This month’s open thread – for appetizers we have: William Nordhaus’s extremely impressive debunking in the NY Review of Books of the WSJ 16 letter and public polling on the issue of climate change. Over to you…
Climate science from climate scientists...
Thanks Jim, error admitted. I still think climate science is uniquely difficult because it has to incorporate both theory and reality in an incredibly complex and critical discipline, but “reductionism” was the wrong tag and certainly I didn’t know nearly enough about what I was talking about!
http://en.wikipedia.org/wiki/Reductionism
511 Ray says, “Dan H.,
A cyclic behavior requires a cyclic forcing. You certainly haven’t proposed any such mechanism–or any mechanism whatsoever that I can see.”
The AMO is often suggested. Here’s a site dealing with the 60 year cycle question. It’s the #1 result for “60 year climate cycle”.
540 GSW said, “Is it valid to take a few weeks of anomalous temperatures in a region as confirmation, either way, of the ‘signal’ of an anthrogenically warmed planet?”
I wonder the same. According to GISS, January and February were relatively cool globally. That the USA happened to be warm seems like a demonstration of variance in distribution, if anything. Are these events – European heatwave, Moscow warming hole, and spring-replaces-US-winter, measures of anything “changing” at all? Can we just ignore them and work with global temperatures, or are there actually larger deviations from the norm at the regional level in a warming world?
Jim Larsen,
Unfortunately the math doesn’t work out. See
http://tamino.wordpress.com/2011/01/30/amo/#comment-47729
http://tamino.wordpress.com/2011/03/02/8000-years-of-amo/
http://tamino.wordpress.com/2011/10/24/decadal-variations-and-amo-part-i/
among others
A response to what Michael A. Lewis, PhD says in a new topic at
23 Mar 2012 at 7:07 PM
(Responding with a pointer to here to avoid disrupting the topic there; I should’ve done that right away, my bad for saying anything there in reply.
He writes there:
> I hope this is not a site promoting the idea that only
> human activity influences climate change.
Not at all.
Beware that strawman — you’ll find it at denier sites, and people do show up here who’ve been fooled into thinking that. It’s a “let’s you and them fight” trick tried to set people who care about multiple ecology issues against each other.
It won’t work on you if you read what’s actually here; the basics (the “Start Here” link at the top is helpful) explain much.
On specific details — there are lots of misconceptions people bring. Usually they just distract from a new topic if someone won’t read the basics and persists in asking the same questions we longtime readers (and the real scientists too) have answered over and over.
I did try to get an idea of what you believe following links from the home page you posted behind your name; this seems to find a lot of misunderstandings:
https://duckduckgo.com/?q=site%3Ahayduke2000.blogspot.com+%22climate+change%22
(Hayduke’s been one of my fictional heros, along with the real ones like Abbey, Sigurd Olsen, and many other writers so I followed those up)
Take just one misunderstanding from your blog — we know the increase in CO2 is from fossil fuel use; that’s been known for decades, and Spencer Weart among others explains it well in his book; the link’s in the right sidebar.
A search finds it equally well:
https://duckduckgo.com/?q=%22spencer+weart%22+fossil+carbon+CO2+isotope
RESULT:
The Carbon Dioxide Greenhouse Effect – The American Institute …History of research on how CO2 affects climate … oil is so old that it entirely lacks the radioactive isotope. Therefore emissions from burning fossil fuels would add only plain carbon … copyright © 2003-2011 Spencer Weart & American Institute of Physics
aip.org/history/climate/co2.htm 
Simon Abingdon quotes the IPCC out of context (Quel surprise!). The rest of the quote is:
“Rather the focus must be upon the prediction of the probability distribution of the system�s future possible states by the generation of ensembles of model solutions. Addressing adequately the statistical nature of climate is computationally intensive and requires the application of new methods of model diagnosis, but such statistical information is essential.”
Note that while Simon throws up his hands, the real scientists roll up their sleeves and get to work on a difficult problem. Note also, that what the sceintists are calling for is prediction based on understanding the system, not a simple “prediction” by a single model.
Simon, Susan embodies the spirit of the scientific enterprise much more fully than timid cowards like you.
Here is a graph relevant to DanH’s cycle plus trend discussion. Random noise (weather), run through a low pass filter (ocean thermodynamics?), plus a trend(CAGW-20,000 excess deaths from European/Russian heatwaves alone), matches observations.
When you’re a hammer, everything looks like a nail; when you’re a Fourier transform, everything looks like a cycle; when you’re too reductionist, the answer to everything is 42.
Readers of and contributors to posts on Skeptical Science should be aware that the site was hacked a little while ago.
Anyone with an account there would be well-advised to log on and change their details as quickly as possible.
551: Jim Larson wrote: “Can we just ignore them and work with global temperatures, or are there actually larger deviations from the norm at the regional level in a warming world?”
What do you mean “work with?” Do you mean: ignore the variations in temperature and then argue that a 3C increase in temperature is no big deal ?
The obvious answer is of course there are variations that are larger than the change in the mean. The mean temperature during the last glacial maximum was something like 7C colder: 5C colder in the tropics and as much as 23C colder in Greenland. http://web.me.com/uriarte/Earths_Climate/9._The_Last_Glacial_Maximum.html
https://www.ipcc.unibe.ch/publications/wg1-ar4/faq/wg1_faq-11.1.html
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch11.html
I’ve scanned some of Michael A. Lewis’s articles that he wrote and co-wrote with Anthony Watts
http://wattsupwiththat.com/author/hayduke/
Mostly argument from naiveté and ignorance. It seems he really has not looked at the wealth of evidence and there is a good possibility, based on the manner and substance of his writing on the subject, that he has been getting most of his info form denialist sites rather than directly from the science itself.
Here’s a nice summary of the weather anomaly from the recent heat wave:
http://www.climatecentral.org/blogs/more-records-broken-as-rare-march-heat-wave-continues/
I see one obvious criticism: the heat wave was moving, so integrating over a week is going to understate its effect at the margins. For example, here in Montreal we got the heat wave just like everyone, but on the map we show up average because it warmed up on March 14, meaning there’s only one or two days included in the picture. How could we plot it better?
The other question: this is using land surface temps. Much of the continent was snowed in at the start of the heat wave. I’m having trouble figuring out which way to expect this to affect the anomalies.
And then there’s the thing about using the warmest decade on record as the baseline, but that’s not a huge effect compared to the magnitude of the anomalies.
[Response: The 7 or 10 day average is what it is. You need to use a different time window if you want to capture a particular area. The bigger issue that a lot of these analyses seem to be overlooking is that this heat wave is a culminating event after an exceptionally mild winter across much of the affected area. I want to see the anomalies for the entire winter in this area. And a large part of that area was definitely not snow covered when this thing hit. It has accordingly had a very large impact on soil temperature and hence, productivity. The entire phenological timeline appears to be set forward by 4 to 6 weeks. It’s truly phenomenal.–Jim]
Skeptical Science hack is causing me some grief. This isn’t my login handle there, since I don’t want to draw attention to my account, but the login name I used leads to other accounts, and the general password I used there can open a couple of other non-critical accounts. Unfortunately, some of these accounts contain a lot of personal information. I have been going through my accounts and changing login information.
John Cook says that the passwords were encrypted, but given enough time, the passwords could be broken.
#554 Ray Ladbury. As a commander of jet transports with over 14000 hours in his logbook, landing a Boeing 767 with 300 trusting passengers on board at night with a gusting crosswind in heavy rain and poor visibility on a short wet runway with no ILS and a raging approaching thunderstorm in close proximity was for me sometimes a daunting reality. Though it was just a job, it did need unflinching concentration. During my career it’s probable that I have been personally responsible for the lives of over half a million passengers. To the best of my knowledge nobody ever suggested the description “timid coward” until now. But perhaps you’re right Ray. I was never faced with a situation that really frightened me.
I’m not convinced a global time window works: I suspect you really want an adaptive time window per point in the plot, otherwise you pick up the background to a different extent depending on location — but then there’s the question of how to pick out the proper time windows. I assume some field has properly analyzed this question somewhere.
I’m also interested in knowing how to reason about the effect of snow cover on temperature anomalies, just for its own sake.
As you say, it’s academic compared to the remarkable winter we’ve had. But I’m an academic by training, it’s how I roll!
(PS: another phenological point — mass protest season is much earlier than usual this year.)
557 John asked, “What do you mean “work with?” Do you mean: ignore the variations in temperature and then argue that a 3C increase in temperature is no big deal ?”
No. I’ll try again: We had a regional extreme during a globally cooler season. Is this a marker of a warmer world? I’ve read that night to day and equator to pole variations will diminish, but are there are more temperature extremes in a warmer world (to go with the precipitation extremes)?
“As I look at my nation, I am generally impressed by the physical courage of its citizenry but distressed by the lack of intellectual or moral courage. I think this is important because most quotes about bravery refer to physical courage. Yet if my nation is to go down the tubes, I suspect it will be more because of a deficit in its intellectual bravery.”
~ M. Scott Peck
“It is curious that physical courage should be so common in the world and moral courage so rare.”
Mark Twain
#561 simon abingdon
Then why are you apparently too afraid, timid, or cowardly, to post your real name?
Why are you afraid to admit the real potential for serious economic consequences from human induced global warming?
I highly suggest you read my book Exposing The Climate Hoax: It’s All About The Economy.
And don’t be afraid of what the evidence indicates. You’re a pilot, and so am I though hardly with as many hours. Pilots have excellent training in methodology and handling emergencies without fear, but rather process and checklists. There is no room for fear in a cockpit when split second decisions determine the outcome.
Use your pragmatism wisely and just as in the cockpit, look at all the potential scenarios regarding what kind of landing we are in for based on our decisions as a global community.
Brian,
Have you tried plotting the temperature against a sine wave with a 60-yr period? That might give a better representation of 6 x 7 than the one you presented.
Any comments on this article?
http://www.sciencedirect.com/science/article/pii/S0012821X12000659
It’s a paper on the temperature record in Antartica showing a MWP.
I expect it to explode pretty soon in the denial sphere.
#561–I’m glad you have that history behind you, Simon. It must be gratifying when faced with life’s petty frustrations. And I’m grateful (as someone who has traveled by air a few times) that the pilots who held my life in their hands were (I presume) just as professional and skilled as you.
And I’m also glad that no-one called you a liar merely because you were an airline pilot; that no-one sent you death threats (I presume) because you were an airline pilot; that no-one subpoenaed your e-mails because you were an airline pilot; that no-one claimed that you as a pilot were attempting to tear down our culture and civilization at the behest of a shadowy cabal with incomprehensible (but evil) motives.
I’m looking forward to a time when I can say the same about our hosts at this site. After all, our lives may well be in their hands, too, albeit less immediately and directly so.
Who else is going to help us chart a reasonable course into the future?
I, too, am glad to hear Simon’s an experienced airline pilot.
As a professional airline pilot, I wonder how he’d react if a climate scientist without so much as a private pilot’s license were to barge into the cockpit during a landing approach and shove Simon aside proclaiming “I know more about flying than you, I’m going to land this airplane with its 300 passengers!”?
Given his willingness to proclaim expertise in climate science I’m sure he’d get up and walk back into the passenger cabin, eh?
Sorry OT but important! Heads up from Open Mind, Tamino’s site! The Skeptical Science website was hacked. If you post there you might want to give this some immediate attention! http://www.skepticalscience.com/Skeptical-Science-hacked-private-user-details-publicly-posted-online.html for details….
[moved]
Following up on my response above to Michael Lewis: I am quite fond of E.O. Wilson’s perspective; I grew up in the rural South long, long ago — not quite as long ago nor quite as far south as he did. And I understand what it’s like to try to talk about ecology and saving biodiversity to people whose favored aim in life is across the barrel of a hunting rifle or shotgun and only become active in protecting nature once they understand that they as a group can affect it. For those who only are used to thinking of their own individual impact, even seeing themselves as part of a group is a stretch at first. Being an individual feels like freedom; being part of a group feels — different to different people.
But our individual impacts add up. We might as well learn to add.
As I said earlier, one of the favorite tactics of the exploiters is “let’s you and them fight” — setting up one environmentally aware group against the others, by making up strawman arguments, pretending to be them, and encouraging people to believe their enemies are their friends and vice versa.
“Just because you’re on their side doesn’t mean they’re on your side” — as the host of Making Light wrote years ago.
“… the war between environmentalists and exploiters, local and national, is far from over…. During the past forty years the United States has come to understand that it is a major player in the deterioration of the global environment.” http://www.pbs.org/moyers/journal/blog/2007/09/eo_wilson_on_rachel_carson_1.html
http://www.pbs.org/moyers/journal/blog/2007/07/what_can_i_do.html
I don’t agree wholeheartedly with many people, if any. But I’m determined to find where agreement can exist about leaving life on the planet in better shape than we’re doing right now.
Y’all come.
One more essay at inclusion, and I’ll sit back and listen a while.
From “The Mad Farmer Liberation Front” by Wendell Berry
Love the quick profit, the annual raise,
vacation with pay. Want more
of everything ready-made. Be afraid
to know your neighbors and to die.
And you will have a window in your head.
Not even your future will be a mystery
any more. Your mind will be punched in a card
and shut away in a little drawer.
When they want you to buy something
they will call you. When they want you
to die for profit they will let you know.
So, friends, every day do something
that won’t compute. Love the Lord.
Love the world. Work for nothing.
Take all that you have and be poor.
Love someone who does not deserve it. …
and
Phil Plait: “THIS is why we invest in science. This.“
“… The standard line extinguished a set fire in a living room in 1 minute and 45 seconds using 220 gallons of water. The [new] system extinguished an identical fire in 17.3 seconds using 13.6 gallons — with a hose requiring only one person to manage….”
and
“I think the key to understanding why advanced social behavior has been so rare, even though it’s highly successful when it happens, is that going from that first step over the threshold is difficult. It has to go through a period in which group selection is powerful enough to overcome this residual, individual level of selection, which is the main form of selection that’s been going on for countless numbers of generations before. Within groups, selfish individuals win and between groups, altruistic groups beat groups of selfish individuals.”
E.O. Wilson … on Human Nature
Here’s something going around the denialsphere — climate sensitivity is much lower than previous thought…
Most abstracts below have their lower sensitivity, except the Aldrin on, so I’ve included the Knappenberger direct quote from the paper:
“Lower Climate Sensitivity Estimates: New Good News”
by Chip Knappenberger, March 19, 2012
http://www.masterresource.org/2012/03/lower-climate-sensitivity-estimates/
Aldrin, M., et al., 2012. Bayesian estimation of climate sensitivity based on a simple climate model fitted to observations oh hemispheric temperature and global ocean heat content. Environmetrics http://onlinelibrary.wiley.com/doi/10.1002/env.2140/abstract;jsessionid=38E88DBEDFC0F5214703FE5877A722A3.d03t03?systemMessage=Wiley+Online+Library+will+be+disrupted+17+March+from+10-14+GMT+%2806-10+EDT%29+for+essential+maintenance&userIsAuthenticated=false&deniedAccessCustomisedMessage=
[from the Knappenberger piece: “The [climate sensitivity] mean is 2.0°C… which is lower than the IPCC estimate from the IPCC Fourth Assessment Report (IPCC, 2007), but this estimate increases if an extra forcing component is added, see the following text. The 95% credible interval (CI) ranges from 1.1°C to 4.3°C, whereas the 90% CI ranges from 1.2°C to 3.5°C.”]
Gillett, N.P., et al., 2012. Improved constraints on 21st-century warming derived using 160 years of temperature observations. Geophysical Research Letters, 39, L01704, doi:10.1029/2011GL050226.
http://www.agu.org/pubs/crossref/2012/2011GL050226.shtml
Olson, R., et al., 2012. A climate sensitivity estimate using Bayesian fusion of instrumental observations and an Earth System model. Journal of Climate, 24, 5521-5537, doi:10.1175/2011JCL13989.1.
http://www.agu.org/pubs/crossref/2012/2011JD016620.shtml
Padilla, L. E., G. K. Vallis, and C. W. Rowley, 2011. Probabilistic estimates of transient climate sensitivity subject to uncertainty in forcing and natural variability. http://journals.ametsoc.org/doi/abs/10.1175/2011JCLI3989.1
Schmittner, A., et al., 2011. Climate sensitivity estimated from temperature reconstructions of the Last Glacial Maximum, Science 9 December 2011:Vol. 334 no. 6061 pp. 1385-1388, DOI: 10.1126/science.1203513 http://www.sciencemag.org/content/334/6061/1385.abstract
New paper:
Rowlands, D.J. et al. (2012) Broad range of 2050 warming from an observationally constrained large climate model ensemble. Nature Geoscience, advance online.
http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo1430.html
Lynn:
Actually Olson et al’s abstract states “Our results are consistent with most previous studies” and “The mode of the climate sensitivity estimate is 2.8°C, with the corresponding 95% credible interval ranging from 1.8 to 4.9°C” (which supports the first quote). So, I’m not sure why that paper would make their list. Except for the fact that the lukewarmer tactic has been to suggest they believe that sensitivity lies “just a bit under 3C” (Tom Fuller some time back accepted 2.5 < CS < 3.0 IIRC), implying that the mainstream "CAGW" position is for much higher sensitivity. They can then argue against that strawman without looking entirely ridiculous regarding the science.
In case people missed it, SteveF’s post serves (intentionally or not) as a response to Lynn’s post. Here’s the crucial line from the abstract cited:
“We find that model versions that reproduce observed surface temperature changes over the past 50 years show global-mean temperature increases of 1.4–3 K by 2050, relative to 1961–1990, under a mid-range forcing scenario.”
That’s up to 3 C within a mere 38 years under a MID-range scenario.
“Julian Hunt, emeritus professor of climate modelling at University College London…said the higher range of the prediction was looking “increasingly likely”, but for three particular reasons:
* release of methane, a powerful greenhouse gas, from seabed and land
* “massive changes” in reflection of light at some places on the Earth’s surface
* reducing air pollution in Asia that will reflect less solar energy back into space.”
http://www.bbc.co.uk/news/science-environment-17488450
Meanwhile, Trenberth has this to say on extreme weather events and GW:
http://thinkprogress.org/romm/2012/03/25/451347/must-read-trenberth-how-to-relate-climate-extremes-to-climate-change/
“The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question. All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be”
RE #573, And here is how I responded, but what do I know, so if you have better responses, let me know ((Excuse my hypens in weird places, I have some spam word)):
I’d love to know for sure that there is absolutely nothing to be concerned about re AGW (for the sake of all those who would be harmed or dying from it), and I sincerely hope these low sensitivity claims stand the scrutiny of further science.
However, I’d still continue to mitigate AGW, since there would still be some level (somewhat higher) at which dangerous warming could occur. Plus everything I’m doing has some other p-ay-offs, fin-anc-ial and/or mitigating other problems and/or living a life of material sim-plic-ity. Hope for the best…..but expect the worst & strive to prevent it, is my motto.
Here’s my take on these articles (which are only individual studies, open to further scru-tiny):
The Aldrin abstract doesn’t give their sensitivity, but using the Knappenberger piece:
Even if this does pan out (and I’d love for even a lower sensitivity to pan out), 2C still puts us in trouble, considering the very high levels of GHGs we are emitting. As the Padilla abstract suggests, it would only raise the ppmv level at which we would expect dangerous warming….giving us a bit more time to turn this big Titan-ic ship around. And it says nothing about the equi-lib-rium warming.
The Gillet article gives 1.3–1.8°C for data going back to 1850, but since proxies are in question (as you are so want to point out), so is his data.
Olson article – their mode is 2.8, very close to the 3 suggested by other scientists, and when you consider the long tail in the positive direction, the mean would probably be a bit larger, maybe 3 or more.
The Padilla article states (with important caveat in caps): 90% confidence the response will fall between 1.3 and 2.6 K, and it is estimated that this interval may be 45% smaller by the year 2030. The authors calculate that emissions levels equivalent to forcing of less than 475 ppmv CO2 concentration are needed to ensure that the transient temperature response will not exceed 2 K with 95% confidence. THIS IS AN ASSESSMENT FOR THE SHORT-TO-MEDIUM TERM AND NOT A RECOMMENDATION FOR LONG-TERM STABILIZATION FORCING; THE EQUI-LIBR-IUM TEMPERATURE RESPONSE TO THIS LEVEL OF CO2 MAY BE MUCH GREATER.
The Schmittner abstract has the median at 2.3….which again with the long positive tail could mean a mean of something higher….maybe even 2.6 (the upper end of the Padilla claim, and he suggested 475 ppmv CO2 would be the tipping point into danger, I suppose for his mean or median, which should be lower than 2.3).
SOME IMPORTANT CONSIDERATIONS:
– 475 ppmv CO2 is also something to be concerned about, only a bit less concerned about than the 350 ppmv that has been suggested by some scientists. And note that the earlier claims (I believe also in the IPCC) were that 450 ppmv was the tipping point into danger, so 475 ppmv is not that far off from earlier claims.
– The main issue is that our actual GHG emissions have pretty much exceeded or are in the “worse-case” scenarios projected in the past. That is the other factor we need to be concerned about, not just sensitivity.
– It is the equi-lib-rium temp response that’s most important – which (I guess Padilla means) would include carbon feedbacks from the warming, such as from melting hydrates and permafrost, or perhaps the lag time for the climate to adjust to all the GHGs in the atmosphere. In this regard Ramanathan & Feng’s article suggest that we already have a 2.4 warming in the pipes just from existing GHGs in the atmosphere, even if we were to go to zero emissions tomorrow (see http://www.pnas.org/content/105/38/14245.full )
Good points, Lynn. At current rate of increase of atmospheric CO2 of about 3ppm/year, that would only be pushing the supposed tipping point out about 8 years.
On the topic of the Trenberth article just cited, this passage jumped out at me:
“in the United States, extremes of high temperatures have been occurring at a rate of twice those of cold extremes (Meehl et al. 2009), and this has accelerated considerably since June 2010 to a factor of 2.7, and in the summer of 2011 to a factor of over 8″
So we’ve gone from 2 to 2.7 to 8 in just three years. This lead to me to wonder what the next number in that sequence might be. Knowing that hank would (rightfully) chide me if I just asked the question here without doing some searching first myself, I found this:
“For the year-to-date, there have been 14,737 warm temperature records set or tied, compared to 1,296 cold records — a ratio of about 11-to-1.”
http://www.climatecentral.org/blogs/heat-wave-sends-temps-soaring-into-uncharted-territory/
I’m expecting that this number will go up further this year, though I hope I am wrong here.
In any case, these stats certainly suggest a climate situation rapidly spinning completely out of whack.
Thoughts?
The passage that particularly struck me was:
“in the United States, extremes of high temperatures have been occurring at a rate of twice those of cold extremes (Meehl et al. 2009), and this has accelerated considerably since June 2010 to a factor of 2.7, and in the summer of 2011 to a factor of over 8″
So from 2 to 2.7 to 8 in just the last few years! What is the next number in this sequence?
Answer (so far this year):
“For the year-to-date, there have been 14,737 warm temperature records set or tied, compared to 1,296 cold records — a ratio of about 11-to-1.”
http://www.climatecentral.org/blogs/heat-wave-sends-temps-soaring-into-uncharted-territory/
I can’t help but get the sense from these numbers that things are spinning out of whack even faster than even I anticipated.
So, another way to deal with troublesome data: stop collecting?
http://www.nunatsiaqonline.ca/stories/article/65674canadas_pearl_of_arctic_research_hit_with_funding_freeze/
@ 578 wili
The bit that caught my eye:
““In fact, the jet stream has been displaced well north of its typical position since the middle of last year,” the NWS stated.”
IIRC, that’s akin to the precursor to the Great Dust Bowl.
Lynn Vincentnathan @573 & @577
Knappenberger reads a bit like desperate propaganda to me.
Do be mindful that the references he makes present two different forms of sensitivity – equilibrium sensitivity & transcient sensitivity or transcient cllmate response (TCR). TCR is a smaller value. The tiny IPCC graph (on page linked below) would convert Gillett et al’s 1.3-1.8 TCR into something like 2.0-3.0 equilibrium.& Padilla’s 1.3-2.6 into 2.0-5.0 equilibrium. These are hardily what you’d call low figures.
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-5-2.html
Of the rest, Schmitter et al was being praised by deniers a few months back for chopping of the “fat tail” from sensitivity estimates. It was not greatly ‘low’ other than that. Chopping the long fat tail is an exercise Knappenberger tries to join in on but gives no supporting evidence for it.
Olson is not lower than the IPCC. That leaves Aldrin et al giving 1.1-4.3. The lower end of the range may be low but note the quote via Knappenberger “..but this estimate increases if an extra forcing component is added, see following text.” The ‘following text’ would perhaps be worth reading before judgement is made. Knappenberger presumably did but says squat.
As I said ‘desperate propaganda.’
Get a headvise. If you thought the usual Daily Mail was bad, check out the scan of the Scottish Daily Mail’s “reality check” on Education Scotland’s rundown of global warming.
***!!! PUT YOUR COFFEE DOWN FIRST !!!*** You have been warned.
Scottish Daily Mail, 24 March 2012… ‘Myth and Reality of Climate Changes’
Must have been written by one of the usual UK Delusionals. Not even wrong. My eyes are bleeding from the rubbing.
H/T to Leo Hickman.
Could someone who knows, please recommend the best climate science or policy textbooks in comments here at Less Wrong (link)?
Anna, see here
RE #77 & “The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question. All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be”
I’ve been saying that for a long time, but sort of in a reverse-science way, as in we live in a globally warmed world, so the null hypothesis should be that. Then the alt hypothesis is AGW is not happening, and we should only accept it if the null — that AGW is a reality — is rejected bec it reaches .05 or less probability ((but we’d still be wise to continue mitigating an extremely unlikely AGW since it saves us so much money and most measures also help solve so many other problems.)) :)
I also thought of this when reading Stephan’s recent post, “Extremely Hot”:
Now, I know that this “reverse null hypothesis” thing is not how science is done, but it should be how laypersons and policy-makers think about the situation….avoiding the false negative (or rather their false positive should be the scientists’ false negative).
Re: #587 (Lynn Vincentnathan)
You may well be right that “AGW is happening” is the scientifically correct default assumption, and that this “should be how laypersons and policy-makers think about the situation.” However, there’s a very good reason that statistics uses the null hypothesis it does, which seems not to have been appreciated in discussions of “reversing the null hypothesis,” namely, that the usual null hypothesis actually enables us to compute probabilities.
Consider a coin flip, for example. Perhaps you already have compelling evidence the coin isn’t fair. That’s great — but it makes a lousy null hypothesis unless you know how much it’s not fair, i.e., the true probability of flipping “heads.” If you don’t, then you can’t compute the probability of whatever data you happen to have observed. The “obviously wrong” null hypothesis of a fair coin at least enables you to compute it.
All of which argues rather persuasively that in such situations one should consider a Bayesian approach to the statistics.
Lynn,
What Tamino said. People generally have a poor understanding of what is meant by a null hypothesis. It is not your “going in” hypothesis. You never “prove” your null. You never accept your null. It’s sole purpose is to serve as a comparison to your hypothesized model/hypothesis, because statistical techniques are inherently comparative rather than absolute. Statistical significance is a matter of saying that your hypothesis fits the data better than some random idea different from your hypothesis.
Hmm. Perhaps something like “obviously wrong” should be part of the popular vocabulary. Not sure how to make that work though…
Anyway, thank you Tamino, Ray, and Lynn. That was informative.
“Have you tried plotting the temperature against a sine wave with a 60-yr period?” DanH
Why 60? Why not 66(3X the 22 year Hale cycle), or 70(third harmonic of the 210 year Suess/DeVries cycle) years? What should the phase be, and why not 30, 60, 90 degrees earlier or later? Why not 180 degrees out of phase, showing that it’s negatively correlated to a 60 year cycle?
In a pendulum, all the energy at the top of the swing is stored gravitational potential energy; at the bottom of the swing, the energy is kinetic; and in between, the energy is transferring smoothly between modes. Where is the energy stored in the climate system, what are the reactive mechanisms that transfer that energy between states, and how much is dissipated in each “60 year” cycle?
Why a sine wave? why not a sawtooth, characteristic of a relaxation oscillator, where something (voltage on a capacitor, ice sheet thickness) accumulates until it reaches a tipping point(neon lamp trigger voltage, basal warming), then suddenly the state changes? Does this process run freely, or is it synchronized to some other forcing – like Huybers & Wunsch propose for ice ages in “Obliquity pacing of the late Pleistocene glacial terminations”?
Is 60 years just an artifact of misanalysis of weather noise?
#589 Ray Ladbury. Ray you’re confused and you’re probably confusing Lynn. You say “You never “prove” your null. You never accept your null”. Of course you do Ray, that’s how it becomes your null. The null hypothesis is the accepted (“proved”) hypothesis until further evidence modifies or replaces it to become a new null hypothesis, for example geocentrism being superseded by heliocentrism, or the space-time continuum superseding the previously accepted Newtonian account, or determinism at the atomic level being replaced by quantum theory. The null hypothesis is always a reflection of our current understanding of how the world works based on the evidence we have managed to unearth so far. Did not Copernicus “prove” that the earth revolved about the sun and Einstein “prove” that the speed of light was invariant? Our personal null hypotheses are what we think science has so far proved. Lynn thinks that the case for AGW is sufficiently convincing to adopt it as her null hypothesis. That is her new starting point in understanding climate. David Bohm’s own null hypothesis was that determinism was a fact which was explained by “hidden variables”, but this idea was later overthrown by John Bell and confirmed by Alain Aspect to become the now accepted null hypothesis of the Standard Model. Tomorrow science may allow us to lift yet another “corner of the great veil” to establish a further generally accepted null hypothesis. Lynn’s null hypothesis of AGW stands firm unless and until climate science says otherwise.
Simon. Bullshit.
Simon Abingdon (#592) completely misunderstands the statistical meaning of “null hypothesis.” The null hypothesis is most definitely not “the accepted (“proved”) hypothesis until further evidence modifies or replaces it.” It’s any convenient hypothesis which both allows us to compute probabilities, and for which we believe that contradicting it will be meaningful or useful.
The real problem is that non-statisticians think of the null hypothesis the way Simon Abingdon does — as the prevailing belief. If you want to talk about that, call it what it is: the “prevailing belief” or “consensus” or “most likely situation.” Don’t call it the “null hypothesis” — that’s just a misuse of terminology.
The null hypothesis is…..null (without value, effect, consequence, or significance. 2. being or amounting to nothing; nil; lacking; nonexistent.)
….goose egg, nada, naught, nil, nix, nothing, zero, zilch, zip, zippo, aught, cypher, cipher
….bugger all, f$%k all, sweet Fanny Adams
….invalid, useless, void, worthless, ineffectual, valueless, inoperative
I declare this discussion null and void, but don’t take my word for it.
#594 tamino. Thank you tamino. I find this most interesting. You say “[The null hypothesis is] any convenient hypothesis … for which we believe that contradicting it will be meaningful or useful”.
In other words any proposed hypothesis does not have to have a unique null hypothesis (its antithesis perhaps), but rather what can be regarded as a null hypothesis is any of a set of hypotheses which are meaningful (semantically logical) and useful (refer to relevant real world objects or ideas) and which can be shown to contain a contradiction.
If our hypothesis was “the earth goes round the sun” then a possible null hypothesis might be “the earth goes round Saturn” which when proved false might not however satisfy the criterion of usefulness any more than black cabs confirm the hypothesis that all swans are white.
I have not so far been able to think of an example hypothesis which would be supported by confounding an apparently unrelated null hypothesis which satisfies your two criteria of meaningfulness and usefulness. I shall try again in the morning and perhaps it will dawn on me what you’re saying.
In the meantime perhaps you might care to give me an everyday example which illustrates your point.
http://en.wikipedia.org/wiki/Null_hypothesis
@simon abingdon (#592), you are very confused about the history of science. Copernicus did not prove that the Earth revolved around the Sun, nor did Galileo for that matter. When Copernicus published his work his contemporary astronomer’s didn’t even accept it. Further, Galileo did not prove it either. He simply showed flaws in some of geocentrism’s tenets, like perfect heavenly bodies (the sun has spots, the moon has craters) and that not everything revolved around the Earth (Jupiter has moons). It wasn’t until a couple centuries later, with the observation of parallax for star 61 Cygni, that we had direct evidence for the Earth going around the Sun. Yet long before this direct evidence, heliocentrism was the accepted scientific theory. Let this be a lesson to all who demand some perfect proof of modern scientifically accepted theories.
“I have not so far been able to think of an example hypothesis which would be supported by confounding an apparently unrelated null hypothesis which satisfies your two criteria of meaningfulness and usefulness. I shall try again in the morning and perhaps it will dawn on me what you’re saying.”
He didn’t specify that it had to be unrelated. Just that it’s not the same thing as prevailing view.
Seems to me people bring up the null hypothesis to make themselves look clever and/or other people look less clever. Sad. Thanks to those who actually know what they’re talking about and provide some education.
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Earth Observatory sent out their weekly summary and I’m still bolluxed by this image of Lake Erie (posted earlier as well) and the potential it represents:
http://earthobservatory.nasa.gov/IOTD/view.php?id=77506&src=eoa-iotd
Newest New Yorker has article on water which appears to have used Dr. Gleick extensively – despite the kerfuffle, his work as shown here is worthwhile. Does not mention global warming much:
http://www.newyorker.com/archive/2006/10/23/061023fa_fact1?currentPage=all
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Don’t know if moderators really want this brought up; our persistent distractors have a long way to go to hit bottom: