View source for Talk:Global surface temperature

{{WikiProject banner shell|class=C|
{{WikiProject Climate change |importance=top}}
{{WikiProject Weather |importance=Low}}
{{WikiProject Environment|importance=}}
}}
{{section sizes}}

==Wiki Education Foundation-supported course assignment==
[[File:Sciences humaines.svg|40px]] This article was the subject of a Wiki Education Foundation-supported course assignment, between <span class="mw-formatted-date" title="2020-08-25">25 August 2020</span> and <span class="mw-formatted-date" title="2020-12-10">10 December 2020</span>. Further details are available [[Wikipedia:Wiki_Ed/Penn_State/IST431_(Fall_2020)|on the course page]]. Student editor(s): [[User:Sxl79|Sxl79]]. Peer reviewers: [[User:Arcpkl|Arcpkl]].

{{small|Above undated message substituted from [[Template:Dashboard.wikiedu.org assignment]] by [[User:PrimeBOT|PrimeBOT]] ([[User talk:PrimeBOT|talk]]) 21:50, 17 January 2022 (UTC)}}

== Possible sources for improving the article ==

*{{Cite web|url=https://data.giss.nasa.gov/gistemp/|title=GISS Surface Temperature Analysis (GISTEMP v4)|website=data.giss.nasa.gov|language=en|access-date=2019-10-23}}
*{{Cite web|url=https://skepticalscience.com/surface-temperature-measurements-advanced.htm|title=Are surface temperature records reliable?|last=|first=|date=|website=|url-status=live|archive-url=|archive-date=|access-date=}}
*{{Cite journal|last=Hansen|first=J.|last2=Ruedy|first2=R.|last3=Sato|first3=M.|last4=Lo|first4=K.|date=2010|title=Global Surface Temperature Change|url=https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2010RG000345|journal=Reviews of Geophysics|language=en|volume=48|issue=4|doi=10.1029/2010RG000345|issn=1944-9208}}
*{{Cite journal|last=Folland|first=C. K.|last2=Rayner|first2=N. A.|last3=Brown|first3=S. J.|last4=Smith|first4=T. M.|last5=Shen|first5=S. S. P.|last6=Parker|first6=D. E.|last7=Macadam|first7=I.|last8=Jones|first8=P. D.|last9=Jones|first9=R. N.|last10=Nicholls|first10=N.|last11=Sexton|first11=D. M. H.|date=2001|title=Global temperature change and its uncertainties since 1861|url=https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2001GL012877|journal=Geophysical Research Letters|language=en|volume=28|issue=13|pages=2621–2624|doi=10.1029/2001GL012877|issn=1944-8007}}
*{{Cite journal|last=Rennie|first=J. J.|last2=Lawrimore|first2=J. H.|last3=Gleason|first3=B. E.|last4=Thorne|first4=P. W.|last5=Morice|first5=C. P.|last6=Menne|first6=M. J.|last7=Williams|first7=C. N.|last8=Almeida|first8=W. Gambi de|last9=Christy|first9=J. R.|last10=Flannery|first10=M.|last11=Ishihara|first11=M.|date=2014|title=The international surface temperature initiative global land surface databank: monthly temperature data release description and methods|url=https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/gdj3.8|journal=Geoscience Data Journal|language=en|volume=1|issue=2|pages=75–102|doi=10.1002/gdj3.8|issn=2049-6060}}

== article lacks a good definition ==

Shouldn't this article be more of a general technical nature on definitions of means of so-called [[Temperature anomaly|Temperature anomalies]] in the field of Meteorology rather than focussing so much on it's development in the context of global warming.

--[[User:Utonsal|Utonsal]] ([[User talk:Utonsal|talk]]) 12:56, 1 August 2021 (UTC)
: I've added a section on definition now. [[User:EMsmile|EMsmile]] ([[User talk:EMsmile|talk]]) 11:29, 15 December 2023 (UTC)

== why the sea level rise in the 3rd paragraph? ==

How is the sealevel rise relevant to surface temperature? And if it is because of the measuring stations being flooded, why having such an positioning in this article?

Isn't the sealevel rising a mere consequence of growing GST and not a property of GST itself?

--[[User:Utonsal|Utonsal]] ([[User talk:Utonsal|talk]]) 12:56, 1 August 2021 (UTC)
: I agree with you and have reworked the article now, removing the sentence about sea level rise from the lead. [[User:EMsmile|EMsmile]] ([[User talk:EMsmile|talk]]) 11:28, 15 December 2023 (UTC)

== Missing information ==

The article really ought to address the '''locations''' of the thousands of temperature measurements around the globe.  Where are they (at least in rough description) ???  

To get an accurate average, the measurements should be taken at points that are more or less '''uniformly distributed''' around the globe.  

At least something like this ought to be stated.
: I've addressed this comment by linking to [[instrumental temperature record]] under "methods". [[User:EMsmile|EMsmile]] ([[User talk:EMsmile|talk]]) 11:27, 15 December 2023 (UTC)

== Physical meaning ==

What is the physical meanung of the global surface temperature? First of all, a surface has no temperature, a volume must always be considered. The temperature is the measure of the average heat or thermal energy in a of a solid, liquid, or gaseous medium in a given place. Therefore, a sum of temperatures has no physical meaning. It follows that the average temperature over different areas over which it varies from one area to another has no direct physical interpretation. The global average temperature must therefore be seen as a statistical indicator of the evolution of the climate on the Earth’s surface.[[Special:Contributions/2003:E5:270C:F200:84CC:F8E8:8DC0:D920|2003:E5:270C:F200:84CC:F8E8:8DC0:D920]] ([[User talk:2003:E5:270C:F200:84CC:F8E8:8DC0:D920|talk]]) 20:43, 4 August 2023 (UTC)
: I've provided some extra information in the article now, is it clearer for you now? And by the way a surface can indeed have a temperature. [[User:EMsmile|EMsmile]] ([[User talk:EMsmile|talk]]) 11:27, 15 December 2023 (UTC)
::Strictly speaking, a surface cannot have a temperature. A surface or area in general has a thickness of zero and therefore cannot contain any atoms. Anyway, surface temperature is a pseudonym for a surface layer. [[Special:Contributions/2003:E5:2747:1200:585C:9A71:85D2:DFBA|2003:E5:2747:1200:585C:9A71:85D2:DFBA]] ([[User talk:2003:E5:2747:1200:585C:9A71:85D2:DFBA|talk]]) 09:23, 3 December 2024 (UTC)
:https://www.encyclopedie-environnement.org/en/climate/average-temperature-earth/
:1.2. Average temperature? A statistical indicator!
:The temperature of a solid, liquid or gaseous medium is a physical quantity that reflects the agitation of the particles that make it up in a given place. The sum of two temperatures therefore has no physical meaning. As a result, an average temperature over a wide range over which it varies from one place to another has no direct physical interpretation. This is therefore the case for the average temperature calculated over the entire surface of the Earth, covering both the warm tropical regions and the cold polar regions. However, this average is a statistical indicator that proves very useful for assessing climate change on a global scale, both in the past and in projection for the coming centuries. The global average temperature reflects changes in climate that can be explained by identifiable underlying physical mechanisms. [[Special:Contributions/2003:E5:2747:1200:585C:9A71:85D2:DFBA|2003:E5:2747:1200:585C:9A71:85D2:DFBA]] ([[User talk:2003:E5:2747:1200:585C:9A71:85D2:DFBA|talk]]) 09:35, 3 December 2024 (UTC)

== Removed content that talks about effects of warming ==

I've removed this content as I think it is covered much better in our other Wikipedia articles. I think it goes beyond the scope of this article:

 +++++++++

Warming oceans:
{{Main|Ocean heat content}}

With the Earth's temperature increasing, the ocean has absorbed much of this increased heat, with the top 700 meters of ocean showing warming of 0.22 C (0.4&nbsp;°F) since 1969.<ref name="NASA evidence">{{cite web |title=Climate Change Evidence: How Do We Know? |url=https://climate.nasa.gov/evidence/ |url-status=live |archive-url=https://web.archive.org/web/20191218104252/https://climate.nasa.gov/evidence/ |archive-date=2019-12-18 |access-date=2019-11-14 |website=Climate Change: Vital Signs of the Planet |publisher=NASA}} {{PD-notice}}</ref> Expansion of the warm water, along with melting ice sheets, causes the sea level to rise.

The distribution of excess heat in the ocean is uneven, with the greatest [[ocean warming]] occurring in the southern hemisphere and contributing to the underground melting of the Antarctic ice shelf.<ref>{{Cite web |date=2017-11-01 |title=Ocean warming |url=https://www.iucn.org/resources/issues-briefs/ocean-warming |url-status=live |archive-url=https://web.archive.org/web/20200919112407/https://www.iucn.org/resources/issues-briefs/ocean-warming |archive-date=2020-09-19 |access-date=2020-09-28 |website=IUCN |language=en}}</ref> The warming of sea water is also related to the thinning of ice shelves and sea ice, both of which have a further impact on the Earth's climate system. Finally, sea warming threatens marine ecosystems and human livelihoods.<ref>{{Cite web |title=Climate Change: Ocean Heat Content {{!}} NOAA Climate.gov |url=https://www.climate.gov/news-features/understanding-climate/climate-change-ocean-heat-content |url-status=live |archive-url=https://web.archive.org/web/20190212110601/https://www.climate.gov/news-features/understanding-climate/climate-change-ocean-heat-content |archive-date=2019-02-12 |access-date=2020-09-28 |website=www.climate.gov |language=en}}</ref> For example, warm water endangers the health of corals, which in turn endangers marine communities that depend on corals for shelter and food. Ultimately, people who rely on marine fisheries for their livelihoods and jobs may face the negative effects of ocean warming.

During the 20th century, the sea surface temperature increased for a century and continued to rise. From 1901 to 2015, the temperature increased by an average of 0.13&nbsp;°F per decade. Since reliable observations began in 1880, the sea surface temperature has been higher than at any other time in the past three decades.<ref>{{Cite web |last=US EPA |first=OAR |date=2016-06-27 |title=Climate Change Indicators: Sea Surface Temperature |url=https://www.epa.gov/climate-indicators/climate-change-indicators-sea-surface-temperature |url-status=live |archive-url=https://web.archive.org/web/20201010231525/https://www.epa.gov/climate-indicators/climate-change-indicators-sea-surface-temperature |archive-date=2020-10-10 |access-date=2020-10-11 |website=US EPA |language=en}}</ref> As greenhouse gases absorb more energy from the sun, the ocean absorbs more heat, leading to rising sea surface temperatures and rising sea levels. Changes in [[ocean temperature]] and ocean currents brought about by climate change will lead to changes in the global climate pattern. For example, warmer waters may promote the development of stronger storms in the tropics, which may cause property loss and loss of life. Impacts related to sea level rise and severe storms are particularly relevant to coastal communities.

Shrinking ice sheets:
{{see|Marine ice sheet instability|Ice-sheet dynamics}}

The [[Antarctic ice sheet|Antarctic]] and [[Greenland ice sheet|Greenland ice sheets]] have decreased exponentially in mass. According to NASA's [[Gravity Recovery and Climate Experiment]], it shows that Greenland has lost an average of 286 billion tons of ice per year.<ref name="NASA evidence" />  The expansion of the warm water and the melting ice sheets cause the sea level to rise.

The ice is changing everywhere on earth. Since 1912, the famous snow of [[Mount Kilimanjaro]] has melted more than 80%. The glaciers in the [[Garhwal Himalayas]] in India are retreating so fast that researchers believe that by 2035, most of the central and eastern Himalayas will actually disappear. For half a century, its range has dropped by about 10% in the past 30 years. NASA repeated [[laser altimeter]] readings showed that the edge of the Greenland ice sheet was shrinking. Now, the spring freshwater ice in the northern hemisphere breaks 9 days earlier than 150 years ago, while the autumn freeze is 10 days later. The melting of frozen ground caused land subsidence in parts of Alaska to exceed {{convert|15|ft|m|abbr=off|sp=us}}. From the Arctic to Peru, from Switzerland to the equatorial glacier in Manjaya, Indonesia, massive ice fields, monstrous glaciers, and sea ice are disappearing, fast.<ref>{{Cite web |last=Glick |first=Daniel |date=5 October 2009 |title=The Big Thaw |url=https://www.nationalgeographic.com/environment/global-warming/big-thaw/#close |url-status=dead |archive-url=https://web.archive.org/web/20201116153038/https://www.nationalgeographic.com/environment/global-warming/big-thaw/#close |archive-date=16 November 2020 |access-date= |website=[[National Geographic Society]]}}</ref>

When the temperature rises and the ice melts, more water flows into the ocean from glaciers and ice caps, and the sea water warms and expands in volume. According to the [[Intergovernmental Panel on Climate Change]] (IPCC), this combined effect has played a major role in raising the global average sea level by {{convert|4|to|8|in|abbr=off|cm}} in the past 100 years.


Greenland's meltwater may greatly affect the flow of huge ocean currents, which are called the [[Atlantic meridional overturning circulation]] or AMOC. Similar to a huge conveyor belt, AMOC helps transport hot water from tropical regions to the Arctic. Its important role in the global distribution of heat also makes it have a significant impact on global weather conditions-AMOC's hot water flow is largely due to the mild climate in places such as Western Europe. As fresh water pours into the ocean from the melting Greenland ice sheet, this may slow down the flow of water.<ref>{{Cite web |last=Harvey |first=Chelsea |date= |title=Melting Ice Sheets Could Worsen Extreme Weather |url=https://www.scientificamerican.com/article/melting-ice-sheets-could-worsen-extreme-weather/ |url-status=live |archive-url=https://web.archive.org/web/20201109194643/https://www.scientificamerican.com/article/melting-ice-sheets-could-worsen-extreme-weather/ |archive-date=2020-11-09 |access-date=2020-11-10 |website=Scientific American |language=en}}</ref> At the same time, studies have shown that melting ice from Antarctica may disrupt the structure of the Southern Ocean. Because the density of fresh water is lower than that of salt water, a large amount of melt water may not be able to merge with the rest of the ocean, but form a layer of material attached to the water surface. This cold liquid traps heat underneath it and causes deeper layers to heat up. This increases the overall temperature of the ocean, which makes it less able to absorb {{CO2}} from the atmosphere. As a result, more {{CO2}} will remain in the atmosphere, leading to an increase in global warming. [[User:EMsmile|EMsmile]] ([[User talk:EMsmile|talk]]) 10:36, 15 December 2023 (UTC)
{{reflist-talk}} [[User:EMsmile|EMsmile]] ([[User talk:EMsmile|talk]]) 10:36, 15 December 2023 (UTC)

== Drastic changes to the article ==

I've just made some drastic changes to the article because I don't think it should repeat the same content on the effects of warming that are already covered better in other articles. Therefore, I have added excerpts instead. What other content (if any) should still be added to this article, keeping in mind that we don't want to create more overlap with other articles than necessary. I can't really think of anything else but we could add more links and excerpts if needed. [[User:EMsmile|EMsmile]] ([[User talk:EMsmile|talk]]) 11:32, 15 December 2023 (UTC)

== Misleading that direct measurements are valid from 1880 ==

Most of the world did not get direct measurements until well into the 20th century. As such, it is misleading to claim that there has been direct measurements since 1880, as most of the world was simply not measured. [[Special:Contributions/5.186.78.167|5.186.78.167]] ([[User talk:5.186.78.167|talk]]) 09:51, 8 April 2024 (UTC)

:You're right. I've changed it to "Series of reliable temperature measurements in some regions began in the 1850—1880 time frame (this is called the instrumental temperature record)." Please check if OK like this? [[User:EMsmile|EMsmile]] ([[User talk:EMsmile|talk]]) 09:37, 19 June 2024 (UTC)

== Improving readability of the lead ==

I've just made some improvements to the readability of the lead and the lead's image caption. I've also made the lead a little bit longer. Pinging [[User:Efbrazil]] in case they have time to look at this as well.
(This article is an example where the lead can remain pretty short, as the article is also short itself. It's not much more than just a definition of the term and then excerpts from other related articles. I think this is correct because otherwise we would introduce too much overlap with the other articles, e.g. [[instrumental temperature record]], [[sea surface temperature]]) [[User:EMsmile|EMsmile]] ([[User talk:EMsmile|talk]]) 11:51, 16 April 2024 (UTC)

== Merger from [[Instrumental temperature record]] completed ==

I've just completed the merger from [[Instrumental temperature record]] (see on the talk page there for previous discussions). I've also done some post-merge tidying work but more is probably needed to weed out any repetition. We also need to improve the new lead more. [[User:EMsmile|EMsmile]] ([[User talk:EMsmile|talk]]) 22:32, 23 August 2024 (UTC)

== Sea surface temperature ==

"estimated global average of near-surface air temperatures over land and sea ice, and sea surface temperature (SST) over ice-free ocean regions, with changes normally expressed as departures from a value over a specified reference period"
The sea surface
The sea surface temperature is the temperature of the water layer near the surface (no clear definition). At least that's how it is measured. [[Special:Contributions/2003:E5:272D:4A00:CC84:FC88:7822:CF66|2003:E5:272D:4A00:CC84:FC88:7822:CF66]] ([[User talk:2003:E5:272D:4A00:CC84:FC88:7822:CF66|talk]]) 21:45, 11 December 2024 (UTC)

:what are you trying to say? What change to the article are you suggesting? [[User:EMsmile|EMsmile]] ([[User talk:EMsmile|talk]]) 22:13, 12 December 2024 (UTC)