Climate change and cities
[12] Climate change adaptation and mitigation investments in cities will be important in reducing the impacts of some of the largest contributors of greenhouse gas emissions: for example, increased density allows for redistribution of land use for agriculture and reforestation, improving transportation efficiencies, and greening construction (largely due to cement's outsized role in climate change and improvements in sustainable construction practices and weatherization).
There is limited progress on making cities and human settlements more appropriate to live in Sub-Saharan Africa, Latin America and the Caribbean and the Pacific Island countries.
[25] With regard to methods of emissions counting cities can be challenging as production of goods and services within their territory can be related either to domestic consumption or exports.
[31][32] Cities are good subjects for study because they can invest heavily in large-scale experimental policies that could be scaled elsewhere (such as San Diego's advanced urban planning practices which could be applied elsewhere in the United States).
[33][34] Multiple scholars approach this in different ways, but describe this "urban laboratory" environment good for testing a wide variety of practices.
[38] Urbanization commonly occurs in cities with low and middle income communities that have high population density and a lack of understanding of how climate change, which degrades their environment, is affecting their health.
[39] Alongside infectious diseases and heatwaves, climate change can create natural hazards such as floods, droughts, and storms due to rising sea levels.
[41]: SPM-11 Low-income and remote populations are more vulnerable to physical hazards, undernutrition, diarrheal and other infectious diseases, and the health consequences of displacement.
[43] These systems concern both physical infrastructure in the city and ecosystems within or surrounding the urban center; while working to provide essential services like food production, flood control, or runoff management.
The failure of these core systems jeopardizes human well-being in these urban areas, with that being said, it is crucial to maintain them in the face of impending environmental disturbances.
[43] The presence of safe failures also plays a critical role in maintaining these systems, which work by absorbing sudden shocks that may even exceed design thresholds.
[44] Other theorists have critiqued this idea of bounce-back, citing this as privileging the status quo, rather advocating the notion of 'bouncing forward', permitting system evolution and improvement.
[43] Agents in urban centers have the capacity to deliberate and rationally make decisions, which plays an important role in climate resiliency theory.
However, one linking factor is their inevitable adherence to "Dominant global patterns of urbanization and industrialization" which often catalyzes "large-scale modification of the drivers for hydrologic and biogeochemical processes".
[50] This rapid urbanization, coupled with the many interlinked and complex challenges as a result of climate change, pose a significant barrier to Africa's sustainable development.
[57] In this way urbanization in China could be understood as intimately related to not only the functionality of their economic system, but the society therein; something that makes climate change mitigation an intersectional issue concerning more than simply infrastructure.
[57] A national-level policy analysis done on the drylands of northern China presents the notion of "sustainable urban landscape planning (SULP)" that specifically aims to "avoid occupying important natural habitats and corridors, prime croplands, and floodplains".
[62] At least 130 million South Asians—more than the entire population of Mexico—live in informal urban settlements characterized by poor construction, insecure tenure and underserviced plots.
As sea levels begin to rise, due to climate change, salinity will move inwards, reducing the amount of safe drinking water available to the people of Khulna.
[66] Areas of South America were also cited in recent studies that highlight the dangers of urbanization on both local and transnational climates, and for a country like Brazil, one of the highest populated nations in the world as well as the majority holder of the Amazon rainforest.
The United Nations Development Programme highlights the Amazon rainforest as serving a "key function in the global climate systems," granted its profound usefulness in capturing CO2 emissions.
Factor analysis and multilevel regression models sponsored by the U.S. Forest Service revealed that for all of Brazil, "income inequality significantly predicts higher levels of a key component of vulnerability in urban Brazilian municipalities" to flood hazards.
[73] The United States, as one of the largest industrialized nations in the world, also has issues regarding infrastructural insufficiencies linked to climate change.
[75] Such unnatural environmental phenomena furthers the notion that urbanization has a role in determining local climate, although researchers acknowledge that more studies need to be conducted in the field.
For example, following the United States withdrawal from the Paris Agreement a coalition of cities, under the banner of Mayors National Climate Action Agenda.
Even then, however, the same research indicated that measurements in the amounts of chemical pollutants contaminating rain, snow, and fog "follows an exponential probability density function at all sites".
[46] Such a finding suggests that alleged variability in rainfall patterns is the likely driving factor for the study's seemingly promising results, as opposed to there being a clear significance stemming from the policy change.
[46] It is within this context that while beneficial, the Clean Air Act alone cannot stand as the only firm rationale for climate policies in the United States moving forward.
[86] Steering committee members include: London, Freetown, Phoenix, Medellin, Copenhagen, Paris, Dhaka North, Nairobi, Tokyo, Rio de Janeiro, Montreal, Milan, Seoul, Oslo and Hong Kong.
The seven outcome targets include safe and affordable housing, affordable and sustainable transport systems, inclusive and sustainable urbanization,[92] protection of the world's cultural and natural heritage, reduction of the adverse effects of natural disasters, reduction of the environmental impacts of cities and to provide access to safe and inclusive green and public spaces.
