Talk:Climate change

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Sources: global warming definitions, relation to climate change

There's been discussion about a source for the definition in the lead, and its relation to to climate change. Having looked for good quality reliable sources, I've listed the most relevant below, grouped by publisher or publication type, showing selected quotes, trimmed for brevity. I'll add and sign my comments under the sources. Please add any further sources you think are worth consideration, comment in the appropriate thread, or expand the quotes if relevant. . . . dave souza, talk 19:23, 17 October 2018 (UTC)

George W Bush Administration Renames Global Warming to Climate Change

• As per the Washington Post, "The gradual change in preferred terminology from "global warming" to "climate change" among scientists and politicians began about a decade ago because that’s what their institutions called for. It also happened to be the preference of the George W. Bush White House." In 2005, the National Academies of Sciences published a pamphlet that expressed the viewpoint that "climate change" was a more scientifically comprehensive description of what was happening to the planet. In 2006, the Environmental Protection Agency changed the name of its Web site on the issue from "Global Warming" to "Climate Change."--Efbrazil (talk) 23:20, 11 February 2019 (UTC)

NASA

• Erik Conway. "What's in a Name? Global Warming vs. Climate Change", NASA, 5 December 2008: "in a 1975 Science article", Wallace Broecker introduced the term global warming, then in 1979, "When referring to surface temperature change, Charney used 'global warming.' When discussing the many other changes that would be induced by increasing carbon dioxide, Charney used 'climate change.'
  Within scientific journals, this is still how the two terms are used. Global warming refers to surface temperature increases, while climate change includes global warming and everything else that increasing greenhouse gas amounts will affect."

The current page on the topic is What's the difference between global warming and climate change? Relevant quote: 'Global warming refers only to the Earth’s rising surface temperature, while climate change includes warming and the 'side effects' of warming—like melting glaciers, heavier rainstorms, or more frequent drought. Said another way, global warming is one symptom of the much larger problem of human-caused climate change. Date- october 2018.

Conway is a historian of science and technology, his books include Atmospheric Science at NASA, A History (2008) and Exploration and Engineering: The Jet Propulsion Laboratory and the Quest for Mars (2015). The page is archived, so superseded by Shaftel's 2016 article as a basic explanation, but remains invaluable as a concise history of terminology. . . dave souza, talk 19:23, 17 October 2018 (UTC)

• "Questions (FAQ)". NASA Climate Change: Vital Signs of the Planet. 18 March 2015. Retrieved 12 June 2018. 'Global warming' refers to the long-term warming of the planet. Global temperature shows a well-documented rise since the early 20th century and most notably since the late 1970s. ... 'Climate change' encompasses global warming, but refers to the broader range of changes that are happening to our planet. .... The terms 'global warming' and 'climate change' are sometimes used interchangeably, but strictly they refer to slightly different things.

• Shaftel, Holly (January 2016). "What's in a name? Weather, global warming and climate change". NASA Climate Change: Vital Signs of the Planet. Retrieved 12 October 2018. "Climate change" and "global warming" are often used interchangeably but have distinct meanings. .... Global warming refers to the upward temperature trend across the entire Earth since the early 20th century .... Climate change refers to a broad range of global phenomena ...[which] include the increased temperature trends described by global warming, ....</ref>

• "Climate change evidence: How do we know?". NASA Climate Change: Vital Signs of the Planet. 21 September 2018. Retrieved 18 October 2018. The Earth's climate has changed throughout history. Just in the last 650,000 years there have been seven cycles of glacial advance and retreat, with the abrupt end of the last ice age about 7,000 years ago marking the beginning of the modern climate era — and of human civilization. Most of these climate changes are attributed to very small variations in Earth's orbit .... Scientific evidence for warming of the climate system is unequivocal. [IPCC] .... The current warming trend is of particular significance because most of it is extremely likely (greater than 95 percent probability) to be the result of human activity since the mid-20th century and proceeding at a rate that is unprecedented over decades to millennia

This highlights the #IPCC WGI SPM statement on observed warming (with a full stop instead of a comma) but does not use the phrase global warming. As compelling "evidence for rapid climate change" it lists "Global temperature rise", "Warming oceans", "Shrinking ice sheets", "Glacial retreat", "Decreased snow cover", "Sea level rise", "Declining Arctic sea ice", "Extreme events" and "Ocean acidification" – treating "global temperature rise" as just one piece of evidence of CC, not the title covering all these points. . . dave souza, talk 10:29, 19 October 2018 (UTC)

NOAA

• "Global Warming Frequently Asked Questions". NOAA Climate.gov. 16 December 2013. Retrieved 17 October 2018. What is global warming, and how is it different from climate change and climate variability?
  "Global warming" refers to an increase in Earth's annually averaged air temperature near the surface. Thermometer readings ..... Most of that warming has occurred since 1976.
  "Climate change" is a broadly inclusive term that refers to a long-term (decades to centuries) change in any of a number of environmental conditions for a given place and time—such as temperature, rainfall, humidity, cloudiness, wind and air circulation patterns, etc. These oscillations and other similar phenomena can influence weather and climate patterns around the globe.
  "Climate variability" refers to short-term (weeks to decades) changes in some of these same environmental conditions for a given place and time. Climate variability is often the result of natural oscillations in Earth's climate system — such as the El Niño-Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), the Pacific-North American Teleconnection Pattern, etc. These oscillations and other similar phenomena can influence weather and climate patterns around the globe.

Climate variability is a redirect to Climate change#Terminology, looks like one or two more sub-articles are needed. . . dave souza, talk 19:23, 17 October 2018 (UTC)

• "What's the difference between global warming and climate change?". NOAA Climate.gov. 17 June 2015. Retrieved 15 October 2018. Global warming refers only to the Earth's rising surface temperature, while climate change includes warming and the "side effects" of warming—like melting glaciers, heavier rainstorms, or more frequent drought. Said another way, global warming is one symptom of the much larger problem of human-caused climate change.
  Another distinction between global warming and climate change is that when scientists or public leaders talk about global warming these days, they almost always mean human-caused warming—warming due to the rapid increase in carbon dioxide and other greenhouse gases from people burning coal, oil, and gas.
  Climate change, on the other hand, can mean human-caused changes or natural ones

This also covers history of terminology, starting with "According to historian Spencer Weart, the use of more than one term to describe different aspects of the same phenomenon tracks the progress of scientists’ understanding of the problem." . . . dave souza, talk 19:23, 17 October 2018 (UTC)

EPA

United States Environmental Protection Agency

• "Overview of Climate Change Science - Climate Change Science". US EPA. 17 June 2016. Retrieved 15 October 2018. Click on the image for a pop-up on the difference between climate change and global warming. >> Climate Change vs. Global Warming
  The term climate change is sometimes used interchangeably with the term global warming. However, the terms do not refer entirely to the same thing.
  Global warming refers to the recent and ongoing rise in global average temperature near Earth's surface. It is caused mostly by increasing concentrations of greenhouse gases in the atmosphere. Global warming is causing climate patterns to change. However, global warming itself represents only one aspect of climate change.
  Climate change refers to any significant change in the measures of climate lasting for an extended period of time. In other words, climate change includes major changes in temperature, precipitation, or wind patterns, among others, that occur over several decades or longer. Climate change can occur at the global, continental, regional, and local levels. Climate change may refer to natural changes in climate, or changes caused by human activities. (not the current EPA website).

This looks the closest to the usage we're presenting. . . dave souza, talk 19:23, 17 October 2018 (UTC) – but for GW and warming of the climate system, see Myths v. Facts below. . . dave souza, talk 11:20, 19 October 2018 (UTC)

• "Myths vs. Facts: Denial of Petitions for Reconsideration of the Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act". US EPA. 25 August 2016. Retrieved 19 October 2018. Fact: Climate change is real and it is happening now. The U.S. Global Change Research Program, the National Academy of Sciences, and the Intergovernmental Panel on Climate Change (IPCC) have each independently concluded that warming of the climate system in recent decades is "unequivocal." This conclusion is not drawn from any one source of data but is based on multiple lines of evidence, including three worldwide temperature datasets showing nearly identical warming trends as well as numerous other independent indicators of global warming (e.g., rising sea levels, shrinking Arctic sea ice).

Equates evidence for "warming of the climate system" to "independent indicators of global warming", including surface temperatures, SLR, shrinking ice. Response to arguments based on Climatic Research Unit email controversy. . . dave souza, talk 11:20, 19 October 2018 (UTC)

Published papers

• Benjamin, Daniel; Por, Han-Hui; Budescu, David (22 September 2016). "Climate Change Versus Global Warming: Who Is Susceptible to the Framing of Climate Change?". Environment and Behavior. 49 (7). SAGE Publications: 745–770. doi:10.1177/0013916516664382. ISSN 0013-9165. The terms global warming and climate change are often used interchangeably, but recent research finds 'global warming' has become more emotive and more polarizing, resulting in less advocacy by some subpopulations. .... We find stronger framing effects for political Independents and those who are disengaged from climate change issues, indicating that polarization overrides framing at the extremes, and those with moderate beliefs are more susceptible to labeling and framing effects, especially when beliefs are inconsistent with one's political identity.
  The terms global warming (GW) and climate change (CC) invoke disparate interpretations and call attention to different aspects of the changing global climate. A GW label induces associations with temperature increases, severe weather, greater concern, human causes, and negative affect, whereas a CC label highlights changes in general weather patterns and the possibility of natural fluctuations, and boosts recollection of non-heat-related consequences like increased precipitation ..... Typically, CC leads to higher reported beliefs that climate change is happening and will have serious consequences ..... Scientists today consider CC to be a general term referring to sustained variations in conditions over time, whereas GW refers only to 'one aspect of climate change' .... A leaked memo describing results of a focus group—commissioned by President G. W. Bush's administration—was one of the first to call attention to the different reactions to the two terms and to suggest that GW is more 'emotional and frightening' .... GW has become the favorite term among skeptics and deniers and in Republican-leaning states. For example, 'global warming hoax' is the consistently preferred Google search term over 'climate change hoax.' ...... [our] key result is that those with partisan political affiliations are least susceptible to framing effects in the climate change context. ... We have shown that it is mostly Independents and only those who fit the disengaged profile that show significant framing effects .... Overall, people reported higher beliefs under a CC frame, so we recommend using this term when communicating to heterogeneous groups.
• Penn, Justin L.; Deutsch, Curtis; Payne, Jonathan L.; Sperling, Erik A. (6 December 2018). "Temperature-dependent hypoxia explains biogeography and severity of end-Permian marine mass extinction". Science. 362 (6419). American Association for the Advancement of Science (AAAS): eaat1327. doi:10.1126/science.aat1327. ISSN 0036-8075. Geochemical evidence provides strong support for rapid global warming and accompanying ocean oxygen (O2) loss {{cite journal}}: Invalid |ref=harv (help)

UNFCCC

• The 1992 articles of the United Nations Framework Convention on Climate Change Article 1 DEFINITIONS "For the purposes of this Convention:
  2. 'Climate change' means a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods."

Not for all time and all purposes, but for the specific purposes of the 1992 convention, they use "climate variability" for any other forcing – but that's just a redirect to climate change, and hasn't come into general usage. . . . dave souza, talk 19:23, 17 October 2018 (UTC)

• UNFCCC Fact sheet: Climate change science - the status of climate change science today, February 2011.

This notes that their usage differs from the usage in the IPCC, says "During 2010.... The WMO stated that .... the sequence of current events matches IPCC projections of more frequent and more intense extreme weather events due to global warming." . . . dave souza, talk 19:23, 17 October 2018 (UTC)

• UNFCCC Climate Change: Impacts, Vulnerabilities and Adaptation in Developing Countries © 2007 UNFCCC, Produced by the Information Services of the UNFCCC secretariat: "The main characteristics of climate change are increases in average global temperature (global warming); changes in cloud cover and precipitation .... The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC 2007) dispelled many uncertainties about climate change. Warming of the climate system is now unequivocal. It is now clear that global warming is mostly due to man-made emissions of greenhouse gases (mostly CO2). .... As a result of global warming, the type, frequency and intensity of extreme events, such as tropical cyclones (including hurricanes and typhoons), floods, droughts and heavy precipitation events, are expected to rise .... Global warming is causing the melting of glaciers in the Himalayas. ... communities who are feeling the effects of climate changes due to global warming"

IPCC

Intergovernmental Panel on Climate Change IPCC Fifth Assessment Report 2013/2014

• AR5 SYR Annex II Glossary p. 120, "Climate change refers to a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer." ... [may be natural or anthropogenic] ... "{WGI, II, III}", p. 124, "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. {WGIII}"

• HOWEVER, in the AR5 synthesis report and other AR5 reports, the term "climate change" clearly means modern climate change driven by global warming. Samples include the first mention of the term in their report: "The SYR highlights that we have the means to limit climate change and its risks, with many solutions that allow for continued economic and human development." Chapter titles include "Climate change risks reduced by adaptation and mitigation" and "Climate change beyond 2100, irreversibility and abrupt changes". In their Summary for Policymakers section 1.2 begin with "Causes of Climate Change: Anthropogenic greenhouse gas emissions have increased since the pre-industrial era, driven largely by economic and population growth, and are now higher than ever. This has led to atmospheric concentrations of carbon dioxide, methane and nitrous oxide that are unprecedented in at least the last 800,000 years. Their effects, together with those of other anthropogenic drivers, have been detected throughout the climate system and are extremely likely to have been the dominant cause of the observed warming since the mid-20th century." As a rule, whenever climate change is used in singular form, it means modern climate change caused by global warming.--Efbrazil (talk) 23:20, 11 February 2019 (UTC)

• WGI SPM p. 4, B. (was previously at this link) Observed Changes in the Climate System; "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", D. Understanding the Climate System and its Recent Changes, p. 16 D.2: "the magnitude of global warming in response to past and future forcing." p. 19, E. Future Global and Regional Climate Change: "Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions."

Note: as discussed, "B" has previously been used as a defining statement, but makes no use of the phrase "global warming". . . dave souza, talk 10:19, 17 December 2018 (UTC)

• WGI TS P. 49 TFE.2 – "ice sheet response to global warming", p. 66 "the observed global warming since 1951", p. 102 "Around the mid-21st century, the rate of global warming begins to be more strongly dependent on the scenario. .... beyond 2100, global warming reaches 2.5 °C ...."

• WGI Chapter 2, Observations: Atmosphere and Surface – 2.5.2 "an increasing trend in global river discharge associated with global warming during the 20th century"

apparently sole use of the term GW in this chapter. . . dave souza, talk 19:23, 17 October 2018 (UTC)

• WGI Chapter 5, Information from Paleoclimate Archives p. 384 "During the last deglaciation ... the mean rate of global warming was very likely 0.3°C to 0.8°C per thousand years", p. 399 "The PETM was marked by .... global warming of 4°C to 7°C", p. 400 "Deglacial global warming .... from 17.5 to 14.5 ka and 13.0 to 10.0 ka"

Global warming occurred over 10,000 year ago during deglaciations, and in the Paleocene–Eocene Thermal Maximum around 55.5 million years ago. . . dave souza, talk 19:23, 17 October 2018 (UTC)

• WGI glossary defines CC and GWP but no mention GW. . . dave souza, talk 19:23, 17 October 2018 (UTC)

• WGIII p. 187, 2.6.6.1 Popular support for climate policy; "The use of language used to describe climate change—such as the distinction between ‘climate change’ and ‘global warming’— play a role in influencing perceptions of risk, as well as considerations of immediate and local impacts", Glossary p. 1263: "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."

• Special Report on Global Warming of 1.5 ºC [1] –an IPCC special report on the impacts of global warming of 1.5 °C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty

• Final Government Draft Glossary IPCC SR1.5 "Do Not Cite, Quote or Distribute" "In press" – defines climate change as SYR Annex II, "Global warming An increase in global mean surface temperature (GMST) averaged over a 30-year period, relative to 1850-1900 unless otherwise specified. For periods shorter than 30 years, global warming refers to the estimated average temperature over the 30 years centred on that shorter period, accounting for the impact of any temperature fluctuations or trend within those 30 years."

This is clearly a definition related to post-1850 climate change, but the methodology and time frame would also apply to earlier periods whether warming or not. . . dave souza, talk 20:54, 17 October 2018 (UTC) Updated link, "in press", as archive apparently broken, dave souza, talk 17:14, 10 February 2019 (UTC)

• General note: links now updated to https://archive.ipcc.ch/ to restore functionality, except first link which is the new link title. . . dave souza, talk 05:13, 28 December 2018 (UTC)

Other

2018 AP Style Guide

• (Source "The terms global warming and climate change can be used interchangeably. Climate change is more accurate scientifically to describe the various effects of greenhouse gases on the world because it includes extreme weather, storms and changes in rainfall patterns, ocean acidification and sea level. But global warming as a term is more common and understandable to the public." NewsAndEventsGuy (talk) 02:43, 26 December 2018 (UTC)

Conclusions for discussion

Draft summary": [citations to be added] Global warming is essentially an increase in global mean surface temperature (GMST) averaged over a 30-year period (the standard period for climate), this is commonly the current (since 1900) and projected future warming, which is predominately human caused. Global warming can also refer to earlier periods of increasing temperature, such as deglaciations, and the Paleocene–Eocene Thermal Maximum. It is an aspect of climate change as a broad topic, and warming has implications of climate change, so in the post–1900 context the terms can be used interchangeably, but climate change also refers to periods when global temperatures were stable or falling, and to local, regional or continental changes of climate which are not necessarily global. In the politicised context of policy, the label "global warming" can increase rejection of science by the uncommitted public, who are more likely to be receptive to discussion of "climate change" – the labelling does not affect opinions of those predisposed to accept or reject the science. . . dave souza, talk 19:23, 17 October 2018 (UTC)

OMG you have done a lot of work on this! Amazing, thank you! And yes, perhaps it warrants a new Wikipedia article on "Climate change versus global warming debate" (unless such an article exists already?)? Then we could just point across to it from the other articles. About your draft summary is that just for discussion here or is this proposed wording for the lead of the Wikipedia article? If the latter then I think its readability needs to be improved as laypersons wouldn't be able to follow that (even I was struggeling and had to think twice about each sentence...). EMsmile (talk) 01:52, 18 October 2018 (UTC)

Thanks, it's just a first stab at a summary of the main points, a kind of checklist for assessing the lead and not a new lead. There are also points for other sections, not sure that a new article is appropriate. The main idea is to get discussion started on where these (and any other) good sources take us. . . . dave souza, talk 09:02, 18 October 2018 (UTC)

Sorry to fall so easily into my usual negativity but "is essentially" is horrible, and the explicit tie to 30-years jars. And you might want to mention pre-industrial, which is teh std ref for "warming from" William M. Connolley (talk) 10:03, 18 October 2018 (UTC)

Ta, that's helpful – sorry about the essentialism! Pre-indust is a detail for later in the lead or article, note definitions cited give various reference points, such as "the early 20th century" which clearly isn't pre-industrial. .. dave souza, talk 21:38, 18 October 2018 (UTC)

I agree. I don't think we need too much detail in the introduction. Maybe:

Global warming is a systematic increase in global mean surface temperature (GMST) over time. The term is commonly used to refer to the current episode of largely human-caused warming of the global climate, and its projected continuation. Global warming can also refer to earlier periods of increasing temperature, such as deglaciations, and the Paleocene–Eocene Thermal Maximum.

--Stephan Schulz (talk) 19:10, 18 October 2018 (UTC)

You could also delete "systematic" and "largely". Shock Brigade Harvester Boris (talk) 21:21, 18 October 2018 (UTC)

Arguably yes. I added "systematic" to indicate that it is not a short-term fluctuation (though my hindbrain seems to suggest that there is an even better word that just does not want to come forward), and "largely" from an overly conservative mindset. --Stephan Schulz (talk) 23:31, 18 October 2018 (UTC)

My concern with "sustained" is that it could be interpreted as meaning increase has to be continual (uninterrupted), whence the "hiatus" nonsense of a few years ago. But maybe I'm over-thinking it. "Over time" seems enough to cover your point about not being a short-term fluctuation. Shock Brigade Harvester Boris (talk) 13:47, 19 October 2018 (UTC)

Thanks Stephan and Boris, that covers two points contradicted by the present lead introduction which implies GW is only the present episode, and leaves mention of future warming to the third paragraph, and doesn't call it GW. Will think over the wording. . . dave souza, talk 21:40, 18 October 2018 (UTC) ... now in progress: see next section. . . dave souza, talk 14:49, 21 October 2018 (UTC)

Update: I've been looking at the sources for "warming of the climate system" which seems good rather than a focus on surface temperatures, they don't use the term "global warming" but it's reasonably clear that's the same thing. Will add these tomorrow. . . dave souza, talk 21:40, 18 October 2018 (UTC)

Sources added: NASA Climate change evidence: How do we know?, and AR5 SPM. .. dave souza, talk 14:49, 21 October 2018 (UTC)

Scope and article titles

Your summary makes it sound like the terms "global warming" and "climate change" are general terms that don't apply to modern times unless scoped that way. For instance, you say "climate change also refers to periods when global temperatures were stable or falling, and to local, regional or continental changes of climate which are not necessarily global." I think if you review references (I added a few) it's clear that whenever the terms are used in isolation without qualifications, such as "global warming is caused by" or "effects of climate change include", then the terms refer to greenhouse gas caused climate change in modern times. The only time the terms can be interpreted more generally is when qualified that way, such as "earlier periods of global warming" or "Paleocene–Eocene Thermal Maximum climate changes include". The distinction is very important when talking about how the topics of global warming and climate change should be scoped as entries on wikipedia. Perhaps you could revisit your summary up above or I could with that in mind?--Efbrazil (talk) 23:20, 11 February 2019 (UTC)

@Dave souza:As per my ask above, here is a proposed update to your draft summary- please let me know any thoughts because I'd like to use this as the basis for article reorganization:

• Global warming: An increase in global mean surface temperature (GMST) averaged over a 30-year period (the standard period for climate), this is commonly the current (since 1900) and projected future warming, which is predominately human caused. When explicitly scoped the term may also be used to refer to earlier periods of increasing temperature, such as deglaciations, and the Paleocene–Eocene Thermal Maximum, but without scoping the term means modern global warming (e.g. "how to limit global warming to 1.5 degrees celcius").
• Climate change: The terms global warming and climate change are commonly used interchangeably, but climate change includes both global warming and its effects, such as changes to precipitation and impacts that differ by region. As with global warming, climate change can refer to earlier time periods, but only if explicitly scoped that way. Without explicit scoping the term refers to modern climate change caused by global warming (e.g. "how to limit climate change and its risks").--Efbrazil (talk) 22:11, 12 February 2019 (UTC)

While I support your efforts here, I don't think the RSs have converged on a requirement that "global warming" be "explicitly scoped" to talk about global warming in general, or far off in the future, or long ago in the past. It would be nice if the phrase was pre-packaged with usage fine print but alas, such is not the case, and we can't dictate such parameters. I am mulling on some reorg ideas of my own and will post soon. NewsAndEventsGuy (talk) 22:47, 12 February 2019 (UTC)

@NewsAndEventsGuy:If you read through the above sources (I added a few), I think it's fair to say reliable sources have converged on saying that global warming and climate change always refer to modern times unless they are explicitly talking about a different time period. NASA, the EPA, and several other US Government sites are very explicit about the issue, as is the UN. The IPCC has that glossary entry that is not explicit, but if you read through the chapter titles and text of their reports then you see that whenever they use the term "climate change" without qualifying it they are talking about modern climate change caused by humans (e.g. "how to limit climate change"). I tried to make that clear in the references up above by including a few quotes and chapter titles. You could also just google the term "climate change" in incognito mode and all of the top articles are about what you think they'd be about- none are about non-modern climate change. I don't see anyone except wikipedia using a more expansive definition for the terms. Why should we be doubling over backwards here to support an interpretation that doesn't exist in the real world?--Efbrazil (talk) 23:20, 12 February 2019 (UTC)

When you say "scoped" I think you mean "explicitly stated". I think you do not mean just figured out from context. The government agencies tasked with dealing with today's world have their viewpoint, and I applaud you for looking at them. But if you go over to the academic literature, its less clear cut, in my view. I do have an alternative to suggest but its broader than you're working on here so its taking me longer to marshall my thoughts, and I'm doing a lot of review of prior archived talk threads in assembling my ideas. NewsAndEventsGuy (talk) 00:03, 13 February 2019 (UTC)

Hi, thanks for contributing. Right now I'm unable to spend a lot of time on this, but my reading is that both terms are used in context: since most of the IPCC discussion is about post-1850 changes, most of the use of these terms relates to that. It's not exclusive, and "explicitly scoped" just seems to be a way of saying "in context". For example, AR5 5.3.2.2 Last Glacial Termination has "higher rates may have occurred, in particular during a sequence of abrupt climate change events", there's quite a lot of discussion of "abrupt climate change" in paleo times as well as "climate changes" which you noted above, for multiple changes. That looks like normal grammar, rather than a special term. For example, "WAIS could be destabilized by projected climate changes, although the time scales of the ice sheets response to climate change are very long". Note, of course, that climate change can be regional rather than worldwide, but of course global warming is always on a global, or at least hemispherical, scale. Similarly, climate change is in the title of several works cited about pre-industrial change. . . dave souza, talk 22:02, 13 February 2019 (UTC)

@Dave souza:Yeah, I can see that "in context" makes more sense than "explicitly scoped". I think my point is that wikipedia should be following common use in an absence of context, and in that scope both climate change and global warming refer to the conceptual space of how the climate is changing in modern times as a result of greenhouse gas emissions. To use an analogy, consider if the article on "evolution" in wikipedia was talking about all the possible causes for things changing gradually or "evolving", instead of being about biological evolution. That could be justified, but wouldn't it be contrary to common usage of the term and contrary to the value of wikipedia to educate and inform?

I think that as things stand with climate change article, we are actively confusing the topic for the public. If people come to wikipedia to learn about this "climate change" thing they've heard about and only skim the article, they will leave with the impression that climate change has tons of possible causes, so who knows what's going to happen. Sure, there's the article on "global warming" but that's an antiquated term that is really frowned on by the educational establishment and that we shouldn't be forcing people to use. Additionally, "global warming" is not supposed to be about the effects of global warming (strictly speaking), so that article is misdirected as well. Do you understand my frustration and have a thought on how to address the issue?--Efbrazil (talk) 00:20, 14 February 2019 (UTC)

@Efbrazil: On the climate change article, surely the best option is to treat that as an overview, and right at the outset say that most interest is in climate change since 1850 which is predominately human caused, as well as putting it in the context of knowledge of earlier climate changes. As the IPCC reports do. Don't know that "global warming" is an antiquated term, but clearly it can be narrowly defined as increase in average worldwide surface temperatures worldwide at a climate scale, and our use of it as an article title for current/future climate change can be reconsidered. Still think we need a general "climate change" article covering the whole topic, got any ideas for a better title for this [global warming] article's coverage? . . . dave souza, talk 15:32, 14 February 2019 (UTC)

@Dave souza:I think we see it the same way mostly. The "whole" topic is what I'd name "climate forcing mechanisms"- it would basically be the same coverage as the existing "climate change" article. So in the end the current "global warming" content is mostly a good fit for "climate change", the existing "climate change" content would become "climate forcing mechanisms", and then a new article on "global warming" could discuss the name change that happened and point people towards climate change or the greenhouse effect or climate forcing mechanisms. As a writer, I could tackle all that without much trouble, but the churn would be huge. Do you know how a major restructuring like that is typically tackled?--Efbrazil (talk) 21:07, 14 February 2019 (UTC)

There is a practical consideration that might throw a wrench in the works, or at least eggs on the windshield. We have already plowed a furrow in terms of article/scope with the way things are now. There are a million crosslinks and redirects that point to these pages the way they are now, and even more talk threads that assert the way things are now. If we "gut and replace" content under these same titles with a differently-defined scope, all those prior links will turn into EGGS. I'm not 100% certian that's an issue here... its a long discussion and I haven't really analyzed it for this quicksand. Just calling attention. In any case, I think the proposal will need to be reformulated and summarized before asking for a strawpoll or other measuring of consensus. NewsAndEventsGuy (talk) 22:53, 14 February 2019 (UTC)

@NewsAndEventsGuy:Yeah, there would be cleanup and there will be push back I expect (change is hard!) The good thing is the articles will cross reference, so if a link is to the wrong article it is easy for people to jump to the right article. Any suggestions you have in doing this successfully would be great- judging by your talk page, reaching consensus on contentious issues is your hobby, so I hope this is up your alley. You suggested I next create a general proposal as rfc|sci, I guess as a new section on this page? The rfc I'm thinking of will be aimed at getting people to agree on what the terms "climate change", "climate forcing mechanisms", and "global warming" should be covering vs what is currently being covered and why. I don't know if that's too leading and long an issue to capture as an rfc. I'll leave out the mechanism for change from the rfc because that would just open up more possibilities for disagreement.--Efbrazil (talk) 23:47, 14 February 2019 (UTC)

Existing first paragraph, suggested rewording

Sometimes easier to try rewording. Here's the existing first paragraph, which confines the meaning to the current observed century-scale warming over the last century , and cites a 2008 [partly superseded] NASA article for usage and definitions. . .

*Global warming is the observed century-scale rise in the average temperature of the Earth's climate system and its related effects, as part of climate change. Multiple lines of scientific evidence show that the climate system is warming. Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record, and in paleoclimate proxy records of climate change over thousands to millions of years. The terms Global warming and climate change are often used interchangeably; a 2008 NASA article defines global warming as "the increase in Earth's average surface temperature due to rising levels of greenhouse gases", and climate change as "a long-term change in the Earth's climate, or of a region on Earth".

Here is the suggestion from the previous subsection. This starts with the more technical meaning which doesn't cover related effects or symptoms, and omits the comparison with climate change. . .

*Global warming is a systematic increase in global mean surface temperature (GMST) over time. The term is commonly used to refer to the current episode of largely human-caused warming of the global climate, and its projected continuation. Global warming can also refer to earlier periods of increasing temperature, such as deglaciations, and the Paleocene–Eocene Thermal Maximum.

Finally, here is a draft rewrite which combines the existing text and the proposed replacement in the grey boxes above. The definition of global warming as "a long term increase in surface temperature averaged across the world" could readily be changed to "systematic increase in global mean surface temperature (GMST) over time", but that's a redlink, nearest article is Instrumental temperature record which is already linked. Not sure if the last sentence should become new paragraph. . . Anyway, here is hte proposed combination...

*Global warming is a long-term rise in the average temperature of the Earth's climate system and related effects, an aspect of climate change. It commonly refers to the mainly human-caused observed warming since pre-industrial times and its projected continuation, though earlier periods of global warming include prehistoric deglaciations and the Paleocene–Eocene Thermal Maximum. The terms Global warming and climate change are commonly used interchangeably in the modern context, but have distinct definitions: climate change is any regional or global statistically identifiable persistent change in the state of climate which lasts for decades or longer, including warming or cooling; global warming is a long term increase in surface temperature averaged across the world. Multiple lines of scientific evidence show that the climate system is warming. Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record, and in paleoclimate proxy records of climate change over thousands to millions of years.

dave souza, talk 14:49, 21 October 2018 (UTC)

Thanks very much for all the effort, I'm impressed :). I very strongly think we should keep the lede as understandable as possible and I propose that we don't include any difficult terms yet. Even as a climate scientist, I have to think a second before I know what the Paleocene-Eocene Thermal Maximum is. I'd prefer if we don't include the abbreviation GMST at all.

*Global warming is a long-term rise in the average temperature of the Earth's climate system and related effects, an aspect of climate change. It commonly refers to the mainly human-caused observed warming since pre-industrial times and its projected continuation, though there have been earlier periods of global warming. The terms Global warming and climate change are commonly used interchangeably in the modern context, but sometimes a distinction is made: climate change is any regional or global statistically identifiable persistent change in the state of climate which lasts for decades or longer, including warming or cooling; global warming is a long term increase in surface temperature averaged across the world.

Femkemilene (talk) 15:57, 21 October 2018 (UTC)

The first sentence and the last sentence of your proposed paragraph are nearly identical which to me seems repetitive but then also confusing because the last sentence omits the "and related effects" which I think would be a crucial difference to the first sentence. Furthermore, I think we need to explain "and related effects" as this means it's a lot broader than just temperature alone.EMsmile (talk) 01:33, 22 October 2018 (UTC)

I agree that we should mention what those related effects are very early in the article. In terms of the confusion: I think, judging from all of the sources listed above, that the difference between the first and last sentence is correct. Our article is about the warming+related effects, but some people define global warming more strictly. We should in addition mention that we use the first definition (where global warming/climate change are used interchangeably) and not only talk about increased surface temperatures. Femkemilene (talk) 09:44, 22 October 2018 (UTC)

Good points; the related effects are covered in NASA 2018. Have tried some rewording below, incorporating the previous suggestions, . dave souza, talk 11:24, 22 October 2018 (UTC)

*Global warming is a long-term rise in the average temperature of the Earth's climate system demonstrated by measurements and by related effects showing the warming, an aspect of climate change. It commonly refers to the mainly human-caused observed warming since pre-industrial times and its projected continuation, though there were much earlier periods of global warming. In the modern context the terms are commonly used interchangeably, but global warming can more specifically concern changes related to worldwide surface temperatures; while climate change is any regional or global statistically identifiable persistent change in the state of climate which lasts for decades or longer, including warming or cooling. Many of the observed warming changes since the 1950s are unprecedented in the instrumental temperature record, and in historical and paleoclimate proxy records of climate change over thousands to millions of years.

Tried to tighten the wording up a bit, added historical climatology to cover changes beyond temperature measurements. .. . dave souza, talk 11:24, 22 October 2018 (UTC)

@Dave souza, Femkemilene, and EMsmile: I tried to load this in my brain and found it very hard to follow at first and second read. So I boldly reformatted and slightly tweaked the "glue" in Dave's first block of text. I don't think the meaning was changed. This makes it very simple for me to follow and hopefully will assist others who arrive here with fresh eyes. If anyone objects, please revert.NewsAndEventsGuy (talk) 13:01, 25 December 2018 (UTC)

Continued in next subsection, "Implemented, with references and minor tweaksNewsAndEventsGuy (talk) 00:19, 28 December 2018 (UTC)

Implemented, with references and minor tweaks

I moved this down here from the subsection above to eliminate redundancy NewsAndEventsGuy (talk) 00:19, 28 December 2018 (UTC)@NewsAndEventsGuy, Femkemilene, and EMsmile: Thanks! To keep the variants to date directly comparable in this section, I've shown below the version as of 22:35, 27 December 2018 (UTC) in the same colour scheme. Hope we can improve the wording while continuing to cover the essential points. . . dave souza, talk 22:35, 27 December 2018 (UTC)

Bit of a marathon, choosing the best references and getting them formatted. Made a couple of minor changes on the way:

Global warming is a long-term rise in the average temperature of the Earth's climate system, an aspect of climate change shown by temperature measurements and by multiple effects of the warming.[2][3] The term commonly refers to the mainly human-caused observed warming since pre-industrial times and its projected continuation,[4] though there were also much earlier periods of global warming.[5] In the modern context the terms are commonly used interchangeably,[6] but global warming more specifically relates to worldwide surface temperature increases; while climate change is any regional or global statistically identifiable persistent change in the state of climate which lasts for decades or longer, including warming or cooling.[7][8] Many of the observed warming changes since the 1950s are unprecedented in the instrumental temperature record, and in historical and paleoclimate proxy records of climate change over thousands to millions of years.[2]

Well, that's a start. Climate change also needs attention. . . dave souza, talk 16:36, 6 November 2018 (UTC)

@Dave souza:, I do have some problems with this version. For one, it introduces the article as if it is about all periods in history wherein the world was warming, which is inaccurate. Secondly, it replaced some concise and relevant statements ("The world is currently warming" etc) and replaced it with more ambiguous and light jargon that could more suitably be described in the main article. Prinsgezinde (talk) 08:58, 29 November 2018 (UTC)

Citation: " IPCC WGI AR5 (Report). pp. 389, 399–400. The PETM [around 55.5–55.3 million years ago] was marked by ... global warming of 4°C to 7°C ..... Deglacial global warming occurred in two main steps from 17.5 to 14.5 ka [thousand years ago] and 13.0 to 10.0 ka." So there were at least three instances of prehistoric global warming. The definition of GW from the IPCC SYR AR5 p. 124. is "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." Perhaps you have a source to add for "is currently warming", or do you feel that's implicit? . . . dave souza, talk 22:07, 8 December 2018 (UTC)

Apologies that I was tuned out for a long while. In my opinion the new text is not nearly as accessible to the nontechnical reader as the replaced text. Ideally this lead should be written in simple language, neither nerdspeark or dronespeak but school kid level normal language. Am I correct in thinking this is an attempt to resolve recent complaints about the article title? Or at least that is the real underlying issue? NewsAndEventsGuy (talk) 00:39, 11 December 2018 (UTC)

See #Existing first paragraph, suggested rewording – the preceding version lacked sources, conflicted with current sources and misidentified GW as applying only to current climate change, when it also applies to past episodes. Simplification of the new language will be welcome, provided it continues to summarise the current sources or other sources of equal quality. . . dave souza, talk 10:28, 11 December 2018 (UTC)

Discussing with the rewrite

@Dave souza: I agree with NewsAndEventsGuy about the new lead being overly complex, and want to add that its focus has also shifted in the wrong direction. You said: "the preceding version lacked sources, conflicted with current sources and misidentified GW as applying only to current climate change, when it also applies to past episodes." For one, the lead doesn't necessarily need sources if they are supported by the body, but I understand that reasoning. I do strongly disagree with "misidentified GW as applying only to current climate change". Both the sources used and the sources you provided tend to use "global warming" as referring to current climate change. Right now, the article lead introduces a minority aspect (general CC) while the article is about the major aspect (current CC). At best, this is confusing; at worst, misleading. In any case, this is a very major change that, in my opinion, needs direct consensus. Prinsgezinde (talk) 09:18, 17 December 2018 (UTC)

The issue of sourcing has been discussed, with #Sources: global warming definitions, relation to climate change covering the relevant points – if you have further defining sources, please add them under that heading. As noted under #IPCC, the defining statement previously used for the introductory statement covers "Warming of the climate system", not "global warming". The tendency in all discussions of climate is to focus on the current warming climate, but that doesn't mean redefining climate to exclude the past.
In any article, the opening statement is a definition of what the topic is about. While there's less coverage of previous episodes of global warming, sources including WGI Chapter 5 clearly show that the term includes these episodes. By coincidence, in today's news, Buncombe, Andrew (16 December 2018). "Scientists who revealed cause of 'great dying' extinction call for action on climate change". The Independent. Retrieved 17 December 2018. states that "Oceanographers based in Seattle said the largest mass extinction in the planet’s history - what has been termed the “great dying” - was caused by extreme global warming that saw ocean temperatures rise by as much as 10C around 252m years ago." . . . dave souza, talk 10:41, 17 December 2018 (UTC)

@Dave souza: That discussion never reached a consensus on all parts, only reactions on a few of its parts and not always agreement. The defining sources just as often say global warming refers to "recent" and "ongoing" GW. But here's the main problem: the article has been written around the definition of current GW. For instance, look at the above Q&A. All mentions of GW are about current GW, and one answer even directly declares that that term usually refers to current GW. Since this scope has been stable for a very long time, the onus is on the editor changing it. Prinsgezinde (talk) 18:15, 18 December 2018 (UTC)

I'd like to support User:Prinsgezinde. Both definitions are quite common in literature, but we should stick to the simple definition. We could maybe mention the other use of global warming in a different sentence, but keeping the lede consistent with the rest of the article is important. Femkemilene (talk) 15:48, 19 December 2018 (UTC)

Which simple definition? #Sources: global warming definitions, relation to climate change shows several. Earlier leads to this article wrongly defined GW as "also referred to as climate change" (as at 13 September), using three sources which made no mention of "global warming" thus relying on WP:SYN to cobble together an inaccurate definition. Several good sources explicitly point out that GW is not the same thing as CC, though in certain contexts the terms can be used interchangeably. The simplest definition is that "Global warming refers to an increase in Earth's annually averaged air temperature near the surface", but this article covers more than that, which is reasonable if we want to show the implications of GW. Fair point that the article needs more on episodes of global warming preceding the current AGW, will try to find time to add a brief section on that point. . . dave souza, talk 20:01, 19 December 2018 (UTC)

No it should not. You are now single handedly choosing to change the scope of this article. I'm tempted to just revert it to its earlier version until this is figured out since you don't seem to plan on getting consensus. Prinsgezinde (talk) 22:44, 19 December 2018 (UTC)

That sounds rather WP:BATTLEFIELD, please don't edit war. The issue of topic area was discussed extensively in Talk:Global warming/Archive 74, more recently above at #Global Warming vs.Climate Change and at Talk:Climate change/Archive 5#Update the politics, scientific discussion, and public opinion subcategory. My efforts to get consensus for the current wording are in subsections of #Sources: global warming definitions, relation to climate change, you made a comment there but didn't continue – suggest making this a subsection under that heading to keep the discussion and sources together. . . dave souza, talk 11:46, 20 December 2018 (UTC)

"Discussing with the rewrite" section moved here, as proposed above. Revert if you object. . . dave souza, talk 11:55, 21 December 2018 (UTC)

Dave, its sometimes hard to set aside details and citations to take the view from the window of the ISS. Since before my time here - circa 2011 - this article has been the exclusive province of the current warming period mostly caused by humans. Now we all know that there was pre-human warming periods and we can all be confident that internal variation or non-human forcings will bring about other warming periods far in the future even if we're gone. QUESTION - Looking out the ISS window, do you think we should keep a focus on the current mostly-human warming, or are you suggesting we strip this down to talk about any warming period? In the latter case, would we also need to overhaul the article Global cooling so it isn't just about the 20th century noise on that subject, and how would all that interact with the climate change article? Once this point is clarified it will be easier to process the rest of the excellent work that has been undertaken, yours included. NewsAndEventsGuy (talk) 02:57, 26 December 2018 (UTC)

NAEG, my feeling is that to suit our way of structuring the relationship between articles it's fully valid to make this article primarily about the current warming period mostly caused by humans. New readers can't be expected to know that there were pre-human warming periods unless we mention it, and it's important to briefly note the exceptions to our primary focus. Also helpful, as it shows the warming in context. The climate change article is the main article covering all change, whether global or regional, warming or cooling. It needs to be gone over to remove detail about the current warming period which belongs in this article, and climate change should only concisely outline the global warming topic, in WP:SUMMARY style. This article needs less change, but I think a short paragraph is needed under Observed temperature changes to mention paleoclimate records of earlier global warming periods. That section already relates instrumental records to earlier conditions, so it's a minor clarification. dave souza, talk 22:54, 27 December 2018 (UTC)

Thanks for the clarification! User: Dave souza: Am I correct in summarizing your point as: the scope of the global warming article should indeed be the current global warming episode, but previous episodes should be summarily mentioned because they are a) mentioned in reliable sources and b) inform us about the current episode.

If so, I agree with you. (and also about the climate change article, but that is a different discussion of course). This is also the choice we made with the Sea level rise article.

On a related point: you showed a lot of sources stating that global warming is defined as covering all paleo period of global warming. The first sentences of the article trying to give a definition of global warming that is consistent with the DEFINITION given in reliable sources. I think that we should instead focus on the SCOPE of these sources: while they often give the definition of global warming as including old episodeses, their scope consistently is the current episode, which is also the scope that we seem to be getting consensus on now. I think the first sentences should clearly define the scope of the article instead of defining the term global warming. This might mean we do not have a bold definition in the first line. Femkemilene (talk) 11:13, 28 December 2018 (UTC)

Thanks Femkemilene, I'm glad to agree! As discussed much earlier, WP:FIRST asks us to define the term at the start if that's feasible. Previous to all this discussion,[2] we had the long-term rise. implying there were no others, and the problematic claim at that outset that GW is also referred to as CC – while common, they're not the same.

*Global warming, also referred to as climate change, is the observed century-scale rise in the average temperature of the Earth's climate system and its related effects. Multiple lines of scientific evidence show that the climate system is warming.

The article now opens with a less specific working definition. It's good to mention early in the article that GW and CC are related, that's currently covered by the second sentence:

*Global warming is a long-term rise in the average temperature of the Earth's climate system, an aspect of climate change shown by temperature measurements and by multiple effects of the warming. The term commonly refers to the mainly human-caused observed warming since pre-industrial times and its projected continuation, though there were also much earlier periods of global warming.

Rewording to make that flow better would be good, perhaps the relationship could be demoted to further down the lead.
Regarding previous episodes, Footnote [5] quotes the AR5 chapter five source, "The PETM [around 55.5–55.3 million years ago] was marked by ... global warming of 4°C to 7°C ..... Deglacial global warming occurred in two main steps from 17.5 to 14.5 ka [thousand years ago] and 13.0 to 10.0 ka."
All we'd need to cover in the Observed temperature changes is a brief comment on the Paleocene–Eocene Thermal Maximum and Deglaciation at the end of Ice ages, mentioning how global warming in those periods has been examined in relation to projected global warming. For example, the recent Independent story I linked above has researchers saying "the situation they examined 250m years ago, with the presence of increased levels of greenhouse gases and warming oceans, was similar to today. .... potential for a mass extinction arising from a similar mechanism under anthropogenic climate change." We don't need that level of detail, as the topic's covered by the linked articles. . . dave souza, talk 13:26, 28 December 2018 (UTC)

@Dave souza: Why bury this within a discussion few new people will look into? There was no need to move the section. Fact remains, this huge change needs consensus. I don't see a single reason not to make this article subject shift a request for consensus. If there is a consensus, great. If not, it shouldn't be done. Prinsgezinde (talk) 20:47, 1 January 2019 (UTC)

It's rather a clarification in line with the sources shown above, not a subject shift. Please add any relevant sources you think I've missed, or propose new wording which accommodates the point that GW and CC aren't the same, though in common (non-scientific) usage they're often used interchangeably. . . dave souza, talk 20:15, 3 February 2019 (UTC)

scientific consensus

Collapse as [{WP:SOAP]] and WP:FORUM. Click show to read anyway

While it is true that the majority of scientists agree that climate change is a thing, there is a VERY wide variety of opinions about the extent of climate change etc. that should be noted. 180.190.182.168 (talk) 11:04, 25 December 2018 (UTC) There ain't a total consensus about evolution either but there's no need to bend over backwards giving contrarian views when the vast majority are in consensus. Consensus does not mean 100%. Dmcq (talk) 11:12, 25 December 2018 (UTC) I'm not saying we totally recreate the article, or even another section. I just think that as it is, the article implies that all scientists who believe in global warming also believe that it is a very extreme problem. Just a little note saying that the consensus is not totally unified. — Preceding unsigned comment added by 180.190.182.168 (talk) 11:21, 25 December 2018 (UTC) Covered in part "Scientific discussion" + broader explained in page Scientific opinion on climate changeJirka Dl (talk) 11:26, 25 December 2018 (UTC) I see the word "consensus" is now gone from the main article - and with good reason. Science is not a majority voting process. One could argue that since most religious followers believe in God, that it it is "settled" that there is a God. This does not prove the existence of God. Proof remains in the evidence, and there will be skepticism in Climate Change as long as the science lacks merit. I could write a novel on why Climate Change fails the scientific method. I'll start with just two that can cause scientific error: 1)the distribution of sensors to measure global temperature is not uniform across the Earth. 2) Yesterday's (much less 100 years ago) temperature at any given location is unverifiable. I can cite many more but for brevity I end here. 2600:6C48:7006:200:B056:6066:1296:EF0B (talk) 01:40, 5 February 2019 (UTC)

Warmest Arctic climate since the end of the previous interglacial

See here. Count Iblis (talk) 12:40, 30 January 2019 (UTC)

Updated some graphics, looking for feedback

I'm working on updating the graphics for this page for a few reasons:

• Much data in the graphics was old, predating the fifth IPCC report that was released in 2014.
• I'm looking to add graphics that help with clarity. For instance, the second graphic shown in the summary previous to my last edit was the RPC input graphs used to create IPCC models, which is really getting into the weeds early on I thought. I moved that down to the modeling area and created a graphic to highlight recorded warming in the last 50 years.
• Some graphics have text that's illegible on mobile or until clicked on if in desktop view. Where possible graphics should be digestible without clicking or pinch zooming.

Please let me know if you have particular wishes or complaints regarding graphics here. I'll look to migrate some of this update over to "climate change" when I reach diminishing returns here.--Efbrazil (talk) 22:09, 1 February 2019 (UTC)

Thanks for your interest in this. Could you please provide some DIFFS (see how here) or filenames for the new images. It's a little hard to know I'm looking at the old ones and new ones you mean to discuss. Thanks! NewsAndEventsGuy (talk) 00:07, 2 February 2019 (UTC)

Doing this through diff is tough because it looks like diffs don't work on image changes. Changes so far just with full links:

• Upped the fonts on the first image and cleaned up the key: Old, New
• Created a new image that is now the second image currently on the page: Temperature Change in the Last 50 Years
• Old second image I moved down to Climate Models section: All forcing agents CO2 equivalent concentration. It replaces this image, which is similar but much older: Global_Warming_Predictions.
• I cut the old warming map further down in the article as it is similar to the new climate map image I added but based on very old data: Older low res version
• Bumped the fonts on Annual Mean Temperature Change for Land and for Ocean NASA GISTEMP 2017 October. Old, New — Preceding unsigned comment added by Efbrazil (talk • contribs) 01:20, 2 February 2019 (UTC)

• THANKS! I know how time consuming organizing that sort of list can be. I went through them all and you're an image genius. Please take a bow. Your changes to the images are great, and thanks for doing that. I may have a question about how we use them, but if so, I will start a new section once I understand what I want to say and ask well enough to be concise.NewsAndEventsGuy (talk) 05:55, 2 February 2019 (UTC)
• Thank you so much :). Before I got distracted with the sea level rise article, I started a similar project on Wikipedia:WikiProject_Environment/Climate_change/Figures_and_art. — Preceding unsigned comment added by Femkemilene (talk • contribs) 08:48, 2 February 2019 (UTC)

@Femkemilene: @NewsAndEventsGuy: Thanks for the happy karma! That project Femkemilene was working on looks really similar, I'll look to digest that before continuing forward. If any of you are in Seattle I'd also be happy to meet face to face and do some of this collaboratively. For now, I've overhauled two more images and continue to tweak the ones I already updated. Here's the two overhauls:

• Representative Concentration Pathway graphic Old New
• Greenhouse Gas Emissions by sector: Old New --Efbrazil (talk) 22:33, 3 February 2019 (UTC)

Seattle is a long way from here. If you do work together in person or by skype etc take care to keep transparency since some eds might complain about WP:OFFWIKI work. I am not a graphics designer, alas, so can't help in executing ideas and I already offer too many ideas that I don't work on. But there is one image I have always kind of wanted to have, and F and I have already discussed it. See Talk:Sea level rise and discussion of IPCC SLR projections over time. NewsAndEventsGuy (talk) 22:40, 3 February 2019 (UTC)

@NewsAndEventsGuy:I could use your help on sea level rise. The existing image has a good range and focus but dates to before AR5 and doesn't seem to align to RCPs in AR5, making the .2 to 2 meter rise really fuzzy. I'd like to update the image with something reliable and probably based on AR5 RCP scenarios. I could adopt the AR5 graphic here, but unfortunately the report graphics are very locked down- they block any modifications and I don't see the graphics being used on wikipedia as a result. Frustrating! So I either need a freely reusable graph (where I can update labels for instance) or source data so I can recreate the graph. What do you recommend?--Efbrazil (talk) 21:14, 4 February 2019 (UTC)

Femkemilene? You've most recently loaded SLR sources in your brain. What do you think? NewsAndEventsGuy (talk) 22:11, 4 February 2019 (UTC)

IPCC AR5 is quite outdated, a lot of new reseach in the last 6 years that imply the high end scenario is not well constrained at all :(. Maybe wait till September when IPCC has next report on SLR or use NCA instead. I'm taking a wikibreak till March, afterwards I'm back on it. Femkemilene (talk) 19:39, 6 February 2019 (UTC)

My goal here is to do a full pass on the article now, so I'd rather not leave the sea level graphic that dated and ugly until September. This looks like the best data / graphics I can find- not bad as it dates to January 2017 and aligns to RCP scenarios: {https://scenarios.globalchange.gov/sea-level-rise}--Efbrazil (talk) 20:49, 6 February 2019 (UTC)

They can always be updated again later. FYI in Feb issue of Scientific American, Penn State Richard Alley writes about the unknown and possibly precarious situation at Antarctica's Thwaites Glacier. In the article he describes what he calls "unzipping" of Greenland's Jakobshavn Glacier. He writes, "If Thwaites, far larger, unzips the way Jakobshavn did, it and adjacent ice could crumble, perhaps in as little as a few decades, raising sea levels 11 feet." NewsAndEventsGuy (talk) 21:09, 6 February 2019 (UTC)

@NewsAndEventsGuy:I took a crack at sea level rise, see here for the graphic. I included arctic projections as RCP extensions, although it sounds like that's being backed off from. The graphic is an adaptation of the many that are posted online since Parris in 2012- it most closely maps to this graphic from the 4th National Climate Assessment, as published here. I didn't want to confuse things by introducing 6 lines that had no relevance to the RCPs though, so I went with this concept instead. The new graph as published is an attempt to merge the concept behind each of the other two graphs into something coherent and current. Thoughts?--Efbrazil (talk) 23:35, 7 February 2019 (UTC)

SLR image looks very pretty! Maybe we'll indeed have to scale down worst case scenario by some 50 cm in September, which is still far above the old IPCC range. Reason is partially that IPCC only gave a likely range (67% chance it's in that range), so high end scenarios not included.

Maybe a matter of taste, but I think the fontsize in the second graph is now too big. First graph looks prettier. Femkemilene (talk) 09:46, 8 February 2019 (UTC)

Pretty indeed. I wish there were a way to include confidence estimates but that's probably asking too much from a single graphic. NewsAndEventsGuy (talk) 13:02, 8 February 2019 (UTC)

Thanks! Any other asks for graphics in this article? Ctrl+F5 the page, a lot of graphics I've been tweaking multiple times, for instance to include 2018 data. @Femkemilene When you mention the font size of the second graphic, you mean the new one I just made? I'm choosing the font size for two goals- to be legible as a thumbnail (similar size to caption text), and to look good on a smartphone. The fact it looks cartoonish zoomed in on desktop is a down side, but a corner case in typical use I think.--Efbrazil (talk) 17:19, 8 February 2019 (UTC)

I'm (indeed?) referring to this one: https://en.wikipedia.org/wiki/Global_warming#/media/File:Change_in_Average_Temperature.png. I agree that it should look good on a small screen the first two graphs of the article (sticking to comparison with first graph for simplicity) both look quite good on mobile phone and an a small laptop. On a normal sized PC screen it looks odd (not zooming in here, I agree it's okay if it looks cartoonish zoomed in). The fact that the heading is so much bigger than figure one distracts me. I don't know whether it's possible, but could you stretch out the legend in width? It's a bit weird that it smaller than the rest of the figure.

I know I'm nitpicking here, and I'm really impressed by everything you do :). Femkemilene (talk) 20:02, 8 February 2019 (UTC)

Thanks! Flattery will get you everywhere, fonts dropped 1 click. I also found the key for degrees celcius and used that, which is much better (before I adapted the Fahrenheit key). I'm frustrated by the fonts in the very first image- the reason they don't match with other images on the page is that the image is generated from a large SVG file that wikipedia scales down to thumbnail size really weirdly. It looks good when chrome renders the svg, but not wikipedia. To fix it means rescaling the entire image. It's a huge PIA to do, but maybe I'll take that on next.--Efbrazil (talk) 21:48, 8 February 2019 (UTC)

PyCCS

I suggest that the follwing sentence be added in the end of the introduction: "Technologies like pyrogenic carbon capture and storage are increasingly discussed as a means to remove greenhouse gas from the atmosphere and, thus, evaluated as to whether they could help to reverse global warming." — Preceding unsigned comment added by Flugscham (talk • contribs) 17:57, 3 February 2019 (UTC)

References

Rewrite of the "effects" paragraph of the summary (the 3rd paragraph)

Goals of the rewrite:

• Improved readability and organization
• Better capturing impacts as scientifically understood
• Greater accuracy and better focus

Here's the current paragraph:

Future climate change and associated impacts will differ from region to region. Ongoing and anticipated effects include rising sea levels, changing precipitation, and expansion of deserts in the subtropics. Future warming is expected to be greater over land than over the oceans and greatest in the Arctic, with the continuing retreat of glaciers, permafrost, and sea ice. Other likely changes include more frequent extreme weather events such as heat waves, droughts, wildfires, heavy rainfall with floods, and heavy snowfall; ocean acidification; and massive extinctions of species due to shifting temperature regimes. Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels. Because the climate system has a large "inertia" and greenhouse gases will remain in the atmosphere for a long time, many of these effects will persist for not only decades or centuries, but tens of thousands of years.

Here's the rewrite:

Future climate change effects include rising sea levels, ocean acidification, regional changes to precipitation, and expansion of deserts in the subtropics. Future surface temperature increases are expected to be greater over land than over the oceans and greatest in the Arctic, with the continuing retreat of glaciers, permafrost, and sea ice. Regional precipitation effects include more frequent extreme weather events such as heat waves, droughts, wildfires, heavy rainfall with floods, and heavy snowfall. Effects directly significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels. Environmental impacts include the extinction or relocation of ecosystems as they adapt to climate change, with coral reefs, mountain ecosystems, and arctic ecosystems most immediately threatened. Because the climate system has a large "inertia" and greenhouse gases will remain in the atmosphere for a long time, most of these changes and their effects will continue to get worse for many centuries after greenhouse gas emissions are stopped.

Here are the changes in detail by sentence number in the new paragraph:

1. ("Future climate change..") is a merge of the first 2 sentences in the old paragraph. I wanted effects enumerated in the lead and thought the effects already clearly differ by region. I also added ocean acidification because it is a key idea that does not fit under the umbrella of other ideas. Previously acidification had been strangely grouped with precipitation changes.
2. ("Future surface temperature increases...") I changed to say "surface temperature" instead of "warming", because if you measure "warming" by energy absorbed then the ocean is actually "warming" much faster than the land, it's just temps that are increasing faster on land. Otherwise unchanged.
3. ("Regional precipitation effects include...") is now focused on precipitation instead of being a grab bag as in the old paragraph ("other effects"). The old "massive extinctions of species due to shifting temperature regimes" is moved to be its own sentence later on to be more precise and readable.
4. ("Effects directly significant to humans...") I added "directly significant" but otherwise left unchanged. Ecosystem changes are very significant to some of us humans.
5. ("Environmental impacts include...") is now its own sentence and made to be more precise, featuring coral reefs, arctic ecosystems, and mountain ecosystems as the most threatened according to the EPA (see reference).
6. ("Because the climate system...") previously could be interpreted as saying the "effects" wouldn't change, just persist. So for instance, a reader could say an "effect" is a sea level increase of 1 meter and that will stop when CO2 emissions stop, but of course sea level rise will continue to get worse. Reworded to try and capture that changes will continue and effects will get much worse. Also removed the long wording on time frame- I think many centuries captures the idea well enough. Saying tens of thousands of years gets increasingly fuzzy as environmental feedback effects kick in and it sounds both hyperbolic and irrelevant- is the key idea of conclusion that we are supposed to be focused on changes 10s of thousands of years from now?

Anyhow, that's that. I committed the change as I thought it was important to get it out there and I'm reasonably confident in it, we'll see if anyone backs it out, hopefully with rationale since this took me a few hours. Thoughts on both the overall direction and any specific edits? --Efbrazil (talk) 22:33, 5 February 2019 (UTC)

Nicely done way to propose this. Thanks. Should have time to think about soonish and of course I'm just one voice, I just wanted to appreciate the approach you have taken here. NewsAndEventsGuy (talk) 23:09, 5 February 2019 (UTC) You had a great start, but I am disappointed you didn't wait for some discussion here before "going live". For one thing, "worse" is a subjective judgment. To say that, we'd need some inline attribution like Dr Hansen says 'worse'. NewsAndEventsGuy (talk) 23:58, 5 February 2019 (UTC)

Sorry if going live right away was too bold- I thought it was a marked enough improvement that it was better to make the change now than wait. That may have been hasty, my feelings won't be hurt if you think it is better to revert the change until we sort out more final wording here. The term "worse" I thought was safe, as we're going through a list of impacts that include abandoning cities and ecosystems going extinct and so forth. While I'm sure it would be easy to find a reference of someone saying the world will be worse because of climate change, I'm not sure that adds much. I tried to address your concern by stripping out the value judgment like this:

Because the climate system has a large "inertia" and greenhouse gases will remain in the atmosphere for a long time, climatic changes and their effects will continue to become more pronounced for many centuries even if further increases to greenhouse gases stop.--Efbrazil (talk) 01:30, 6 February 2019 (UTC)

refs for this section

References

Semi-protected edit request on 12 February 2019

Gigantic glaciers are melting, rainforest are dying and animals are suffering due to colossal damage us humans have Caused. As The national Geographic has stated that Green house gasses are [1] There needs to be a change in humans to keep out planet alive. Most people don’t realize that our damaging effects on our plant will eventually come back to hurt us. Our crops will suffer and weather will be much more intense.

“higher now than at any time in the last 800,000 years.”

Stephaniemgonzalez (talk) 19:46, 12 February 2019 (UTC)

Rejected; no change proposed William M. Connolley (talk) 19:49, 12 February 2019 (UTC)

Graph

The graph at the following link was created from official NOAA/NCDC databases footnoted at the bottom. Over a century of actual measurements of both CO2 and global temperature demonstrates precisely zero correlation between CO2 and temperature. https://chiefio.files.wordpress.com/2013/01/dbstealeyco2vst.png216.152.255.199 (talk) 15:35, 15 February 2019 (UTC)

"Some graph" made by "some dude" on "some blog" is not a reliable source. For more information see Wikipedia:Reliable sources. GMG^talk 15:40, 15 February 2019 (UTC),

The temperature change is small compared to the maximum and minimum temperatures over the years but the average temperature over a year is most definitely going up as can be seen even in their graph. Dmcq (talk) 19:13, 15 February 2019 (UTC)

• NAEG Says

(A) As 90% of global warming goes into the ocean, asserting this conclusion based strictly on graph of the US is misleading.

(B) As polar regions are warming 3x faster than temperate ones, the IP who started this thread is again being misleading.

(C) What happens at sea and at the poles matters a great deal to the US because we all share the same climate system and Earth's energy budget which produce the Effects of global warming, worldwide

(D) But even though I don't usually get into the details of NOTHERE IP's, look at this graph on a full size screen, and lay a soft straightedge (e.g. piece of paper) near the higher and lower temps. As Dmcq says, you can clearly see recent years have had both warmer low temps and warmer high temps even though the limited data is US only.

(E) Better graph

NewsAndEventsGuy (talk) 20:42, 15 February 2019 (UTC)

Proposed rewrite of the "aerosols and soot" section

I tried to clean up the first and third paragraphs and add new references. It's a big enough change that I figured I'd solicit input here before flipping the switch. Here's the rewrite, description of what change down below:

Ship tracks can be seen as lines in these clouds over the Atlantic Ocean on the East Coast of the United States. Atmospheric particles from these and other sources could have a large effect on climate through the aerosol indirect effect.

Global dimming, a gradual reduction in the amount of sunlight reaching the Earth's surface, was observed from 1961 until 1990. Solid and liquid particles known as aerosols, produced by volcanoes and human-made pollutants, are thought to be the main cause of this dimming. They exert a cooling effect by reflecting incoming sunlight, with NASA estimating that between 1850 and 2010 aerosols limited global warming by 1 degree Celsius. Aerosol removal by precipitation gives tropospheric aerosols an atmospheric lifetime of only about a week, while stratospheric aerosols can remain for a few years. Since 1990 global aerosols have been declining, removing some of the masking of global warming that aerosols had been providing.

In addition to their direct effect by scattering and absorbing solar radiation, aerosols have indirect effects on the Earth's radiation budget. Sulfate aerosols act as cloud condensation nuclei and thus lead to clouds that have more and smaller cloud droplets. These clouds reflect solar radiation more efficiently than clouds with fewer and larger droplets, a phenomenon known as the Twomey effect. This effect also causes droplets to be of more uniform size, which reduces growth of raindrops and makes the cloud more reflective to incoming sunlight, known as the Albrecht effect. Indirect effects are most noticeable in marine stratiform clouds, and have very little radiative effect on convective clouds. Indirect effects of aerosols represent the largest uncertainty in radiative forcing.

While aerosols typically limit global warming by reflecting sunlight, black carbon in soot can also increase global warming when deposited on snow and ice. Not only does it increases the absorption of sunlight, it also directly exacerbates melting and sea level rise. Limiting new black carbon deposits in the arctic could reduce global warming by 0.2 degrees Celcius by 2050.. When soot is suspended in the atmosphere it directly absorbs solar radiation, heating the atmosphere and cooling the surface. In isolated areas with high soot production, such as rural India, as much as 50% of surface warming due to greenhouse gases may be masked by atmospheric brown clouds. The influences of atmospheric particles, including black carbon, are most pronounced in the tropics and sub-tropics, particularly in Asia, while the effects of greenhouse gases are dominant in the extratropics and southern hemisphere.

First paragraph (global dimming...): Added NASA research/references saying aerosols have limited warming by 1 degree Celcius since 1850. Added research/references saying aerosols have declined since 1990. Combined and trimmed sentences at the end that were redundant or inaccurate. Cut all this as I think it adds nothing and is arguably inaccurate: "The effects of the products of fossil fuel combustion – CO2 and aerosols – have partially offset one another in recent decades, so that net warming has been due to the increase in non-CO2 greenhouse gases such as methane. Radiative forcing due to aerosols is temporally limited due to the processes that remove aerosols from the atmosphere. Carbon dioxide has a lifetime of a century or more, and as such, changes in aerosols will only delay climate changes due to carbon dioxide." The offsetting except for methane is more accurately laid out through the 1 degree estimate. The temporal statement is redundant with other stuff already in the paragraph, and the claim about "only delaying climate change" is not necessarily accurate- climate engineering is focused on stratospheric aerosol injection as a long term strategy. I also cut the final sentence in the first paragraph as it didn't fit the paragraph, plus it was overly assertive about numbers that it looks to me like were from 2002 and that were questionable (even the citation said "second or third" biggest cause of GW, but the sentence declared "second").

Last paragraph (While aerosols...): I tried to improve the intro, to make it clear we are going from a cooling effect to a warming effect on balance. Added research/references saying new black carbon could add 0.2 degrees Celcius to global warming by 2050.

Thoughts?--Efbrazil (talk) 00:37, 16 February 2019 (UTC)

Looks good thanks for doing that. It's been awhile, but sometimes if I want to check in at talk first I will "go live" anyway, and then self-revert. That way, there's a diff that shows exactly what changed, making it easy to see. This looks great. Thanks.NewsAndEventsGuy (talk) 02:12, 16 February 2019 (UTC)

References

Possible climate transitions from breakup of stratocumulus decks under greenhouse warming

Possible climate transitions from breakup of stratocumulus decks under greenhouse warming

"Stratocumulus clouds cover 20% of the low-latitude oceans and are especially prevalent in the subtropics. They cool the Earth by shading large portions of its surface from sunlight. However, as their dynamical scales are too small to be resolvable in global climate models, predictions of their response to greenhouse warming have remained uncertain. Here we report how stratocumulus decks respond to greenhouse warming in large-eddy simulations that explicitly resolve cloud dynamics in a representative subtropical region. In the simulations, stratocumulus decks become unstable and break up into scattered clouds when CO2 levels rise above 1,200 ppm. In addition to the warming from rising CO2 levels, this instability triggers a surface warming of about 8 K globally and 10 K in the subtropics. Once the stratocumulus decks have broken up, they only re-form once CO2 concentrations drop substantially below the level at which the instability first occurred. Climate transitions that arise from this instability may have contributed importantly to hothouse climates and abrupt climate changes in the geological past. Such transitions to a much warmer climate may also occur in the future if CO2 levels continue to rise." Count Iblis (talk) 22:38, 25 February 2019 (UTC)

It's an interesting new WP:PRIMARY source. Does it really need including now (see FAQ 21 in this list? How would you include it, writing in our own words? Got a good SECONDARY source to go with? NewsAndEventsGuy (talk) 23:06, 25 February 2019 (UTC)

Answering myself, Phys.org puts this in context for the layer reader... and wow. NewsAndEventsGuy (talk) 23:25, 25 February 2019 (UTC)

Also; Johnson, Scott K. (25 February 2019). "Striking study finds a climate tipping point in clouds". Ars Technica. Retrieved 27 February 2019. . . dave souza, talk 10:02, 27 February 2019 (UTC)

Planck 'feedback': mathematical correctness vs readability

In the current version of the article, we are stating that the Planck 'feedback' is a feedback. Strictly speaking this is not true, for a feedback is defined as something that makes the initial change (in T) to a forcing larger or smaller, compared to a reference system. Since we cannot define a reference system without the plank 'feedback', it doesn't make sense to call it a feedback. For a better explanation, see this review paper: https://www.annualreviews.org/doi/full/10.1146/annurev.earth.061008.134734.

I have not been able to think of wording that is understandable to young or non-expert readers and also correct, and think that the current mistake is not really bad. I imagine that most popular science sources will make a comparable mistake. Do we want a rewording here? Femkemilene (talk) 14:26, 27 February 2019 (UTC)

I disagree with you that it is not strictly true William M. Connolley (talk) 14:54, 27 February 2019 (UTC)

I'm not familiar with a definition of feedback in which the Planck 'feedback' is actually a feedback. What makes you say you disagree? Femkemilene (talk) 15:47, 27 February 2019 (UTC)

New model section

@Ebrafil: thanks for the rewrite. While an update was definitely necessary, in my opinion, the updated version is in some aspects worse than the outdated version.

First of all, I think the new model section focuses disproportionately on the RCPs and the IPCC. Statements like: the IPCC predicts are really weird to me. The IPCC assesses the whole literature on climate models and is not making predictions itself but reporting on predictions of the entire climate research community. Neither does the IPCC study the carbon cycle: they assess and report on the literature around the carbon cycle, which they try to streamline as well. Additionally, it also doesn't make sense to say the IPCC ignores the carbon cycle as climate centres have done a tremendous effort to improve that part of climate models. Lastly: the new version feels more technical to me and doesn't address the basics of what a climate model is and does.

I'll try to further update the section and combine your improvements with the spirit of the old version. Femkemilene (talk) 11:05, 2 March 2019 (UTC)

Thanks for critically reading my rewrite. I will explain a bit more in detail why I'm not completely satisfied with our work. First of all: a lot of climate models (for instance, Earth system Models of intermediate complexity, EMICs) can actually be run on simple laptops. It's only the state-of-the-art high resolution models that need to be run on supercomputers. These EMICs are still in widespread use in the climate community and many applications can only be done on those. I don't want to mention them, but I do think we should not give the false impression all climate models are run on supercomputers.

I think the section was way too long. If you compare this to f.i. adaptation (which tbf is too short), it doesn't make any sense. I've removed the lines on feedbacks as these are described in a previous section. More later Femkemilene (talk) 09:28, 3 March 2019 (UTC)

Nice NewsAndEventsGuy (talk) 11:41, 3 March 2019 (UTC)

3C to 5C rise in Arctic likely even if Paris agreement emission targets met

"Sharp and potentially devastating temperature rises of 3C to 5C in the Arctic are now inevitable even if the world succeeds in cutting greenhouse gas emissions in line with the Paris agreement, research has found." Seems relevant to the article, but I am unsure where best to insert it. Should it be mentioned here, or on the Paris Agreement article, or both? Zazpot (talk) 20:50, 14 March 2019 (UTC)

References

History

In June 1989, Noel Brown, the director of United Nations Environment Program claimed by year 2000, flooding and crop failures would create an exodus of "eco-refugees", that would threaten political chaos. Reportedly, coastal regions would be inundated. Brown claimed, entire nations could be wiped off the face of the Earth by rising sea levels if the global warming trend is not reversed by the year 2000. Excess carbon dioxide was pouring into the atmosphere because of human beings use of fossil fuels and the destruction of the rain forests. ~ Bought the farm (talk) 19:37, 19 March 2019 (UTC)

• Peter James Spielmann | AP News, U.N. Predicts Disaster if Global Warming Not Checked, https://apnews.com/bd45c372caf118ec99964ea547880cd0, June 30, 1989