Talk:Global warming

Global warming

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Article Checklist for "Global warming"

Workgroup category or categories	Earth Sciences Workgroup [Categories OK]
Article status	Developing article: beyond a stub, but incomplete
Underlinked article?	Yes
Basic cleanup done?	No
Checklist last edited by	Nereo Preto 08:23, 26 May 2007 (CDT)

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This article talk page is now under dispute watch

See CZ:Dispute Watch. You're going to have to start using the {{prop}} template in the way that page describes, illustrated here: Talk:Oriental (word). We're testing out a dispute resolution idea, but I'm taking the test seriously. From now on, disputation on this page must be on-topic, and on-topic means (1) aimed at a specific proposition, (2) the proposition must concern the wording of the text, and (3) engaging in a dispute, as opposed to how to characterize the dispute, is off-topic. Call it the Anti-Bloviation Rule!  :-)

Note, for this topic in particular, that how much dispute there is about this topic is itself (pretty obviously) a matter of dispute. So we must not take a stand on that dispute, but must describe it. --Larry Sanger 07:17, 3 August 2007 (CDT)

So we must suggest a different and specific change in the article's text to dispute the content herein? Benjamin Seghers 09:20, 3 August 2007 (CDT)

Yep. But notice that the change can be: delete it. --Larry Sanger 09:22, 3 August 2007 (CDT)

Global warming and hurricanes

Proposition: I think we should expand on the role of global warming on hurricanes. I think this one area of higher amount of debate in the scientific community, with regards to how large an impact sea surface temperatures are having on intensity and frequency of hurricanes across the globe (as opposed to more natural factors, such as wind shear, for example). I don't know exactly what should be written, but there is much to say about the issue. Benjamin Seghers 12:43, 3 August 2007 (CDT)

"Very likely" as opposed to 100%

Our intro reads, "The prevailing scientific view, as represented by the science academies of the major industrialized nations and the Intergovernmental Panel on Climate Change (IPCC), is that most of the temperature increase since the mid-20th century has been caused by increases in atmospheric greenhouse gas concentrations produced by human activity." I wonder if it should say "is very likely caused by increases in atmospheric . . ." so as to mimic the IPCC language that suggest 90% certainty rather absolute certainty? Benjamin Seghers 14:02, 5 August 2007 (CDT)

Ben (Benjamin?), I am still assembling research for the counter-point. I have already identified several peer-reviewed papers which do not support some of the claims of Global Warming alarmists. However, one of of the founding arguments I'm running across is that the IPCC is fundamentally biased due various reasons. How do we expect to address those claims? I'm trying to run through Larry's new dispute resolution formula on other pages, but I've not gotten a good enough handle on my argument to approach the article sentence by sentence. I'm not a "global warming scoffer", but rather an ardent neutrality proponent. Thus, I'd sure appreciate some help "writing for the enemy" as they say. Please let me know if you are interested in collaborating on that effort. If so, I'll start sharing some of my research. Will Nesbitt 14:30, 5 August 2007 (CDT)

Mr. Nesbitt, I don't get exactly what your counter-point is. Are you trying to negate everything in the article? There are many (scientific) papers that do indeed differ in conclusion with some of the IPCC's. I haven't really found any that in fact attack the IPCC as biased or fundamentally flawed. It's a body of scientists that synthesize a multitude of scientific papers into their Assessment Reports. I'm sure there are editorials or blog postings out there, but that's another thing. That said, I am sure there are genuine and bona fide critiques of the organization. But I think if we want to discuss the IPCC in that light, it should be done on the IPCC's own article. I'm for anything that will make this article neutral, but at the same time am opposed simply trying insert obviously flawed points or arguments in attempt to make it seem as if this were some 50:50 argument. Elsewhere, I've been labeled as one "writes for the enemy," whether correctly or not, simply through the introduction of scientific thoughts that do not mesh with the majority or some other. You and I are interested in the same objective, but we have to be careful to do so in the correct manner. For example, just above I'm suggesting we move from the absolutism currently in the sentence and go to the more appropriate and veracious language. I am also interested in exploring more in depth the roles of global warming and hurricanes, as pointed out above. It's just a matter of being neutral rather than countering each claim as false, because the latter is not neutral. Benjamin Seghers 15:37, 5 August 2007 (CDT)

Proposition: Our intro reads, "The prevailing scientific view, as represented by the science academies of the major industrialized nations and the Intergovernmental Panel on Climate Change (IPCC), is that most of the temperature increase since the mid-20th century has been caused by increases in atmospheric greenhouse gas concentrations produced by human activity." I wonder if it should say "is very likely caused by increases in atmospheric . . ." so as to mimic the IPCC language that suggest 90% certainty rather absolute certainty? Benjamin Seghers 14:02, 5 August 2007 (CDT)

I'd like to see the math formula that led a precise percentage of certitude, mainly because I doubt it exists. *smile* However, I would prefer that we quote the IPCC rather than state this as a matter of fact. We know that this is the IPCC's position. We don't really know if they are correct or not. Will Nesbitt 09:39, 6 August 2007 (CDT)

Well, in the AR4 SPM, the footnote reads, "In this Summary for Policymakers, the following terms have been used to indicate the assessed likelihood, using expert judgement, of an outcome or a result: Virtually certain > 99% probability of occurrence, Extremely likely > 95%, Very likely > 90%, Likely > 66%, More likely than not > 50%, Unlikely < 33%, Very unlikely < 10%, Extremely unlikely < 5%. (See Box TS.1.1 for more details)." The box doesn't appear in the SPM, but I was able to find it in chapter 1 of the WGI contribution to the AR4. It states:

Box 1.1: Treatment of Uncertainties in the Working Group I Assessment

The importance of consistent and transparent treatment of uncertainties is clearly recognised by the IPCC in preparing its assessments of climate change. The increasing attention given to formal treatments of uncertainty in previous assessments is addressed in Section 1.6. To promote consistency in the general treatment of uncertainty across all three Working Groups, authors of the Fourth Assessment Report have been asked to follow a brief set of guidance notes on determining and describing uncertainties in the context of an assessment .1 This box summarises the way that Working Group I has applied those guidelines and covers some aspects of the treatment of uncertainty specific to material assessed here

Uncertainties can be classified in several different ways according to their origin. Two primary types are ‘value uncertainties’ and ‘structural uncertainties’. Value uncertainties arise from the incomplete determination of particular values or results, for example, when data are inaccurate or not fully representative of the phenomenon of interest. Structural uncertainties arise from an incomplete understanding of the processes that control particular values or results, for example, when the conceptual framework or model used for analysis does not include all the relevant processes or relationships. Value uncertainties are generally estimated using statistical techniques and expressed probabilistically. Structural uncertainties are generally described by giving the authors’ collective judgment of their confidence in the correctness of a result. In both cases, estimating uncertainties is intrinsically about describing the limits to knowledge and for this reason involves expert judgment about the state of that knowledge. A different type of uncertainty arises in systems that are either chaotic or not fully deterministic in nature and this also limits our ability to project all aspects of climate change.

The scientific literature assessed here uses a variety of other generic ways of categorising uncertainties. Uncertainties associated with ‘random errors’ have the characteristic of decreasing as additional measurements are accumulated, whereas those associated with ‘systematic errors’ do not. In dealing with climate records, considerable attention has been given to the identification of systematic errors or unintended biases arising from data sampling issues and methods of analysing and combining data. Specialised statistical methods based on quantitative analysis have been developed for the detection and attribution of climate change and for producing probabilistic projections of future climate parameters. These are summarised in the relevant chapters.

The uncertainty guidance provided for the Fourth Assessment Report draws, for the first time, a careful distinction between levels of confidence in scientific understanding and the likelihoods of specific results. This allows authors to express high confidence that an event is extremely unlikely (e.g., rolling a dice twice and getting a six both times), as well as high confidence that an event is about as likely as not (e.g., a tossed coin coming up heads). Confidence and likelihood as used here are distinct concepts but are often linked in practice.

The standard terms used to define levels of confidence in this report are as given in the IPCC Uncertainty Guidance Note, namely:

Confidence Terminology Degree of confidence in being correct

Very high confidence At least 9 out of 10 chance

High confidence About 8 out of 10 chance

Medium confidence About 5 out of 10 chance

Low confidence About 2 out of 10 chance

Very low confidence Less than 1 out of 10 chance

Note that ‘low confidence’ and ‘very low confidence’ are only used for areas of major concern and where a risk-based perspective is justified.

Chapter 2 of this report uses a related term ‘level of scientific understanding’ when describing uncertainties in different contributions to radiative forcing. This terminology is used for consistency with the Third Assessment Report, and the basis on which the authors have determined particular levels of scientific understanding uses a combination of approaches consistent with the uncertainty guidance note as explained in detail in Section 2.9.2 and Table 2.11.

The standard terms used in this report to define the likelihood of an outcome or result where this can be estimated probabilistically are:

Likelihood Terminology Likelihood of the occurrence/ outcome

Virtually certain > 99% probability

Extremely likely > 95% probability

Very likely > 90% probability

Likely > 66% probability

More likely than not > 50% probability

About as likely as not 33 to 66% probability

Unlikely < 33% probability

Very unlikely < 10% probability

Extremely unlikely < 5% probability

Exceptionally unlikely < 1% probability

The terms ‘extremely likely’, ‘extremely unlikely’ and ‘more likely than not’ as defined above have been added to those given in the IPCC Uncertainty Guidance Note in order to provide a more specific assessment of aspects including attribution and radiative forcing.

Unless noted otherwise, values given in this report are assessed best estimates and their uncertainty ranges are 90% confidence intervals (i.e., there is an estimated 5% likelihood of the value being below the lower end of the range or above the upper end of the range). Note that in some cases the nature of the constraints on a value, or other information available, may indicate an asymmetric distribution of the uncertainty range around a best estimate. Benjamin Seghers 11:32, 6 August 2007 (CDT)

Dispute Watch cancelled

The CZ:Dispute Watch experiment failed interestingly--so this article is back to usual. Just bear in mind we are still operating under CZ:Professionalism as well as CZ:Neutrality Policy. Among other things, this latter means that it is not CZ's official view that global warming is caused by human beings. We are officially agnostic (not skeptical--there's a difference!). We can, of course, report the facts about the proportions of the relevant experts who believe this, though--and the grounds on which they've issued their findings! --Larry Sanger 05:27, 10 August 2007 (CDT)

That's a curious statement, Dr. Sanger. Either way, I don't believe it ought to be the purpose of any encyclopedia to "take sides." We ought to simply report the facts as they are presented in the scientific literature, and let them speak for themselves. Benjamin Seghers 09:14, 10 August 2007 (CDT)

Perhaps you misunderstood me, Ben. I agree that encyclopedias should not take sides, and indeed that was my point. Moreover, I of course agree that we should report the facts as they are presented in the scientific literature. (How else?) To all this I am adding that it is our policy to attribute the view that global warming is caused by human beings to its adherents, instead of simply asserting it ourselves. Moreover, we will acknowledge and fairly, without asserting to be false, characterize views that are in disagreement with this. And we will also fairly characterize how the skeptics have been received by the larger scientific community. In short, we will fairly represent the entire dialectical situation--without, indeed, not take sides. This sort of thing is explained in painful detail in Neutrality Policy. --Larry Sanger 10:17, 10 August 2007 (CDT)