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> 99% of experts Ah, the fabled /9[789]%(.9)?/ argument raises its ugly head again. This claim has several sources, let's have a look at them. In 2009, the Un

> 99% of experts Ah, the fabled /9[789]%(.9)?/ argument raises its ugly head again. This claim has several sources, let's have a look at them. In 2009, the University of Illinois sent a survey [1] online to about 10200 scientists (of many disciplines) with the following two questions: 1: Do you agree that global temperatures have generally risen since the pre-1800s? 2: Do you think that human activity is a significant contributing factor? 3146 responses were received of ~10,200, and of that 31%, 90% said yes to the first question while 82% said yes to the second question. When narrowed down to actual experts in the field (mostly meteorologists) 64% answered 'yes' to the second question. Of the 3146 responses 77 were selected which came from self-professed 'climate experts'. Of these 77 individuals 75 answered 'yes' to the second question. 75/77 = 0.97 -> 97% of experts agree In reality a self-professed "expert" group of 2.4% of the answerers were selected who in turn formed 0.8% of those who received the survey. The well-known saying about statistics - there's lies, damned lies and statistics [2] - comes to mind here. Then there was the '2013 Cook study' [3] entitled 'Quantifying the consensus on anthropogenic global warming in the scientific literature' which is often cited as another source for the '97%'. Cook and his team searched the Web of Science for the phrases "global warming" and "global climate change", then categorised the results to what they considered to be their level of endorsement of anthropogenic global warming. While Cook's conclusion - “Cook et al. (2013) found that over 97 percent [of papers he surveyed] endorsed the view that the Earth is warming up and human emissions of greenhouse gases are the main cause.” - was taken for gospel by those who were looking for more endorsement of the earlier '97%' study. What is it based on? Cook created a category called “explicit endorsement without quantification” (papers in which the author did not say whether 1 percent or 50 percent or 100 percent of the warming was caused by man). He had also created a category called “implicit endorsement” for papers that imply (but don’t say) that there is some man-made global warming without quantification of the effect. These were the categories used to calculate the '97%'. Many scientists whose papers were classified in these categories protested to Cook [4] for being selective in which papers were cited and misrepresentation of their positions on the subject of anthropogenic climate change. Cook's data is available in the study [3], the positions on anthropogenic global warming look like this: Explicitly endorse AGW 50+% = 0.54% Explicitly endorse – does not quantify = 7.72% Explicitly endorse AGW without minimizing it = 24.36% No Position = 66.73% Implicit minimizes/rejects AGW = 0.45% Explicit minimizes/rejects AGW = 0.13% Explicitly minimizes/rejects AGW as <50% = .08% These 7 groups are summarised in 4 categories by Cook: Endorse AGW 32.6% No AGW Position 66.4% Reject AGW .7% Uncertain on AGW .3% The study arrives at the '97% endorsement' by leaving out the 66% who do not have a position which leaves the 32.6% who endorse some form of AGW against the 0.7% who reject it. Apart from the mentioned problems with the categorisation this is another example of lies, damned lies and statistics [2]. In short, don't use the /9[789]%(.9)?/ argument in an attempt to appeal to authority, especially not in the context of a discussion around the viability of global climate models as evidence for future climate change. First because of the mentioned reasons but also because the '97%' argument has no bearing on the validity of climate models since it just - rightly or wrongly - claims that '97% of experts agree that anthropogenic climate change is a fact'. [1] https://www.sciencedaily.com/releases/2009/01/090119210532.htm https://www.sciencedaily.com/releases/2009/01/090119210532.h... [2] https://en.wikipedia.org/wiki/Lies,_damned_lies,_and_statistics https://en.wikipedia.org/wiki/Lies,_damned_lies,_and_statist... [3] https://iopscience.iop.org/article/10.1088/1748-9326/8/2/024024 https://iopscience.iop.org/article/10.1088/1748-9326/8/2/024... [4] http://www.populartechnology.net/2013/05/97-study-falsely-classifies-scientists.html http://www.populartechnology.net/2013/05/97-study-falsely-cl...

geysersam 4y ago
You claim your standpoint is scientific. But the only peer reviewed article you cite is the one that contradict your claims! There's no doubt a scientific consensus that human carbon emissions are causing global warming. There are multiple extremely heavyweight sources for this, starting with the IPCC reports. I'm not a climatologist and can't claim to know the extensive literature. But I do understand the proposed mechanism, I trust people are generally not falsifying data, and I don't see any reason for why thousands of scientists and the IPCC would conspire to make up a lie like that. On the other hand, the fossile fuel industry has a very clear incentive, and it's well documented they have financed researchers supporting their interests.
- the_third_wave 4y ago
  I did study meteorology (but not climatology). I do understand the proposed mechanism but I do not trust the models, mostly because I know the limitations of weather and climate models and recognise the magnitude of 'fudge factors' in play when these models are proposed. In many ways they resemble the old joke about the theoretical physicist who was charged with figuring out how to increase the milk production of cows. Although many farmers, biologists, and psychologists had tried and failed to solve the problem before him, the physicist had no trouble coming up with a solution on the spot. “First,” he began, “we assume a spherical cow ... ”. You mention the clear incentives the fossil fuel industries have in toning down the environmental impact - I explicitly use that term instead of 'climate impact' which has replaced it in popular media since I consider the former to be a known and proven problem - their products have. This is certainly the case and stands without doubt. You do not mention the clear incentives the 'green' industry has in pushing climate panic. Don't you think this is a factor or do you simply agree with their messaging? Does it bother you that several fossil fuel giants have jumped on the 'green' bandwagon so they get to play both sides in this game of charade? > There's no doubt a scientific consensus that human carbon emissions are causing global warming. Sure, when you increase the emission of greenhouse gases there is some impact. How large this impact is is less clear, nor is it clear that the increased CO₂ concentration in the atmosphere is the main cause of the recent warm spell or whether it is caused by it. Historical climate records show CO₂ concentration trailing temperature changes, not leading them, the theory being that change in concentration is caused by the change in seawater temperature with colder water absorbing CO₂ (and other gases) which is released when the water warms up again. Another factor in play is the concentration of water vapour in the atmosphere - it shares 3 of the 4 main absorption areas in the spectrum with CO₂ - as is cloud cover (which has a significant effect on the planet's albedo (reflection coefficient)). Since temperature, CO₂ concentration, water vapour concentration and cloud cover are related and interdependent a change in one causes a change in the others. These relationships have not been not taken into account in most models until recently [1] while they are sure to play a role. There are many other factors which are either not taken into account or set at assumed values. [1] this is one of the areas in which climate models have been improved in the last years: 'Cloud feedbacks have been confirmed as a primary source of these differences, with low clouds making the largest contribution. New observational and modelling evidence strongly supports a combined water vapour-lapse rate feedback of a strength comparable to that found in General Circulation Models (approximately 1 W m–2 °C–1, corresponding to around a 50% amplification of global mean warming). The magnitude of cryospheric feedbacks remains uncertain, contributing to the range of model climate responses at mid- to high latitudes.'(https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg1-chapter8-1.pdf:3 https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg1-chap...)

geysersam 4y ago

You claim your standpoint is scientific. But the only peer reviewed article you cite is the one that contradict your claims! There's no doubt a scientific consensus that human carbon emissions are causing global warming. There are multiple extremely heavyweight sources for this, starting with the IPCC reports. I'm not a climatologist and can't claim to know the extensive literature. But I do understand the proposed mechanism, I trust people are generally not falsifying data, and I don't see any reason for why thousands of scientists and the IPCC would conspire to make up a lie like that. On the other hand, the fossile fuel industry has a very clear incentive, and it's well documented they have financed researchers supporting their interests.

the_third_wave 4y ago
I did study meteorology (but not climatology). I do understand the proposed mechanism but I do not trust the models, mostly because I know the limitations of weather and climate models and recognise the magnitude of 'fudge factors' in play when these models are proposed. In many ways they resemble the old joke about the theoretical physicist who was charged with figuring out how to increase the milk production of cows. Although many farmers, biologists, and psychologists had tried and failed to solve the problem before him, the physicist had no trouble coming up with a solution on the spot. “First,” he began, “we assume a spherical cow ... ”. You mention the clear incentives the fossil fuel industries have in toning down the environmental impact - I explicitly use that term instead of 'climate impact' which has replaced it in popular media since I consider the former to be a known and proven problem - their products have. This is certainly the case and stands without doubt. You do not mention the clear incentives the 'green' industry has in pushing climate panic. Don't you think this is a factor or do you simply agree with their messaging? Does it bother you that several fossil fuel giants have jumped on the 'green' bandwagon so they get to play both sides in this game of charade? > There's no doubt a scientific consensus that human carbon emissions are causing global warming. Sure, when you increase the emission of greenhouse gases there is some impact. How large this impact is is less clear, nor is it clear that the increased CO₂ concentration in the atmosphere is the main cause of the recent warm spell or whether it is caused by it. Historical climate records show CO₂ concentration trailing temperature changes, not leading them, the theory being that change in concentration is caused by the change in seawater temperature with colder water absorbing CO₂ (and other gases) which is released when the water warms up again. Another factor in play is the concentration of water vapour in the atmosphere - it shares 3 of the 4 main absorption areas in the spectrum with CO₂ - as is cloud cover (which has a significant effect on the planet's albedo (reflection coefficient)). Since temperature, CO₂ concentration, water vapour concentration and cloud cover are related and interdependent a change in one causes a change in the others. These relationships have not been not taken into account in most models until recently [1] while they are sure to play a role. There are many other factors which are either not taken into account or set at assumed values. [1] this is one of the areas in which climate models have been improved in the last years: 'Cloud feedbacks have been confirmed as a primary source of these differences, with low clouds making the largest contribution. New observational and modelling evidence strongly supports a combined water vapour-lapse rate feedback of a strength comparable to that found in General Circulation Models (approximately 1 W m–2 °C–1, corresponding to around a 50% amplification of global mean warming). The magnitude of cryospheric feedbacks remains uncertain, contributing to the range of model climate responses at mid- to high latitudes.'(https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg1-chapter8-1.pdf:3 https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg1-chap...)