# brazil84's Global Warming Thread **URL:** \ **Category:** Great Debates\ **Created:** [December 12, 2007, 2:16am UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693 "2007-12-12T02:16:11Z")\ **Posts on this page:** 20\ **Page:** 9
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [January 3, 2008, 2:04am UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/161 "2008-01-03T02:04:01Z")
[QUOTE=aptronym] I don’t know. I neither run the models nor review the papers they were published in nor do I have the expertise to evaluate the models. If you have technical questions about the models, you are free to contact the authors of the paper. In scientific publications, one author (usually either the first or last author) is starred and contact information is provided. [/quote] You’re the one who cited that chart. If you do not wish to defend it, it’s your choice. But to me, this is a key issue. The models include an unknown natural forcing that causes temperatures to rise through the 20th century until around 1950, and then drop thereafter. If you are developing a climate model, why would you put in an unknown natural forcing? To me, there’s only one reasonable explanation: It’s a fudge factor to make the models fit the data. > [@](#): > > I’ve been dodging and weaving intentionally :rolleyes: whatever. Anyway, if you link to this list of forcings, I’ll look at it a lot sooner. > [@](#): > > I demand a cite from you first. If you can’t provide a valid cite, then my counterclaim is moot. :rolleyes: whatever. See my economic growth thread. ---
**Author:** ![aptronym](https://avatars.discourse-cdn.com/v4/letter/a/e47774/32.png) [@aptronym](https://boards.straightdope.com/u/aptronym)\ **Post date:** [January 3, 2008, 2:20am UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/162 "2008-01-03T02:20:39Z")
[QUOTE=brazil84] Does that mean “yes” or “no”? Simple question. Not that I’m expecting a simple answer. [/QUOTE] The simplest way to answer the question would be to read the quote I provided. You’ve already quoted what I said about Lindzen; I’ve quoted what Lindzen said himself. Do they match? At some point, reading through these non-answers is going to be easier than looking at the quote yourself. And, honestly, that’s the point I’m striving for. This thread is about getting you to look at the evidence yourself and to make a rational, educated decision based on the available evidence. You’re right that you shouldn’t expect a simple answer, neither from me, nor from the evidence. If you want a simple answer, go watch Al Gore’s movie, or read [blogs.globalwarmingisafraud.com](http://blogs.globalwarmingisafraud.com). They’re full of simple, yes-or-no answers - is global warming serious? _Yes, it will kill us all in 77.8 years unless we stop burning fossil fuels by April 19, 2008._ Is global warming anthropogenic? _No, the Earth will find a way to adapt so we can do whatever we want. __100 Ways to Save the Earth!__ 202 Lies that Michael Mann Has Told!_ **All trash.** If you want the _correct_ answer, you’re going to have to put in a little effort yourself, not just in reading what I quote, but also in determining whether what I quote is representative of the general document. If you’re unwilling to do the former, then you certainly aren’t doing the latter, and the point is to get you to do the latter. ---
**Author:** ![aptronym](https://avatars.discourse-cdn.com/v4/letter/a/e47774/32.png) [@aptronym](https://boards.straightdope.com/u/aptronym)\ **Post date:** [January 3, 2008, 2:34am UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/163 "2008-01-03T02:34:53Z")
[QUOTE=brazil84] The models include an unknown natural forcing that causes temperatures to rise through the 20th century until around 1950, and then drop thereafter. [/quote] No - the models include a _known_ natural forcing. That I don’t know what it is doesn’t mean it’s not known. I could guess, and I doubt you’d catch it even if I were wrong, but that’s not helpful for my primary goal. > [@brazil84](#): > > if you link to this list of forcings, I’ll look at it a lot sooner. I’ve already provided a link and an exact chapter. The document is a multi-page, 7.7 MB PDF, so I can’t link to the chart directly nor could I simply download it and E-mail it to you. However, it’s posted for free online. [http://www.ipcc.ch/](http://www.ipcc.ch/) -\> Working Group I Report “The Physical Science Basis” -\> FULL REPORT -\> Chapter 2 Changes in Atmospheric Constituents and in Radiative Forcing -\> FAQ 2.1, Figure 2 (Page 8 of 106, or Page 136, depending on which version of Acrobat you have. > [@brazil84](#): > > See my economic growth thread. I’m not hopping back and forth between every global warming thread just to discuss issues with you. Either repost it here or give me a post number. This topic is tangential to the economic growth thread anyway so it doesn’t really belong there; in that thread you’re arguing economics will grow, which is not contested. The question is whether it will grow enough, or grow slower/faster, in the presence of global warming. You’ve already admitted that in some (admittedly improbable) set of circumstances, that negative effects could outweigh economic growth. Now it just remains as to whether the scientific evidence supports that set of circumstances. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [January 3, 2008, 11:00am UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/164 "2008-01-03T11:00:39Z")
[QUOTE=aptronym] The simplest way to answer the question would be to read the quote I provided. [/quote] Lol. Gosh, what a surprise - you evaded the question. > [@](#): > > You’ve already quoted what I said about Lindzen; I’ve quoted what Lindzen said himself. Do they match? It’s not clear to me. > [@](#): > > You’re right that you shouldn’t expect a simple answer, neither from me, nor from the evidence. I want a simple answer from you about exactly what you are claiming. Which you refuse to give. I wonder why? ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [January 3, 2008, 11:10am UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/165 "2008-01-03T11:10:19Z")
[QUOTE=aptronym] No - the models include a _known_ natural forcing. That I don’t know what it is doesn’t mean it’s not known. [/quote] If you claim it’s known, you should be able to back up your claim. The simplest way to do so would be to tell me exactly what this natural forcing is. To me, this is a critical point. It looks to me like those models have a fudge factor built in to tune them to the historical data. You have every right to decide that you no longer want to defend the position that you have staked out. I however, will draw my own inferences and consider the debate concluded (at least on this point). ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [January 5, 2008, 6:09am UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/166 "2008-01-05T06:09:09Z")
[QUOTE=brazil84] It looks to me like those models have a fudge factor built in to tune them to the historical data. [/QUOTE] If that turns out to be the case, why would that be a problem? ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [January 5, 2008, 10:33am UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/167 "2008-01-05T10:33:33Z")
[QUOTE=scr4] If that turns out to be the case, why would that be a problem? [/QUOTE] Among other things, if the models have been tuned to match the instrumental record, and then you remove the CO2 forcing that you had put into the model, then it’s hardly a surprise that the model will no longer match the instrumental record. It doesn’t prove anything at all. ---
**Author:** ![jshore](https://avatars.discourse-cdn.com/v4/letter/j/b5e925/32.png) [@jshore](https://boards.straightdope.com/u/jshore)\ **Post date:** [January 5, 2008, 3:36pm UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/168 "2008-01-05T15:36:00Z")
[QUOTE=brazil84] If you claim it’s known, you should be able to back up your claim. The simplest way to do so would be to tell me exactly what this natural forcing is. [/QUOTE] The natural forcing in the first half of the twentieth century was an increase in solar luminosity coupled with a lack of negative forcings from any major volcanic eruption (which contribute a negative forcing due to their production of stratospheric aerosols). The rise in greenhouse gas levels was also a contributor to the warming during that time. See figure 1 of [this](http://pubs.giss.nasa.gov/docs/2005/2005_Hansen_etal_1.pdf) paper. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [January 5, 2008, 4:31pm UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/169 "2008-01-05T16:31:28Z")
[QUOTE=jshore] The natural forcing in the first half of the twentieth century was an increase in solar luminosity coupled with a lack of negative forcings from any major volcanic eruption (which contribute a negative forcing due to their production of stratospheric aerosols). The rise in greenhouse gas levels was also a contributor to the warming during that time. See figure 1 of [this](http://pubs.giss.nasa.gov/docs/2005/2005_Hansen_etal_1.pdf) paper. [/QUOTE] Just so we are clear, are you claiming that absent any man-made forcings, solar luminosity and the presence or absence of volcanic activity would have caused temperatures to rise through the 20th century until around 1950 and then drop thereafter? ---
**Author:** ![jshore](https://avatars.discourse-cdn.com/v4/letter/j/b5e925/32.png) [@jshore](https://boards.straightdope.com/u/jshore)\ **Post date:** [January 5, 2008, 10:56pm UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/170 "2008-01-05T22:56:27Z")
[QUOTE=brazil84] Just so we are clear, are you claiming that absent any man-made forcings, solar luminosity and the presence or absence of volcanic activity would have caused temperatures to rise through the 20th century until around 1950 and then drop thereafter? [/QUOTE] Roughly speaking, yes. I don’t think the drop since 1950 would have been dramatic. I believe the best estimates are that it would be flat to slightly dropping. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [January 5, 2008, 11:08pm UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/171 "2008-01-05T23:08:00Z")
[QUOTE=jshore] Roughly speaking, yes. I don’t think the drop since 1950 would have been dramatic. I believe the best estimates are that it would be flat to slightly dropping. [/QUOTE] Do you have a cite for that? The figure you cite to seems to show the forcing for solar irradiance to be essentially flat through the entire 20th century, and if anything a little bit higher later in the century. It doesn’t appear to have a line for the effects of vulcanism. ---
**Author:** ![jshore](https://avatars.discourse-cdn.com/v4/letter/j/b5e925/32.png) [@jshore](https://boards.straightdope.com/u/jshore)\ **Post date:** [January 5, 2008, 11:25pm UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/172 "2008-01-05T23:25:22Z")
[QUOTE=brazil84] Do you have a cite for that? The figure you cite to seems to show the forcing for solar irradiance to be essentially flat through the entire 20th century, and if anything a little bit higher later in the century. It doesn’t appear to have a line for the effects of vulcanism. [/QUOTE] What’s important in determining the temperature rise is the derivative of the forcing…i.e., while the forcing is rising, the temperature will rise and while the forcing is steady, the temperature will not rise. (Well, in reality, there is some hysteresis so that if the forcing rises and then flattens out, the temperature will flatten out more slowly…but you get the basic picture.) As I noted a few posts back, the “stratospheric aerosols” line represents the effects of vulcanism. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [January 6, 2008, 12:31am UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/173 "2008-01-06T00:31:34Z")
[QUOTE=jshore] What’s important in determining the temperature rise is the derivative of the forcing…i.e., while the forcing is rising, the temperature will rise and while the forcing is steady, the temperature will not rise. [/quote] According to the article you linked, “solar irradiance is taken as increasing by 0.22 W/m^2 between 1880 and 2003, with an estimated uncertainty factor of 2” Also, if you imagine the derivative of the graph for solar irradiance, it would also seem pretty flat. > [@](#): > > As I noted a few posts back, the “stratospheric aerosols” line represents the effects of vulcanism. Ok, thank you. In any event, looking at your chart, I don’t see what happened with solar irradiance or stratospheric aerosols around 1950 that flipped the natural forcing. Do you? ---
**Author:** ![jshore](https://avatars.discourse-cdn.com/v4/letter/j/b5e925/32.png) [@jshore](https://boards.straightdope.com/u/jshore)\ **Post date:** [January 6, 2008, 3:07pm UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/174 "2008-01-06T15:07:14Z")
[QUOTE=brazil84] According to the article you linked, “solar irradiance is taken as increasing by 0.22 W/m^2 between 1880 and 2003, with an estimated uncertainty factor of 2” Also, if you imagine the derivative of the graph for solar irradiance, it would also seem pretty flat. [/quote] Yes…The solar forcing is pretty small but it is still there. > [@](#): > > Ok, thank you. In any event, looking at your chart, I don’t see what happened with solar irradiance or stratospheric aerosols around 1950 that flipped the natural forcing. > > Do you? Well, I would have to see the solar irradiance forcing on an expanded scale to make out exactly what is going on. In terms of stratospheric aerosols, note that the period from about 1910 to 1960 is notable for the lack of any significant eruptions and thus any significant negative forcings. Also, note how the sum of all the forcings run through the climate model reproduces the temperature record quite well. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [January 6, 2008, 4:43pm UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/175 "2008-01-06T16:43:24Z")
[QUOTE=jshore] Well, I would have to see the solar irradiance forcing on an expanded scale to make out exactly what is going on. In terms of stratospheric aerosols, note that the period from about 1910 to 1960 is notable for the lack of any significant eruptions and thus any significant negative forcings. [/quote] It appears that NASA has a PDF version of the graph. You can zoom in as close as you like: [http://data.giss.nasa.gov/modelforce/radf.pdf](http://data.giss.nasa.gov/modelforce/radf.pdf) Looks to me like nothing particularly special happened in 1950 with solar irradiance or vulcanism. Agreed? ---
**Author:** ![vison](https://avatars.discourse-cdn.com/v4/letter/v/e47774/32.png) [@vison](https://boards.straightdope.com/u/vison)\ **Post date:** [January 6, 2008, 6:57pm UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/176 "2008-01-06T18:57:24Z")
Thanks for posting that link, Brazil84. ---
**Author:** ![jshore](https://avatars.discourse-cdn.com/v4/letter/j/b5e925/32.png) [@jshore](https://boards.straightdope.com/u/jshore)\ **Post date:** [January 6, 2008, 7:24pm UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/177 "2008-01-06T19:24:43Z")
[QUOTE=brazil84] It appears that NASA has a PDF version of the graph. You can zoom in as close as you like: [http://data.giss.nasa.gov/modelforce/radf.pdf](http://data.giss.nasa.gov/modelforce/radf.pdf) Looks to me like nothing particularly special happened in 1950 with solar irradiance or vulcanism. Agreed? [/QUOTE] Bad link. Try [this](http://data.giss.nasa.gov/modelforce/RadF.pdf). I already explained what the graph shows. What part do you disagree with and what is your point? ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [January 6, 2008, 8:07pm UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/178 "2008-01-06T20:07:26Z")
[QUOTE=jshore] Bad link. Try [this](http://data.giss.nasa.gov/modelforce/RadF.pdf). I already explained what the graph shows. What part do you disagree with and what is your point? [/QUOTE] The graph does not appear to show the alleged natural forcing that would have caused temperatures to rise until 1950 and then flip and cause temperatures to start dropping in 1950. Agreed? ---
**Author:** ![jshore](https://avatars.discourse-cdn.com/v4/letter/j/b5e925/32.png) [@jshore](https://boards.straightdope.com/u/jshore)\ **Post date:** [January 7, 2008, 3:06am UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/179 "2008-01-07T03:06:03Z")
[QUOTE=brazil84] The graph does not appear to show the alleged natural forcing that would have caused temperatures to rise until 1950 and then flip and cause temperatures to start dropping in 1950. Agreed? [/QUOTE] I have no idea what you are talking about. As you can see from that paper, the forcings run through the climate models gives good agreement with the observed temperature. The only remaining question that we are really discussing is the question of attributing the trends over very periods to various factors. ---
**Author:** ![ianzin](https://avatars.discourse-cdn.com/v4/letter/i/ed655f/32.png) [@ianzin](https://boards.straightdope.com/u/ianzin)\ **Post date:** [January 7, 2008, 9:04am UTC](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693/180 "2008-01-07T09:04:32Z")
Very good OP, **Aptronym** , even though I suspect we would disagree about almost everything pertaining to this subject. However, in the middle of what seemed to me to be a very intelligent post and presentation of the key issues, I was surprised to find this: > [@](#): > > We can then use computers to determine whether natural data can explain the temperature record we see. Not so. We can use computers to crunch data, and that’s all. Once the number crunching is done, ten different lobby groups and vested interests will ‘determine’ ten different things, according to what they want to find. The tool we use to handle numbers, be it computer or abacus, doesn’t determine anything, and is in any event less relevant than who is using the tool (computer or whatever) and what bias they may or may not bring to the process of ‘determining’ something. I think I understand what you meant to say, but I don’t think this is the best way to say it. I think you meant to say that making sense of the mass of data is difficult, but we’re lucky enough these days to have computer technology that can handle the necessary number crunching to help intelligent people draw intelligent conclusions. Now would be a good time to dig out all those forecasts from the 1970s about how the next ice age could soon be upon us, and the ‘fact’ that the oil would run out by 2000. I expect a lot of those ‘experts’ had data to hand derived from computers and computer models. Better still, re-read ‘Extraordinary popular delusions and the madness of crowds’, and wonder why nobody ever seems to learn anything from this fine, fine book. [Previous page](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693.md?page=8) [Next page](https://boards.straightdope.com/t/brazil84s-global-warming-thread/429693.md?page=10)