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Merge?

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Do the references support the concept - or just mention the words? Seems this is a fork and should be redirected ... somewhere? Yeah, more white, more reflection, but does that simple truism rate an article?... don't think so. Vsmith (talk) 15:15, 7 February 2009 (UTC)[reply]

There's no doubt that ice-albedo feedback occurs and is important to climate (we could find hundreds if not thousands of peer-reviewed references to this effect). I'm less sure that it merits an article. Short Brigade Harvester Boris (talk) 16:11, 7 February 2009 (UTC)[reply]
Agree, its genuine. But also agree, does it merit an article, even a harmless one? I don't mind. I've edited a bit: the albedo feed back is (IMHO) more of a local than a planetary effect William M. Connolley (talk) 17:36, 7 February 2009 (UTC)[reply]

Truth?

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Shouldn't an decrease in reflectiveness in the polar regions equate to more cooling, not less? I was taught the sun doesn't shine in polar regions in the winter, so how can this be causing warming? Black body radiation would indicate more radiation from low albedo surfaces under such conditions. I would like to see a link to a peer reviewed study that indicated solar warming during the long polar night. Otherwise the tone of this article supports misleading information on global warming and polar melting. — Preceding unsigned comment added by 71.141.118.172 (talk) 22:40, 12 September 2011 (UTC)[reply]

That sounds muddled. I removed [1] - was that yours? - which mixes up IR and viz albedo William M. Connolley (talk) 18:54, 15 October 2012 (UTC)[reply]

Time scales

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We should not forget that although increased ice cover at and near the poles reflects more sunlight, it is only a local effect with the increase mainly at the margins. Ice albedo must be considered in terms of the water>vapour>ice>water cycles over thousands and millions of years. Huge quantities of water are transferred from the oceans through the atmosphere to the poles and back again at varying rates that balance the global energy equation over long periods of time. The reason we need to consider that is that circulating atmospheric moisture around the globe has a far greater cooling effect than increasing the thickness of polar ice caps and marginally extending their perimeters in areas that have low sunlight in summer and long winters with hardly any sunlight. Removing moisture from the atmosphere and storing that at the poles reduces the albedo of the much larger atmosphere in high sunlight zones and minimizes global cooling by maintaining temperatures at the warmer lower latitudes. Hence, polar ice caps are part of a global temperature maintenance and feedback loop that minimizes the impacts of fluctuations in solar irradiance and other energy contributions from external and internal sources. It follows that polar icecaps that are increasing can be a sign of global cooling with decreasing ocean levels, slowing oceanic convection currents, decreased atmospheric convection, drying out of continents, de-vegetation (as is evident from loess deposits and other windblown sediments), dying out of organisms at all levels, decreasing CO2 production and absorption, and less methane production. Decreasing icecaps are a sign of the opposite effects that more favourable to life generally. Clearly, without global warming since about 14.5 - 12.5 Kya there would not be around 6.8 billion of us and blaming our impact on the world environment on CO2 and trying to solve that by reducing CO2 emissions is erroneous and a waste of effort and taxes. Milankovitch cycles and other longer period cycles cause climate change and affect the extent of polar ice caps over periods > 10 Ky. Short period climate and ice cap changes are more likely caused by variability in ocean circulation and volcanic activity in response to transfers of huge amounts of water from the oceans (the equator) through the atmosphere to the poles and back again over periods generally < 10 Ky. For example, calving of glaciers is a slow gravity based process that can be linked to cooling events up to over a thousand years ago. The retreat of polar ice caps is in response to ocean convection currents transferring the Sun's heat and ocean salinity away from the equator towards the poles over periods that can be greater than 1500 years. Contrasting with that, sublimation and variations in the amount of surface melt water runoff provide evidence of ambient and very recent climatic conditions during the same season. Since the Phanerozoic began 542 Mya four severe warming events have occurred. They were counteracted by the properties and abundance of water forming a protective sheet of clouds, including 'cirrus clouds' (ice particles at high altitudes >7000 m), able to reflect up to 95% of insolation. Additionally, the Earth's magnetosphere plays an important role by deflecting the solar wind that would otherwise cause water to be lost into space and Earth to become similar to Venus, which is closer to the Sun and has a much higher mean surface temperature of around 460o C and an opaque atmosphere containing around 96% CO2. Mars is further away from the Sun and has a much lower mean surface temperature of around – 46oC and similar to Venus it has 95% CO2 in its atmosphere. Orbiting the Sun at a medium distance, having a liquid iron core producing the magnetosphere and having huge quantities of water circulating from the equator to the poles and back through the atmosphere and the oceans, Earth has a mean surface temperature of about 12oC and is in a very favourable position to sustain life with photosynthesizing organisms on land and in the oceans keeping CO2 down to minimal levels that are small fractions of 1%. The CO2 draw down is said to have begun about 2.7 billion years ago when the atmospheric CO2 content may have been over 30%. The current capacity to do so has only increased as is evident from the less than the just 385ppmv (0.0385%) current concentration. It all shows that it is not the very low atmospheric CO2 concentration that makes the difference on Earth, but our distance from Sun (insolation) and the presence of copious quantities and distribution of water in its various forms. Bearing all this in mind, there appears to be good reason to develop ‘ice-albedo feedback’ further and include the effects of atmospheric snow and ice as well as the distribution of snow and ice across mountain ranges over time. The latter will lead to the incidence of orogenesis (mountain building) over millions of years under the influence of the ever present lunar orbit and our orbit around the Sun massaging the Earth’s crust (facilitating platetectonics), and the impacts of that on the global climate over very long periods of time. Snowball Earth is a related issue. John Bruyn —Preceding unsigned comment added by Avetar (talkcontribs) 16:46, 3 July 2010 (UTC)[reply]

Very little of that makes sense to me. But to begin at the beginning: why are we only allowed to consider the feedback over thousands of year scales? William M. Connolley (talk) 20:10, 3 July 2010 (UTC)[reply]
Most of the processes controlling the global climate are slow and take thousands to millions of years. Exceptions are Sun cycles that impact much more quickly. Leaving out time does not make sense to people who are genuinly trying gain a thorough understanding of the factors driving climate change and global warming events, and their long term implications.
PS I've overwrittin the previous text with a new edit from my Word file. Hopefully that made my points clearer. —Preceding unsigned comment added by Avetar (talkcontribs)
Please *don't* rewrite talk page posts; your own or anyone else's. Most of the processes controlling the global climate are slow and take thousands - I don't believe you. Our articles, e.g. global warming, say otherwise and quote the scientific literature. You provide no references, but will have to if you wish to be convincing William M. Connolley (talk) 07:32, 4 July 2010 (UTC)[reply]
Much of what I've said is my personal understanding. Your articles on Milankvitch cycles and on Ocean currents and many others, including on the planets bear out what I've said. The CO2 saga promoted by 'An Inconvenient Truth' did a good job promoting climate research and getting funding for that. The inconvenient truth is that CO2 has no capacity to outperform H2O and photosynthesis. How else can you explain the cycles in climate graphs that cover thousands and millions of years and the CO2 draw down that began around 2.7 billion years ago. John Bruyn —Preceding unsigned comment added by Avetar (talkcontribs) 11:49, 4 July 2010 (UTC)[reply]
Your timelines are wrong. AIT was 2006. By 2001 the TAR had already concluded There is new and stronger evidence that most of the warming observed over the past 50 years is attributable to human activities. AIT merely reports the scintific opinion, it doesn't influence it. Your views about CO2 are no doubt interesting to you but with no references to back them up are of no value here. Try reading the GW article and follow the references William M. Connolley (talk) 13:46, 4 July 2010 (UTC)[reply]
You're changing the issue. Here are some links you may find useful: http://www.climatechangefacts.info/ and http://www.co2science.org/nd. Good luck. John Bruyn —Preceding unsigned comment added by Avetar (talkcontribs) 04:00, 5 July 2010 (UTC)[reply]

Editing page for class

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Hello, I am a graduate student in astronomy and astrobiology. I will be editing this page for a planetary atmospheres class. Tovarg (talk) 19:15, 12 June 2019 (UTC)[reply]

GA Review

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The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.


This review is transcluded from Talk:Ice–albedo feedback/GA1. The edit link for this section can be used to add comments to the review.

Nominator: InformationToKnowledge (talk · contribs) 17:45, 11 April 2024 (UTC)[reply]

Reviewer: RoySmith (talk · contribs) 13:24, 1 July 2024 (UTC)[reply]


prose

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  • The main body of the article is about 1800 words; WP:LEADLENGTH suggests one or two paragraphs for the lead, about half what you have.
  • In the 1950s ... have already been making attempts to describe I'm not sure what you intended to say here, but I think you want just "... attempted to describe"
  • ... have published papers presenting => "published papers presenting" (i.e. drop "have")
  • could act as a powerful feedback => "could act as a powerful feedback mechanism". Also, this is cited to four different references, see WP:CLUMP.
  • This process was soon recognized..., I'd tie that back to the previous paragraph by saying, "This feedback process was soon recognized..."
  • This process was soon recognized as a crucial part of climate modelling in a 1974 review,[3] and in 1975, the general circulation model used by Manabe and Richard T. Wetherald to describe the effects of doubling CO2 concentration in the atmosphere - a key measurement of climate sensitivity - has also already incorporated what it described as "snow cover feedback".[17] this is a very long and complicated sentence; it could probably be broken into two or maybe even three sentences. Certainly a full stop after "1974 review".
  • Snow– and ice–albedo feedback I think you want plain hyphens there (see MOS:DASH). @Gog the Mild: who knows that stuff better than I do.
I am not sure about that, but yes, both en dashes should be replaced with hyphens, per MOS:HYPHEN. And very eagle eyed picking it up. Gog the Mild (talk) 15:06, 1 July 2024 (UTC)[reply]
  • most of which was concentrated in West Antarctica.[18][19][20]]] WP:CLUMP again.
  • Southern Ocean, which had absorbed 35–43% of the total heat if the information is available, it would be interesting to compare that with the size of the Southern Ocean compared with other oceans (but that's definitely beyond the scope of WP:GACR).
  • which produced cooling of about 0.06 W/m2 per decade This is confusing. You start out talking about "radiative forcing" which is measured in W/m2. Now you switch to "cooling", measured in W/m2/decade. I can't follow this. Is "radiative forcing" the same thing as "cooling"?
  • The impact of ice-albedo feedback on temperature will intensify in the future as the Arctic sea ice decline is projected to become more pronounced, with a likely near-complete loss of sea ice cover (falling below 1 million km2) at the end of the Arctic summer in September at least once before 2050 under all climate change scenarios,[22] and around 2035 under the scenario of continually accelerating greenhouse gas emissions.[24] this is all one monster sentence.
  • the nadir of sea ice cover I know what that is, but I suspect a lot of people won't. Link to nadir#Figurative usage or use a more common word.
  • Notably, while the loss of sea ice cover..., I'd drop the "Notably"; let the reader judge for themselves. And you've already called it a "historic event".
  • a source of "additional" warming why is "additional" in quotes?
  • Relative to now => "Relative to 2022" (the date of the cited paper).
  • mountain glaciers, Greenland ice sheet, West Antarctic and East Antarctic ice sheet see WP:SEAOFBLUE. I'd make it "the Greenland ice sheet, as well as the West Antarctic and East Antarctic ice sheets" (correctly piped, of course).
  • loss in area between now and 2100 => "loss in area by 2100"
  • 0.05 °C (0.090 °F) (0.04–0.06 °C) I don't understand what this means.

OK, that does it for a basic read-through. Next up is a source spot-check, but I'll come back and do that probably tomorrow. RoySmith (talk) 14:28, 1 July 2024 (UTC)[reply]

source spot-check

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I'm going to look in detail at a randomly chosen 10% of the citations, namely:

  • 14-d
    • Very high levels of global warming could prevent Arctic sea ice from reforming during the Arctic winter. Unlike an ice-free summer, this ice-free Arctic winter may represent an irreversible tipping point. It is most likely to occur at around 6.3 °C (11.3 °F), though it could potentially occur as early as 4.5 °C (8.1 °F) or as late as 8.7 °C (15.7 °F).
    • Verified
  • 12-c
    • There are also model estimates of warming impact from the loss of both mountain glaciers and the ice sheets in Greenland and Antarctica. However, warming from their loss is generally smaller than from the declining sea ice, and it would also take a very long time to be seen in full.
    • Verified
  • 24
    • and around 2035 under the scenario of continually accelerating greenhouse gas emissions
    • Verified
  • 4-a
    • However, if warming occurs, then higher temperatures would decrease ice-covered area, and expose more open water or land. The albedo decreases, and so more solar energy absorbed, leading to more warming and greater loss of the reflective parts of the cryosphere. Inversely, cooler temperatures increase ice cover, which increases albedo and results in greater cooling, which makes further ice formation more likely.
    • I found the paper on the AMSO website, but I'm having trouble locating where it talks specifically about this. Could you walk me through it?
  • 4-b
    • Snow– and ice–albedo feedback have a substantial effect on regional temperatures. In particular, the presence of ice cover and sea ice makes the North Pole and the South Pole colder than they would have been without it
    • Same comment as with 4-a.
  • 23-c
    • Very high levels of global warming could prevent Arctic sea ice from reforming during the Arctic winter. Unlike an ice-free summer, this ice-free Arctic winter may represent an irreversible tipping point. It is most likely to occur at around 6.3 °C (11.3 °F), though it could potentially occur as early as 4.5 °C (8.1 °F) or as late as 8.7 °C (15.7 °F).
    • Oh, wait, this is the same statement that was cited to 14. Let me pick another one...
  • 12-h
    • Ice–albedo feedback also occurs with the other large ice masses on the Earth's surface, such as mountain glaciers, Greenland ice sheet, West Antarctic and East Antarctic ice sheet. However, their large-scale melt is expected to take centuries or even millennia, and any loss in area between now and 2100 will be negligible. Thus, climate change models do not include them in their projections of 21st century climate change: experiments where they model their disappearance indicate that the total loss of the Greenland Ice Sheet adds 0.13 °C (0.23 °F) to global warming (with a range of 0.04–0.06 °C), while the loss of the West Antarctic Ice Sheet adds 0.05 °C (0.090 °F) (0.04–0.06 °C), and the loss of mountain glaciers adds 0.08 °C (0.14 °F) (0.07–0.09 °C)
    • Mostly verified. I don't see where the paper mentions the year 2100. It's also not clear than when you say climate change models do not include them in their projections, if that's completely supported by the paper which says "we also consider the regional warming caused solely by the loss of the Arctic summer sea ice". Are they talking about models in general from most researchers in the field, or specifically their own models?

This has been on hold for over a week, with no response. The nom hasn't edited in 3 weeks and failed to respond to both pings and email. Unfortunately, I'm going to have to close this as failed. RoySmith (talk) 23:21, 10 July 2024 (UTC)[reply]

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.