Talk:Climate change

"Burning fossil fuels and deforestation" in lead

There's been some debate about using that phrase in the lead. For a long time, (2 years?) there has been no WP:LEADCITE, but the body text does support it, with a citation to TAR (2000). AR5 WG1 SPM identifies several things, but also says the dominant contributor is the buildup of greenhouse gas, especially CO2 since 1750. Maybe we can make something of that. In any case, if "Burning fossil fuels and deforestation" goes back into the lead, it should do so in a way that does not take an ax to all AR5 WG1 SPM references.... so add proposed text back manually please. NewsAndEventsGuy (talk) 21:06, 10 January 2014 (UTC)

AR5 WG1 SPM says, in the summary to section B5 (P. 9), "Carbon dioxide concentrations have increased by 40% since pre-industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions." AR4 (cited at the end of the relevant sentence, but not in the quote used in the <ref>) says in bold, "Global increases in CO₂ concentrations are due primarily to fossil fuel use, with land-use change providing another significant but smaller contribution."[1] We should base article text (especially in a lead summary) on the conclusions drawn by the cited source's authors, not by trawling around in the raw data, the sub-bullet points, or the diagrams, for snippets. Therefore, I would say that the only debate is whether to replace "deforestation" by "net land use change". I suggest that we should make it clear that we are talking about the cause of CO₂ concentration increases, and use a phrase very close to "primarily from fossil fuel emissions and secondarily from net land use change emissions". --Nigelj (talk) 21:55, 10 January 2014 (UTC)

That's good, thanks. I totally agree. NewsAndEventsGuy (talk) 22:01, 10 January 2014 (UTC)

That's in the "forcings" section of the report. It's not warming. Forcings correlate to warming but are not the same. If you look at the AR4 section on warming (and the title is "Global Warming" not net energy forcings) , it's anthropogenic green house gases, including methane and water vapor, that are attributed for more than half the warming. It's not burning of fossil fuels or cement plants (try to find the difference) or land use changes (which in AR5 are a cooling, not a warming effect). It is pure synthesis to attribute a number (0.3 to 0.7C in the last 50 years) to 2 causes. It's rubbish. IPCC does not attribute any amount of warming to the singular effect of fossil fuel burning. It's fair to discuss the various forcings in the body, but fossil fuel burning associated with a specific amount of warming is not. Therefore, it's not a lead item in article global warming--DHeyward (talk) 02:48, 11 January 2014 (UTC)

Apart from forcings, the other things that affect global temperatures are mostly feedbacks. Water vapour, methane released due to warming tundra etc, and changes in albedo due to melting ice, are as much effects of the initial forcings as they are causes of further warming in their own rights. The sentence is about the main cause, and the sources say that main cause is the main source of CO₂, i.e. human activity. Forcings cause global warming, feedbacks are part of the response, and cause further effects – usually more warming although negative feedback loops do also exist. --Nigelj (talk) 15:03, 11 January 2014 (UTC)

It's all modeled as a forcing. The citation for the wording doesn't support it. Cement plants are nearly half the source of man-made direct CO2. Land use change including deforestation is modeled as a net cooling effect. Read the citation for that sentence and find the table. It's anthropogenic greenhouse gases as the sum that is responsible for warming. It's countered by anthropogenic cooling. Natural variation is modeled as near 0. This why warming tracks forcing but warming is not forcing. Without cooling offsets like land use changes, the observed increase in surface temperature is estimated to be nearly double the current observed amount. It's simply incorrect to call out fossil fuel burning (a definite component of warming, but not whole) and deforestation (modeled as a net cooling). Tundra exposure is not deforestation. --DHeyward (talk) 16:15, 11 January 2014 (UTC)

AR5 WG1 SPM says

• land-use-related albedo change is somewhat cooling, but it also references
• land-use-related greenhouse gases buildup, though it seems to stop short of directly connecting the dots to compare to albedo change without wikipedia editors doing original research.

So why do keep saying IPCC claims "land use is cooling"?

At any rate, if AR5 WG1 draft paragraph 6.3.1 (CO2 Emissions and Their Fate Since 1750) survives until official publication we can probably say ""...human activities, especially the burning of fossil fuels, cement production, and land use changes (mainly deforestation)."

NewsAndEventsGuy (talk) 17:28, 11 January 2014 (UTC)

Ar5 SPM page 12, chart SPM.5. Seconde to last line in the chart and the last anthropogenic item. Called "Albedo change due to land use" -0.15 W m^-2. That's the forcing. There's also a temperature chart in the WG details. --DHeyward (talk) 18:45, 11 January 2014 (UTC)

Here's the statement behind the chart in the document we can't cite (another reason not to even mention it). [2]. Chapter 8-4 (page 6 in the PDF). They discuss whether the CO2 contribution of land use change offsets albedo changes of land use (the difference is the net effect of land use change). Bolding is theirs. Basically, it says "keep it out" as albedo is cooling and the net change of whether it's overall a cooling or warming effect has low agreement. They keep the albedo in the forcing models and any change to GHG's are lumped into the larger forcing. No support for saying that land use change contributes to global warming.

There is robust evidence that anthropogenic land use change has increased the land surface albedo, which leads to a RF of -0.15 ± 0.10 W m–2

. There is still a large spread of estimates due to different assumptions for the albedo of natural and managed surfaces and the fraction of land use changes before 1750. Land use change causes additional modifications that are not radiative, but impact the surface temperature, in particular through the hydrologic cycle. These are more uncertain and they are difficult to quantify, but tend to offset the impact of albedo changes. As a consequence, there is low agreement on the sign of the net change in global mean temperature as a result of land use change. [8.3.5]

— Preceding unsigned comment added by DHeyward (talk • contribs)

No need to prove the WP:POINT that land use's albedo shift is a neg forcing; no is disputing that so please stop arguing about it. In addition, when you do mention the neg forcing related to land use, let's be NPOV and mentioned GHG emissions related to the same phenomena.NewsAndEventsGuy (talk) 14:31, 12 January 2014 (UTC)

I've just tweaked the lead with what SPM says about overall forcing (pos), the largest contributor (CO2), and the main sources of CO2 (ff burning, cement production, and land use especially deforestration.NewsAndEventsGuy (talk) 14:31, 12 January 2014 (UTC)

Where did you get deforestation? It is clearly misleading. Land use change is only listed as a cooling forcing. There is no agreement on it's net overall effect. "Deforestation" is NOT SUPPORTED as being significant. Please tell me where "deforestation" is listed as GHGs that have a consensus of warming? It doesn't. -DHeyward (talk) 21:50, 12 January 2014 (UTC)

Check the citation I included, which contains the direct quote and page number.NewsAndEventsGuy (talk) 22:41, 12 January 2014 (UTC)

Land-use is responsible for roughly 1/3 of carbon emissions - 1/3 of the carbon forcing is 0.54 W/m² which is significantly higher than the 0.15 W/m² of albedo change. That makes it your responsibility to find it explicitly stated in the AR5 that land-use is a negligible factor (especially since the AR5 states (directly) that uncorrected for urban-heat+landuse change could be responsible for as high as 10% of total warming - though more likely significantly lower, but still positive). --Kim D. Petersen 04:25, 14 January 2014 (UTC)

Explicitly the AR5 estimates carbon emissions from land-use change to be (0.17–0.51 W/m²)[AR5 WGI 8.3.2.1] which is significantly higher than albedo changes which is (-0.15±0.10 W/m²) [AR5 WGI 8.3.5.6] --Kim D. Petersen 04:41, 14 January 2014 (UTC)

Bullshiat. They explicitly say it isn't because the carbon contribution is an extremely low confidence and agreement while albedo changes have robust data and high confidence. (and I quote)

There is still a large spread of estimates due to different assumptions for the albedo of natural and managed surfaces and the fraction of land use changes before 1750. Land use change causes additional modifications that are not radiative, but impact the surface temperature, in particular through the hydrologic cycle. These are more uncertain and they are difficult to quantify, but tend to offset the impact of albedo changes. As a consequence, there is low agreement on the sign of the net change in global mean temperature as a result of land use change. [8.3.5]

Why is that bolded part hard to understand? They practically say "don't list land use change as a cause of warming because we don't." Do all the original research on the numbers you want but net result from AR5 is that albedo is quantifiable while carbon emissions is less so. If AR5 can't even figure out the sign of temperature regarding land use changes, listing it as a "main driver" for warming seems to be a bit wrong. --DHeyward (talk) 00:29, 15 January 2014 (UTC)

Also, you are confusing listing forcings with temperature. Albedo offsets the loss trees. Blackened areas decrease albedo and non-blacked areas increase it. They know with high confidence that albedo is a net cooling effect with robust data high confidence. What they don't know is the effect of the loss of trees and what latitude deforestation/land use change is w.r.t. the temperature. So as of now, they don't know and say so very explicitly. Search for deforestation in your source and you will see. Read the bullet point that says "low agreeement on the sign of the net change". The certainly don't conclude deforestation is a warming factor. --DHeyward (talk) 00:54, 15 January 2014 (UTC)

No, i am not "confusing listing forcings with temperature" - since i have not at any point addressed temperature. Never mentioned. At. All. --Kim D. Petersen 07:54, 15 January 2014 (UTC)

When they say " largest driver of global warming is carbon dioxide (CO2)" that, by definition, is surface temperature (read the article, it says so). When they say "total radiative forcing is positive" they are talking about the net radiative forcing of all components. The model is a radiative model so that's how everything is modeled. The statement "total radiative forcing is positive" includes both positive and negative forcings for various human and natural causes. "land use" happens to be a net zero forcing. It does not contribute anything to the "total radiative forcing is positive" equation. It is a net neutral activity for GW. When the statement cites "total radiative forcing is positive" it means both positive and negative forcings for modeled phenomenon on balance come out positive. It's not just CO2 or carbon forcings. The leap from "total radiative forcing is positive" to "global warming" has to acknowledge that it includes forcings from all activities. Anthropogenic land use change is one activity that has a zero sum for that model. --DHeyward (talk) 23:42, 15 January 2014 (UTC)

Why the devil are you only rapping on about albedo? Albedo is not the only forcing factor in land-use change. Your bolded part is in a section about albedo - not in a section about land-use change in general. There is low agreement on the sign of land-use change albedo - it is in the uncertainty:

Albedo change: -0.15±0.10 W/m² - which gives a range of -0.25 to +0.5 <---- can you see that the sign is uncertain?? There is no high confidence in cooling!

The confidence on greenhouse forcing from land-use change (you know the one you want to ignore, and which isn't addressed in the section that you keep repeating), is:

The impact of land use change on CO2 from 1850 to 2000 was assessed in AR4 to be 12–35 ppm (0.17–0.51 W m–2). (AR5 WG1 8.3.2.1)

To summarize: You ignore that land-use change is more than albedo, you assert certainty where no such certainty is evident. You then remove sourced statements from the article based upon your own interpretation of albedo => WP:OR. --Kim D. Petersen 07:52, 15 January 2014 (UTC)

(A) In the sentence in question, deforestation and land use are listed as being GHG sources. (B) They are included as GHG sources with a direct quote from the RS (C) I think DHeyward is fixated on net land use changes, but that is not what the text is talking about and it is not what the direct quote was talking about. NewsAndEventsGuy (talk) 12:13, 15 January 2014 (UTC)

Incorrect. The lead is talking about the main contributions to a phenomenom known as "Global warming." It's those big characters at the top. The lead is talking about drivers of global surface "temperature change." Net global warming temperature change has low agreement As a consequence, there is low agreement on the sign of the net change in global mean temperature as a result of land use change. [8.3.5]... You are synthesizing from CO² contributions to surface warming by land use changes when the net effect is explicitly addressed. Deforestation will increase albedo (cooling, with very high certainty using satellite data) and that the resulting change will possibly emit GHGs. There is no agreement that it causes warming. Certainly not something we should say or infer is a major contributor to global warming. It isn't. 'Global warming' is this article, not net greenhouse gas contributors. It is perfectly fine to list fossil fuel burning and concrete plants (as I suggested) but not land use changes. Planting a forest where there is high albedo might have a negative effect (warming), removing a tree where there is high albedo may cause cooling. You cannot synthesize that deforestation has contributed to global warming because of CO2 when the net effect is zero. AR5 explicitly says this in 8.3.5. Do all the math you want, but when the experts do it, there is disagreement about whether deforestation/afforestation will have any impact on warming. . It's directly stated in AR5 that land use change, such as deforestation/afforestation, is unknown. The confidence in surface albedo rising from land use change has risen since AR4 (it's in that same source) while contributions to CO2 have remained the same. Whence, it is now different and there is low agreement that deforestation has contributed to global warming. Take the blinders off and read it. Keep in mind that this article is about "global warming" and not greenhouse gases. --DHeyward (talk) 14:52, 15 January 2014 (UTC)

Let's make it simpler. The statement "Affirming these findings in 2013, IPCC says that the largest driver of global warming is carbon dioxide (CO2) emissions from fossil fuel combustion, cement production, and land use changes such as deforestation." Is based on a source about radiative forcings being positive for CO2. Fossil fuel certainly adds a positive radiative forcing through CO2, CH4, etc. Cement plants have a positive radiative forcing. Land use changes, however do not have a positive net radiative forcing. It is unknown. New in AR5. Certainly, it's added CO2, but that's not the net radiative forcing that is sourced, it's synthesized by WP to only be CO2. IPCC AR5 certainly DOES NOT SAY and in fact SAYS THE EXACT OPPOSITE "IPCC says that the largest driver of global warming...land use changes such as deforestation." is flat out wrong. Land use change is not a large driver of global warming. We should not state the exact opposite of IPCC's own statement. --DHeyward (talk) 14:52, 15 January 2014 (UTC)

Poll

Background: IN AR5 WG1 SPM, the IPCC said

"Total radiative forcing is positive, and has led to an uptake of energy by the climate system. The largest contribution to total radiative forcing is caused by the increase in the atmospheric concentration of CO2 since 1750." (p 11) "From 1750 to 2011, CO2 emissions from fossil fuel combustion and cement production have released 375 [345 to 405] GtC to the atmosphere, while deforestation and other land use change are estimated to have released 180 [100 to 260] GtC." (p 10)

— IPCC AR5 WG1 SPM

Question: In light of the quoted text, is it appropriate to say in the lead of Global warming that "IPCC says that the largest driver of global warming is carbon dioxide (CO2) emissions from fossil fuel combustion, cement production, and land use changes such as deforestation"? If you answer "no" please indicate how you would change the text and then explain why.NewsAndEventsGuy (talk) 15:07, 15 January 2014 (UTC)

• Yes Our analysis doesn't really need to go beyond the language IPCC opted to flag in their nutshells, from which the quotes were taken, and the quotes say the biggest driver of global warming is GHG and that GHG comes from 3 main sources: Fossil fuels, cement manufacture, and land use such as deforestation. They say it in their nutshell, so it is appropriate to say it in our lead. Other ways land use contributes +/- forcings is worthy of mention in the body of the article, but doesn't change fact that this RS says land use is a mighty source of GHG emissions. NewsAndEventsGuy (talk) 15:06, 15 January 2014 (UTC)
• Yes Most certainly. The IPCC is the most reliable source to their own conclusions, and if they summarize their conclusions this way, then we as editors cannot do original research and determine that "they really shouldn't have done that", string up some readings of various subsections in the report, reach a different conclusion, and then remove the parts that we do not like. That much should be obvious ... but apparently isn't. --Kim D. Petersen 15:17, 15 January 2014 (UTC)

Correct that we should not summarize their conclusions incorrectly. They don't interpret land use change as increasing global warming. They attribute carbon in the atmosphere to land use change and albedo to land use change and other effects to land use change and come with a near zero forcing of temperature. Net forcings of land use change (warming and cooling) are near 0 and have have little support as a source of significant warming or cooling. Read page [3]. --DHeyward (talk) 21:59, 15 January 2014 (UTC)

• No, should mention methane specifically too: from the methane article: "Cattle belch methane accounts for 16% of the world's annual methane emissions to the atmosphere.[41] One study reported that the livestock sector in general (primarily cattle, chickens, and pigs) produces 37% of all human-induced methane.[42]" (This article should mention cow-belch methane too.) Raquel Baranow (talk) 15:24, 15 January 2014 (UTC)

Nonresponsive. Telling us what else it should say does not address the question.NewsAndEventsGuy (talk) 15:38, 15 January 2014 (UTC)

• No Because because that statement conflates one aspect of surface warming (CO2 radiative forcing) with the entire spectrum of warming. WP is synthesizing the connection of land use changes to imply warming when AR5 says the exact opposite. This is a significant change from AR4. Land use change is not considered a significant driver of "Global warming" despite CO2 emissions. Below are direct quotes from IPCC AR5 sources.

• From 8.3.5 in WG There is robust evidence that anthropogenic land use change has increased the land surface albedo, which leads to a RF of -0.15 ± 0.10 W m–2

There is still a large spread of estimates due to different assumptions for the albedo of natural and managed surfaces and the fraction of land use changes before 1750. Land use change causes additional modifications that are not radiative, but impact the surface temperature, in particular through the hydrologic cycle. These are more uncertain and they are difficult to quantify, but tend to offset the impact of albedo changes. As a consequence, there is low agreement on the sign of the net change in global mean temperature as a result of land use change. [8.3.5]

• From page 8-35: "There is no agreement on the sign of the temperature change induced by anthropogenic land use change. It is very likely that land use change led to an increase of the Earth albedo with a RF of –0.15 ± 0.10 W m–2, but a net cooling of the surface — accounting for processes that are not limited to the albedo — is about as likely as not." page 8-33 in IPCC AR5 WG1 2013

--DHeyward (talk) 15:56, 15 January 2014 (UTC)

D, at most all that says albedo change might have offset landuse's contribution to warming due to GHG buildup. Since the sentence that is the subject of this poll is not about net effect of land use, but rather is about (A) GHG being the single biggest warming and (B) a list of the big GHG sources, your remarks here seem to be unfounded, at least to me. NewsAndEventsGuy (talk) 16:29, 15 January 2014 (UTC)

The quoted text is saying that (increased) atmospheric CO₂ makes the largest contribution to total (increased) radiative forcing, and that fossil fuel combustion, cement production, deforestation and other land use change are the main contributors to atmospheric CO₂. That is very clear and I have to say that talk of albedo is off-topic here. --Nigelj (talk) 18:38, 15 January 2014 (UTC)

I would be fine if the quoted text actually matched the article. But it doesn't. The WP article says "global warming" (not total radiative forcing from CO2). Land use change is not relevant to global warming. Using "Global warming" as a euphemism for "radiative forcing from carbon/CO2" is also incorrect because it's used two ways in section B and C. One way, (section B.5), is only the WMGHG/carbon in the atmosphere, the other is the net radiative forcing (section C). Our lead sentences synthesizes a connection that the authors did not. Land use change contributes to carbon. Land use change does not contribute to overall global warming. "IPCC says that the largest driver of global warming is carbon dioxide (CO2) emissions from ... land use change." Wrong. Dead wrong. Author never says it. IPCC says "Total radiative forcing is positive" (meaning pluses outweigh negatives) but NEVER claims that land use change is a net positive or negative on global warming like the article does because IT DOESN'T. The WP article is just wrong to state land use change as a contributor to "gobal warming" when the authors only intent was to state that carbon in the atmosphere went up but the net surface temp change due to land use change is near 0. Read page 8.3.5 [4]. Search the SPM and you will find that Wikipedia made that connection up. --DHeyward (talk) 21:11, 15 January 2014 (UTC)

Reword to "IPCC says that the largest driver of global warming is carbon dioxide (CO2) emissions from fossil fuel combustion cement production"

Reword to "IPCC says that the largest contributions to atmospheric green house gases is carbon dioxide (CO2) emissions from fossil fuel combustion, cement production, and land use changes such as deforestation"

"Global warming" needs to be explained as a sum of radiative forcings and no-radiative forcings, of which land use change is near 0. -DHeyward (talk) 22:09, 15 January 2014 (UTC)

• Yes But could be extended (did not checked if this is addressed elsewhere), with pointing out slow feedbacks (slow climate inertia). Prokaryotes (talk) 16:38, 15 January 2014 (UTC)
• Yes The quoted text is very clear, and the first part of it at least is from the overall summary to section C, 'Drivers of Climate Change'. When summarising summaries, e.g. for a lede in a top-level article such as this, it is much better to use the original authors' actual summary or conclusions, rather than digging around in the sub-bullet points, or the captions to diagrams, looking for text, which is often a sign of quote-mining rather than summarising. --Nigelj (talk) 19:02, 15 January 2014 (UTC)

Except the original authors never intended (and doesn't) say that "land use change" is, was or will be a major contributor to global warming. It is a major contribution to CO2 but that is not the entire warming story. Section B is about carbon in the atmosphere and mentions land use because it contributes to CO2 in the atmosphere. Section C is about net forcings of warming, but doesn't connect it to land use changes. Well-Mixed Greenhouse Gases are the largest forcing of warming - it's offset by other non-radiative and albedo land use changes. WMGHG's come from all the sources listed. However "global warming" is sum of all the temperature affecting processes. Net land use changes such as deforestation is clearly NOT a large force for "global warming" despite the contribution it makes to CO2 because the total "net forcing" for land use change is a 50/50 shot at 0. That is made very clear in the report. Read page 8.3.5 [5]. Search the SPM and you will find that Wikipedia made that connection up. Insinuating that land use change is a component to average rise in surface temperature is akin to saying humans evolved from monkeys. The different is lost on the casual reader but not the scientists that do the work. --DHeyward (talk) 20:46, 15 January 2014 (UTC)

The section you're looking for regarding land use and CO₂ says, "Between 1750 and 2011, the combustion of fossil fuels (coal, gas, oil, and gas flaring) and the production of cement have released 365 ± 30 PgC (1 PgC = 10¹⁵ gC) to the atmosphere (Table 6.1; Boden et al., 2011). Land use change activities, mainly deforestation, has released an additional 180 ± 80 PgC (Table 6.1). This carbon released by human activities is called anthropogenic carbon."Section 6.3.1 However, as I have said repeatedly here, we should be writing our top-level summary from the scientists' top-level summary, not from the detail. --Nigelj (talk) 12:23, 21 January 2014 (UTC)

You are correct about top-level summary. However, it is synthesis to attribute the activity in a statement about warming because the summary doesn't do that. IPCC doesn't do that at either a high level or the details. It's subtle. It's synthesis to attribute the warming Bayesian test for GHG's to activities (the test passes for fossil fuels and cement, but does not for land use change). The logical fallacy is apparent if we use atmospheric sulfur in coal in the opposite fashion. Anthropogenic sulfur has a measurable cooling effect. Sulfur from coal burning is a major source of anthropogenic sulfur in the atmosphere. Using the synthesis type argument above, we should be able to say "anthropogenic forcings of cooling include sulfur in the atmosphere caused by such activities as coal burning." This should raise immediate red flags because it creates the impression that the activity of coal burning is "cooling." It's not. Even though cooling and sulfur are related, and sulfur and coal are related, the synthesis is not because the relationship to activity is more complicated. The same is true for land use change. Warming and GHGs are related. Land-use change adds GHGs. Synthesizing a connection about the causes of warming with land use change, though, is no more valid than synthesizing a connection between burning coal and cooling. IPCC is meticulous about not making those types of connections and we are synthesizing an untrue statement by creating a cause/effect relationship of activity to warming which IPCC never makes. --DHeyward (talk) 21:30, 21 January 2014 (UTC)

• apples and oranges. The quoted IPCC report says what has caused change over the past 261 years. The proposed change in the lead says what is driving change today. Minor secondary point: The quoted IPCC report states two major causes of radiative forcing, and then mentions a third cause about half as large as the other two combined, but does not say it is the third greatest cause, though I assume it is. Rick Norwood (talk) 18:45, 15 January 2014 (UTC)

Not sure about anyone else, but I did not follow any of that due to pronouns and implied references that assume I know exactly what is meant. Speaking for myself, I'll be happy to think about your comment when I know what you were trying to say... care to rephrase? NewsAndEventsGuy (talk) 19:05, 15 January 2014 (UTC)

Sorry. The IPCC report quoted says "From 1750 to 2011". The proposed change in the lead says "the largest driver of global warming is..." The use of "is" implies that currently these are the three largest drivers, while the IPCC report says that historically these are causes. It makes a difference. I suspect a lot of the apparent contradictions in the various assertions above arises because changes in land use are important historically but have a more ambiguous impact today.Rick Norwood (talk) 13:04, 16 January 2014 (UTC)

Are you saying that there has been a change in the main causes of global warming between 2011 and today?! You'll need a good citation for that claim. --Nigelj (talk) 12:23, 21 January 2014 (UTC)

No, I'm saying that there may have been a change in the main causes of global warming between 1750 and today.Rick Norwood (talk) 15:03, 21 January 2014 (UTC)

Section on food security

I think that the section of the article on global warming#Food security is in need of revision. I'm concerned that it places too much weight on a few studies, and does not explain that projected changes are highly uncertain. Another problem is how it explains changes in food production in relation to socio-economic changes. It mentions changes in population, but does not discuss how, even including the effects of climate change, socio-economic development may help to reduce malnutrition from present levels (see Easterling et al 2007). The section also heavily emphasizes negative impacts on food but places very little weight on positive effects.

References:

• Easterling, WE (2007). "5.6.5 Food security and vulnerability". In ML Parry, et al, (eds.) (ed.). Chapter 5: Food, Fibre, and Forest Products. Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press. ISBN 0-521-88010-6. {{cite book}}: |editor= has generic name (help); Invalid |display-authors=1 (help)CS1 maint: multiple names: editors list (link)

• Gornall, J., et al. Implications of climate change for agricultural productivity in the early twenty-first century. Phil. Trans. R. Soc. B. 2010 365 2973-2989 doi:10.1098/rstb.2010.0158 (published 16 August 2010)

• HLPE, 2012. Food security and climate change (section 2.2). A report by the High Level Panel of Experts on Food Security and Nutrition of the Committee on World Food Security, Rome 2012

• US NRC (2011), Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millennia, Washington, D.C., USA: National Academies Press{{citation}}: CS1 maint: ref duplicates default (link), Sec 5.1 FOOD PRODUCTION, PRICES, AND HUNGER, pp.160-162

Enescot (talk) 08:32, 11 January 2014 (UTC)

Yep, and it doesn't even mention the likely increased food production in Northern climages if the world continues to warm... cwmacdougall 11:29, 11 January 2014 (UTC)

user:cwmacdougall, yes it does - the whole second paragraph is about that, and don't forget that it only applies for small increases in future temperature, not for the larger projections. Which we get will depend on future cuts in global CO₂ emissions, and we still have seen nothing but increases so far. User:Enescot, your well-sourced alterations are always interesting, and usually very good. I'm sure you're well aware that this section is a short summary of the main article at Climate change and agriculture, which might be in need of an upgrade too. It hasn't been on my watchlist until now. And of course we have AR5 coming out bit by bit just at the moment too. --Nigelj (talk) 14:50, 11 January 2014 (UTC)

While WG1 is scheduled for public release Jan 30, the other parts are still some months out, though maybe their SPM's will arrive sooner. NewsAndEventsGuy (talk) 14:53, 11 January 2014 (UTC)

Chap. 7 of the AR5 deals with food production http://www.ipcc-wg2.gov/AR5/ar5-outline.html (not yet released) The IPCC AR4 Impact report also states: "Ecosystems and species are very likely to show a wide range of vulnerabilities to climate change, depending on imminence of exposure to ecosystem-specific, critical thresholds (very high confidence)." http://www.ipcc.ch/pdf/assessment-report/ar4/wg2/ar4-wg2-chapter4.pdf Prokaryotes (talk) 19:15, 11 January 2014 (UTC)

Thanks for the responses. I agree that the AR5 Working Group II report will be a useful source when its finaly released. However I think that the food security section should be revised before then. I suggest that the more detailed information on food impacts be moved to climate change and agriculture. In my view, it would be preferable to revise the entire section so that it presents a more generalized description of the social impacts of climate change. For example, it could be mentioned are that:

- The impacts of climate change on social systems will be uneven, but will be increasingly negative at higher temperatures.

- Some people are at risk from even small increases in global mean temperature.

References

- IPCC 4th Assessment Working Group II report: Summary for Policymakers: Magnitudes of impact; Technical Summary: Box TS.5. The main projected impacts for systems and sectors: Industry, settlement and society; Chapter 19, Section 19.3.7: Update on 'Reasons for Concern'

- National Research Council (2011), Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millennia, Washington, D.C., USA: National Academies Press, p.25

- UK Committee on Climate Change: Fourth Carbon Budget Review – part 1: Chapter 1: Section 3 (pp.28-30)

Enescot (talk) 07:22, 24 January 2014 (UTC)

I've prepared a draft revision of the "Observed and expected effects on social systems" section of the article:

"The social impacts of climate change are expected to be uneven. Vulnerable regions include small island states and low-latitude, developing countries. In some regions, negative impacts are expected even for low increases in global mean temperature (less than 2.6 degrees C above the pre-industrial level). Negative impacts include increased coastal flooding, reduction in water supplies, and increased malnutrition. Many risks are expected to increase for higher magnitudes and rates of global warming.

There are expected to be some benefits from global warming. For example, there will likely be fewer deaths due to cold weather extremes."

The first paragraph of my draft is supported by the citations I gave in my previous post. The reference for the second paragraph is chapter 8, section 8.7 of the IPCC Working Group II 4th Assessment Report.

Enescot (talk) 07:07, 3 February 2014 (UTC)

I'm worried that a casual reader could get an impression from that that does not reflect the balance of coverage in the sources. At a first reading such a reader may see the proposal above as, "Impacts uneven: some flooding and stuff, but also benefits like fewer deaths." That is not the balance of what the sources say. I would prefer to base our text on the authors' own summaries, rather than choose our own couple of points from long reports. So, if we're working from AR4 SP2, I would look at the SPM,[6] and then concentrate on the pull-out summaries in the coloured boxes. Here they are:

Section B

Observational evidence from all continents and most oceans shows that many natural systems are being affected by regional climate changes, particularly temperature increases.

A global assessment of data since 1970 has shown it is likely that anthropogenic warming has had a discernible influence on many physical and biological systems.

Other effects of regional climate changes on natural and human environments are emerging, although many are difficult to discern due to adaptation and non-climatic drivers.

Section C, Magnitudes of impact

Magnitudes of impact can now be estimated more systematically for a range of possible increases in global average temperature.

Impacts due to altered frequencies and intensities of extreme weather, climate and sea-level events are very likely to change.

Some large-scale climate events have the potential to cause very large impacts, especially after the 21st century.

Impacts of climate change will vary regionally but, aggregated and discounted to the present, they are very likely to impose net annual costs which will increase over time as global temperatures increase.

Section D

Some adaptation is occurring now, to observed and projected future climate change, but on a limited basis.

Adaptation will be necessary to address impacts resulting from the warming which is already unavoidable due to past emissions.

A wide array of adaptation options is available, but more extensive adaptation than is currently occurring is required to reduce vulnerability to future climate change. There are barriers, limits and costs, but these are not fully understood.

Vulnerability to climate change can be exacerbated by the presence of other stresses.

Future vulnerability depends not only on climate change but also on development pathway.

Sustainable development can reduce vulnerability to climate change, and climate change could impede nations’ abilities to achieve sustainable development pathways.

Many impacts can be avoided, reduced or delayed by mitigation.

A portfolio of adaptation and mitigation measures can diminish the risks associated with climate change.

Summarising and paraphrasing these, I could come up with the following:

Many of the natural systems in all continents and in most of the oceans are being affected already by global warming. The effects of anthropogenic warming since 1970 are discernible in many physical and biological systems, and upon natural and human environments. The magnitude of these impacts in the future depend on the extent of global warming, and they are very likely to be the result of the frequencies and intensities of extreme weather, and of coastal flooding, which may cause very large impacts especially after the 21st century. Such impacts will vary regionally but collectively they are very likely to impose net annual costs that increase over time as global temperatures continue to rise.

Some adaptation to these changes is occurring already, but on a limited basis. Adaptation will be necessary to address impacts resulting from the warming which is already unavoidable due to past emissions, but more extensive efforts are required to reduce vulnerability to expected future climate change. The barriers, limits and costs of these efforts are not yet fully understood. Vulnerability to climate change can be exacerbated by the presence of other stresses, so future well-being depends not only on climate change but also on other aspects of social change and development strategies. With the best portfolio of mitigation strategies in place, many impacts can be avoided, reduced or delayed.

That's only a first pass, and is not specific enough regarding food and fresh water security yet. I also haven't been through any other sources at the moment. What I have here could be further condensed to make room for some more food-specific statements, but I would hesitate simply to quote-mine these, preferring to summarise an existing summary. --Nigelj (talk) 20:06, 3 February 2014 (UTC)

Change to opening sentence.

Just reading, "Global warming refers to an unequivocal and continuing rise in the average temperature of Earth's climate system" sounds a little ridiculous. I mean, do you really need to have "unequivocal" there? It's like whoever wrote it was trying to rub it in that they were right to someone who disagreed with them.

I request someone edit the line to the more neutral-sounding "Global warming refers to a rise in the average temperature of Earth's climate system." Much more succinct and appropriate as the opening sentence the article. — Preceding unsigned comment added by 58.96.39.78 (talk) 16:22, 17 January 2014 (UTC)

It is an expression of the level of scientific certainty; IPCC AR5 WG1's big assessment report due out at the end of the month will be ~1000 pages; their summary is already out and is linked as the RS for the statement. The very first nutshell bubble of that summary of that 1000 page report begins as follows

Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia.

— IPCC AR5 WG1 SPM p 2

Given the enormous amounts of money and energy spent in prior decades debating whether earth is warming up in the first place, when the international scientific community comes out and says there is so much data that part of the debate is now "unequivocal", including that in our coverage is not POV on our part, but rather is diligently reporting on the major aspects of the reliable sources of greatest WP:WEIGHT. So no, I'm opposed to removing the word the RS went out its way to trumpet in the first 10 words of the first nutshell bubble. NewsAndEventsGuy (talk) 16:34, 17 January 2014 (UTC)

I'm actually with the IP on this one. I somehow missed that "unequivocal" got moved to the first sentence in the midst of all the tagging/untagging and hatting/unhatting of the past few weeks. This is not okay for exactly the reasons pointed out by the IP. It's not encyclopaedic to have the opening line of an article refer to its subject as unequivocal. And it sounds like we're trying too hard. And now the opening sentence doesn't really communicate that some warming has already happened. I strongly suggest restoring the wording that was there before the new year and I'm sorely tempted to do it myself. Sailsbystars (talk) 16:43, 17 January 2014 (UTC)

Sails, I always love your thoughtfulness and r-a-r-e-l-y disagree (no wonder I love it and find it thoughtful!) In that spirit, I'd love to see your mark up suggestions of what we should do, but I'd also love to see it here at talk. I suggest doing it here instead of the article for the following reasons

(A) to avoid article-disruption while we work toward consensus,

(B) my opinion that it is hard to argue with the first nutshell on page 2 of the WG1 SPM. We've long treated IPCC assessments as the heaviest hitting of all RSs.

(C) to ask you to explain something I don't get. You say having this word in the first sentence is "unencyclopedic". As you probably know, it is generally thought that "unencyclopedic" is an empty argument. What I fail to understand is how the text of the second sentence, live since October 2011, can say

Warming of the climate system is unequivocal....

but the new text based on the first nutshell bubble of AR5 WG1 SPM (page 2) can not say

Global warming refers to an unequivocal and continuing rise in the average temperature of Earth's climate system.

Seems entirely subjective to me, but I suppose I might not understand your opinion yet. Can you elaborate? NewsAndEventsGuy (talk) 17:16, 17 January 2014 (UTC)

I can see the unequivocal point from both sides, and so could go either way on that at the moment. What I don't like is the refers to bit. I can't find it, but I'm sure there's a guideline somewhere that says that encyclopedia articles differ from dictionary entries in that they are about the subject itself, not about the words used in the title. I can't come up with somtheing better right now, but an old version, reproduced here for reference, read, "Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation"[7] --Nigelj (talk) 18:04, 17 January 2014 (UTC)

OK, so what about "Global warming is the unequivocal rise in the average temperature... etc etc"? After all, it is a key word in the first few words of the first sentence of the first nutshell bubble of the summary of the ~1000 page WG1 AR5 report. NewsAndEventsGuy (talk) 18:53, 17 January 2014 (UTC)

I don't know. That seems to beg the question as to whether or not global warming would be the slightly dubious rise, if the rise was indeed slightly dubious. It does sound like we're trying too hard. Maybe it's time to try a sentence that doesn't have global warming as the subject, or maybe doesn't even have global warming (WP:BOLDTITLE) at all. --Nigelj (talk) 19:14, 17 January 2014 (UTC)

At that link, check out the Mississippi example. There is a bright red X on the parallel to "Global warming is a rise in temperature of the climate system, which scientists say is 'unequivocal'." There is a bright green checkmark next to the parallel to "Global warming is among the most unequivocal scientific observations..." and that, more or less, is the proposed text based on the first nutshell of the SPM. If you've got another approach, let's hear it!NewsAndEventsGuy (talk) 19:44, 17 January 2014 (UTC)

I think the problem with "The 2011 Mississippi River floods were a series of floods affecting the Mississippi River in April and May 2011" is the straight repetition of each of the words of the title, immediately after having stated them apparently purely for the purpose of bolding them. Here, if we have an opening sentence whose subject is 'global warming' we need to get straight onto saying something definitive about it. "Global warming, since the 1950s, has led to many observed changes in the earth's climate that are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased." This is very close to the AR5 summary (the second sentence here is unchanged). However, I don't like has led to as there is no separation, but "GW is" seems awkward. Actually, that whole AR5 summary is perfect, if we go without bolding, but I assume that using it would be a copyvio, and I don't think we can start an article in quotes. "Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased"[AR5] --Nigelj (talk) 20:12, 17 January 2014 (UTC)

"Due to global warming, the earth's atmosphere and oceans have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased. The warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia." That's mostly just swapping the two sentences over. Still too close as WP:COPYVIO, but we could hack it about some more. --Nigelj (talk) 20:20, 17 January 2014 (UTC)

I don't see how that is substantively different, but if enough of ya'll simply like it better, that text is faithful to AR5 SPM WG1 I suppose. NewsAndEventsGuy (talk) 22:23, 17 January 2014 (UTC)

So I had a gander at the SPM now and I have to admit I'm a bit surprised they don't actually have a summary of the summary. I.e. where they define global warming and climate change and the differences between them. Which is a bit surprising given that would be a crucial thing to convey to policy makers. Anyway, I think Nigel's suggestion might work. Here's my tweaked suggestion, where I built upon nigel's suggestion and added a bit about continuation (albeit a bit awkward):

• "Due to global warming, the earth's atmosphere and oceans have warmed, the amounts of snow and ice have diminished, and sea level has risen, primarily due to increasing concentrations of greenhouse gases in Earth's atmosphere from burning fossil fuels. Many of the observed changes since the 1950s are unprecedented over decades to millennia. This warming is predicted to continue, with the magnitude of future warming dependent largely on future greenhouse gas emissions."

Basically, we need to hit the following points:

• It's already happening
• Here are some of the manifestations
• It'll continue
• We done it

My suggestion is still a little awkward. I deleted the unequivocal bit, but it could go back in. We do need to talk a bit about strength of the evidence in the lede, but I don't think in the lede paragraph, which should be mostly about defining the subject. For a good example, see how the wiki article on Evolution (the other famous "teach the controversy" punching bag) mentions the evidence (e.g. the fossil record) while not having to point out that the evidence is overwhelming. Sailsbystars (talk) 06:57, 18 January 2014 (UTC)

Thanks for working on this here. I'll post another approach in an outdented section, but my main comment is that it is hard to evaluate suggestions when we can't see what would be deleted. NewsAndEventsGuy (talk) 12:20, 18 January 2014 (UTC)

• Here is a possible alternative for the current first paragraph. I agree the first paragraph should define the subject, and the most important thing missing from most coverage is careful explanation whether the term "global warming" is being used to talk about surface temps or the overall climate system. This will be especially true when WG1's final-final version is released at end of January, because it will talk about the "hiatus" (aka "global warming paused).... unless you look at the main energy repository - the ocean - where the RSs say there was no pause. The dual usage of the term is a top-level part of the definition to establish right up front. Accordingly, here's one way to address concerns that were raised about having "unequivocal" in the first sentence.....

width=300

Global warming refers to the rising average temperature of Earth's climate system, in which the oceans have stored 90% of the accumulated energy in recent decades. Despite the oceans' dominant role in energy storage, the term "global warming" is also used to refer to increases in average temperature of the air and sea at earth's surface. Since the early 20th century, the global air and sea surface temperature has increased about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. Since 1998, the rate of warming of these surface temperatures has slowed, a phenomena sometimes called a "pause" or "hiatus" of warming surface temperatures. Meanwhile, scientists say there has been no slowdown in ocean warming and describe warming of the overall climate system as "unequivocal".RSs for ocean warming might include....

• Inside the warming hiatus: A 15-year pause for some regions and seasons, but not in the ocean
• Global Warming 'Pause' Isn't What Climate Change Skeptics Say It Is
• Climate change: The case of the missing heat

NewsAndEventsGuy (talk) 12:20, 18 January 2014 (UTC)

Meanwhile, scientists say there has been no slowdown in ocean warming - no. SPM page 6, bullet 4. 50/50 chance that ocean heat content from 0–700 m increased more slowly during 2003 to 2010 than during 1993 to 2002. That ocean depth accounts for 60% net climate energy storage overall. Again, more detail will be released with AR5 but it's a stretch to say that ocean warming hasn't slowed when scientists say there's a 50/50 chance that it has. Certainly no consensus that it hasn't slowed and nothing that is juxtaposed against the pause/hiatus. Make sure you are comparing the right timeframes if you are taking about the last 10-15 years vs. the last 40. --DHeyward (talk) 23:35, 18 January 2014 (UTC)

Thanks for reminding me that SPM differentiated between the different depths which I had forgotten, having been reading other sources. You neglected to pick the other cherry in that SPM paragraph, "Ocean heat uptake from 700–2000 m, where interannual variability is smaller, likely continued unabated from 1993 to 2009." NewsAndEventsGuy (talk) 23:58, 18 January 2014 (UTC)

Oh please. You have no idea what you are talking about. Top 700 meters is where nearly all the warming happens. To put it in perspective, the top 700m contribute nearly 10x to sea level rise than between 700-2000m. Below 2000 meters, there's no measured warming trend. They also changed sensors for the top 700 meters in the last decade. It is completely inaccurate to claim that scientists have observed no slowdown in ocean warming during the pause/hiatus. It's not a matter of cherrypicking, it's a statement of fact. The only reason why it's 50/50 is the change in sensor, otherwise it would be "likely" that ocean warming has slowed. --DHeyward (talk) 00:14, 19 January 2014 (UTC)

Well, I'll at least admit that I am interested in how others read the RSs also. We're better able to do that when we know what they all are. NewsAndEventsGuy (talk) 01:15, 19 January 2014 (UTC)

Meanwhile, scientists say there has been no slowdown in ocean warming - this statement is still wrong and none of your sources support it, or the SPM or the upcoming AR5 when juxtaposed against the hiatus/pause. Scientists don't say that at all. There's lot's of theories as to why the oceans have behaved the way they are including depth, regional, hemispheric and seasonal hypotheses - but none say "that ocean warming continues unabated" especially after saying land temps are static. Land models and measurements are also atmospheric, regional, hemispheric and seasonally dependent. If you simply state that there is a worldwide average "pause/hiatus" in land temps, a similar phenomenon is observed in the ocean over roughly the same time period. All the sources that have been listed say this. --DHeyward (talk) 03:29, 19 January 2014 (UTC)

Before this discussion wanders off into fairyland, I should note that official NOAA figures show a clear continuation in ocean warming:

http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/

Let's not start spouting nonsense when the facts are so easy to obtain. --TS 16:11, 19 January 2014 (UTC)

And that's what the SPM says. "continues unabated" however is inaccurate. Warming continues at a different rate. It's not juxtaposed against the land temperature record as unobservable. No one ever claimed ocean warming has been zero. Let's try to stay out of fairyland that ocean warming has been decoupled from land warming. I quoted what's in SPM and it's obvious in the graph: 50/50 chance that ocean heat content from 0–700 m increased more slowly during 2003 to 2010 than during 1993 to 2002. Do you not see that? --DHeyward (talk) 21:20, 19 January 2014 (UTC)

For the opening sentence (the topic of this thread), and indeed for most of the lede, we need do no more than summarise the red-box 'nutshell' summaries in the SPM. There is no need to start digging into the individual bullet points, let alone other sources or our own understanding of the science, the models or the sensors, to produce a top level summary of global warming for this top level article on the subject. This is not a blog or a forum for debating science. Has anyone else noticed that at seven paragraphs the lede is already far too long. It needs dramatically shortening to three or four paras (WP:LEADLENGTH) --Nigelj (talk) 21:52, 19 January 2014 (UTC)

Exactly, so "Meanwhile, ocean warming continues unabated" should be removed as a completely inaccurate synthesis. It's not in the nutshell summary, it's not supported by the bullets and it's not in the underlying research. Where did it come from? --22:04, 19 January 2014 (UTC)

(edit conflict) Preach it brother Nigel, preach it! We can argue forever about details, and the details should all be in wikipedia somewhere. But the lede should be a simple summary so that someone who's never studied global warming before (think high school student) broadly understands what it's all about. For an introduction, the whole hiatus thing, ocean heat content or what have you is basically irrelevant. Broadly, the intro paragraphs should be something like: 1.) simple lede (like I've suggested) 2.) History (Arrhenius -> Keeling -> IPCC) 3.) Observational evidence/previous warming (i.e. what it's done so far) 4.) Predicted future warming/emission pathways. The current lede is too far bogged down in the details. Sailsbystars (talk) 22:10, 19 January 2014 (UTC)

Whatever gets axed, "global warming" is used to mean EITHER surface temps OR climate system overall. If you want a lead that gives a top level intro, it is imperative that BOTH MEANINGS make the cut, else the lead just tells one of the meanings but not the other. NewsAndEventsGuy (talk) 22:16, 19 January 2014 (UTC)

Easily solved by replacing "earth's atmosphere and oceans" with "earth's climate" in my suggested lede. The climate article goes on to explain that it includes the lithosphere, atmosphere, cryosphere, and hydrosphere, so your concerns are covered without bloating the lede, but the nitpickers also can't claim we're leaving out the oceans. Sailsbystars (talk) 22:45, 19 January 2014 (UTC)

It's my understanding that "Global warming is the observed increase in the average surface temperatures across both land and ocean and its projected rise from anthropogenic greenhouse gases." That's about as simple as it needs to be. The HADcrut and GISS datasets were created to measure it. How those datasets are defined is the essence of the definition of global warming. GW is generally expressed as a global temperature anomaly or global temperature change over time. Everything else is measurements to support models, observations and theories about what drives the measured data observed in those datasets, or derivative effects. The "climate system" seems to be more of a modeling concept with potentially varying degrees of complexity and coupling that's beyond "Global warming". --DHeyward (talk) 23:20, 19 January 2014 (UTC)

No. That's a misleading statement. Global warming is fundamentally about an energy imbalance created by increased GHG concentrations, and how Earth returns to equilibrium, which involved both the surface and subsurface and the cryosphere. Surface temperature is one (important!) way of measuring the changes in the climate system, but should not be labelled as the sole definition of global warming. Sailsbystars (talk) 23:39, 19 January 2014 (UTC)

arbitrary break

I think you are conflating the broader topic of drivers of climate change with what is characterized as 'global warming.' GW is generally narrowly stated in terms of observed temperature and the temperature records. Climate change has a number of related metrics. The distinction is important in terms stating various levels of confidence with regard to what is changing, where, how fast, cause, etc. Climate models define the various components you listed and try to reproduce the historical temperature record both spatially and temporally. You are correct that the underlying interactions that drive surface warming are complex but it doesn't change how it is known and represented which is temperature at the surface. See the category definition at [[Category:Climate change]] for the definition of climate change and global warming. --DHeyward (talk) 02:46, 20 January 2014 (UTC)

Do you have a source to back you up on that? I've tried looking for a source to define global warming starting from pretty reliable sources, but most seem to avoid a definition one way or the other (the IPCC is particularly bad in this regard).This source supports your definition. I would also point out something, of which you may not be aware, namely that the distinction between this article and climate change is that this article is about the current man-made climate change characterised by warming, whereas the climate change article is about climate changes in general, not just the current one (ostensibly). Anthropogenic climate change redirects to this article, and perhaps it might be worth referring to that redirected name in the lede as well. So basically, what I'm saying in a roundabout way, is that our current article deals with all aspects of the current warming, not just the surface temperature, so we either need to: change the name, remove anything that's not about the temperature, define in terms of the surface temperature, but make clear the interrerlation with oceans etc, or use a more expansive definition of global warming. Sailsbystars (talk) 03:37, 20 January 2014 (UTC)

I'm not sure what you are requesting. Category "Climate change" has been around quite awhile along with its definition. The established warming of 0.8C net increase to date has also been well-established. If the redirect for climate is wrong, please feel free to update it. 'Global warming', though, has always been about surface temperature measured by thermometers in both the past, present and future projections. HADcrut and GISS exist for this very purpose and their measurement units confirm it. IPCC is about climate change which is a broader topic that includes elements of modeling. A single temperature in degrees Celsius has always been the measurement for global warming. Other measurements of stored energy and flux are relegated to models and simulations of the climate system as it is perceived today. --DHeyward (talk) 07:12, 20 January 2014 (UTC)

From you source Global warming is the unusually rapid increase in Earth’s average surface temperature over the past century primarily due to the greenhouse gases released by people burning fossil fuels. is accurate though I would either delete burning fossil fuels. (leaving by people) or add cement production which is very close to fossil fuels in terms of contribution to AGW. Singling out fossil fuels over cement seems unwarranted. Land use change is an order of magnitude less than fossil fuels and cement. --DHeyward (talk) 07:33, 20 January 2014 (UTC)

I'd agree that the state of all the articles regarding climate change are rather pathetic. The comment way above about "fantasy land" explains why. It seems that entrenched political positions have created blinders that don't allow scientific statements to be made without filtering. I've pointed out a few of the statements that are factually inaccurate (and those with scientific backgrounds understand the distinction). Those without, however, make the political statement before they make the scientific statement. The definition of 'Global warming' only became complex when the politics and science diverged. I'd submit that the definition ought not be submitted to such gyrations. --DHeyward (talk) 07:48, 20 January 2014 (UTC)

Talk about sources and not editors, please. NewsAndEventsGuy (talk) 14:26, 20 January 2014 (UTC)

width=300

Since we are not a technical journal, but an encyclopedia, we need to explain that "global warming" is used in technical writing to mean a very limited metric (based on global surface temp) as well as the common English overall climate system warming. On the technical side, I'll add these RSs, which repeat the same limited-metric definition in terms of global surface temperature, (another technical term of art)

• IPCC AR4 WG3 Glossary "Global warming refers to the gradual increase, observed or projected, in global surface temperature, as one of the consequences of radiative forcing caused by anthropogenic emissions.
"
• USA EPA glossary "Global Warming - The recent and ongoing global average increase in temperature near the Earths surface."]

But I agree with Sailsbystars that we're trying to report on contemporary warming of the overall climate system. I submit that IPCC AR4 and AR5 WG1 both imply that "global warming" refers to the systemic phenomena (not just surface temps) in their nutshell statements that "Warming of the climate system is "unquivocal".

Then there is

• RealClimate: What ocean heating reveals about global warming by Stefan Ramstorf "The amount of heat stored in the oceans is one of the most important diagnostics for global warming...."
• Comments on Stefan Rahmstorf’s Post at RealClimate “What ocean heating reveals about global warming” by Bob Tisdale, which starts off noting the different metrics used

• "when we talk about 'global warming', we're really talking about ocean warming" - Dr Steve Rintoul, CSIRO, video

The current first paragraph was my attempt to address the two-meanings of the term, as we introduce the topic in the lead. NewsAndEventsGuy (talk) 15:23, 20 January 2014 (UTC)

It's a tortured paragraph. "Despite the ocean?" Do you really think it was misnamed? "Despite the ocean," the rest of the paragraph, graphs and statements are about mean land+ocean surface temperatures. There is a disambig note at the top. Here's the category of "climate change" Climate change refers to the variation in the Earth's greenhouse or regional climates over time. It describes changes in the variability or average state of the atmosphere - or average weather - over time scales ranging from decades to millions of years. In recent usage, especially in the context of environmental policy, the term "climate change" is often used to refer only to the ongoing changes in modern climate, including the average rise in surface temperature known as global warming.[8]. I've bolded the hard part. It doesn't have to be more complicated. --DHeyward (talk) 16:41, 20 January 2014 (UTC)

(A) Re Global warming definition, you cite something else in wikipedia which is not an RS; please just discuss the RSs (and lose the personal digs, 2nd request).

(B) Re First paragraphs stats on global surface temps, I'd be happy to move those sentences out of the lead to reduce lead details.

NewsAndEventsGuy (talk) 20:55, 20 January 2014 (UTC)

Yet another RS to add to the list, An apparent hiatus in global warming?; Discussing multiple phenomena besides global surface temps they conclude "Global warming has not stopped; it is merely manifested in different ways." So we have one set of RSs that give the techspeak technically limited definition, and another set that talks about it in terms of the overall climate system. A NPOV presentation of these sources would explain both meanings. NewsAndEventsGuy (talk) 21:34, 20 January 2014 (UTC)

Not sure where you are seeing personal digs. Lead definitions are written in the WP voice. The opening lead paragraph is tortured through various views about overall climate change components when it ought not be: "Global warming refers to the rise in the observed land and sea surface temperatures. More than half of the observed warming is attributed to anthropogenic greenhouse gases from such activities as fossil fuel consumption and cement production. Since <date> the mean global surface temperature has risen <X>. IPCC AR5 has adopted four [[Representative Concentration Pathways]] to estimate the effect of different greenhouse gas emission scenarios on future [[climate change]] including temperature. The estimated range of temperature increase for those scenarios in the year 2100 is <Y>. The term "global warming" is often used to describe the broad aspect of [[Climate change]]." But here's NASA's take: [9]. They have a nice "Definition" box and explanation why it's just surface temperature and why WP shouldn't confuse the matter by usin GW when we mean CC. Definitions - Global warming: the increase in Earth’s average surface temperature due to rising levels of greenhouse gases. --DHeyward (talk) 21:43, 20 January 2014 (UTC)

Here's another. [10]. --DHeyward (talk) 21:48, 20 January 2014 (UTC)

When we finally do talk about RCPs, it will be SYNTH to manufacture a range by combining the low end of the likely range for the lowest RCP emissions pathway and the high end of the highest. We made that mistake after AR4 and thoroughly debated the issue a year and half ago. Meanwhile, DHeyward, do you explicitly deny the existence of RSs that talk of "global warming" as referring to the overall climate system, such as those linked above? Do you explicitly deny the existence of a 2003 paper in Science, where the authors write "the popular term for the human influence on global climate is “global warming,” although it really means global heating, of which the observed global temperature increase is only one consequence"? If you don't explicitly deny such RSs, how do you propose we deal with the fact that "global warming" has a WP:JARGON meaning, as well as a WP:COMMONNAME meaning? You can't just point at "climate change" since that is prone to similar complaints that "climate change" doesn't necessarily mean on earth, or net positive forcings, or a contemporary process. NewsAndEventsGuy (talk) 23:43, 20 January 2014 (UTC)

DHeyward's suggested lead is I think a reasonable one, although I would add a bit more to the last sentence about the climatic changes induced by warming (e.g. sea level rise). NewsAndEventsGuy, I think DHeyward's last sentence addresses the fact that global warming and climate change are often conflated. I think things actually aren't too bad with the article if we tweak the section headings to identify the difference between global warming and resulting climate changes caused by global warming. And perhaps add a section on changes caused by Co2, but not by warming (e.g. ocean acidification) Not sure I agree that there are WP:SYN issues with using the low end of the lowest RCP and the high end of the highest RCP in the lede. In the article we should explain the ranges and the difference between modelling uncertainty and emission uncertainty. I also think the oceans would fit in nicely with a physics paragraph in the lede and section in the body of the article (oceans absorbing heat are why even though we're at crazy concentrations of CO2, we're not hitting the equivalent climates just yet). Sailsbystars (talk) 00:11, 21 January 2014 (UTC)

The biggest nutshell of the biggest RS of the greatest weight starts off with warming of the climate system, not just surface temps, so I'm vigorously opposed to starting off talking about a small metric of the total picture. NewsAndEventsGuy (talk) 00:26, 21 January 2014 (UTC)

Indeed it does, and were that all the assessment reports said I would agree with you. But it also lacks an introduction (which bothers me to no end), and as I think you yourself pointed out, the AR4 glossary defines global warming in terms of surface temperature (does the AR5 glossary even exist yet?). So I wouldn't read too much into it starting with the warming of the climate system.... This sort of thing is why I was talking about earlier that either the title for this article is inappropriate or we need to recast the article in terms of appropriately-defined "global warming" and it's resulting climate changes.... Sailsbystars (talk) 01:03, 21 January 2014 (UTC)

Climate change is the appropriate place for warming of the climate system. It is quite clear that for fourty years, scientists have made distinctions between global warming and the broader climate system changes. You were concerned about synthesizing something that AR5 doesn't say. This is one of them. "Global warming" didn't change it's definition in either the science or understanding so please don't synthesize a new definition. The NASA source is a complete source dediocated to the definition and it explitly says what it is. AR4 apparently does as well. Read it. --DHeyward (talk) 01:33, 21 January 2014 (UTC)

I prefer to stick to authoritative sources that define the term. NASA did it. It's all there with historical references. [11]. As for ranges, that's for AR5 to decide what to report. I don't "synth" anything nor do I need to find obscure ways to say simple things. Read the NASA reference. It explains what "Global warming" is and the distinction from "Climate change." It goes all the way back to the original use of the term in scientific literature. While individual papers can be sloppy with referring to "Global warming," WP does not have to be sloppy as we have articles on the relevant topics as is listed at the top of the page. NASA explains it all in that source. As a style, we should adopt their methodology as it is the scientific one used by our sources and avoids having to re-explain context with every element of climate change. I am not sure why you want exceptional uses of the phrase to be in the lead. It just makes it overly complicated. NASA's definition (in the Merriam Webster dictionary too) is Global warming: the increase in Earth’s average surface temperature due to rising levels of greenhouse gases. We can fill in a bit more but that's all we need to say. Torturing it to mean the heat content of the ocean, is whimsical but not supported. Climate change, of which global warming is but a single metric, is the main topic where ocean heat storage belongs and can branch off from there. If people are confused about the difference/usage, we should correct it, not feed it. --DHeyward (talk) 01:33, 21 January 2014 (UTC)

An aside to the above conversation, if we want to strictly follow IPCC convention... climate change=humans and climate variability=natural according to another page of the glossary. Personally, I would prefer we come up with a solution that doesn't involve completely rewriting three contentious articles... Sailsbystars (talk) 01:43, 21 January 2014 (UTC)

AAAARRRGGGGGHHH but then they contradict themselves and say that climate variability can be caused by people too! this is what the IPCC authors make me want to acquire.... Sailsbystars (talk) 01:47, 21 January 2014 (UTC)

@DHeyward, I once tried doing something similar vis-a-vis "global warming" and "climate change" though I think it was on a different article. Anyway, the subject has been discussed before here. A quick check of archives on "climate change" produced this thread for one example. See also our talk page FAQ #22. NewsAndEventsGuy (talk) 04:51, 21 January 2014 (UTC)

And this edit by you. [12]. You seemed to understand that NASA was authoritative then. --DHeyward (talk) 00:28, 22 January 2014 (UTC)

You misrepresent that diff because I left with my approval text (based on the RSs) that under popular semantics, "climate change" and "global warming" are synonyms. Plus I was a newbie (3 months editing) who probably did not know about Wikipedia:NOTJOURNAL, WP:COMMONNAME, nor the past consensus when this same issue was previously debated and eventually produced our FAQ 22. Worth repeating - see Wikipedia:NOTJOURNAL and WP:COMMONNAME. You keep repeating your opinion that we should ignore NOTJOURNAL and embrace the scientific semantics of the phrase "global warming" to the exclusion of the popular meaning, but you haven't framed your opinion on the basis of any wikipedia policies or guidelines, just your desire to change the existing consensus (as expressed in FAQ 22). Suppose you persuade us to embrace the scientific semantics of the term "global warming" such that we only talk about things specifically related to increasing global surface temperature, and shove all the rest over to "climate change". How would that effect each of the subsections in Global warming, Climate change, and any other articles that would have to be modified? In other words, to avoid disruptively restating/repeating/re-reviewing your opinion that we should do something-or-other based on the scientific meaning of the term, please formulate a comprehensive proposal so we know what you're talking about beyond the few paragraphs of the lead. I acknowledge that is a large job, but it's your proposal to articulate beyond vaguely embracing the principle of following the technical meaning to the exclusion of the popular one. What's that gonna do to our articles overall? NewsAndEventsGuy (talk) 00:59, 22 January 2014 (UTC)

Not at all. I didn't misrepresent anything. FAQ 22 doesn't support anything you said. None of your references support your synthesis. The FAQ cites a number of references that all refer to the increase in temperature when defining "global warming". That's the colloquial meaning. Not all the other climate change pheomena. The scientific definition is more precise as defining "global warming" as the average surface sea and land temperatures, rather than just rising temperature. Your arguments border on the absurd that IPCC should be extensively covered in "global warming" but not in the "Climate change" article despite the fact that CC is "Climate Change", it's a scientific document (not "commoner" document) and IPCC adheres to NASA's definition and distinction of the difference between the two. You have no sources that say "climate change is global warming", rather you have specific articles that conflate the pause/hiatus of surface warming with climate change and attempt to correct the misconception that the "pause = climate change has stopped." Please stop gyrating over what bloggers say and keep the articles concentrated on their topic. IPCC deserves intensive coverage of all facets in "Climate change" and this article focuses on "Global warming" which is the most publicly visible of all the metrics of climate change. It does not need to be redefined because a blogger says "Global warming has stopped." Move on already. This article should focus on "surface temps." It has plenty of history, science, and data for a complete article. --DHeyward (talk) 02:09, 22 January 2014 (UTC)

I'm just coming to the conversation and it's pretty large and circular. DHeyward would you mind at this point summarizing your proposal edit please? Regards. Gaba ^(talk) 02:59, 22 January 2014 (UTC)

"Global warming refers to the rise in the observed land and sea surface temperatures. More than half of the observed warming is attributed to anthropogenic greenhouse gases from such activities as fossil fuel consumption and cement production. Since <date> the mean global surface temperature has risen <X>. IPCC AR5 has adopted four [[Representative Concentration Pathways]] to estimate the effect of different greenhouse gas emission scenarios on future [[climate change]] including temperature. The estimated range of temperature increase for those scenarios in the year 2100 is <Y>. The term "global warming" is often used to describe the broad aspect of [[Climate change]]." --DHeyward (talk) 03:10, 22 January 2014 (UTC)

Take us thru the rest of the article, telling us whether each section can stay or go as currently presented, i.e., in an article about increasing global surface temps, can we have a section on feedbacks or computer models covering as much of the overall system as possible? Can we still talk about thermal expansion's contribution to sea level rise? What do we do with the scope of climate change, for which long-standing consensus has been to have that article talk about the general concept regardless of geologic era? Where do we put the assessment that 90% of the accumulated warming goes into the sea, or the RS that says "when we talk about global warming we're really talking about ocean warming" (linked elsewhere in thread). Rattling off a few summary sentences without at least summarizing the implications in light of current context does not answer anyone's question, seems to me.

If the community dislikes my attempted lead rewrite (discussed in next subsection) another approach is to tweak the Dec 31 2013 lead for SPM 5 and and create a small sub-article specifically related to Global warming (technical meaning). NewsAndEventsGuy (talk) 05:24, 22 January 2014 (UTC)

Why do we need it? We have IPCC reports and Climate change articles to cover it. "Global warming" doesn't have "two meanings". It has the scientific definition and then a misnomer for Climate change. It's absurd to argue that IPCC results should be extensively covered in "Global warming" but not in "Climate change." Really, the rest of the article would be about the measured metric, greenhouse gasses, history and projections. Misnomers that refer to climate systems and climate change should be moved to articles that cover it and our header tells people where to go for that information. Top italics: "This article is about the measured increase in the average surface temperature of the ocean and land. For general discussion of how the climate can change, see Climate change. For other uses, see Global warming (disambiguation)." Why does this article have to cram all the other subjects into it? It's very clear this article started properly with two graphs and charts on the right that hit the definition dead center. It's ballooned into an absurd response to bloggers and the "pause/hiatus." The definition did not change and the proper place to address climate change is in the climate change article. --DHeyward (talk) 05:45, 22 January 2014 (UTC)

Why? Because it's basic to good editing of major topics. See WP:SUMMARY. This is a top-level summary article. --Nigelj (talk) 23:46, 31 January 2014 (UTC)

Attempted Lead Rewrite

When I last revised the lead, I preserved a lot of stuff that was there when I showed up, and a bit that was added over the next couple of years. Earlier today, in response to comments on Talk, I attempted a full rewrite, keeping nothing just because someone else had once liked it. Some of the text was recycled, and you can see what it looks like in this demo edit (which I have already self-reverted). I did not think about the images or whether they should be changed. To help discuss specifics here at talk, here is the text of the demo edit

Global warming is the popular term for the human influence on the earth's climate system. Scientists are certain that the system is warming, and say that 90% of the added energy is being stored in the ocean. The term "global warming" also has a technical meaning in the scientific literature, where it refers to increasing temperatures as measured at the surface of the land and sea.

According to the International Panel on Climate Change (IPCC), it is "extremely likely" (i.e., 95-100% certain) that human activities have been the dominant cause. The largest single contributor is carbon dioxide (CO₂) emissions from fossil fuel combustion, cement production, and land use changes such as deforestation.

The effects of global warming include rising sea levels, ocean acidification, and likely climate responses such as changes in the amount and timing of precipitation, desertification, and retreat of glaciers, permafrost, and sea ice. Also likely are more extreme weather events including heat waves, droughts and heavy rainfall, as well as species extinction. Effects significant to humans include the threat to food security from decreasing crop yields and the loss of habitat from inundation.

Researchers assess past climate change using geologic and other evidence, and project future climate change using computer models. These projections describe different possible futures in terms of greenhouse gas emissions and other factors. Such work supports the mission of the United Nations Framework Convention on Climate Change (UNFCCC), whose ultimate objective is to prevent dangerous climate change. Possible policy responses to global warming include mitigation (i.e., prevention), adaptation to its effects, and climate engineering.

The result was a reduction in over 14,000 bytes. Thoughts? NewsAndEventsGuy (talk) 04:14, 21 January 2014 (UTC)

Nope. It's not a colloquial term. It has a specific scientific meaning. To the extent that people misunderstand it is not a reason to create your definition. You are synthesizing a definition that has multiple sources all saying surface warming of the land and sea is the definition. NASA has answered this specifically with the terms creation and use. Even your "colloquial sources" which address only the hiatus/pause/whatever is incredulously undue weight and the start off acknowledging the scientific definition. There is no need to come up with a new definition because of the hiatus/pause. Climate change is larger in scope than surface temperature measurements and the contortions and gyrations to make them the same gives too much weight to the pause/hiatus and a complete ignorance of the history and scientific use of the term. WP should strictly adhere to the sourced scientific definition for "global warming" and "climate change" and not merge them into a giant run-on sentence. The article correctly has the global surface temperature as graphics because they are exactly what "global warming" is. --DHeyward (talk) 05:00, 21 January 2014 (UTC)

I have provided RSs that describe "global warming" as a colloquial term as well as a scientific one. An RS that demonstrates this use is Mann & Kump's

• "Dire Predictions - Understanding Global Warming: The illustrated guide to the findings of the IPCC".

which is not called

• "Dire Predictions - Understanding Global Warming: The illustrated guide to increasing global surface temps"

One might dislike RSs that admit a dual meaning to this phrase, and one might despise so-called "sloppy" sources that use the phrase's colloquial meaning. That doesn't change the fact that both meanings are in the sources.NewsAndEventsGuy (talk) 11:23, 21 January 2014 (UTC)

You're citation in the article is "Modern Global Climate Change" from Science magazine. It doesn't even mention "Global warming" in the abstract and strictly follows scientific convention for "Climate change." If anything, it supports the scientific naming, not your created colloquial naming which is abstract, vague and obtuse and not supported by reliable sources as a definition for "Global warming." NASA and every scientific journal article does this and we should do the same. "warming of the climate system" cannot and should not be synthesized into "Global warming." You seem to have made that leap without support. You again have synthesized that findings of the IPCC imply that it does not cover the scientific definition of "Global warming." The IPCC certainly does cover land+sea temperature rise and predictions for it's continued rise and for the public, increase in surface temperature is the most visible aspect of climate change so addressing it would be perfectly valid. Scientists use both terms with different meaning. We could easily have papers "Understanding Sea level rise: The illustrated guide to the findings of the IPCC" and no one would bat an eye because, like Global warming, Sea level rise is a consequence of climate change. --DHeyward (talk) 21:03, 21 January 2014 (UTC)

Also, I thought we buried the land use nonsense on Connelly's talk page? The equivalent statement about sulfur in coal highlights the logical fallacy of synthesis as well as the complete synthesis of a relationship not supported by AR5 as cited. Climate change is driven by greenhouse gases. Land use change contribute greenhouse gases. They are both separately true statement. But the net effect is "as likely as not" to cause climate change. Just like "Sulfur in the atmosphere is a source of cooling" and "burning coal is a major source of sulfur in the atmosphere" (both of those statements are true) we cannot synthesize that burning coal is a major cooling effect. Neither of the synthesis statements (land use and warming, coal burning and cooling) are supported by AR5. --DHeyward (talk) 05:19, 21 January 2014 (UTC)

At wmc's page, I said the opposite but more importantly....

Please follow WP:MULTI by continuing this discussion at its primary locationNewsAndEventsGuy (talk) 11:23, 21 January 2014 (UTC)

It is politicization of a Wikipedia page, poignantly illustrated by the Warmist editorializing in the first sentence, that prevents Wikipedia from being accepted as a credible, objective source on this subject. Boulder "Denier" — Preceding unsigned comment added by 67.165.218.19 (talk) 23:04, 31 January 2014 (UTC)

Good time to return to the lead section

FYI Wikipedia:The Core Contest NewsAndEventsGuy (talk) 02:07, 5 February 2014 (UTC)

Global warming is a WP:Featured article so it is not eligible in that contest. --Kim D. Petersen 02:16, 5 February 2014 (UTC)

Sure enough, my bad. Thanks for catching that. Still, we had some discussion happening. So.... now what? Anyone? NewsAndEventsGuy (talk) 02:24, 5 February 2014 (UTC)

Some day if I ever have free time again, I'll make a userspace draft to try to clear up the current mess of usage involving climate change/global warming. That day is not today.... Sailsbystars (talk) 15:47, 5 February 2014 (UTC)

It's a long thread, but it's an important topic. It looks like NewsAndEventsGuy has proposed two rewrites for the first paragraph or two. FWIW, although I don't think they're perfect, I think either of those rewrites is better than what's currently in the article. 107.3.156.34 (talk) 04:44, 7 February 2014 (UTC)

FAQ Improvement

Normally I don't close threads, but Godwin's law seems like a univerally acceptable standard for lack of useful discussion. Sailsbystars (talk) 20:53, 25 January 2014 (UTC)

The current FAQ fails to answer the question as to why the main article is not considered in violation of Wikipedia policy by not mentioning controversy in the lead section.Slamond (talk) 18:35, 19 January 2014 (UTC) When you say 'controversy', what exactly are you referring to? — TPX 18:56, 19 January 2014 (UTC) I think that is clear. Large numbers of people think that talk radio hosts know more about global warming than scientists. The answer is: Wikipedia policy mentions genuine controversy, but not manufactured "controversy". For example, the article on vaccines does not mention the vaccines cause autism "controversy" in the lead. Rick Norwood (talk) 20:12, 19 January 2014 (UTC) The "autism theory" is not mentioned in the lead, and in general silly theories with no evidence should not be mentioned in scientific articles, though there may be a place for them in articles about current events. Second, there is not a "lot more scientific support" for doubts about global warming. Ten years ago, there were a few dozen scientists who "doubted" global warming, but almost all of them have changed their minds due to a) the overwhelming increase in scientific evidence and b) the total lack of logic in the political discussion of the subject e.g. Fox News repeatedly telling their viewers that global warming is "only a theory", thus misrepresenting how scientists use the word "theory". There is an article on the controversy, but this article is about the science. Rick Norwood (talk) 15:12, 21 January 2014 (UTC) But articles gain more credence when they acknowledge the existence of other view points. Wikipedia is not a scientific document, bound by the Scientific Method. It is intended as a repository for information. The majority of Americans distrust scientific opinion when it is overwhelmingly funded by government. That is the nature of American Exceptionalism: to be skeptical of government. In 1930's Germany, 100% of the scientists agreed with the government's policies. I am open-minded to the science that proves Global Warming and my skepticism lies more within the realm of questioning whether it is a bad thing; considering the coming Ice Ages, et al. My overall point is that the article reads like a government brochure rather than a credible information source for the inquisitive among us. Slamond (talk) 19:45, 25 January 2014 (UTC) Which government? And sorry, but your Nazi reference both earns you a Godwin and is ahistorical nonsense. You might want to take a look at David Hilbert, Emmy Noether, Kurt Huber. --Stephan Schulz (talk) 20:05, 25 January 2014 (UTC)

Add template

Can the requested template be added (once done) ? KVDP (talk) 09:41, 22 January 2014 (UTC)

Why? We have the Keeling curve itself which is more informative. Second, you defined a term called "winning" in a way that is not grounded in a reliable source or as a model of how climate would respond to reduced anthropogenic CO2. If human caused GHG's went away tomorrow, that very small portion of the carbon cycle would be subject to balancing by other physical forces (i.e. How does an acidic ocean, a massive carbon reservoir, respond to reduced atmospheric CO2, Does it create a buffering source of CO2 that declines as slowly as it was added? I don't know. - And the ocean is just one of many of the climate systems that would respond.) --DHeyward (talk) 23:57, 22 January 2014 (UTC)

Are these three things lacking?

Potentially Ambiguous or Inconsistent Observations

This article is currently difficult to read in the following sense. The typical reader, for better or worse, is aware through the mainstream media and elsewhere that not 100% of the observations about this topic support the conclusion. Many readers look to Wikipedia to present references and links to original source material on both sides of an issue. If there are references and links in this article to data and studies that might be ambiguous or do not fully support the conclusion, they are quite cumbersome to identify here. By Wikipedia standards I would have expected to find a section in the article titled something like "potentially ambiguous observations" or "potentially inconsistent data," but I don't see that here. I also can't find this type of information presented in a Wikipedia-friendly way on any of the "see also" or "disambiguation" links. Yes, there's an article about the public debate, but not a good Wikipedia-style write-up of the data and observations that are possibly ambiguous or inconsistent.

"Anthropogenesis"

There's no question of the importance of the topic in this article and elsewhere of anthropogenic factors in climate change, i.e. human influences on the climate. If I were reading a typical Wikipedia article I would expect to have a major heading called something like "anthropogenesis" or "anthropogenic factors in climate change." With such a big topic, most readers probably expect a separate Wikipedia article with a section heading here linking to that. Indeed, I tried searching for the topic and was surprised what I found -- nothing related to climate, but a redirect to an article on "homonization," "the process of becoming human."  :) Similarly, searching for "anthropogenic climate change" brings the reader to this page which deals with much more than just anthropogenic factors. Additionally, none of the "see also" or disambiguate links provide much useful material on the topic. The article on "climate change," for example, has just one section entitled "human influences" that is predominantly one long quote. In keeping with Wikipedia standards, I would expect a section heading and/or separate article with that title, at the very least cross-referencing to other articles and/or sections.

Other possible causes besides humans

Wikipedia is generally reader friendly for users who are well read. In this context, readers are likely already aware that much/most/almost all of the data on climate change points to the human influences as the main source. What many readers are looking for, and by Wikipedia standards would ordinarily find, is a convenient way to read about alternative viewpoints and hypotheses. Unfortunately, as currently written, while this article might have some of this information scattered under various headings and subheadings, there's no convenient place to get this type of information in an easily readable format. On other topics in Wikipedia, even, nay especially, controversial ones, there's often a page or at least a heading labeled something like "alternative viewpoints" or "alternative theories." The absence of that here keeps the article from living up to the high standards many have come to expect of Wikipedia. Similarly, none of the "see also" or disambiguate pages have this information. There is a page on the "global warming controversy," but that is about the "public debate" not the observations and theories, and, in any event, alternatives are relegated to scattered remarks in a long section on the "mainstream position." I propose a new section and/or page presenting this information in a format many Wikipedia users are familiar with. 107.3.156.34 (talk) 18:50, 6 February 2014 (UTC)

People just make up all sorts of things, but what you read in the article is a discussion of the issue as you will find it discussed in what wikipedia defines as reliable sources. If you make a specific proposal that isn't base don handwaving, but is rather based on what wikipedia defines as reliable sources then we can discuss it. As for "anthropogenisis" if you searched for that and arrived at an article about human origins, that is a good thing, because that's what that word means. As for searching variants of the more relevant term "anthropogenic" and eventually finding your way here, note that the section on initial causes it says that the article that focuses specifically on causes of the current global warming is Attribution of climate change. If there is an easier way to help people navigate to that article, we're open to suggestions. NewsAndEventsGuy (talk) 20:36, 6 February 2014 (UTC)

I don't think this is about sources being objectively reliable. I was curious so I looked at one of the primary sources relied upon throughout this article, the 2013 IPCC Climate Change report. The IPCC is cited in six out of the first ten footnotes to the current Wikipedia article and shows up extensively in the body of the article and the remaining 233 footnotes. What I found in the 2013 report was more nuanced than the way it's currently described. For example, from the article, I would have had little idea that the IPCC defines guidelines about how it uses words like "likely," "very likely," and "almost certain" in virtually every aspect of the report, and that "likely" can be as low as 66%. This suggests that I was right to say that "[t]he typical reader, for better or worse, is aware through the mainstream media and elsewhere that not 100% of the observations about this topic support the conclusion."

But even more to the point was an entire section of the IPCC report that's a potential start for some of the topics above that are lacking. Section TS.6 of the report is a "short overview of the key uncertainties in the understanding of the climate system and the ability to project changes in response to anthropogenic influences." The title of that section of the report is "Key Uncertainties." In it are about two dozen bullet pointed items including:

• "On a global scale the mass loss from melting at calving fronts and iceberg calving are not yet comprehensively assessed. The largest uncertainty in estimated mass loss from glaciers comes from the Antarctic, and the observational record of ice–ocean interactions around both ice sheets remains poor."

• "Observational uncertainties for climate variables other than temperature ... continue to hamper attribution of changes in many aspects of the climate system."

• "There is low confidence in semi-empirical model projections of global mean sea level rise, and no consensus in the scientific community about their reliability."

If this is what I find in one of the main references for the article, I imagine there's a lot more material that would be relevant from other reliable sources. Again, I think the typical reader is looking for clear section headings and/or pages that address the "potentially ambiguous or inconsistent data and observations" and "other possible causes besides human." Without those or something like it I think readers would sense something about this article is not living up to Wikipedia's reputation for thoroughness and reliability. 107.3.156.34 (talk) 02:55, 7 February 2014 (UTC)

The TS.6 section (a technical summary actually) is a mere one and a half pages long section in a report of over 1500 pages. We'd have to be very careful so as not to breach WP:UNDUE. Would you like to propose an edit to the article mentioning some of these uncertainties? Feel free to add as many reliable sources as you can find. If you present it here we can discuss it to see what could be a proper way to present the information you propose. Regards. Gaba ^(talk) 12:09, 7 February 2014 (UTC)

The comparison of the length of TS.6 to "1500 pages" is inapt. First, section TS.6 is written as a sub-section of an 80 page summary of the entire report. Second, section TS.6 explicitly states:

"This final section of the Technical Summary provides readers with a short overview of key uncertainties in the understanding of the climate system and the ability to project changes in response to anthropogenic influences. The overview is not comprehensive and does not describe in detail the basis for these findings. These are found in the main body of this Technical Summary and in the underlying chapters to which each bullet points in the curly brackets."

Third, other parts of the technical summary besides TS.6 include "uncertainties." For example, the second page of the report summary, front-and-center in section TS.1, is dedicated entirely to the "Treatment of Uncertainty." And here are just a few other examples in the report summary outside TS.6 and TS.1:

• P. 112, "There continues to be a lack of evidence and thus low confidence regarding the sign of trend in the magnitude and/or frequency of floods on a global scale over the instrumental record."

• P. 112, "Compelling arguments both for and against significant increases in the land area affected by drought and/or dryness since the mid-20th century have resulted in a low confidence assessment of observed and attributable large-scale trends."

• P. 76, "[T]here is still no universal strategy for transferring a model’s past performance to a relative weight of this model in a multi-model-ensemble mean of climate projections."

And these are just a few from just the summary of the IPCC report that is relied on extensively. Yet, nothing similar to these show up in the Wikipedia article, or at least not in a way that's practically noticeable. Again, on this topic, as well as many others, Wikipedia readers expect to see clear major section headings entitled something like "ambiguous or inconsistent observations and data" and "other possible causes besides anthropogenesis." 107.3.156.34 (talk) 16:55, 7 February 2014 (UTC)