital forcing.
While there are still some aspects which require further study, we can be quite sure that the earth is in for a Long Thaw. That’s even without adding AGW effects.
cce // August 9, 2008 at 1:08 am
Hank linked the article but this prediction was made just after Pinatubo erupted:
http://www.giss.nasa.gov/research/briefs/hansen_02/figure2.GIF
Rainman // August 9, 2008 at 1:14 am
Hank: I believe it was Chelyk. The story was pulled fairly quickly once the bloggers got a hold of it, but it was there.
Your statement about the AP is part of my exhaustion. The media is saturating the channel such that those in the general populace who had some skepticism to begin with are actively looking for reasons to dismiss the deluge.
I’m still on the fence, but believe there are a lot of tasks we can undertake to make a better future that would have positive impacts with regard to AGW.
Raven // August 9, 2008 at 1:17 am
Hank Roberts says:
“Tell us what you’re looking at and we may be able to determine where the blind spot is.”
I was looking at AR4 Chp 9 and some papers by Soden et. al. written in the 2000.
Your link does confirm that there was a prediction with a “primitive model” so I won’t claim it was a hindcast again. However, if the primitive model was representative of GCMs they would not need GCMs. IOW, I don’t see how a successful prediction with a primitive model validates the GCMs.
More importantly, your link does not address problem with huge range (see AR4 Chp 9) for the ensemble of models. A huge range may allow modellers to claim that virtually any outcome is “consistent with” then models. However, a huge range also means the models do have much useful predictive skill.
Raven // August 9, 2008 at 1:18 am
However, a huge range also means the models do NOT have much useful predictive skill.
Hank Roberts // August 9, 2008 at 2:39 am
Raven, that’s not what the AR4 Ch. 9 says at all. Bogus to claim a source that’s not real.
Do you actually have any source for that belief? Your own original? based on something?
Look up what the climatologists say about it:
http://www.google.com/search?q=ipcc+ar4+chapter+9+%2Bstoat+%2Bannan
Look up the actual document you claim to be reading:
IPCC Fourth Assessment Report: Working Group I Report, Chapter 9 Understanding and Attributing Climate Change …
http://www.ipcc.ch/ipccreports/ar4-wg1.htm
____from P. 727_____
“The lower bound is consistent with the view that the sum of all atmospheric feedbacks affecting climate sensitivity is positive. Although upper limits can be obtained by combining multiple lines of evidence, remaining uncertainties that are not accounted for in individual estimates (such as structural model uncertainties) and possible dependencies between individual lines of evidence make the upper 95% limit of ECS uncertain at present. Nevertheless, constraints from observed climate change support the overall assessment that the ECS is likely to lie between 2°C and 4.5°C with a most likely value of approximately 3°C …”
Raven // August 9, 2008 at 4:37 am
Hank,
http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch09.pdf
Look at Figure 9.5. Look at the response after Pinatubo. You will see that according to the models cooling from Pinatubo ranged from 0 to 0.6 degC. The actual cooling was around 0.2 degC. IOW, it is impossible for the models to be wrong because all plausible cooling events would fall inside the huge range of the model ensemble. Anyone with a pen and chart of El Chichon could have made the same prediction. I don’t see why you can say the Pinatubo provides evidence of the reliability of the models.
Lazar // August 9, 2008 at 9:17 am
Raven,
Glorianna.
The model used in the 1988 prediction, GISS model II, is a GCM.
Ray Ladbury // August 9, 2008 at 12:11 pm
Raven, Good lord, where are you getting this stuff? Do you just make it up? The fact that not all models agreed or nailed the effects of Pinatubo does not indicate that ALL models are not skillful. It indicates that some are more skillful than others. To contend that there is a significant probability that the models are “wrong,” is simply not supportable.
Look, there are 2 courses–we can either do nothing or we can take appropriate action based on the best models we have. Given that the chances of very serious consequences are a virtual certainty, I would contend that arguing for complacency as you are doing is simply not tenable.
Gerda // August 9, 2008 at 1:59 pm
Hank Roberts // August 6, 2008 at 11:17 pm
thanks for the links to ruddiman’s ‘early anthropocene’ hypothesis.
now i have some research to point people to when they boggle at the idea that removing millions of square kilometres of woodland (neolithic onwards and that’s just europe) could affect the climate - dur….
blue // August 9, 2008 at 4:11 pm
Rainman,
does this come close to what you remember:
http://environment.newscientist.com/article/mg19726465.600-earthquake-activity-is-frozen-by-ice-sheets.html
According to the research ice-sheets seem to suppress many types of faults from slipping, but not the stresses from building up. When the ice-sheet goes, quakes come back “with a vengeance”, so to speak. It’s a “short” step from “melting ice” to “more and worse quakes”. I don’t know, whether or not the findings will hold up and how large the “vengeance factor” is. I don’t really worry about it right now.
Hank Roberts // August 9, 2008 at 4:26 pm
Raven:
“I don’t see”
“I don’t find”
Try asking an intelligent question about the math — perhaps ask about the black line inside the colored range on both the upper and the lower chart on that page, and the black line outside the colored range on the lower chart.
Read and think. If you’re here to learn, get past simply proclaiming your innocent incomprehension over and over and over.
Raven // August 9, 2008 at 5:50 pm
Ray Ladbury says:
“The fact that not all models agreed or nailed the effects of Pinatubo does not indicate that ALL models are not skillful. It indicates that some are more skillful than others. ”
I am simply following the process that RealClimate uses whenever they need to explain why less than expected tropospheric warming or a 8 year flat trend is not significant. Gavin has repeatedly insisted that the entire ensemble needs to be considered and before claiming that temperature observations are inconsistent with the models.
I am happy to hear that you think that only the skillful models should be considered be evaluating models. If that is the case I curious to compare the models that were skillful with the Pinatabo eruption fare when compared to the tropospheric trends and the recent series of flat temperatures.
I am also curious why this has not been done already because eliminating the models that were not skillful during the Pinatabo eruption would likely help policy makers by reducing the future distribution possible temperature rises. (I am being facietious here because I know that no individual model is skillful all of the time and the claim is the ‘ensemble’ is more reliable - of course this logic also means that you can’t claim the ensemble was skillful when it comes to the Pinatobu eruption).
In any case, I have never said we do nothing. I have simply said that we cannot adopt policies that will likely have extremely adverse economic consequences based on the output of computer models that have never demonstrated any consistent skill when it comes to predicting temperature trends. That does not mean we do nothing. There is a wide range of policy options that will reduce GHGs but still allow us to hedge our bets in the event that the models are wrong and the CO2 threat has been exaggerated.
Raven // August 9, 2008 at 6:21 pm
Hank Roberts says
“Try asking an intelligent question about the math — perhaps ask about the black line inside the colored range on both the upper and the lower chart on that page, and the black line outside the colored range on the lower chart. ”
The answer is easy. If the assumptions built into the models are correct then the warming can only be explained by GHGs. However, the question under consideration is whether those assumptions are actually correct. The only way to determine that is to use the models to predict the future and compare the results. If the model predictions don’t match reality then we have reason to question whether the assumptions built into the models are correct.
[Response: Perhaps the reason you're so skeptical is that your information about model-data comparisons comes from propaganda rather than scientific research. Read this.]
Ray Ladbury // August 9, 2008 at 9:26 pm
Raven says: “I have simply said that we cannot adopt policies that will likely have extremely adverse economic consequences based on the output of computer models that have never demonstrated any consistent skill when it comes to predicting temperature trends.”
This is horsecrap! You make investments based on the best estimates of the risks. You hedge your bets based on the uncertainties. You certainly wouldn’t make it as a hedge fund manager with your attitude. In this case, the probabilities suggest that if the models are wrong, they are wrong in predicting too little warming rather than too much.
You claim not to be advocating complacency. So what specific actions DO YOU think should be taken?
David B. Benson // August 9, 2008 at 10:40 pm
Especially in light of what
Diminished ocean organisms as acidity increases:
Hall-Spencer, J. M. et al. Nature advance online publication doi:10.1038/nature07051 (2008).
http://www.sciencemag.org/cgi/reprint/sci;314/5799/595c .pdf?ck=nck
http://www.bioedonline.org/picks/news.cfm?art=3235
http://www.ethlife.ethz.ch/archive_articles/080613-ozea nansauerung/index_EN
http://www.nature.com/news/2008/080606/full/news.2008.8 77.html
http://news.bbc.co.uk/2/hi/science/nature/7437862.stm
portends.
Raven // August 9, 2008 at 10:51 pm
Ray Ladbury says:
“You make investments based on the best estimates of the risks.”
Estimating of the risks based on what? The distributions of unvalidated model outputs? Apparently the using those calculations would give a 1% chance of a 20 degC rise which is absolute horse crap if one looks at the historical variability of the climate system (i.e. there is no evidence that the GMST was ever more than 34 degC which means there is vanishingly small chance that it will happen no matter what we do) .
You keep saying that the models likely underestimate the warming yet the most recent data suggests the exact opposite. More importantly, if the models are wrong it is most likely because they underestimated the influence of other plausible mechanisms that could cause warming such as land use changes, aerosols, the sun, the oceans or the clouds. Errors the understanding of any of these phenomena would result in lower CO2 sensitivity which means less warming.
Actions that should be take regardless of the reliability of the models:
- fast track construction of nuclear power plants.
- increase energy efficiency standards
- fund large scale projects to produce energy from solar, wind or geothermal and demostrate their viability
- develop of industry specific targets for reducing Co2 output that are technically and economically achievable.
- fund R&D into alternative energy sources.
- fund public transit initiatives.
Things which are not justified:
- arbitrary schemes which don’t take into account that CO2 emissions in many cases is unavoidable (i.e. no carbon taxes).
- schemes which are extremely vulnerable to fraud, manipulation and pork barreling (i.e. no cap and trade).
- putting the energy supply at risk by blocking the development of coal based sources before alternatives have been proven.
- binding international agreements which would be difficult to get rid of if CO2 turns out to be a non-issue.
[Response: The models have been validated, vastly more than you believe. Did you bother to read the link I gave you?
And: the bleak future which looms as a result of man-made greenhouse gases doesn't depend on the models; saying they do is a propaganda trick. Computer models are our best tool for estimating climate sensitivity, but there are *many* lines of evidence indicating it's dangerously high which have absolutely nothing to do with computer models.
You sound a lot like a smoker who's been told of the risk, but keeps inventing rationalizations to refuse to quit smoking.]
Hank Roberts // August 10, 2008 at 1:12 am
> like a smoker
More like a royal libertarian, q.v.
Could the political position-pounding be given a thread of its own somewhere, to free up the site for discussing climate science and statistics?
It’d be courteous for those who want to learn something not to keep taking over the threads to insist there’s nothing to learn.
[Response: Done.]
tamino // August 10, 2008 at 1:23 am
There’s a new open thread (#5); further discussion of things not related to this post should be taken there.
Barton Paul Levenson // August 10, 2008 at 5:49 pm
Raven writes:
Raven, when a scientist talks about a trend being significant, he doesn’t mean he thinks it’s important. “Significant” has a mathematical meaning. It can be measured with a probability figure. For a trend to mean something you’re usually looking for p (of error) < 0.05, or “significance at the 95% level.” Eight years of temperature anomalies do not yield a significant trend. This isn’t something that can be argued about — do the math yourself. If you don’t know how to do a linear regression, Excel can do it for you. Just regress a column of temperature anomalies on one of the corresponding years. And pay attention to the figure for p.
[Response: Unfortunately, Excel won't compensate for autocorrelation, so it'll get the slope of the regression line right but the p value will be too low (the trend estimate is much more uncertain than Excel says).]
Hank Roberts // August 13, 2008 at 6:41 pm
http://calculatedrisk.blogspot.com/2008/08/us-miles-driven-declines-47-from-june.html
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