My 'reality-based decision making' post prompted a comment asking for my thoughts about sea level rise, which is more than sufficient excuse to turn to that. An additional excuse is that it provides a chance to look at how to decide climate time scales for something other than temperatures. For global mean temperature trends, I found that you need 20-30 years to determine a climate trend. We'll see that it is 40-60 years, 60 for preference, for sea level.
My starting point for data was the University of Colorado sea level group. They provide satellite data back to late 1992. High quality data, but only for a short period of time. If global sea level's time scales are like global mean temperature's, then it's only just gotten long enough to provide a climate number. Fortunately they list links to other sea level groups, including the Permanent Service for Mean Sea Level. They have three global reconstructions available. I'll take this one -- published in the scientific literature as: Recent global sea level acceleration started over 200 years ago?", Jevrejeva, S., J. C. Moore, A. Grinsted, and P. L. Woodworth (2008), Geophys. Res. Lett., 35, L08715, doi:10.1029/2008GL033611 -- on the grounds that it covers the longest time period and has the most recent literature publication date. It will be a good project for a reader to see if the conclusions here change, and how, if you use one of the others instead.
31 January 2013
11 January 2013
Looking back at blogs 1
Some of these might still be active, at least the author might be. Please let me know the new locations if I don't have one. If not, well, they still wrote some articles worth consideration.
Trees for the Forest
Rust Never Sleeps
Old Man in a Cave
mutantClimate
Rationally Thinking Out Loud (new location) http://rationallythinkingoutloud.wordpress.com/ -- old location
Respectful Insolence -- The blog certainly has continued, this is the link to the new feed location. But some good older articles on science, in particular medicine, vs. nonscience.
The Questionable Authority Old location: http://scienceblogs.com/authority/, New location: The Questionable Authority
The Middle Way (low volume, more philosophical, blog, by a friend)
Vickie's Prostitution Blog (my wife)
Trees for the Forest
Rust Never Sleeps
Old Man in a Cave
mutantClimate
Rationally Thinking Out Loud (new location) http://rationallythinkingoutloud.wordpress.com/ -- old location
Respectful Insolence -- The blog certainly has continued, this is the link to the new feed location. But some good older articles on science, in particular medicine, vs. nonscience.
- http://scienceblogs.com/insolence/2009/02/08/why-am-i-not-surprised-it-looks-as-thoug/
- http://scienceblogs.com/insolence/2009/06/11/the-ap-shoots-and-scores-again/
- http://scienceblogs.com/insolence/2009/11/18/really-rethinking-breast-cancer-screenin/
- http://scienceblogs.com/insolence/2009/12/03/mammography-and-the-risk-of-breast-cance/
- http://scienceblogs.com/insolence/2010/03/30/best-sign-ever/
- http://scienceblogs.com/insolence/2010/08/06/basic-science-an-obstacle-to-students-wh/
- http://scienceblogs.com/insolence/2010/08/19/another-worthless-acupuncture-study-misi/
- http://scienceblogs.com/insolence/2011/01/06/piltdown-medicine-andrew-wakefields-scie/
- http://scienceblogs.com/insolence/2011/03/11/for-the-anti-vaccinationists-out-there-t/
- http://scienceblogs.com/insolence/2011/05/23/dr-andrew-weil-versus-evidence-based-med/
- http://scienceblogs.com/insolence/2011/11/05/pox-packages-child-abuse-and-the-violati/
The Questionable Authority Old location: http://scienceblogs.com/authority/, New location: The Questionable Authority
- http://scienceblogs.com/authority/2009/02/02/google-the-oceans-and-mars/
- http://scienceblogs.com/authority/2009/02/07/scientific-misconduct-and-the/
- http://scienceblogs.com/authority/2009/03/03/holds-on-noaa-administrator-sc/
- http://scienceblogs.com/authority/2009/05/16/an-open-letter-for-the-parents/
The Middle Way (low volume, more philosophical, blog, by a friend)
Vickie's Prostitution Blog (my wife)
- http://vickiesprostitutionblog.blogspot.com/2009/10/how-much-money-do-prostitutes-make-part.html
- http://vickiesprostitutionblog.blogspot.com/2009/10/how-much-money-do-prostitutes-make-part_12.html
- http://vickiesprostitutionblog.blogspot.com/2009/10/edgar-allan-poe-call-for-halloween.html
- http://vickiesprostitutionblog.blogspot.com/2009/10/halloween-and-some-updates.html
- http://vickiesprostitutionblog.blogspot.com/2009/11/dear-h.html
- http://vickiesprostitutionblog.blogspot.com/2010/05/why-do-women-prostitute-part-iii.html
- http://vickiesprostitutionblog.blogspot.com/2010/07/grieving-for-lilian.html
- http://vickiesprostitutionblog.blogspot.com/2012/08/yana-women-are-great-art.html
10 January 2013
Bits from 2012
Some items that interested me in 2012 that I never made full posts from ...
As you've no doubt heard, the 5th review from IPCC is in progress. I passed up yet another opportunity to be an expert reviewer.
One method of getting science together is a special issue or theme issue of a scientific journal. One that crossed my desk and I thought might be interesting to blog readers are:
As you've no doubt heard, the 5th review from IPCC is in progress. I passed up yet another opportunity to be an expert reviewer.
One method of getting science together is a special issue or theme issue of a scientific journal. One that crossed my desk and I thought might be interesting to blog readers are:
- Call for Papers – Climate Consensus: Steps Toward a Global Understanding of Climate
- European Earth System and Climate Modelling School sponsored by ENES
09 January 2013
Happy New Year 2013
Happy near year!
I see that I have been away from here for quite a while, including past a spectacular (again) new minimum in Arctic sea ice extent this past September. Certainly lost me at least one of my bets with Alastair, maybe both. I'll be looking in to it and write up a full evaluation of the predictions I worked with.
One of the reasons for the quiet here is that I've been working on articles for professional journals. 2 now out in Deep Sea Research, 1 to be appearing in Ocean Modeling, 1 already in review at Weather and Forecasting. And two in pre-submission review, one for Climate Dynamics and another for Weather and Forecasting. 4 more in progress towards the internal review stage -- one a technical note on what I've been doing the last 15 years for sea ice concentration analysis, two for the Journal of Climate, and one for sea ice modeling. Not sure where/how I'll be publishing that. Somehow the brain cells for writing get fatigued, so if I'm writing much at work, I don't do so much here. The exercise is starting to pay off, though, so they seem to feel like they can do both now.
Good news in the background is that I'll be producing better plots when I do start more regular posting here. Had to bite some bullets to get figured out how to make publishable plots for the journals. More of an issue than it should have been. But now resolved well enough, with the side benefit that it also lets me make better plots for blogging.
I see that I have been away from here for quite a while, including past a spectacular (again) new minimum in Arctic sea ice extent this past September. Certainly lost me at least one of my bets with Alastair, maybe both. I'll be looking in to it and write up a full evaluation of the predictions I worked with.
One of the reasons for the quiet here is that I've been working on articles for professional journals. 2 now out in Deep Sea Research, 1 to be appearing in Ocean Modeling, 1 already in review at Weather and Forecasting. And two in pre-submission review, one for Climate Dynamics and another for Weather and Forecasting. 4 more in progress towards the internal review stage -- one a technical note on what I've been doing the last 15 years for sea ice concentration analysis, two for the Journal of Climate, and one for sea ice modeling. Not sure where/how I'll be publishing that. Somehow the brain cells for writing get fatigued, so if I'm writing much at work, I don't do so much here. The exercise is starting to pay off, though, so they seem to feel like they can do both now.
Good news in the background is that I'll be producing better plots when I do start more regular posting here. Had to bite some bullets to get figured out how to make publishable plots for the journals. More of an issue than it should have been. But now resolved well enough, with the side benefit that it also lets me make better plots for blogging.
06 September 2012
The Relativity of Wrong
Recent political comment brings me back to a point I'd written about before, under the label of Successive Approximation. The better title, unsurprisingly, is Isaac Asimov's The Relativity of Wrong.
I first became aware of Paul Ryan's lie when my wife asked me, having mentioned nothing about context, whether a runner could conceivably mis-remember his marathon of somewhat over 4 hours as having been somewhat under 3 hours. As has been reported in many places, and some reporters having done some experiments, the answer is no. It is completely implausible that someone, especially someone with only one marathon, could make that mistake as an honest mistake. Confusing a little over 4 for a little under ... maybe. You would likely have trained for some time under 4 and that number could have stayed with you longer than your disappointment in not making your goal.
But confusing your over-4 hours, a perfectly respectable time to cover a marathon if nothing to brag about for an open class man, for sub-3 -- a time that entitles you to some bragging (as a friend worked to earn the right to) and is achievable only with some serious training and talent -- is not an accident.
The political side of this, well, not so very interesting. Except for the fact, perhaps, that Ryan is supposed to be a leading light for Republican number-crunching. Number types are even less likely to make a mistake like that. At least as a mistake.
More interesting, and perhaps useful, to the local purpose is to look some at how to assess the relativity of wrong. The route I took in the successive approximation post was quantitative. Some articles have taken something like that, observing that his claimed time was about 70% of his actual time, or, conversely, that he lied by about 30%. That's actually much too generous to his lie. The problem with that is that if he had claimed the world record time (a bit less than 2 hours faster than he ran, as opposed to the somewhat more than 1 hour of his actual lie), it would only be scored as 50% wrong. You can't run faster than the world record, or you'd be the record holder, which even Ryan didn't claim. So, the most he could have lied by is about 2 hours (iirc his actual time was 4:01, and the world record back then was about 2:07, so 114 minutes). His actual lie is about 65 minutes (taking 2:50-something as 2:56) wrong, so 57%, more than half, of the span that he could possibly have lied by. That could be refined some by comparison against, say, the race winner's time, or the Olympic qualifying time. But you get the idea. And the 57% is about double what the other approach shows. Compare how wrong something is with how wrong it could be.
But some things, and this is where I'll especially invite comments, don't lend themselves to that kind of quantification. For instance, I'm comfortable with saying that it is more wrong to say that the earth has no greenhouse effect than it is to say that CO2 is not a greenhouse gas. But how can we assess this comparative wrongness with the error in saying that CO2 levels have not risen over the past 200 years?
So I'll invite description of approaches to assessing relative errors, preferably with examples. Note, too, that it's best to have them be objective examples -- so which candidate is better kinds of things are not going to work. Marathon times and the radiative properties of the earth's atmosphere aren't partisan matters.
I first became aware of Paul Ryan's lie when my wife asked me, having mentioned nothing about context, whether a runner could conceivably mis-remember his marathon of somewhat over 4 hours as having been somewhat under 3 hours. As has been reported in many places, and some reporters having done some experiments, the answer is no. It is completely implausible that someone, especially someone with only one marathon, could make that mistake as an honest mistake. Confusing a little over 4 for a little under ... maybe. You would likely have trained for some time under 4 and that number could have stayed with you longer than your disappointment in not making your goal.
But confusing your over-4 hours, a perfectly respectable time to cover a marathon if nothing to brag about for an open class man, for sub-3 -- a time that entitles you to some bragging (as a friend worked to earn the right to) and is achievable only with some serious training and talent -- is not an accident.
The political side of this, well, not so very interesting. Except for the fact, perhaps, that Ryan is supposed to be a leading light for Republican number-crunching. Number types are even less likely to make a mistake like that. At least as a mistake.
More interesting, and perhaps useful, to the local purpose is to look some at how to assess the relativity of wrong. The route I took in the successive approximation post was quantitative. Some articles have taken something like that, observing that his claimed time was about 70% of his actual time, or, conversely, that he lied by about 30%. That's actually much too generous to his lie. The problem with that is that if he had claimed the world record time (a bit less than 2 hours faster than he ran, as opposed to the somewhat more than 1 hour of his actual lie), it would only be scored as 50% wrong. You can't run faster than the world record, or you'd be the record holder, which even Ryan didn't claim. So, the most he could have lied by is about 2 hours (iirc his actual time was 4:01, and the world record back then was about 2:07, so 114 minutes). His actual lie is about 65 minutes (taking 2:50-something as 2:56) wrong, so 57%, more than half, of the span that he could possibly have lied by. That could be refined some by comparison against, say, the race winner's time, or the Olympic qualifying time. But you get the idea. And the 57% is about double what the other approach shows. Compare how wrong something is with how wrong it could be.
But some things, and this is where I'll especially invite comments, don't lend themselves to that kind of quantification. For instance, I'm comfortable with saying that it is more wrong to say that the earth has no greenhouse effect than it is to say that CO2 is not a greenhouse gas. But how can we assess this comparative wrongness with the error in saying that CO2 levels have not risen over the past 200 years?
So I'll invite description of approaches to assessing relative errors, preferably with examples. Note, too, that it's best to have them be objective examples -- so which candidate is better kinds of things are not going to work. Marathon times and the radiative properties of the earth's atmosphere aren't partisan matters.
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