Editing Urbanization (section)

==Environmental effects==
{{Pollution sidebar|Noise}}
Furthermore, urbanization improves environmental eminence through superior facilities and standards in urban areas as compared to rural areas. Lastly, urbanization curbs pollution emissions by increasing innovations.<ref>{{Cite journal|last1=Yasin|first1=Iftikhar|last2=Ahmad|first2=Nawaz|last3=Chaudhary|first3=M. Aslam|date=2019-07-22|title=Catechizing the Environmental-Impression of Urbanization, Financial Development, and Political Institutions: A Circumstance of Ecological Footprints in 110 Developed and Less-Developed Countries|journal=Social Indicators Research|language=en|volume=147|issue=2|pages=621–649|doi=10.1007/s11205-019-02163-3|issn=0303-8300|s2cid=199855869}}</ref> In his 2009 book ''[[Whole Earth Discipline]]'', Stewart Brand argues that the effects of urbanization are primarily positive for the environment. First, the birth rate of new urban dwellers falls immediately to replacement rate and keeps falling, reducing environmental stresses caused by population growth.<ref>{{Cite web |url=https://www.prb.org/urbanization-an-environmental-force-to-be-reckoned-with/ |title=Urbanization: An Environmental Force to Be Reckoned With |access-date=19 July 2019 |archive-date=3 December 2019 |archive-url=https://web.archive.org/web/20191203161352/https://www.prb.org/urbanization-an-environmental-force-to-be-reckoned-with/ |url-status=live }}</ref> Secondly, emigration from rural areas reduces destructive [[subsistence farming]] techniques, such as improperly implemented [[slash and burn]] agriculture. [[Alex Steffen]] also speaks of the environmental benefits of increasing the urbanization level in "Carbon Zero: Imagining Cities that can save the planet".<ref>Carbon Zero: Imagining Cities that can save the planet by Alex Steffen</ref>

However, existing infrastructure and city planning practices are not sustainable.<ref>{{cite journal |last1=Luqman |first1=Muhammad |last2=Rayner |first2=Peter J. |last3=Gurney |first3=Kevin R. |title=On the impact of urbanisation on CO2 emissions |journal=[[npj Urban Sustainability]] |date=2023 |volume=3 |issue=1 |page=6 |doi=10.1038/s42949-023-00084-2 |doi-access=free|bibcode=2023npjUS...3....6L }}</ref> In July 2013 a report issued by the United Nations Department of Economic and Social Affairs<ref>[http://sustainabledevelopment.un.org/content/documents/2843WESS2013.pdf "World Economic and Social Survey (WESS) 2013"] {{Webarchive|url=https://web.archive.org/web/20140407104105/http://sustainabledevelopment.un.org/content/documents/2843WESS2013.pdf |date=7 April 2014 }} World Economic and Social Affairs. July 2013.</ref> warned that with 2.4 billion more people by 2050, the amount of food produced will have to increase by 70%, straining food resources, especially in countries already facing food insecurity due to changing environmental conditions. The mix of changing environmental conditions and the growing population of urban regions, according to UN experts, will strain basic sanitation systems and health care, and potentially cause a humanitarian and environmental disaster.<ref>Auber, Tamar (17 July 2013) [http://unearthnews.org/2013/07/17/climate-change-and-rapid-urban-expansion-in-africa-threaten-childrens-lives/ "Climate change and rapid urban expansion in Africa threaten children’s lives."] {{Webarchive|url=https://web.archive.org/web/20141113014025/http://unearthnews.org/2013/07/17/climate-change-and-rapid-urban-expansion-in-africa-threaten-childrens-lives/ |date=13 November 2014 }} UNEARTH News. Retrieved 10 August 2013.</ref>

=== Urban heat island ===
[[Urban heat island]]s have become a growing concern over the years. An urban heat island is formed when industrial areas absorb and retain heat. Much of the solar energy reaching rural areas is used to evaporate water from plants and soil. In cities, there are less vegetation and exposed soil. Most of the sun's energy is instead absorbed by buildings and asphalt; leading to higher surface temperatures. Vehicles, factories, and heating and cooling units in factories and homes release even more heat.<ref>Park, H.-S. (1987). [[hdl:2241/4711|Variations in the urban heat island intensity affected by geographical environments]]. Environmental Research Center papers, no. 11. Ibaraki, Japan: Environmental Research Center, The University of Tsukuba.</ref> As a result, cities are often {{convert|1 to 3|C-change}} warmer than other areas near them.<ref>[http://www.epa.gov/heatisland/ "Heat Island Effect"] {{Webarchive|url=https://web.archive.org/web/20150814070412/http://www.epa.gov/heatisland/ |date=14 August 2015 }}. Epa.gov (17 November 2010). Retrieved on 7 April 2014.</ref> Urban heat islands also make the soil drier and absorb less carbon dioxide from emissions.<ref>{{cite web|title=Heating Up: Study Shows Rapid Urbanization in China Warming the Regional Climate Faster than Other Urban Areas|url=http://gtresearchnews.gatech.edu/newsrelease/china-climate.htm|access-date=31 July 2008|archive-date=20 October 2019|archive-url=https://web.archive.org/web/20191020041109/http://gtresearchnews.gatech.edu/newsrelease/china-climate.htm|url-status=live}}</ref> A Qatar University study found that land-surface temperatures in Doha increased annually by 0.65&nbsp;°C from 2002 to 2013 and 2023.<ref>Patel, S., Indraganti, M., & Jawarneh, R. N. (2024). Urban planning impact on summer human thermal comfort in Doha, Qatar. ''Building and Environment'', ''254''. <nowiki>https://doi.org/10.1016/j.buildenv.2024.111374</nowiki></ref>

=== Water quality ===
[[Urban runoff]], polluted water created by rainfall on impervious surfaces, is a common effect of urbanization. Precipitation from rooftops, roads, parking lots and sidewalks flows to [[storm drain]]s, instead of [[Infiltration (hydrology)|percolating]] into [[groundwater]]. The contaminated [[stormwater]] in the drains is typically untreated and flows to nearby streams, rivers or coastal bays.<ref name="USGS-runoff">{{cite web |url=https://water.usgs.gov/edu/runoff.html |title=Runoff (surface water runoff) |author=<!--Not stated--> |date=2018-06-06 |website=USGS Water Science School |publisher=U.S. Geological Survey (USGS) |location=Reston, VA}}</ref>

[[Eutrophication]] in water bodies is another effect large populations in cities have on the environment. When rain occurs in these large cities, it filters CO<sub>2</sub> and other pollutants in the air onto the ground. These chemicals are washed directly into rivers, streams, and oceans, making water worse and damaging ecosystems in them.<ref name=":0">{{cite journal|last1=Jiang|first1=Leiwen|last2=Hoepf Young|first2=Malea|last3=Hardee|first3=Karen|year=2008|title=Population, Urbanization, And The Environment|journal=World Watch|volume=21|issue=5|pages=34–39}}</ref>

Eutrophication is a process which causes low levels of oxygen in water and algal blooms that may harm aquatic life.<ref>{{Cite web|url=https://www.wri.org/our-work/project/eutrophication-and-hypoxia/about-eutrophication|title=About Eutrophication {{!}} World Resources Institute|website=wri.org|date=12 September 2013|access-date=2018-11-18|archive-date=19 November 2018|archive-url=https://web.archive.org/web/20181119010905/https://www.wri.org/our-work/project/eutrophication-and-hypoxia/about-eutrophication|url-status=live}}</ref> [[Harmful algal bloom]]s make dangerous toxins. They live best in nitrogen- and phosphorus-rich places which include the oceans contaminated by the aforementioned chemicals.<ref>{{Cite web|url=https://www.epa.gov/nutrientpollution/harmful-algal-blooms|title=Harmful Algal Blooms|website=US Environmental Protection Administration|date=3 June 2013|access-date=2018-11-18|archive-date=4 February 2020|archive-url=https://web.archive.org/web/20200204072812/https://www.epa.gov/nutrientpollution/harmful-algal-blooms|url-status=live}}</ref> In these ideal conditions, they choke surface water, blocking sunlight and nutrients from other life forms. Overgrowth of algal blooms makes water worse overall and disrupts the natural balance of aquatic ecosystems. Furthermore, as algal blooms die, CO<sub>2</sub> is produced. This makes the ocean more acidic, a process called acidification.<ref name=":12">{{Cite web|url=http://www.nutrientchallenge.org/sites/default/files/documents/files/FINAL%20Ocean%20Acidification%20policy%20brief%20spread_press%20quality_print.pdf|title=Eutrophication and Ocean Acidification|last1=Ramesh|first1=R|last2=Lakshmi|first2=A|date=2013|last3=Purvaja|first3=R|last4=Costanzo|first4=S.D|last5=Kelsey|first5=R.H|last6=Hawkey|first6=J|last7=Datta|first7=A|last8=Dennison|first8=W.C|access-date=18 November 2018|archive-date=21 April 2021|archive-url=https://web.archive.org/web/20210421212836/http://www.nutrientchallenge.org/sites/default/files/documents/files/FINAL%20Ocean%20Acidification%20policy%20brief%20spread_press%20quality_print.pdf|url-status=live}}</ref>

The ocean's surface can absorb CO<sub>2</sub> from the Earth's atmosphere as emissions increase with the rise in urban development. In fact, the ocean absorbs a quarter of the CO<sub>2</sub> produced by humans.<ref name=":03">{{Cite web|url=https://nca2014.globalchange.gov/report/our-changing-climate/ocean-acidification|title=National Climate Assessment|website=National Climate Assessment|access-date=2018-11-18|archive-date=18 November 2018|archive-url=https://web.archive.org/web/20181118145133/https://nca2014.globalchange.gov/report/our-changing-climate/ocean-acidification|url-status=live}}</ref> This helps to lessen the harmful effects of greenhouse gases. But it also makes the ocean more acidic.<ref>{{Cite journal|last1=Feely|first1=Richard A.|last2=Alin|first2=Simone R.|last3=Newton|first3=Jan|last4=Sabine|first4=Christopher L.|last5=Warner|first5=Mark|last6=Devol|first6=Allan|last7=Krembs|first7=Christopher|last8=Maloy|first8=Carol|date=August 2010|title=The combined effects of ocean acidification, mixing, and respiration on pH and carbonate saturation in an urbanized estuary|journal=Estuarine, Coastal and Shelf Science|volume=88|issue=4|pages=442–449|doi=10.1016/j.ecss.2010.05.004|issn=0272-7714|bibcode=2010ECSS...88..442F}}</ref> A drop in pH the prevents the proper formation of calcium carbonate, which sea creatures need to build or keep shells or skeletons.<ref>{{Cite web|url=https://www.fisheries.noaa.gov/insight/understanding-ocean-acidification|title=Understanding Ocean Acidification {{!}} NOAA Fisheries|last=Fisheries|first=NOAA|date=2018-09-09|website=fisheries.noaa.gov|access-date=2018-11-18|archive-date=19 November 2018|archive-url=https://web.archive.org/web/20181119053040/https://www.fisheries.noaa.gov/insight/understanding-ocean-acidification|url-status=live}}</ref><ref name=":03" /> This is especially true for many species of molluscs and coral. However, some species have been able to thrive in a more acidic environment.<ref>{{Cite web|url=https://ocean.si.edu/ocean-life/invertebrates/ocean-acidification|title=Ocean Acidification|website=Smithsonian Ocean|date=30 April 2018 |access-date=2018-11-18|archive-date=9 November 2020|archive-url=https://web.archive.org/web/20201109050311/https://ocean.si.edu/ocean-life/invertebrates/ocean-acidification|url-status=live}}</ref>

=== Food waste ===
Rapid growth of communities creates new challenges in the developed world and one such challenge is an increase in [[food waste]]<ref>{{Cite journal|last1=Thyberg|first1=Krista L.|last2=Tonjes|first2=David J.|date=2016|title=Drivers of food waste and their implications for sustainable policy development|url=https://www.tib.eu/en/search/id/tema:TEMA20151218325/Drivers-of-food-waste-and-their-implications-for/|journal=Resources, Conservation and Recycling|volume=106|pages=110–123|doi=10.1016/j.resconrec.2015.11.016|bibcode=2016RCR...106..110T |s2cid=30784882 |issn=0921-3449|access-date=31 October 2018|archive-date=27 December 2019|archive-url=https://web.archive.org/web/20191227062136/https://www.tib.eu/en/search/id/tema:TEMA20151218325/Drivers-of-food-waste-and-their-implications-for/|url-status=live|url-access=subscription}}</ref> also known as urban food waste.<ref>{{Cite web|url=http://www.inderscience.com/info/inarticle.php?artid=24696|title=Article: "Urban Food Waste generation: challenges and opportunities" Journal: Int. J. of Environment and Waste Management, 2009 Vol.3 No.1/2 pp.4 - 21 Abstract: Greater economic activity and a wider economic gap between rural and urban areas is leading to accelerated urbanisation and the generation of 35% more Urban Food Waste (UFW) from 2007 to 2025. Besides landfilling, this paper examines the advantages of introducing onsite composting and anaerobic digestion for the environmental recycling of UFW and the lowering of handling cost. For Asia and Africa, these solutions for UFW could reduce the mass of MSW by 43% and 55%, respectively, thus help there cities manage almost all of their MSW. For North America and Europe, such practice could reduce earth warming trends. - Inderscience Publishers - linking academia, business and industry through research|website=inderscience.com|access-date=2018-10-07|archive-date=1 November 2018|archive-url=https://web.archive.org/web/20181101015658/https://www.inderscience.com/info/inarticle.php?artid=24696|url-status=live}}</ref><ref name=":02">{{Cite journal|last1=Adhikari|first1=Bijaya K.|last2=Barrington|first2=Suzelle|last3=Martinez|first3=José|date=October 2006|title=Predicted growth of world urban food waste and methane production|journal=Waste Management & Research|volume=24|issue=5|pages=421–433|doi=10.1177/0734242X06067767|issn=0734-242X|pmid=17121114|bibcode=2006WMR....24..421A |s2cid=34299202}}</ref><ref>{{Cite journal|last1=Adhikari|first1=Bijaya K.|last2=Barrington|first2=Suzelle F.|last3=Martinez|first3=Jose|date=2009|title=Urban Food Waste generation: challenges and opportunities|journal=International Journal of Environment and Waste Management|volume=3|issue=1/2|pages=4|doi=10.1504/ijewm.2009.024696|bibcode=2009IJEWM...3....4A |s2cid=96476310 |issn=1478-9876|url=https://hal.archives-ouvertes.fr/hal-00615443/file/RE2009-PUB00026234.pdf|access-date=1 February 2019|archive-date=26 July 2018|archive-url=https://web.archive.org/web/20180726174058/https://hal.archives-ouvertes.fr/hal-00615443/file/RE2009-PUB00026234.pdf|url-status=live}}</ref> Food waste is the disposal of food products that can no longer be used due to unused products, expiration, or spoilage. The increase of food waste can raise environmental concerns such as increase production of [[methane]] gases and attraction of [[Vector (epidemiology)|disease vectors]].<ref name=":02" /><ref>{{Cite web|url=https://www.who.int/news-room/fact-sheets/detail/vector-borne-diseases|title=Vector-borne diseases|website=World Health Organization|access-date=2018-10-19|archive-date=4 January 2023|archive-url=https://web.archive.org/web/20230104001515/https://www.who.int/news-room/fact-sheets/detail/vector-borne-diseases|url-status=live}}</ref> Landfills are the third leading cause of the release of methane,<ref>{{Cite web|url=https://www.epa.gov/ghgemissions/overview-greenhouse-gases#methane|title=Overview of Greenhouse Gases {{!}} US EPA|last=EPA, OA|first=US|website=US EPA|access-date=2018-10-16|date=2015-12-23|archive-date=12 August 2016|archive-url=https://web.archive.org/web/20160812082641/https://www.epa.gov/ghgemissions/overview-greenhouse-gases#methane|url-status=live}}</ref> causing a concern on its impact to our ozone and on the health of individuals. Accumulation of food waste causes increased fermentation, which increases the risk of rodent and bug migration. An increase in migration of disease vectors creates greater potential of disease spreading to humans.<ref>{{Cite journal|last=Venkateswaran|first=Sandhya|date=1994|title=Managing Waste: Ecological, Economic and Social Dimensions|journal=Economic and Political Weekly|volume=29|issue=45/46|pages=2907–2911|jstor=4401996}}</ref>

Waste management systems vary on all scales from global to local and can also be influenced by lifestyle. Waste management was not a primary concern until after the Industrial Revolution. As urban areas continued to grow along with the human population, proper management of solid waste became an apparent concern. To address these concerns, local governments sought solutions with the lowest economic impacts which meant implementing technical solutions at the very last stage of the process.<ref name=":9">{{Cite journal|last1=Bai|first1=Xuemei|last2=McPhearson|first2=Timon|last3=Cleugh|first3=Helen|last4=Nagendra|first4=Harini|last5=Tong|first5=Xin|last6=Zhu|first6=Tong|last7=Zhu|first7=Yong-Guan|date=2017-10-17|title=Linking Urbanization and the Environment: Conceptual and Empirical Advances|journal=Annual Review of Environment and Resources|language=en|volume=42|issue=1|pages=215–240|doi=10.1146/annurev-environ-102016-061128|issn=1543-5938|doi-access=free}}</ref> Current waste management reflects these economically motivated solutions, such as incineration or unregulated landfills. Yet, a growing increase for addressing other areas of life cycle consumption has occurred from initial stage reduction to heat recovery and recycling of materials.<ref name=":9" /> For example, concerns for mass consumption and [[fast fashion]] have moved to the forefront of the urban consumers' priorities. Aside from environmental concerns (e.g. climate change effects), other urban concerns for waste management are public health and land access.

=== Habitat fragmentation ===
Urbanization can have a large effect on biodiversity by causing a division of habitats and thereby alienation of species, a process known as [[habitat fragmentation]].<ref>{{Cite book|title=Urbanization, habitat loss, biodiversity decline: solution pathways to break the cycle |last1=Elmqvist |first1=Thomas |last2=Zipperer |first2=Wayne |last3=Güneralp |first3=Burak|year=2016|pages=139–151|chapter=10}}</ref> Habitat fragmentation does not destroy the habitat, as seen in [[habitat loss]], but rather breaks it apart with things like roads and railways.<ref>{{cite journal | vauthors = Liu Z, He C, Wu J | title = The Relationship between Habitat Loss and Fragmentation during Urbanization: An Empirical Evaluation from 16 World Cities | journal = PLOS ONE| volume = 11 | issue = 4 | pages = e0154613 | date = 2016 | pmid = 27124180 | pmc = 4849762 | doi = 10.1371/journal.pone.0154613 | bibcode = 2016PLoSO..1154613L | doi-access = free }}</ref> This change may affect a species ability to sustain life by separating it from the environment in which it is able to easily access food, and find areas that they may hide from predation.<ref>{{Cite journal|doi = 10.1676/04-038|title = Nest Survival Relative to Patch Size in a Highly Fragmented Shortgrass Prairie Landscape|journal = The Wilson Bulletin|volume = 117|pages = 23–34|year = 2005|last1 = Skagen|first1 = Susan K.|last2 = Yackel Adams|first2 = Amy A.|last3 = Adams|first3 = Rod D.| issue=1 | bibcode=2005TWBu..117...23S |s2cid = 85173365|url = https://www.biodiversitylibrary.org/part/210478|access-date = 25 December 2020|archive-date = 27 February 2021|archive-url = https://web.archive.org/web/20210227094952/https://www.biodiversitylibrary.org/part/210478|url-status = live}}</ref> With proper planning and management, fragmentation can be avoided by adding corridors that aid in the connection of areas and allow for easier movement around urbanized regions.<ref>{{Cite web |url=https://conservationcorridor.org/wp-content/uploads/Connectivity_lesson_plan_habitat_fragmentation.pdf |title=Habitat Fragmentation and Wildlife Corridors |access-date=11 July 2022 |archive-date=25 September 2022 |archive-url=https://web.archive.org/web/20220925215417/https://conservationcorridor.org/wp-content/uploads/Connectivity_lesson_plan_habitat_fragmentation.pdf |url-status=live }}</ref><ref>{{cite web|url=https://www.forestresearch.gov.uk/tools-and-resources/fthr/urban-regeneration-and-greenspace-partnership/greenspace-in-practice/practical-considerations-and-challenges-to-greenspace/habitat-fragmentation-practical-considerations/|title=Habitat fragmentation – Practical considerations|work=Forest Research |access-date=2022-08-04|quote="Features such as footpaths, rivers and canals already offer green corridors in many urban areas. Greenspace that is not suitable breeding habitat for many species may still serve to improve permeability, and therefore movement, between breeding sites."|archive-date=24 September 2022|archive-url=https://web.archive.org/web/20220924185410/https://www.forestresearch.gov.uk/tools-and-resources/fthr/urban-regeneration-and-greenspace-partnership/greenspace-in-practice/practical-considerations-and-challenges-to-greenspace/habitat-fragmentation-practical-considerations/|url-status=live}}</ref>

Depending on the various factors, such as level of urbanization, both increases or decreases in "species richness" can be seen.<ref>{{Cite journal|last=McKinney|first=Michael L.|date=2008-01-29|title=Effects of urbanization on species richness: A review of plants and animals|journal=Urban Ecosystems|volume=11|issue=2|pages=161–176|doi=10.1007/s11252-007-0045-4|bibcode=2008UrbEc..11..161M |s2cid=23353943|issn=1083-8155}}</ref><ref>{{cite journal|last1=Sidemo-Holm|first1=William|last2=Ekroos|first2=Johan|last3=Reina García|first3=Santiago|last4=Söderström|first4=Bo|last5=Hedblom|first5=Marcus|title=Urbanization causes biotic homogenization of woodland bird communities at multiple spatial scales|journal=Global Change Biology|year=2022|volume=28 |issue=21 |doi=10.1111/gcb.16350|doi-access=free|pages=6152–6164|pmid=35983686 |pmc=9804485 |bibcode=2022GCBio..28.6152S }}</ref> This means that urbanization may be detrimental to one species but also help facilitate the growth of others. In instances of housing and building development, many times vegetation is completely removed immediately in order to make it easier and less expensive for construction to occur, thereby obliterating any native species in that area. Habitat fragmentation can filter species with limited dispersal capacity. For example, aquatic insects are found to have lower species richness in urban landscapes.<ref>{{cite journal|last1=Lundkvist|first1=E.|last2=Landin|first2=J.|last3=Karlsson|first3=F.|title= Dispersing diving beetles (Dytiscidae) in agricultural and urban landscapes in south-eastern Sweden |journal= Annales Zoologici Fennici |year=2002 }}</ref> The more urbanized the surrounding of habitat is, the fewer species can reach the habitat.<ref>{{cite journal|last1=Liao|first1=W.|last2=Venn|first2=S.|last3=Niemelä|first3=J.|title=Environmental determinants of diving beetle assemblages (Coleoptera: Dytiscidae) in an urban landscape|journal=Biodiversity and Conservation|year=2020|doi=10.1007/s10531-020-01977-9|doi-access=free|volume=29|issue=7|pages=2343–2359|bibcode=2020BiCon..29.2343L }}</ref> The negative effects of urbanisation on aquatic insects can be long-lasting from the temporal perspective.<ref>{{cite journal|last1=Liao|first1=W.|last2=Soininen|first2=J.|title=Temporal alpha and beta diversity of diving beetles (Coleoptera: Dytiscidae) reveals biotic heterogenisation in urban ponds|journal=Freshwater Biology|year=2025|volume=70 |issue=1 |doi=10.1111/fwb.14374|doi-access=free|bibcode=2025FrBio..70E4374L }}</ref> Other times, such as with birds, urbanization may allow for an increase in richness when organisms are able to adapt to the new environment. This can be seen in species that may find food while scavenging developed areas or vegetation that has been added after urbanization has occurred i.e. planted trees in city areas.<ref>{{Cite journal|last=McKinney|first=Michael|date=October 2002|title=Urbanization, Biodiversity, and Conservation|journal=BioScience|volume=52|issue=10|pages=883|doi=10.1641/0006-3568(2002)052[0883:UBAC]2.0.CO;2|doi-access=free}}</ref>