# The Evidence Against Global Warming? READ BEFORE FLAMING! **URL:** \ **Category:** Great Debates\ **Created:** [March 18, 2009, 4:00pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897 "2009-03-18T16:00:24Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [March 21, 2009, 4:35pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/61 "2009-03-21T16:35:08Z")
> [@brazil84](#): > > I’m a little confused. Are you claiming that recent warming is NOT within the range of natural variation? Since you haven’t answered the question, I will answer it. Recent warming is within the range of natural variation as far as anyone knows. Moreover, there are numerous candidate drivers of the climate which are not very well understood. Thus, anyone claiming that recent warming can be ascribed to CO2 is starting the game with a strike against him or her. Further, the evidence I have seen which ascribes recent warming to CO2 emissions is weak at best, as far as I know. ---
**Author:** ![The\_Tao\_s\_Revenge](https://avatars.discourse-cdn.com/v4/letter/t/73ab20/32.png) [@The\_Tao\_s\_Revenge](https://boards.straightdope.com/u/The_Tao_s_Revenge)\ **Post date:** [March 21, 2009, 5:26pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/62 "2009-03-21T17:26:07Z")
> [@brazil84](#): > > I’m a little confused. Are you claiming that recent warming is NOT within the range of natural variation? Are you claiming atmospheric greenhouse gas levels ARE natural? ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [March 21, 2009, 5:49pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/63 "2009-03-21T17:49:19Z")
> [@The\_Tao\_s\_Revenge](#): > > Are you claiming atmospheric greenhouse gas levels ARE natural? \*\*brazil84 \*\*will never leave something that obvious to get in the way of his FUD. BTW his “as far as I know” reply is just weasel words. Answering a question by himself if beyond silly. Instead of him realizing that we are expecting to see an acknowledgment of the evidence presented so far we see only just evasion. I only see a naked effort to avoid checking the previously shown evidence in the guise of “getting an answer”, he is not worthy of a reply now. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [March 21, 2009, 5:58pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/64 "2009-03-21T17:58:34Z")
> [@The\_Tao\_s\_Revenge](#): > > . . I have started a pit thread about you here: > **[A Mild Pitting of The Tao's Revenge](https://boards.straightdope.com/sdmb/showthread.php?t=511184)** > > For reasons to be explained shortly, I do not engage with the poster known as “The Tao’s Revenge.” Since it’s apparently against the rules to mention this fact outside of the Pit, I am doing so here. In case anyone is curious, here’s why. In a... ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [March 21, 2009, 6:03pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/65 "2009-03-21T18:03:28Z")
> [@GIGObuster](#): > > BTW his “as far as I know” reply is just weasel words. :shrug: I don’t bear the burden of proof on this point. As far as I know, recent warming is within the range of natural variation. If you have evidence or proof otherwise, please feel free to share it. > [@](#): > > Answering a question by himself if beyond silly. I don’t see why. You wouldn’t answer the question and still will not answer it: **Are you claiming that recent warming is NOT within the range of natural variation?** It’s a simple yes or no question, with no unfair assumptions (as far as I can tell). ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [March 21, 2009, 6:05pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/66 "2009-03-21T18:05:04Z")
> [@The\_Tao\_s\_Revenge](#): > > Are you claiming atmospheric greenhouse gas levels ARE natural? What? Water vapour and C02 don’t occur naturally? ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [March 21, 2009, 6:16pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/67 "2009-03-21T18:16:14Z")
> [@Leaffan](#): > > What? Water vapour and C02 don’t occur naturally? The isotope evidence shows that the recent increase in CO2 is not natural. (And this was already mentioned.) ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [March 21, 2009, 6:26pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/68 "2009-03-21T18:26:51Z")
> [@brazil84](#): > > :shrug: I don’t bear the burden of proof on this point. As far as I know, recent warming is within the range of natural variation. If you have evidence or proof otherwise, please feel free to share it. It is your burden to show us that it is caused naturally, the evidence so far has dismissed the natural reasons, stomping your feet repeating that it is within the range of natural variation **does** imply that **you know** that there is a natural cause for the current temperature increase. > [@](#): > > I don’t see why. You wouldn’t answer the question and still will not answer it: > > **Are you claiming that recent warming is NOT within the range of natural variation?** > > It’s a simple yes or no question, with no unfair assumptions (as far as I can tell). Not playing your game, you are the one that needs to stop weaseling, for “CAGW” there is a lot of issues that are not resolved, for **AGW** there is almost none. When you only return to FUD again and again regarding AGW you are demonstrating that the difference of it with CAGW is meaningless to you and it is still ok to return to discuss evidence that was investigated several times before and that in reality you are continuing to ignore. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [March 21, 2009, 6:44pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/69 "2009-03-21T18:44:07Z")
> [@Leaffan](#): > > What? Water vapour and C02 don’t occur naturally? Actually there have been times in the past when CO2 levels were far higher than they are now. Neverthless, I do not deny that it’s likely that mankind’s activities are raising CO2 levels. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [March 21, 2009, 6:47pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/70 "2009-03-21T18:47:54Z")
> [@GIGObuster](#): > > It is your burden to show us that it is caused naturally, the evidence so far has dismissed the natural reasons, That’s nonsense. > [@](#): > > Not playing your game, If you refuse to answer reasonable questions so that I can understand your position, then our discussion is concluded. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [March 21, 2009, 7:06pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/71 "2009-03-21T19:06:56Z")
> [@brazil84](#): > > That’s nonsense. Every time I see that coming from you it is the moment when all can see that you really have nothing else to say in defense of your FUD, better distract all with the “yes or no” trick. All the evidence out there shows the majority of CO2 to be man made, and so is the current increase in temperature, the evidence I have seen so far shows that scientists already take into account the natural increases in the background. So AGW is still there, now CAGW does refer to the “what will happen as the result of that?” The problem from many deniers is that they jump to the defense of yahoos like lord Monkton that **still want to deny AGW**. I noticed that on the whole, it is meaningless to deny AGW when the current problem is: people that concentrate on the possible catastrophe when adaptation could be the best pragmatic solution. ---
**Author:** ![The\_Tao\_s\_Revenge](https://avatars.discourse-cdn.com/v4/letter/t/73ab20/32.png) [@The\_Tao\_s\_Revenge](https://boards.straightdope.com/u/The_Tao_s_Revenge)\ **Post date:** [March 21, 2009, 7:40pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/72 "2009-03-21T19:40:01Z")
> [@brazil84](#): > > I have started a pit thread about you here: > > [A Mild Pitting of The Tao's Revenge - The BBQ Pit - Straight Dope Message Board](http://boards.straightdope.com/sdmb/showthread.php?t=511184) \<3 > [@Leaffan](#): > > What? Water vapour and C02 don’t occur naturally? Yes they do. However normally carbon dioxide is taken from the atmosphere and converted to oxygen and biomass at a rate pretty steady with it it’s release. Except the last century or so carbon dioxide levels are increasing faster then they can be reabsorbed. Now it just so happens around this time these almost hairless apes figured out they could burn coal and oil (which happened to contain carbon that’d long since been sequestered naturally, and removed from the carbon cycle) for energy to make electricity and do mechanical labor. I know statisticians warn us about correlation not necessarily meaning causation but I’m going to be so bold as to say I think there might be relationship here. Interestingly water while a greenhouse gas also might be part of a cooling mechanism. There was an interesting Nova episode about this. See dust, soot, particulates and the like produced from things such as con-trails from jets, factories and the like tend to seed clouds. Water condenses around the dust. Now these clouds block out some sunlight reflecting potential heat back into space. This is called global dimming. When 9/11 grounded the jets there was IIRC a 1 degree C temp rang increase over the country. Such a thing was unheard of. No con-trails seeding light reflecting clouds in the day, no contrail seeded clouds keeping the heat in at night. Also pan evaporation levels have decreased indicating less and less sunlight making it through, 10% less in fact. The people who measured this are like my science heros. Everyday they’d check the water levels in pans of water to see how much they evaporated, just to see if evaporation rates changed. It just blows my mind someone would think to do that, then do that, then get someone else to take over. They’ve been measuring it since the turn of the century at least. That’s dedication. Anyway the thinking is industrial soot and the like seeds clouds, which block sunlight, which mask some of the affects of increased CO2. As we clean up our sooty ways for health reasons we’ll loose that mask and start to feel the full affects of global warming. Some links if you want to read more on it. While not reference level authority I think they might do better then my layman understanding and explanation of the phenomena > **[NOVA | Dimming the Sun | PBS](https://www.pbs.org/wgbh/nova/sun/)** > > In this companion Web site to the NOVA program Dimming the Sun, find a history of global dimming, learn about clean air technologies, discover how aircraft contrails might affect regional temperatures, read a personal essay by filmmaker David Sington... > **[Global dimming](https://en.wikipedia.org/wiki/Global_dimming)** > > Global dimming is a decline in the amount of sunlight reaching the Earth's surface. It is caused by atmospheric particulate matter, predominantly sulfate aerosols, which are components of air pollution. Global dimming was observed soon after the first systematic measurements of solar irradiance began in the 1950s. This weakening of visible sunlight proceeded at the rate of 4–5% per decade until the 1980s. During these years, air pollution increased due to post-war industrialization. S Aerosols... And a transcript of the episode: > **[NOVA | Transcripts | Dimming the Sun | PBS](https://www.pbs.org/wgbh/nova/transcripts/3310_sun.html)** > > Find the complete program transcript, including credits, for the NOVA program Dimming the Sun originally broadcast on PBS on March 28, 2006. You might be able to watch it online on the Nova website as you can a lot of their episodes, if you’re interested. I looked but I couldn’t find it. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 21, 2009, 7:57pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/73 "2009-03-21T19:57:02Z")
> [@](#): > > As far as I know, recent warming is within the range of natural variation. This is incorrect on multiple levels. First of all, recent warming is far greater than any known natural variation. Second, it’s not even honest to say that it’s so “as far as you know”, since you have been informed in many previous threads of this fact. The best you can say is something along the lines that as far as you choose to believe contrary to the evidence, it’s within natural ranges. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [March 21, 2009, 8:21pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/74 "2009-03-21T20:21:26Z")
> [@Chronos](#): > > This is incorrect on multiple levels. First of all, recent warming is far greater than any known natural variation. Cite? > [@](#): > > Second, it’s not even honest to say that it’s so “as far as you know”, since you have been informed in many previous threads of this fact. Nobody has made a convincing case to me. I’m open to considering whatever evidence or arguments are out there. “as far as I know” reflects the fact that it’s difficult to know what global surface temperatures were like hundreds or thousands of years ago. ---
**Author:** ![The\_Tao\_s\_Revenge](https://avatars.discourse-cdn.com/v4/letter/t/73ab20/32.png) [@The\_Tao\_s\_Revenge](https://boards.straightdope.com/u/The_Tao_s_Revenge)\ **Post date:** [March 21, 2009, 8:45pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/75 "2009-03-21T20:45:31Z")
> [@brazil84](#): > > Cite? (both graphs have their data sources cited) > **[File:2000 Year Temperature Comparison.png](https://en.wikipedia.org/wiki/File:2000_Year_Temperature_Comparison.png)** > > The single, unsmoothed annual value for 2016 is also shown for comparison. (Image:Instrumental Temperature Record.png shows how 2004 relates to other recent years). > For the purposes of this comparison, the author is agnostic as to which, if any, of the reconstructions of global mean temperature is an accurate reflection of temperature fluctuations during the last 2000 years. However, since this plot is a fair representation of the range of reconstructions appearing in the published scientific ... > **[File:Mauna Loa Carbon Dioxide-en.svg](https://en.wikipedia.org/wiki/File:Mauna_Loa_Carbon_Dioxide-en.svg)** > > The annual fluctuation in carbon dioxide is caused by seasonal variations in carbon dioxide uptake by land plants. Since many more forests are concentrated in the Northern Hemisphere, more carbon dioxide is removed from the atmosphere during Northern Hemisphere summer than Southern Hemisphere summer. This annual cycle is shown in the inset figure by taking the average concentration for each month across all measured years. > La fluctuation annuelle de dioxyde de carbone est dûe aux variation sai... Pretty interesting how CO2 data lines up with temperature increases. ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [March 22, 2009, 3:20am UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/76 "2009-03-22T03:20:17Z")
> [@The\_Tao\_s\_Revenge](#): > > \<3 > > When 9/11 grounded the jets there was IIRC a 1 degree C temp rang increase over the country. Such a thing was unheard of. No con-trails seeding light reflecting clouds in the day, no contrail seeded clouds keeping the heat in at night. You have got to be kidding me. You’re going to pull a one day statistic, however erroneous it may be, and somehow use that 24 hour period as proof of anything? Wow! ---
**Author:** ![The\_Tao\_s\_Revenge](https://avatars.discourse-cdn.com/v4/letter/t/73ab20/32.png) [@The\_Tao\_s\_Revenge](https://boards.straightdope.com/u/The_Tao_s_Revenge)\ **Post date:** [March 22, 2009, 6:19pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/77 "2009-03-22T18:19:22Z")
> [@Leaffan](#): > > You have got to be kidding me. You’re going to pull a one day statistic, however erroneous it may be, and somehow use that 24 hour period as proof of anything? Wow! Why do you feel it’s erroneous? It’s based on weather measurements all over the lower 48, 5,000 data stations in fact. It happened right when the jets were grounded. It was the largest temperature swing in 30 years. Are you claiming all these data stations were improperly calibrated? If it wasn’t the jets what did affect temperatures all over the bloody country? Wow indeed. But don’t take my word for it. (quotes from the transcript link, first one modified to give credentials) > [@](#): > > Dr. DAVID TRAVIS (University of Wisconsin-Whitewater, [Phd .in Geology (Atmospheric Sciences) from Indiana University](http://facstaff.uww.edu/travisd/)) We found that the change in temperature range during those three days was just over one degree centigrade. And you have to realize that from a layman’s perspective that doesn’t sound like much, but from a climate perspective that is huge. On the issue of data collection: > [@](#): > > DAVID TRAVIS: …initially, data from over 5,000 weather stations across the 48 United States, the area that was most dominantly affected by the grounding. On magnitude: > [@](#): > > DAVID TRAVIS: As we began to look at the climate data and the evidence began to grow, I got more and more excited. The actual results were much larger than I expected. > > So here we see, for the three-day period preceding September 11th, a slightly negative value of temperature range with lots of contrails, as normal. Then we have this sudden spike right here of the three-day period. This reflects lack of clouds, lack of contrails, warmer days cooler nights, exactly what we expected, but even larger than we expected. > > NARRATOR: During the three-day grounding, the nights had gotten colder and the days, warmer. Averaged over the whole continental U.S., the temperature difference between day and night had suddenly increased by over a degree Celsius or two degrees Fahrenheit. Travis had never seen anything like it before. > > DAVID TRAVIS: This was the largest temperature swing of this magnitude in the last 30 years. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [March 22, 2009, 7:52pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/78 "2009-03-22T19:52:31Z")
> [@brazil84](#): > > Cite? Since you [**chronos**] have not given me a cite, I will quote to you from my analysis of this point on a blog I set up: > [@](#): > > The next set of evidence frequently cited in support of CAGW is that some aspect of weather, climate, or whatever is unprecedented. Essentially, the argument is that if something significant happens with the weather which has not happened before, then that thing is likely to be a result of mankind’s activities. > > However, on closer inspection, these “unprecedented” claims usually turn out to be either (1) false; (2) unsupported by the evidence; or (3) not based on a sufficiently long time period to mean much, if anything. > > For example, it is often said that temperatures in the 1990s were the highest since instrumental temperature monitoring began in the 19th century. Assuming this is true, the time period in question does not seem long enough to mean much, since we have been coming out of the Little Ice Age. > > Similarly, it has been claimed that the 1990s were the warmest decade in 1000 years. However, the evidentiary support for this is rather weak. Since temperatures were not measured with thermometers 1000 years ago, you have to guesstimate temperatures using “proxies,” like tree rings. How do we know that we are interpreting these proxies correctly? Or even that they can be used to measure past temperatures at all? > > The obvious way to check these proxy methods is to use the same methods to estimate recent temperatures, and then to compare the results to intstrumental records. As far as I know, proxies have not done so well when checked this way. This is the so-called “divergence problem.” So any claim that current temperatures are unprecedentedly warm is at best a guess. > > At the same time, there does exist evidence of warm temperatures in the past. The classic example of this is the VIking colonization of Greenland during the Medieval Warm Period. Of course, one can debate the significance of this and similar evidence. But the bottom line is that there is not a good case at this point that recent temperatures are unprecedentedly warm. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 22, 2009, 8:23pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/79 "2009-03-22T20:23:40Z")
It’s not the temperature that’s unprecedented, it’s the rate of temperature change. Remember, we’re talking about global warm_ing_ here, not global warm_th_. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [March 22, 2009, 8:41pm UTC](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897/80 "2009-03-22T20:41:34Z")
> [@Chronos](#): > > It’s not the temperature that’s unprecedented, it’s the rate of temperature change. (1) Cite? (2) Do you agree that the rate of temperature increase in roughly the first half of the 20th century is approximately the same as the rate of temperature increase in the second half of the 20th century? [Previous page](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897.md?page=3) [Next page](https://boards.straightdope.com/t/the-evidence-against-global-warming-read-before-flaming/489897.md?page=5)