Editing Climate variability and change (section)

==== Variability between regions {{anchor|Contemporaneous regional variability}} ====
{{Gallery
|align=right | height=150 |mode=packed
|title= Examples of regional climate variability

| File:Land vs Ocean Temperature.svg
 | '''Land-ocean.''' Surface air temperatures over land masses have been increasing faster than those over the ocean,<ref name="NASA GISS">{{cite web |title=GISS Surface Temperature Analysis (v4) / Annual Mean Temperature Change over Land and over Ocean |url=https://data.giss.nasa.gov/gistemp/graphs_v4/ |website=NASA GISS |archive-url=https://web.archive.org/web/20200416074510/https://data.giss.nasa.gov/gistemp/graphs_v4/ |archive-date=16 April 2020 |url-status=live}}</ref> the ocean absorbing about 90% of excess heat.<ref name="Harvey-2018">{{cite magazine |last1=Harvey |first1=Chelsea |title=The Oceans Are Heating Up Faster Than Expected |url=https://www.scientificamerican.com/article/the-oceans-are-heating-up-faster-than-expected/ |magazine=Scientific American |date=1 November 2018 |archive-url=https://web.archive.org/web/20200303222236/https://www.scientificamerican.com/article/the-oceans-are-heating-up-faster-than-expected/ |archive-date=3 March 2020 |url-status=live }} Data from [https://web.archive.org/web/20200416074510/https://data.giss.nasa.gov/gistemp/graphs_v4/ NASA GISS].</ref>

|File:20200505 Global warming variability - Northern vs Southern hemispheres.svg
 | '''Hemispheres.''' The Hemispheres' average temperature changes<ref name="NASA GISS-3">{{cite web |title=GISS Surface Temperature Analysis (v4) / Annual Mean Temperature Change for Hemispheres |url=https://data.giss.nasa.gov/gistemp/graphs_v4/ |website=NASA GISS |archive-url=https://web.archive.org/web/20200416074510/https://data.giss.nasa.gov/gistemp/graphs_v4/ |archive-date=16 April 2020 |url-status=live}}</ref>  have diverged because of the North's greater percentage of landmass, and due to global ocean currents.<ref name="Freedman-2013">{{cite web |last1=Freedman |first1=Andrew |title=In Warming, Northern Hemisphere is Outpacing the South |url=https://www.climatecentral.org/news/in-global-warming-northern-hemisphere-is-outpacing-the-south-15850 |website=Climate Central |archive-url=https://web.archive.org/web/20191031123759/https://www.climatecentral.org/news/in-global-warming-northern-hemisphere-is-outpacing-the-south-15850 |archive-date=31 October 2019 |date=9 April 2013 |url-status=live }}</ref>

| File:20200314 Temperature changes for three latitude bands (5MA, 1880- ) GISS.svg
 | '''Latitude bands.''' Three latitude bands that respectively cover 30, 40 and 30 percent of the global surface area show mutually distinct temperature growth patterns in recent decades.<ref name="NASA GISS-2">{{cite web |title=GISS Surface Temperature Analysis (v4) / Temperature Change for Three Latitude Bands |url=https://data.giss.nasa.gov/gistemp/graphs_v4/ |website=NASA GISS |archive-url=https://web.archive.org/web/20200416074510/https://data.giss.nasa.gov/gistemp/graphs_v4/ |archive-date=16 April 2020 |url-status=live}}</ref>

| File:1960- Warming stripes global temperature graphic - atmospheric heights and ocean depths.png
 | '''Altitude.''' A [[warming stripes]] graphic ({{blue|blues}} denote cool, {{red|reds}} denote warm) shows how the greenhouse effect traps heat in the lower atmosphere and oceans, so that the upper atmosphere, receiving less reflected energy, cools.<ref name=AMS_20250501>{{cite journal |last1=Hawkins |first1=Ed |last2=Williams |first2=Richard G. |last3=Young |first3=Paul J. |last4=Berardelli |first4=Jeff |last5=Burgess |first5=Samantha N. |last6=Highwood |first6=Ellie |last7=Randel |first7=William |last8=Roussenov |first8=Vassil |last9=Smith |first9=Doug |last10=Placky |first10=Bernadette Woods |title=Warming Stripes Spark Climate Conversations: From the Ocean to the Stratosphere |journal=Bulletin of the American Meteorological Society |volume=6 |issue=5 |date=1 May 2025 |pages=E964-E970 |doi=10.1175/BAMS-D-24-0212.1}}</ref><ref name=Hawkins-2019>{{cite web |last1=Hawkins |first1=Ed |title=Atmospheric temperature trends |url=http://www.climate-lab-book.ac.uk/2019/atmospheric-temperature-trends/ |website=Climate Lab Book |archive-url=https://web.archive.org/web/20190912192530/http://www.climate-lab-book.ac.uk/2019/atmospheric-temperature-trends/ |archive-date=12 September 2019 |date=12 September 2019 |url-status=live }} (Higher-altitude cooling differences attributed to ozone depletion and greenhouse gas increases; spikes occurred with volcanic eruptions of 1982–83 (El Chichón) and 1991–92 (Pinatubo).)</ref>
 
| File:20200505 Global warming variability - global vs Caribbean.svg 
 | '''Global versus regional.''' For geographical and statistical reasons, larger year-to-year variations are expected<ref name="Meduna-2018">{{cite news |last1=Meduna |first1=Veronika |title=The climate visualisations that leave no room for doubt or denial |url=https://thespinoff.co.nz/science/17-09-2018/the-climate-visualisations-that-leave-no-room-for-doubt-or-denial/ |work=The Spinoff |date=17 September 2018 |archive-url=https://web.archive.org/web/20190517104250/https://thespinoff.co.nz/science/17-09-2018/the-climate-visualisations-that-leave-no-room-for-doubt-or-denial/ |archive-date=17 May 2019 |location=New Zealand |url-status=live }}</ref> for localized geographic regions (e.g., the Caribbean) than for global averages.<ref name="NCDC_NOAA">{{cite web |title=Climate at a Glance / Global Time Series |url=https://www.ncdc.noaa.gov/cag/global/time-series/globe/land_ocean/12/12/1880-2019 |website=NCDC / NOAA |archive-url=https://web.archive.org/web/20200223062050/https://www.ncdc.noaa.gov/cag/global/time-series/globe/land_ocean/12/12/1880-2019 |archive-date=23 February 2020 |url-status=live}}</ref>

| File:20200509 Emergence of temperatures from range of normal historical variability - tropical vs northern Americas (Hawkins).gif 
 | '''Relative deviation.''' Though northern America has warmed more than its tropics, the tropics have more clearly departed from normal historical variability (colored bands: 1σ, 2σ standard deviations).<ref name="Hawkins-2020">{{cite web |last1=Hawkins |first1=Ed |title=From the familiar to the unknown |url=https://www.climate-lab-book.ac.uk/2020/from-the-familiar-to-the-unknown/ |website=Climate Lab Book (professional blog) |archive-url=https://web.archive.org/web/20200423232229/https://www.climate-lab-book.ac.uk/2020/from-the-familiar-to-the-unknown/ |archive-date=23 April 2020 |date=10 March 2020 |url-status=live }} ([https://web.archive.org/web/20200502073245/http://www.climate-lab-book.ac.uk/files/2020/03/emerge_example.png Direct link to image]; Hawkins credits [[Berkeley Earth]] for data.) "The emergence of observed temperature changes over both land and ocean is clearest in tropical regions, in contrast to the regions of largest change which are in the northern extra-tropics. As an illustration, northern America has warmed more than tropical America, but the changes in the tropics are more apparent and have more clearly emerged from the range of historical variability. The year-to-year variations in the higher latitudes have made it harder to distinguish the long-term changes."</ref>
}}
[[File:1880- Global warming by latitude zone - NASA - GISS data.webm|thumb| upright=1.15| Global warming has varied substantially by latitude, with the northernmost latitude zones experiencing the largest temperature increases.]]
In addition to global climate variability and global climate change over time, numerous climatic variations occur contemporaneously across different physical regions.

The oceans' absorption of about 90% of excess heat has helped to cause land surface temperatures to grow more rapidly than sea surface temperatures.<ref name="Harvey-2018"/> The Northern Hemisphere, having a larger landmass-to-ocean ratio than the Southern Hemisphere, shows greater average temperature increases.<ref name="Freedman-2013"/> Variations across different latitude bands also reflect this divergence in average temperature increase, with the temperature increase of northern [[wikt:extratropics|extratropics]] exceeding that of the tropics, which in turn exceeds that of the southern extratropics.<ref name="NASA GISS-2"/>

Upper regions of the atmosphere have been cooling contemporaneously with a warming in the lower atmosphere, confirming the action of the greenhouse effect and ozone depletion.<ref name="Hawkins-2019"/>

Observed regional climatic variations confirm predictions concerning ongoing changes, for example, by contrasting (smoother) year-to-year global variations with (more volatile) year-to-year variations in localized regions.<ref name="Meduna-2018"/> Conversely, comparing different regions' warming patterns to their respective historical variabilities, allows the raw magnitudes of temperature changes to be placed in the perspective of what is normal variability for each region.<ref name="Hawkins-2020"/>

Regional variability observations permit study of regionalized [[Tipping points in the climate system|climate tipping point]]s such as rainforest loss, ice sheet and sea ice melt, and permafrost thawing.<ref name="Lenton-2019">{{Cite journal|last1=Lenton|first1=Timothy M.|last2=Rockström|first2=Johan |last3=Gaffney|first3=Owen|last4=Rahmstorf|first4=Stefan|last5=Richardson|first5=Katherine|last6=Steffen |first6=Will|last7=Schellnhuber|first7=Hans Joachim|date=27 November 2019|title=Climate tipping points – too risky to bet against|journal=Nature|language=en|volume=575|issue=7784|pages=592–595|pmid=31776487 |bibcode=2019Natur.575..592L|doi=10.1038/d41586-019-03595-0|doi-access=free|hdl=10871/40141|hdl-access=free}} Correction dated 9 April 2020</ref> Such distinctions underlie research into a possible [[abrupt climate change|global cascade of tipping points]].<ref name="Lenton-2019" />