Editing Mountain (section)

==Climate==
{{Main|Alpine climate}}
[[File:Ural_mountains_3_448122223_93fa978a6d_b.jpg|thumb|The [[Ural Mountains|northern Urals]] at high latitude and elevation have an alpine climate and barren ground.]]
[[File:Villnoess St Magdalena 1.JPG|thumb|The [[Dolomite Mountains]], [[Italy]], in summer. The climate of the Dolomites is characterized by short but warm and mild summers, while winters are long and very cold.]]
Climate in the mountains becomes colder at high [[elevation]]s, due to an interaction between [[radiation]] and convection. Sunlight in the [[visible spectrum]] hits the ground and heats it. The ground then heats the air at the surface. If radiation were the only way to transfer heat from the ground to space, the [[greenhouse effect]] of gases in the atmosphere would keep the ground at roughly {{convert|333|K|C F}}, and the temperature would decay exponentially with height.<ref name="goodywilson">{{Cite book |last=Goody |first=Richard M. |title=Atmospheres |last2=Walker |first2=James C. G. |publisher=Prentice-Hall |year=1972 |chapter=Atmospheric Temperatures |chapter-url=http://lasp.colorado.edu/~bagenal/3720/GoodyWalker/AtmosCh3sm.pdf |archive-url=https://web.archive.org/web/20160729075851/http://lasp.colorado.edu/~bagenal/3720/GoodyWalker/AtmosCh3sm.pdf |archive-date=29 July 2016 |url-status=live}}</ref>

However, when air is hot, it tends to expand, which lowers its density. Thus, hot air tends to rise and transfer heat upward. This is the process of [[convection]]. Convection comes to equilibrium when a parcel of air at a given altitude has the same density as its surroundings. Air is a poor conductor of heat, so a parcel of air will rise and fall without exchanging heat. This is known as an [[adiabatic process]], which has a characteristic pressure-temperature dependence. As the pressure gets lower, the temperature decreases. The rate of decrease of temperature with elevation is known as the [[adiabatic lapse rate]], which is approximately 9.8&nbsp;°C per kilometre (or {{convert|5.4|°F-change|°C-change|abbr=on}} per 1000&nbsp;feet) of altitude.<ref name="goodywilson" />

The presence of water in the atmosphere complicates the process of convection. Water vapor contains latent [[heat of vaporization]]. As air rises and cools, it eventually becomes [[Dew point|saturated]] and cannot hold its quantity of water vapor. The water vapor condenses to form clouds and releases heat, which changes the lapse rate from the [[dry adiabatic lapse rate]] to the [[moist adiabatic lapse rate]] (5.5&nbsp;°C per kilometre or {{cvt|3|°F-change|°C-change}} per 1000&nbsp;feet)<ref>{{Cite web |title=Dry Adiabatic Lapse Rate |url=http://meteorologytraining.tpub.com/14312/css/14312_47.htm |url-status=dead |archive-url=https://web.archive.org/web/20160603041448/http://meteorologytraining.tpub.com/14312/css/14312_47.htm |archive-date=3 June 2016 |access-date=2 May 2016 |website=tpub.com}}</ref>
The actual lapse rate can vary by altitude and by location.
Therefore, moving up {{Convert|100|m|ft|abbr=on|sp=us}} on a mountain is roughly equivalent to moving 80&nbsp;kilometres (45&nbsp;miles or 0.75° of [[latitude]]) towards the nearest pole.<ref name="Blyth2002" />{{rp|15}} This relationship is only approximate, however, since local factors such as proximity to oceans (such as the Arctic Ocean) can drastically modify the climate.<ref>{{Cite web |title=Factors affecting climate |url=http://www.ecn.ac.uk/Education/factors_affecting_climate.htm |archive-url=https://web.archive.org/web/20110716163841/http://www.ecn.ac.uk/Education/factors_affecting_climate.htm |archive-date=16 July 2011 |publisher=The United Kingdom Environmental Change Network}}</ref> As the altitude increases, the main form of [[precipitation]] becomes snow and the winds increase.<ref name="Blyth2002" />{{rp|12}}

The effect of the climate on the ecology at an elevation can be largely captured through a combination of amount of precipitation, and the [[biotemperature]], as described by [[Leslie Holdridge]] in 1947.<ref>{{Cite journal |last=Lugo |first=Ariel E. |last2=Brown |first2=Sandra L. |last3=Dodson |first3=Rusty |last4=Smith |first4=Tom S. |last5=Shugart |first5=Hank H. |year=1999 |title=The Holdridge Life Zones of the conterminous United States in relation to ecosystem mapping |url=http://www.epa.gov/wed/pages/publications/abstracts/archived/lugo.htm |url-status=live |journal=Journal of Biogeography |volume=26 |issue=5 |pages=1025–1038 |bibcode=1999JBiog..26.1025L |doi=10.1046/j.1365-2699.1999.00329.x |s2cid=11733879 |archive-url=https://web.archive.org/web/20130428164559/http://www.epa.gov/wed/pages/publications/abstracts/archived/lugo.htm |archive-date=28 April 2013}}</ref> Biotemperature is the mean temperature; all temperatures below {{convert|0|C|F}} are considered to be 0&nbsp;°C. When the temperature is below 0&nbsp;°C, plants are dormant, so the exact temperature is unimportant. The peaks of mountains with permanent snow can have a biotemperature below {{convert|1.5|C|F}}.

===Climate change===
Mountain environments are particularly sensitive to anthropogenic climate change and are currently undergoing alterations unprecedented in last 10,000 years.<ref>{{Cite journal |last=Knight |first=Jasper |date=24 October 2022 |title=Scientists' warning of the impacts of climate change on mountains |journal=[[PeerJ]] |volume=10 |pages=e14253 |doi=10.7717/peerj.14253 |pmc=9610668 |pmid=36312749 |doi-access=free}}</ref> The effect of global warming on mountain regions (relative to lowlands) is still an active area of study. Observational studies show that highlands are warming faster than nearby lowlands, but when compared globally, the effect disappears.<ref name="Pepin">{{Cite journal |last=Pepin |first=N. C. |last2=Arnone |first2=E. |last3=Gobiet |first3=A. |last4=Haslinger |first4=K. |display-authors=et al |year=2022 |title=Climate Changes and Their Elevational Patterns in the Mountains of the World |url=https://boris.unibe.ch/169026/ |journal=Reviews of Geophysics |volume=60 |issue=1 |bibcode=2022RvGeo..6000730P |doi=10.1029/2020RG000730 |s2cid=247008935 |hdl-access=free |hdl=2318/1842344}}</ref> Precipitation in highland areas is not increasing as quickly as in lowland areas.<ref name="Pepin" /> [[Climate modeling]] give mixed signals about whether a particular highland area will have increased or decreased precipitation.<ref>{{Cite web |last=Derouin |first=Sarah |date=7 November 2023 |title=Carbon Dioxide's Effect on Mountain Climate Systems |url=https://eos.org/research-spotlights/carbon-dioxides-effect-on-mountain-climate-systems |website=Eos}}</ref>

Climate change has started to affect the physical and ecological systems of mountains. In recent decades mountain ice caps and glaciers have experienced accelerating ice loss.<ref>{{Cite book |last=Pelto |first=Mauri |title=Recent Climate Change Impacts on Mountain Glaciers |publisher=Wiley |year=2016 |isbn=9781119068143}}</ref> The melting of the glaciers, permafrost and snow has caused underlying surfaces to become increasingly unstable. Landslip hazards have increased in both number and magnitude due to climate change.<ref>{{Cite book |last=Deline |first=Philip |title=Snow and Ice-Related Hazards, Risks, and Disasters |last2=Gruber |first2=Stephan |last3=Amann |first3=Florian |last4=Bodin |first4=Xavier |publisher=Elsevier |year=2021 |isbn=9780128171295 |editor-last=Haeberli |editor-first=Wilfried |edition=2nd |series=Hazards and Disasters |pages=501–540 |chapter=Ice loss from glaciers and permafrost and related slope instability in high-mountain regions |doi=10.1016/B978-0-12-817129-5.00015-9 |display-authors=et al |editor-last2=Whiteman |editor-first2=Colin |s2cid=234301790}}</ref> Patterns of river discharge will also be significantly affected by climate change, which in turn will have significant impacts on communities that rely on water fed from alpine sources. Nearly half of mountain areas provide essential or supportive water resources for mainly urban populations,<ref>{{Cite journal |last=Viviroli |first=D. |last2=Kummu |first2=M. |last3=Meybeck |first3=M. |last4=Kallio |first4=M. |last5=Wada |first5=Y. |year=2020 |title=Increasing dependence of lowland populations on mountain water resources |journal=Nature Sustainability |volume=3 |issue=11 |pages=917–928 |bibcode=2020NatSu...3..917V |doi=10.1038/s41893-020-0559-9 |s2cid=220375949}}</ref> in particular during the dry season and in semiarid areas such as in central Asia.

Alpine ecosystems can be particularly climatically sensitive. Many mid-latitude mountains act as cold climate refugia, with the ecosystems occupying small environmental niches. As well as the direct influence that the change in climate can have on an ecosystem, there is also the indirect one on the soils from changes in stability and soil development.<ref>{{Cite journal |last=Chersich |first=S |last2=Rejšek |first2=K |last3=Vranová |first3=V. |last4=Bordoni |first4=M. |last5=Meisina |first5=C. |year=2015 |title=Climate change impacts on the Alpine ecosystem: an overview with focus on the soil |journal=J. For. Sci. |volume=61 |issue=11 |pages=496–514 |doi=10.17221/47/2015-JFS |doi-access=free}}</ref>