Abstract and Figures

Extreme heat is a growing concern for cities, with both climate change and the urban heat island (UHI) effect increasingly impacting public health, economies, urban infrastructure, and urban ecology. To better understand the current state of planning for extreme heat, we conducted a systematic literature review. We found that most of the research focuses on UHI mapping and modeling, while few studies delve into extreme heat planning and governance processes. An in-depth review of this literature reveals common institutional, policy, and informational barriers and strategies for overcoming them. Identified challenges include siloed heat governance and research that limit cross-governmental and interdisciplinary collaboration; complex, context-specific, and diverse heat resilience strategies; the need to combine extreme heat “risk management” strategies (focused on preparing and responding to extreme heat events) and “design of the built environment” strategies (spatial planning and design interventions that intentionally reduce urban temperatures); and the need for extensive, multidisciplinary data and tools that are often not readily available. These challenges point to several avenues for future heat planning research. Ultimately, we argue that planners have an important role to play in building heat resilience and conclude by identifying areas where scholars and practitioners can work together to advance our understanding of extreme heat planning.
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Planning for Extreme Heat: A Review
Ladd Keith
*
,
, Sara Meerow
and Tess Wagner
*
*
School of Landscape Architecture and Planning
University of Arizona, Tucson, AZ, USA
School of Geographical Sciences & Urban Planning
Arizona State University, Tempe, AZ, USA
ladd@arizona.edu
Published 21 November 2020
Extreme heat is a growing concern for cities, with both climate change and the urban heat
island (UHI) effect increasingly impacting public health, economies, urban infrastructure,
and urban ecology. To better understand the current state of planning for extreme heat, we
conducted a systematic literature review. We found that most of the research focuses on
UHI mapping and modeling, while few studies delve into extreme heat planning and
governance processes. An in-depth review of this literature reveals common institutional,
policy, and informational barriers and strategies for overcoming them. Identied challenges
include siloed heat governance and research that limit cross-governmental and interdisci-
plinary collaboration; complex, context-specic, and diverse heat resilience strategies; the
need to combine extreme heat risk managementstrategies (focused on preparing and
responding to extreme heat events) and design of the built environmentstrategies (spatial
planning and design interventions that intentionally reduce urban temperatures); and the
need for extensive, multidisciplinary data and tools that are often not readily available.
These challenges point to several avenues for future heat planning research. Ultimately, we
argue that planners have an important role to play in building heat resilience and conclude
by identifying areas where scholars and practitioners can work together to advance our
understanding of extreme heat planning.
Keywords: Extreme heat; heat waves; urban heat; urban heat island; urban planning; urban
resilience.
Corresponding author.
This is an Open Access article published by World Scientic Publishing Company. It is distributed
under the terms of the Creative Commons Attribution 4.0 (CC BY) License which permits use,
distribution and reproduction in any medium, provided the original work is properly cited.
OPEN ACCESS
J Extreme Events, Vol. 6, Nos. 3&4 (2020) 2050003 (27 pages)
©The Author(s)
DOI: 10.1142/S2345737620500037
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1. Introduction
Climate change and the urban heat island (UHI) effect are increasing the number of
dangerously hot days in cities worldwide. Climate change is raising average global
temperatures and leading to more frequent and prolonged heat waves (Edenhofer
et al. 2014). Through the UHI effect, the form of the built environment, including
the materials used in buildings and urban infrastructure and anthropogenic heat
waste, increases urban temperatures beyond rural and natural areas (Oke 1973;
Stone and Rodgers 2001). We use the term extreme heatto encompass both the
acute and chronic heat risk that is exacerbated by the UHI effect and climate
change. Extreme heat is context specic, with variables such as day and nighttime
temperatures, humidity, exposure, and acclimation impacting risk (U.S. Environ-
mental Protection Agency 2006).
Extreme heat is the deadliest of all weather-related disasters (Hondula
et al. 2015) and was attributed to over 700 deaths in the 1995 Chicago, Illinois
heat wave (Davis et al. 2003), over 70,000 deaths in Europe during the 2003 heat
wave (Robine et al. 2008), and 55,736 deaths in the Russian heat wave of 2010
(Guha-Sapir et al. 2011). Vulnerable populations, including children, the elderly,
and low-income households, are especially at risk for heat-related health concerns
(Chow et al. 2012;Kovats and Hajat 2008). Hospital admissions for mental health
and behavioral disorders also increase as much as 7.3 percent during heat waves
(Hansen et al. 2008). In 2017, an estimated 153 billion hours of labor was lost
globally due to extreme heat (Watts et al. 2018) and heat increases are projected to
decrease global economic productivity by 20 percent during hot months by 2050
(Zander et al. 2015). In addition to the quality of life and economic impacts,
extreme heat can also raise energy demands (Magli et al. 2015;Santamouris
et al. 2015), increase water usage (Guhathakurta and Gober 2007), impact the
functionality of urban infrastructure (Dobney et al. 2010;Golden 2004;Jenkins
et al. 2014), cause additional stress to urban ecosystems (Brans et al. 2018; Grimm
et al. 2015; Nitschke et al. 2017), and in extreme cases, may threaten the viability
of cities (Pal and Eltahir 2016).
While the UHI effect was rst documented in London, UK in the 19th Century
by Howard (1833), extreme heat was not a widespread concern until recently
(ONeill et al. 2009). Consideration of extreme heat in the design and planning of
cities was mainly the purview of scholars of desert cities, such as Golany (1983),
who articulated best practices in urban design, and Vek Alp (1991), who argued
for the use of traditional architectural vernacular as a heat-adaptive solution.
Extreme heat is distinct from other climate risks for several reasons, including its
historic lack of governance and legal regulatory structure (Bernard and
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McGeehin 2004;Kaloustian et al. 2016), spatial and temporal complexity
(Coseo and Larsen 2014;Good 2016), compounding of other risks and impacts
(Bouchama et al. 2007), and invisibility (Luber and McGeehin 2008). In contrast,
ood risk has established governance structures (oodplain managers and ood
insurance in the US), mapped risks (FEMA oodplain maps in the US), directly
measurable impacts (loss of property and life), and is a more visible risk (images in
the media of ood devastation) (Plate 2002;Schanze 2007).
As concerns about extreme heat grow, scholars from different disciplines are
advancing the understanding of causes and responses to this risk. Advances
include documenting the contributions and interactions of controllable and non-
controllable factors in the UHI effect (Memon et al. 2008), identifying and
managing sources of heat vulnerability among the population (Reid et al. 2009),
managing heat risk through emergency response preparation and inter-agency
collaboration (Berisha et al. 2017), and long-term heat reduction in the built en-
vironment through efforts such as green infrastructure and reective or lighter
building materials (Kleerekoper et al. 2012;Solecki et al. 2005;Stone
et al. 2013). We use the inclusive term heat resilienceto describe these efforts
undertaken at a local level to both prepare for and adapt to extreme heat risks. Heat
governance includes the full range of publicprivate networks and actors that
deliberate and make decisions about heat resilience (Mees et al. 2014).
The planning professions specic role in heat governance remains unclear. In
one recent US survey, 70 percent of planners were worried about extreme heat risk
in the community they work, and heat ranked 4th out of 14 possible natural hazards
in terms of concern (National Drought Mitigation Center 2018). In contrast, an
assessment of over 3,500 climate adaptation resources in the US found that only 4
percent focused specically on heat (Nordgren et al. 2016). Even when heat risks
are widely acknowledged and heat resilient practices are understood locally, they
are often not given priority over other community values such as aesthetics
(Hatuka and Saaroni 2014).
Recognizing the urgency of extreme heat as a mounting climate risk to cities,
we conducted a systematic literature review to advance the understanding of
planning for extreme heat and to answer the following questions: (1) what are the
trends in peer-reviewed literature related to planning for extreme heat; (2) what
barriers and strategies do studies identify to increase heat resilience; and (3) what
are the critical next steps needed in research and practice to support planning for
extreme heat?
In the next section, we outline the methods used for a systematic review of the
literature on heat planning. In Section 3, we provide an overview of this literature,
including the primary methodological and geographic focus of the articles,
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trajectory, and source titles. We then delve into the smaller subset of articles that
specically address planning processes in Section 4, discussing key themes.
We conclude by summarizing the ndings of our review and reecting on the role that
planners play in heat resilience and meaningful avenues for future research.
2. Methods
To assess the current state of knowledge on heat planning, we conducted a sys-
tematic literature review (Xiao and Watson 2017). We searched Scopus, the largest
citation database of peer-reviewed literature, for all English language articles and
review papers published through the end of 2018 containing the terms urban heat
or extreme heatand planningin the title, abstract, or keywords. We excluded
articles in subject areas that were highly unlikely to be publishing urban planning
work, such as medicine, the natural sciences, and computer science. These search
criteria resulted in a dataset of 589 articles.
We then carefully read the title and abstract of each paper in the dataset, and
categorized them based on their primary focus: (1) planning processes;
(2) modeling; (3) impacts; (4) design; (5) literature review; and (6) other. Planning
processes papers included those that focused primarily on planning, governance,
and how information is used in policymaking. Modeling studies included any
paper focused on the development or application of a map or model to understand
extreme heat. Papers categorized as impacts included those focused primarily on
understanding the effects of extreme heat, for example, public health, perceptions,
and the economy. Design studies included those exploring relationships between
extreme heat and elements of the built environment but did not focus primarily on
a model. We categorized any papers that reviewed the literature on a topic or
established a research agenda as literature review studies. Papers that did not t
into one of these six categories were coded as others. We also noted the geo-
graphical focus of the study, for example, the city the study modeled.
Through this initial coding exercise, 39 articles were categorized as planning
processes. Two researchers independently read through the titles, abstracts, and in
some cases the full article, to determine whether the papers really were focused on
planning processes, and therefore should be reviewed in depth. We discussed and
reconciled any discrepancies in our determinations. Ultimately, 21 of the original 39
articles were included in the in-depth review. We analyzed each of these papers,
focusing on their denition of extreme heat, theoretical framework, and barriers and
strategies related to procedural and institutional concerns, policies, technical and
design considerations, and climate information. We then synthesized these notes and
identied common themes across the studies, which we discuss in Section 4.
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While our primary goal was to be systematic in our review in order to apply a
replicable approach and get a representative overview of the heat planning liter-
ature, we acknowledge several limitations of our approach. First, some research is
excluded from the Scopus database, for example, books and non-peer-reviewed
reports or the so-called grey literature (Archambault and Lariviere 2010). We were
also limited to English language publications. Our initial screening and categori-
zation of the literature were based on the title, abstract, and subject area of journal,
therefore it is possible that some articles included more planning-related content
than was apparent from the abstract. We also recognize that some relevant literature
may not be included in our dataset. The results are sensitive to the search terms, for
example, a study might not use the terms extreme heator urban heatspecif-
ically, and some heat planning work may be in public health journals categorized
within the eld of medicine.
3. Overview of Literature
In this section, we summarize the characteristics of the extreme heat planning
literature, including the main approaches used in research, the trajectory of papers
published, geographic focus of studies, and the journals. We discuss both the full
body of literature identied in Scopus and the much smaller selection of these
papers that focus specically on planning processes.
3.1. Overview of the extreme heat planning literature
Of the 589 articles on extreme heat planning identied in the Scopus database,
the vast majority are not primarily focused on planning processes. In fact, we
initially categorized just 39 studies, less than 7 percent of the dataset, as focused
on planning processes. In contrast, we categorized 68 percent (399) of the studies
as modeling papers, 14 percent (82) as design, 5 percent (32) look at heat
impacts, 4 percent (22) are literature reviews, and 3 percent (15) do not tinto
any of these categories. In addition, we identied 20 of the 589 studies in the
dataset as not being relevant to urban heat planning despite tting the search
terms (e.g., a paper that was focused on groundwater heating). Other scholars
have also recognized the lack of research on heat planning processes. For ex-
ample, Mahlkow and Donner (2017: 385) observe that only recently has the
scientic community given more attention to the way planners and policymakers
perceive and deal with the particular climate change adaptation issue of urban
heat.Indeed, looking at the number of publications by year (Figure 1), it is clear
that the overall research on heat planning has increased over time, with over 60
percent of all papers in the dataset having been published in the last ve years.
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The papers are quite diverse in terms of their geographic focus, although some
countries and cities are overrepresented. The greatest number of studies focus on
China and the US (Figure 2); in fact, these two countries together represent over 30
percent of the dataset. This is likely indicative of academic publishing patterns
more broadly since China and the US are the largest producers of scientic articles
(Tollefson 2018). While Australia, Germany, and the UK are all among the top ve
most commonly studied countries, they collectively account for just 10 percent of
the dataset. It is notable that Australia is third, despite its relatively small popu-
lation, perhaps because of the saliency of heat for the county. Looking at specic
cities, the most common study sites are in China, with Beijing, Wuhan, Hong
Kong, and Shanghai being the focus of over 10 publications. Other cities in Asia
such as Seoul, South Korea, and Singapore are also popular study sites. In the US,
Fig. 1. Number of publications on extreme heat planning in the Scopus database, by year
Fig. 2. The geographic focus of heat planning publications (all countries with more than 5
publications)
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Phoenix, Arizona stands out, with over ten studies, which is not surprising given its
high summer temperatures. In Europe both Paris, France, and London, UK are
common research locations. Both cities saw a major increase in mortality rates
during the 2003 heat wave (DIppoliti et al. 2010). Thus, the geographic focus of
the papers seems to reect both broader publication patterns as well as literal
hotspots where extreme heat is a particularly salient issue such as in Phoenix or in
Australian cities.
Extreme heat planning literature is published in a wide range of journals. In
terms of the number of studies in the dataset, the top ve titles are Building and
Environment (35 papers), Landscape and Urban Planning (33), Sustainability
(28), Urban Climate (28), and Energy and Buildings (26).
3.2. Overview of the literature on extreme heat planning processes
The geographic focus and source titles for the 21 studies focused on planning
processes are somewhat different from the overall dataset, as shown in Table 1.
Table 1. Extreme Heat Planning Process Studies Reviewed in Depth
Citation Journal Geographic Focus
Bolitho and Mille (2017) Local Environment Australia
Corburn (2009)Urban Studies USA
Dhalluin and Bozonnet (2015)Sustainable Cities and Society France
Donner et al. (2017)Journal of Environmental Assessment Policy
and Management
Germany
Downes and Storch (2014)Planning Practice and Research Vietnam
Guindon and Nirupama (2015)Natural Hazards Canada
Hamilton et al. (2010)Proceedings of the Institution of Civil Engi-
neers: Urban Design and Planning
UK
Hatvani-Kovacs et al. (2018)Urban Climate Australia
Icaza et al. (2016)Sustainability Netherlands
Kingsborough et al. (2017)Climate Risk Management UK
Koop et al. (2017)Water Resources Management Netherlands
Lambert-Habib et al. (2013)Urban Climate France
Lu et al. (2017)Sustainability Taiwan
Mahlkow and Donner (2017)Journal of Planning Education and Research Germany
Mahlkow et al. (2016)Urban Climate Germany
Morawetz and Koemle (2017)Journal of Urban Planning and Development Austria
Quattrochi et al. (2000)Photogrammetric Engineering and Remote
Sensing
USA
Richardson et al. (2009)Canadian Journal of Urban Research Canada
Sailor et al. (2016)Sustainability USA
Stone (2005)Journal of the American Planning Association USA
Zaidi and Pelling (2015)Urban Studies UK
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Only two cities in Asia are represented, with the majority of the studies focusing on
cities in Europe (11), the US (4), and Canada (2). Similar to the full dataset, the
articles are published in many different journals, with only Urban Climate, Sus-
tainability, and Urban Studies containing more than one study. The planning
process studies represent a variety of different disciplines or theoretical frameworks
including urban planning, urban governance, urban climatology, economics, and
political ecology.
4. Common Themes from the Literature on Extreme Heat
Planning Processes
Our in-depth review of the 21 papers that focus on heat planning processes sug-
gests that there are important institutional, policy, technical, and informational
barriers that need to be addressed in order for cities to more effectively plan for
growing heat risks. On a more positive note, the literature seems to largely agree on
what these challenges are, and it is beginning to identify potential strategies to
overcome them.
When it comes to dening the extreme heat challenge, which will naturally
inuence proposed solutions, most studies acknowledge the combined heat threat
posed by climate change and the UHI effect (e.g., Bolitho and Miller 2017;
Guindon and Nirupama 2015;Mahlkow and Donner 2017;Richardson
et al. 2009;Zaidi and Pelling 2015). However, at least one study does not ex-
plicitly refer to climate change (Morawetz and Koemle 2017). A smaller subset of
the papers also emphasize the relationship of the extreme heat risk to indoor
temperatures (Donner et al. 2017;Hatvani-Kovacs et al. 2018;Sailor et al. 2016)
and the relationship between increased temperatures and air quality, specically
ozone levels (Quattrochi et al. 2000;Stone 2005).
4.1. Institutional challenges and opportunities
Almost all of the heat planning process studies identify institutional barriers and
potential strategies for overcoming them. In general, there is a recognized need for
more governance capacityaround extreme heat risk, which is seen as lacking in
comparison to other challenges cities face, including other climate risks (Koop
et al. 2017: 3437).
4.1.1. Breaking down extreme heat planning siloes
One of the most persistent themes across the papers is the recognition that siloes
and fragmented decision-making inhibit effective extreme heat planning and that
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more collaboration, or knowledge integration, is needed across city departments,
levels of government, academic disciplines, and stakeholder groups. Case studies
from cities in Germany (Mahlkow and Donner 2017), Australia (Bolitho and
Miller 2017), and Vietnam (Downes and Storch 2014) all point to the need for
more coordination.
This need for more collaboration begins with extreme heat research. Studying
extreme heat is complex and necessarily involves different disciplines, including
climatology, public health, as well as urban planning (Bolitho and Miller 2017;
Hatvani-Kovacs et al. 2018;Richardson et al. 2009). This means that extreme heat
research must be interdisciplinary (Sailor et al. 2016). Research should also be co-
produced, or the product of close collaborations between urban heat practitioners
and researchers (Mahlkow et al. 2016). This requires that researchers engage with
stakeholders at all stages of the research process ideally iteratively to ensure
that research outputs and information are relevant and get used. As Sailor et al.
(2016: 3) note, a fuller integration of stakeholders throughout the scientic re-
search process is a necessary step to assure that results will be more relevant and
readily implemented by policy-makers.Similarly, Quattrochi and Colleagues
(2000) argue that heat data (e.g., maps identifying hotter areas), plans, and mon-
itoring all need to be undertaken through an iterative process with both stake-
holders and researchers participating.
Much of the literature recognizes that extreme heat planning issues cut across
traditionally separate sectors or planning departments and that more integrative
approaches to addressing heat are needed (Hatvani-Kovacs et al. 2018;Mahlkow
and Donner 2017). As Bolitho and Miller (2017: 687) write:
A demanding issue for policy implementation is the complex
coordination required to ensure the reach of communications and
services to protect vulnerable people. Whilst health has been the
primary area where research and responses have occurred, it is
increasingly recognised that extreme heat cuts across a number of
policy areas, including emergency management, social services,
critical infrastructure, housing, urban planning, and local
government.
Besides nding ways to bring different city departments together, it is also crucial
to increase collaboration between different neighboring local government jur-
isdictions (Sailor et al. 2016) and vertical levels of government (Mahlkow and
Donner 2017). In the case of Berlin, Mahlkow et al. (2016: 276) nd that con-
icting notions of responsibilities and respective endowment with resources be-
tween the district and city level as well as other actors lead to an overall loss of
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potential for strategic risk reduction action.Heat governance is of course not
solely within the purview of governments, thus it is equally important to involve
nongovernmental stakeholders, such as private developers, whose decisions have a
major impact on heat vulnerability (Bolitho and Miller 2017;Dhalluin and
Bozonnet 2015).
4.1.2. Mainstreaming and nding the appropriate planning scales
Related to the issue of siloes, studies recognize the challenge of mainstreaming
urban climate considerations across different city units (Mahlkow and
Donner 2017) and day-to-day processes (Donner et al. 2017). For example,
Mahlkow et al. (2016) see the failure to incorporate the climate impacts of
development into mandatory comprehensive plans as a missed opportunity. They
suggest that a solution might be to create a Climate Commissioner position whose
job it is to coordinate heat issues into different departments and districts (Mahlkow
et al. 2016).
The literature is somewhat divided on the ideal scale for extreme heat planning.
On the one hand, studies recognize that climatic effects of different land use or
policy changes cut across jurisdictional scales, suggesting the need for a more
regional approach (cf. Sailor et al. 2016). On the other hand, studies suggest that
there are signicant microclimates and impacts of many interventions are very
localized so there is a need to address heat at a neighborhood scale (Richardson
et al. 2009). Lambert-Habib et al. (2013) argue that the growing emphasis on
regional planning for sustainability more broadly may be problematic for extreme
heat planning, which they argue needs a much ner-scale focus on microclimates.
This leads us to conclude that extreme heat planning will ultimately need to take a
nested governance approach, working simultaneously across different scales from
the design of microclimates at sites to larger neighborhoods, city, and regional
planning scales.
4.1.3. Legal structures needed for extreme heat planning
Studies identify a number of legal and regulatory barriers to effective extreme heat
planning and propose different strategies for addressing them, either by integrating
heat efforts into existing regulatory frameworks or enacting new policies. Case
studies of French cities suggest that the lack of a national regulatory framework
for urban heat is problematic (Dhalluin and Bozonnet 2015;Lambert-Habib
et al. 2013). Kingsborough et al. (2017) bemoan the fact that Londons only heat-
related legal requirement is to have a plan for heat waves, which as previously
noted is limited in scope (Zaidi and Pelling 2015). Building standards provide a
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potential opportunity for enhancing heat resilience, especially underexamined yet
deadly indoor overheating; however, this is rarely considered (Hatvani-Kovacs
et al. 2018). Even when local climate is a legally protected environmental good, as
in Germany, local plans are already overloadedwith concerns such as soil health,
biodiversity, and noise pollution. This makes it difcult to prioritize heat (Mahlkow
et al. 2016: 274). Stone (2005) argues that ambient heat should be regulated in the
US as an air pollutant, which would provide more support through the Clean Air
Act for regulation and ultimately, resilience. On the heat response side, Bolitho and
Miller (2017) argue that heat should be ofcially recognized as an emergency (i.e.,
heat waves lead to an emergency declaration), which could help focus more
resources and attention on the issue. In short, these legal and regulatory barriers,
spanning local to national governance levels, were similar across all papers.
4.1.4. Acknowledging complexities, different priorities, and limited resources
Another major institutional challenge discussed in many of the studies focuses on
the fact that extreme heat planning must compete for limited time and resources
with numerous other urgent urban issues, some of which are usually seen as higher
priority (Downes and Storch 2014;Mahlkow and Donner 2017;Mahlkow
et al. 2016). For example, Mahlkow et al. (2016) note that in Germany, the top
priorities for urban policy are increasing housing and facilitating investment.
Similarly, Donner et al. (2017)nd that in Berlin, despite available information on
heat-at-risk areas, these considerations are not incorporated into planning processes
because the lack of housing is seen as more important. The suggestion is that to be
effective, planners will need to identify policies that are compatiblewith other
priorities (Icaza et al. 2016: 2). It is also important to acknowledge the complexity
of both urban planning generally, and extreme heat planning specically. Land use
planning inevitably requires balancing many competing priorities and integrating
climate considerations adds to this burden (Donner et al. 2017;Hamilton
et al. 2010). Planning action on extreme heat planning will thus be limited until it
becomes a priority or is seen as complimentary with other community issues such
housing availability.
4.2. Strategies for addressing extreme heat
One of the reasons that extreme heat planning is so complicated is that there are
many different approaches to enhancing heat resilience, or in other words, many
different strategies that could be included in plans. The difculty lies in choosing
from among them, especially as the universal appropriateness and effectiveness of
different strategies continue to be debated. Guindon and Nirupama (2015) divide
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these into two categories: so-called activestrategies that focus on emergency
response and preparedness and passivestrategies that focus on spatial planning
and design. While this categorization is helpful as there is a strong focus within the
literature on spatial planning and design to reduce the UHI effect, we nd this
somewhat contradictory with existing hazard mitigation planning terminology. For
this reason, we will refer to these as extreme heat risk managementand design
of the built environment,hereafter just design,strategies respectively. Examples
of risk management strategies promoted in the reviewed studies include various
warning systems for extreme heat events (Bolitho and Miller 2017;Hatvani-
Kovacs et al. 2018). Some of the most commonly cited heat reduction strategies
include adding vegetation (Dhalluin and Bozonnet 2015;Guindon and
Nirupama 2015;Hamilton et al. 2010;Stone 2005) and increasing the reectivity,
or albedo, of roofs, roads, and other surfaces (Corburn 2009;Hatvani-Kovacs
et al. 2018;Quattrochi et al. 2000;Stone 2005). To be most effective, extreme
heat planning should probably combine these approaches. Indeed, Kingsborough
and colleagues (2017: 74) argue that a range of actions including land-use
planning, building design, community resilience, and emergency planning and
response must be considered together for cities to manage long-term heat-risk.
Focusing rst on the risk management approaches, the studies suggest that there
is a tension between managing heat threats primarily as an emergency as opposed
to a chronic social issue, and policy strategies differ depending on the approach. As
Bolitho and Miller (2017: 685) put it:
The way events and processes are framed has implications for
individual actions and institutional responses. Current policy and
institutional responses reect a tension between framing heat as an
emergency and as a source of chronic stress, and that different
kinds of impacts and responses are prioritised as a result.
Zaidi and Pellings(2015) case study of London nds that the city focuses on heat
specically as a medical emergency, rather than a chronic social issue. Thus,
Londons Heat Wave Plan is implemented through the health department and
healthcare providers, meaning that it is mostly reactive. This excludes other social
care workers, limits awareness of the plan outside the health care sector, and sties
learning and innovation from other perspectives. This focus on reacting to heat as
an emergency is particularly problematic given that several studies recognize the
need to better understand the root or social causes of heat vulnerability (Bolitho
and Miller 2017;Richardson et al. 2009;Zaidi and Pelling 2015). In addition to
understanding what drives vulnerability, there appears to be a lack of research on
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what specicpolicy instrumentsare effective in reducing health risks (Mahlkow
and Donner 2017: 386)
While the literature did not provide much in the way of solutions to address
social factors (e.g., rising inequality or racial inequities) that increase vulnerability
to heat, many of the studies we reviewed analyze and recommend specic planning
and design of the built environment strategies in order to reduce the UHI effect and
its impacts. These design strategies relate to adding vegetation, buildings and urban
infrastructure, and land use and urban form, each of which is described in more
detail below. A consistent theme across these studies is how context-specic these
design strategies are based on climate, geography, urban form, and the different
scales of the built environment. Several papers also acknowledge that it is easier to
plan for these strategies and ensure that they are implemented on public buildings
and land than on privately owned infrastructure. As Mahlkow and Donner (2017:
392) note with respect to vegetation, even though private greening initiatives are
crucial to achieve the goals set by the government, especially on private plots, they
can only be an addition to a publicly planned comprehensive approach to realize a
heat-adapted urban design.
4.2.1. Vegetation
Many of the papers discuss increasing vegetation as a heat resilience design
strategy including urban forestry, green roofs, and parks. For example, multiple
studies propose mandatory green space ratios or requirements for green roofs and
walls (Hatvani-Kovacs et al. 2018;Mahlkow and Donner 2017). Dhalium and
Bozonnet (2015) nd that urban vegetation, including green spaces, facades, and
roofs, is the action most often taken in response to the UHI effect in several cities
in France. In particular, many papers recommend increasing the urban canopy
(Guindon and Nirupama 2015;Hamilton et al. 2010;Kingsborough et al. 2017;
Mahlkow and Donner 2017;Mahlkow et al. 2016;Quattrochi et al. 2000;
Richardson et al. 2009), although treesability to decrease the UHI effect is
context-specic. The two main benets of the urban canopy are increased shade
and evaporative cooling (Richardson et al. 2009). After several sequential com-
munity workshops and models, Corburn (2009) reports that additional tree planting
is the preferred solution to mitigate the UHI effect in the South Bronx area of New
York City, New York, despite uncertainty about their effectiveness after multiple
analyses. Morawetz and Koemle (2017)nd that 92 percent of survey respondents
in Vienna, Austria also preferred additional trees over other potential options, such
as the installation of drinking fountains. Both Sailor et al. (2016) and Mahlkow
et al. (2017) discuss the need for robust maintenance plans and ongoing invest-
ment if vegetation is used as a heat resilience strategy, since, for example, the full
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benets of added canopy cover are not realized until the trees reach maturity. This
is part of a bigger challenge for extreme heat planning, namely that nancial
support for climate adaptation projects are often short-term where many heat-
related strategies need long-term support (Mahlkow et al. 2016). Vegetation
strategies, while one of the most discussed design strategies across the papers, are
also inherently specic to a citys geography and climate, making it difcult to
make generalized recommendations.
4.2.2. Buildings and urban infrastructure
Another common design strategy that the reviewed studies recommend is im-
proved and updated standards for buildings and urban infrastructure. Zaidi and
Pelling (2015) point out that in cities with older housing stock, such as London,
UK, there may be limited capacity for additional greening or land use changes to
mitigate heat, which increases the need for better understanding of building and
urban infrastructure resilience strategies. Another study of London nds that ex-
tensive greening alone is likely not sufcient to address increasing heat risk and
concludes that more widespread adoption of air conditioning will likely be required
(Kingsborough et al. 2017).
4.2.3. Land use and urban form
Hatvani-Kovacs et al. (2018) discuss the increased heat risk posed by newer more
energy-efcient buildings that have higher levels of insulation, yet in the future
heating needs are likely to decrease and cooling needs will increase. This challenge
is also discussed by Dhalliun and Bozonnet (2015), who recommend the instal-
lation of low energy mechanical cooling systems or passive cooling designs to
overcome the overheating of newer buildings. The use of reective and lighter-
colored materials in both buildings and urban infrastructure is another theme
throughout many of the papers, often in the form of reective roofs, lighter streets,
and lighter parking lots (Guindon and Nirupama 2015;Quattrochi et al. 2000;
Stone 2005). Less commonly mentioned design strategies included the installation
of more public drinking fountains, non-vegetated shade structures, and mechanical
pavement humidication to reduce temperatures on the street level (Dhalluin and
Bozonnet, 2015; Lambert-Habib et al. 2013). These strategies could increase
initial construction costs by 515 percent, making the calculation of benets over
the life of the project important (Dhalluin and Bozonnet 2015).
Several papers discuss land use congurations and the design of the urban form
to reduce the UHI effect. Hamilton et al. (2010) recommend that new development
be considered with heat resilience factors including the size of development
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(number of units, oor space, or plan area), location (vulnerable heat risk areas),
energy intensity (high waste heat), and signicant land use changes (loss or ad-
dition of greenspace). Conservation of natural lands, in the form of oases of
freshness,to help ensure that the UHI effect does not drastically increase due to
new development, is also recommended (Lambert-Habib et al. 2013: 17). Several
trends in land use planning are specically recognized for their UHI effect re-
duction benets. Stone (2005) identies efcient land use patterns that decrease
automobile usage, and the waste heat associated with it, as a design strategy.
Several papers also reference the UHI effect reduction benets of smaller parking
lots (Quattrochi et al. 2000;Richardson et al. 2009). Mahlkov et al. (2016) dis-
cuss how urban forms that support walkability and bicycle use increase public
health outcomes, which in itself leads to reduced vulnerability to extreme heat. The
land use strategies discussed in the papers related to reducing the UHI effect are
within the regulatory toolbox of the planning profession and overlap with other
common professional goals such as improved public health outcomes and reduc-
tion of greenhouse gas emissions.
4.2.4. Complexities, trade-offs, and maladaptation
Most papers recognize the need to combine various design strategies to reduce the
UHI effect and complexities related to how these strategies interact. Regardless of
whether a policy is more focused on reducing the UHI effect through design or
managing extreme heat risk, studies suggest that solutions need to be targeted to a
citys unique needs. For example, when considering increased vegetation as a
design strategy, it is important to consider a citys climate and potential temper-
ature and humidity tradeoffs, thus it may not be a universal heat solution (Sailor
et al. 2016). Similarly, when developing heat alerts, they should be customized for
particular social groups (Hatvani-Kovacs et al. 2018). Engaging the public in local
planning processes could help to contextualize these strategies.
There are many potential trade-offs that need to be weighed in heat and broader
climate planning. For example, Sailor (2016) suggests that cool roofs on tall
buildings may reduce the overall UHI effect, but not measurably reduce tem-
peratures at street level. An Australian study by Hatvani et al. (2018) warns that
water conservation efforts may potentially lead to decreases in vegetation and
stymie heat reduction efforts. While only Dhaliun and Bozonnet (2015) specically
refer to the term maladaptation, many papers discuss the vicious cycle whereby
increasing temperatures will lead to more widespread air conditioning as an ad-
aptation, also increasing greenhouse gas emissions and raising temperatures fur-
ther. Strategies that cool buildings and reduce cooling costs in the summer may
also increase heating costs in the winter and vice versa (Sailor et al. 2016).
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Increased density has clear greenhouse gas emissions benets, but denser areas
often have a higher UHI effect. Despite this, the quantity of excess heat generated
per person is often higher in lower density areas (Mahlkow and Donner 2017).
Mahlkov and Donner (2017) also make the point that current energy efciency
efforts often also reduce waste heat, yet are not frequently discussed in terms of
heat mitigation. To that end, while maladaptive strategies are possible, there are
also actions currently being taken for greenhouse gas mitigation efforts that may
also provide unrecognized heat reduction benets.
4.3. Information to inform extreme heat planning
Almost all the studies reviewed discuss challenges and barriers related to infor-
mation for extreme heat planning. Common themes include the need for better
understanding of UHI modeling and mapping, the use of future climate change
scenarios, heat-health risks and vulnerabilities, and quantifying costs and benets.
4.3.1. UHI modeling and mapping
While the majority of papers focused on UHI mapping and modeling were ex-
cluded from this review based on our selection criteria, the use of satellite imagery
for UHI mapping is still the most prevalent heat data source (Corburn 2009;
Dhalluin and Bozonnet 2015;Hatvani-Kovacs et al. 2018;Icaza et al. 2016;Lu
et al. 2017;Mahlkow and Donner 2017;Quattrochi et al. 2000;Richardson
et al. 2009). In these cases, UHI mapping is developed through a combination of
satellite imagery and land-cover models to display a thermal gradient showing
temperature differences. These UHI maps are useful for an overview of landscape
patterns and heat differences (Icaza et al. 2016) and can be used to identify areas
with higher heat risk for extreme heat planning interventions (Hatvani-Kovacs
et al. 2018;Quattrochi et al. 2000).
Other papers urge the appropriate use of UHI mapping in planning, as heat is
highly temporal and spatially diverse (Corburn 2009;Icaza et al. 2016;Mahlkow
et al. 2016). Mahlkow and Donner (2017) argue that the low resolution of many
UHI maps limits their practical usability, and Dhalluin and Bozonnet (2015) rec-
ommend improved mapping at both the city and neighborhood scale. Corburn
(2009: 419) also points out the importance of other heat data sources such as,
near-surface temperature, or the temperature at 2 m above the ground in the
human breathing zone, rather than just the surface temperature.Sailor et al. (2016:
10) further recommends that research focus on additional parameters, such as
humidity, mixing heights, and urban wind elds.The complexities of measuring
heat, whether via satellite imagery or ambient air temperature readings, can make it
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difcult for decision-makers to use the information. Two of the papers note the
particular need for more UHI mapping data in mid-latitude and temperate cities
(Koop et al. 2017;Mahlkow et al. 2016). Koop et al. (2017: 3437) argue that
northern cities such as Amsterdam may face more risk to extreme heat as they have
fewer adaptations to it, such as air conditioning. While the papers reviewed
demonstrated the growing sophistication in UHI modeling and mapping, im-
proving the understanding of how the maps and models are used by decision-
makers was not well covered.
4.3.2. Climate change projections
In contrast to the prevalence of UHI modeling and mapping, fewer papers examine
the use of climate change projections to guide extreme heat planning. The fact that
policymakers rely on previous experiences, rather than climate change projections,
means that scientic information is not well integrated into the decision-making
process (Lu et al. 2017: 12). Mahlkow et al. (2016) also report that planning is
most often focused on responding to historic conditions and past experiences,
making incorporating projections of future conditions difcult. Richardson et al.
(2009) reason that communities need to incorporate climate projections into plans
in order to appropriately prepare for future temperature increases. When discussing
international building standards, Hatvani-Kovacs et al. (2018: 56) conclude that
To design and build sustainable buildings that can withstand the test of time,
historical climate data should be replaced with modeled future climate data.The
focus on historic conditions and past experiences could leave communities
approaching new climate thresholds unprepared for unprecedented extreme heat
impacts.
4.3.3. Heat-health risks and vulnerabilities
The papers also identify a lack of information on heat-health risks and vulner-
abilities for extreme heat planning. While UHI maps and models provide a spatial
approximation for areas of heat risk, many factors affect exposure, so it is difcult
to implement strategies based on spatial data alone (Mahlkow and Donner 2017).
Several papers recommend assessing additional contributors to heat stress beyond
spatially identifying areas of high vulnerability on UHI maps (Donner et al. 2017;
Mahlkow and Donner 2017;Zaidi and Pelling 2015). The fact that little is known
of the interactions between health, infrastructure, and social factors, and between
emergency and chronic experiences of extreme heat,further complicates under-
standings of heat-health risks (Bolitho and Miller 2017: 685). Zaidi and Pelling
(2015) also note that typical ways of measuring heat resilience focus on spatial
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mapping and do not capture social variables, individual perceptions, and social
networks. They go further and state that, The spatially, temporally and socially
diffuse distribution of vulnerability to urban heat waves is not easy to reconcile
with traditional vulnerability assessment approaches that frequently rely on sec-
ondary information derived from census data sets(Zaidi and Pelling 2015: 1221).
Richardson et al. (2009: 77) recommend three questions that planners need to
address to reduce heat-health risk, How do UHIs form and what can be done to
reduce their frequency and severity? What measures may be used to keep people
away from areas prone to dangerous UHIs? What factors contribute to human
vulnerability to heat and what can be done to fortify peoples ability to withstand
heat stress?The lack of information on heat-health risks and vulnerabilities
contributes to the higher risk that marginalized communities in particular face
related to extreme heat impacts.
4.3.4. Quantifying costs and benets
Another information need identied in several papers is the quantication of costs
and benets of heat mitigation strategies. Interviews with key stakeholders in
several French cities in the Dhalluin and Bozonnet (2015: 296) study reveal that
interviewees reported difculty in quantifying UHI effect mitigation benets,
leading to uncertainty over how to prioritize strategies. Both Richardson et al.
(2009) and Kingsborough et al. (2017) also discuss the lack of quantication of
costs and benets for specic adaptation actions. Another theme is the lack of
strategies in place for planners to monitor changes in the UHI effect due to new
development. A study of a Southern Taiwan Science Park, for example, identies
strategies to monitor changes in ooding with construction but recognizes that
planners have no information or tools available to monitor similar changes in the
UHI effect (Lu et al. 2017: 10). Hamilton et al. (2010) similarly point to limited
knowledge on how new development increases the UHI effect and what building
types should be recommended to reduce heat. These ndings are not surprising
given the nascent stage of planning for extreme heat, but could limit efforts to
increase heat resilience if decision-makers do not know the costs and benets of
their actions.
4.3.5. Awareness and expertise
Several studies suggest that decision-makers lack the necessary training for
extreme heat planning. Planners need to know how to interpret satellite imagery as
the maps and the information they display is not straightforward,(Icaza
et al. 2016: 6). Hatvani-Kovacs et al. (2018: 52) nd that Current knowledge is
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incomplete about the means through which to develop a policy to implement heat
stress resistance in building regulations.It is also not always clear who the actual
end-user of the information is and thus what extreme heat planning tool should be
used (Hamilton et al. 2010). Similarly, Donner et al. (2017)nd that despite the
availability of heat information, the stakeholders they interviewed did not know
how to incorporate the data into their daily activities. Dhalluin and Bozonnet
(2015: 295) also nd that stakeholders involved in the development of retirement
and nursing homes in several cities in France were largely unaware of extreme heat
impacts on their projectsresidents and heat-related adaptation measures happen-
ing in their city. Complicating matters further, heat risk is typically a lower priority
than disruptive disasters like ooding that receive more interest than gradual
changes in temperature (Lu et al. 2017: 12). As previously noted, this lack of
concern and awareness hinders extreme heat from being addressed in relation to
other pressing planning issues (Donner et al. 2017). This suggests a need for im-
proved awareness and education on extreme heat planning across the spectrum of
disciplines associated with it and the broader public that must live with heat impacts.
4.3.6. Potential solutions
Anal key theme across the papers acknowledges that the extreme heat infor-
mation being produced is not always useful for decision-makers. Koop et al.
(2017: 3439) state that, existing knowledge often fails to provide applicable
insights that can help decision-makers achieve their intended goals and objec-
tives,and Downes and Storch (2014: 232) conclude that, A lack of information
has resulted in a failure to identify and implement policies and measures to address
the risks posed.To help increase the production or translation of more usable
extreme heat information for planning purposes, studies offer several recommen-
dations and possible solutions, such as adaptation pathways (Kingsborough
et al. 2017); constellation analysis (Mahlkow et al. 2016); and creative mapping
processes (Icaza et al. 2016). Corburn (2009: 425) recommends the co-production
of climate science, suggesting that it offers a framework for regulatory science or
science policy that: crosses disciplinary lines; enters into previously unknown
investigative territories; requires the deployment of new methods, instruments,
protocols, and experimental systems; and involves politically sensitive processes
and results.Kingsborough et al. (2017) demonstrate that the use of adaptation
pathways could be a useful framework to approach the complex trade-offs involved
in extreme heat planning. Dhalliun and Bozonnet (2015) recommend the devel-
opment of more practical heat mitigation guides aimed at various professions
involved in building and suggest that successful energy savings programs could
serve as a template for UHI effect mitigation programs. Research guided by the
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decision-maker needs identied in our review would help advance heat resilience
planning.
5. Conclusion
Extreme heat is already one of the deadliest hazards and the threat is worsening in
cities worldwide because of the combined impacts of climate change and the UHI
effect. It is therefore increasingly critical to effectively plan for extreme heat re-
silience. Our systematic literature review of extreme heat planning to our
knowledge the rst such effort has shown that while there is a signicant and
growing literature that connects extreme heat and planning, the vast majority of
these studies (68 percent) are focused on modeling as opposed to planning pro-
cesses. These modeling studies often suggest that their results can be used to
inform planning but provide a limited discussion of how this would work in
practice or with the many constraints planners face. We identied just 21 studies
that focused on extreme heat planning processes, which we then reviewed in depth.
This analysis revealed common themes related to institutional barriers and
opportunities, different risk management and design strategies, and informational
gaps for extreme heat planning.
Institutionally, extreme heat planning in both practice and research is chal-
lenging because it requires different disciplines, government departments, levels of
government, and stakeholders to all collaborate. Traditional siloed governance is a
barrier to the knowledge integration needed for effective management of extreme
heat risk and reduction of the UHI effect.
Research also suggests that it is important to mainstream extreme heat con-
siderations into relevant departments and planning processes. This includes cre-
ating a legal or regulatory basis for extreme heat risk management and UHI effect
reduction, which is currently lacking when compared to other climate risks such as
ooding. Mainstreaming is especially important because planners must juggle
many conicting priorities, and extreme heat is frequently not perceived as an
urgent issue.
To further complicate matters, there are many different proposed strategies for
increasing extreme heat resilience. We divide these into extreme heat risk man-
agementstrategies that focus on preparing for and responding to extreme heat
events, and design of the built environmentstrategies that use spatial planning
and design to intentionally cool the urban environment and reduce the UHI effect.
We found more studies focused on the latter, with recommendations including
increased vegetation, updated building standards, and land use patterns that in-
corporate extreme heat considerations. This tendency to focus on technological
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and material solutionsas opposed to addressing social inequities to enhance heat
resilience ts with broader critiques of the current shift toward climate urbanism
(Long and Rice 2019: 994). Also, while there is a growing literature on climate
justice (e.g., Schlosberg and Collins 2014;Shi et al. 2016), this was not a focus of
the heat planning literature. Where inequities were discussed, they were usually
framed around vulnerability and vulnerable populations. Ultimately, a combination
of both risk management and design strategies are needed, but a key challenge is
how to customize the suite of strategies to each citys unique physical and social
context and negotiate trade-offs. Indeed, decision-making for heat resilience, like
planning for sustainability more generally, means nding some balance between
conicting goals: economy, environment, and equity (Campbell 1996).
Selecting the appropriate strategies for a particular city requires considerable
information, including ne-grained UHI maps and models, future climate sce-
narios, socio-demographic data, and the costs and benets of different strategies.
Decision-makers often lack this information, and even if it does exist, they may not
have the time or expertise to interpret and use it. More co-produced research might
help to address this gap between modeling research and practice. Extreme heat
varies by city and is spatially and temporally complex within particular sites in the
same city. Extreme heat is also less visible than other hazards, such as ooding,
which makes it challenging to raise awareness of the risk. UHI mapping is the most
visual method to identify areas most vulnerable to extreme heat risk, but UHI
mapping does not capture all the actual complexities of the risk. Additional cultural
and economic characteristics and local perceptions of extreme heat that inuence
vulnerability and must be considered as strategies are weighed (Sampson
et al. 2013;Wilhelmi and Hayden 2010).
Despite the challenges, we argue that planners are well situated to play a leading
role in advancing extreme heat resilience. That extreme heat currently has no
problem owner(Klok and Kluck 2018) has been identied as the most im-
portant barrier to action,(Runhaar et al. 2012: 786). First, planners have a history
and professional expertise in working across disciplines (Levy 2016). Second,
planning as a profession is committed to enhancing the health and safety of
communities (Corburn 2007). This commitment is part of the stated mission of the
American Planning Association, which also formally recognizes the threat of cli-
mate change and the need for planners to address it (Meerow and Woodruff 2019).
Third, the regulatory tools that planners have at their disposal (e.g., long-range
plans, zoning, land use regulations, and building codes) play an important role in
shaping land use and urban form (Kaiser and Godschalk 1995), which are key
factors in reducing the magnitude of the UHI effect. While public participation was
not a major theme across the papers reviewed, the planning professions expertise
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at engaging the public and elevation of local knowledge (Fischer, 2000) could
better contextualize geographic and climate-specic extreme heat strategies. En-
gaging stakeholders in heat-related policies has been shown to improve outcomes
(Akompab et al. 2013). Moreover, current planning ideals such as increased
density and walkability may simultaneously affect, and be impacted by,
changing local climates.
Future research can help planners meet these challenges, and our review reveals
several promising avenues. First and foremost, there is a clear need for more
studies of extreme heat planning processes including public participation, not just
modeling the risk or urban form and design factors. Given the fact that extreme
heat is currently impacting public health and well-being around the world, research
outputs need to be useful for decision-makers. This suggests that planners and
urban climatologists need to work together (Hebbert and Mackillop 2013).
Moreover, while this study focuses on planning, we recognize that it is just one
part of broader extreme heat governance, which necessarily involves other elds
such as public health professionals and engineers. Our review has clearly dem-
onstrated that extreme heat planning is complex and challenging. Future empirical
work needs to examine what institutional and policy approaches actually lead to
increased heat resilience in different cities. In particular, research should address
unresolved questions such as, what is the most appropriate scale for extreme heat
planning? What institutional structures facilitate collaboration? What is the right
balance between strategies that manage or reduce extreme heat? What type and
format of information are most useful for decision-makers? Answering these
questions can help cities to increase extreme heat resilience, improve quality of
life, and save lives.
References
Akompab, DA, Bi P, Williams S, Saniotis A, Walker IA and Augoustinos M (2013).
Engaging stakeholders in an adaptation process: Governance and institutional
arrangements in heat-health policy development in Adelaide, Australia. Mitigation
and Adaptation Strategies for Global Change, 18(7): 10011018.
APA (2018). Drought Planning in a Multihazards Context Survey Report.
Archambault, É and Lariviere V (2010). The limits of bibliometrics for the analysis of the
social sciences and humanities literature. In: World Social Science Report Knowl-
edge: Knowledge Divides. Paris: UNESCO Publishing et International Social
Science Council, pp. 251254.
Berisha, V, Hondula D, Roach M, White JR, McKinney B, Bentz D, Mohamed A,
Uebelherr J and Goodin K (2017). Assessing adaptation strategies for extreme heat:
A public health evaluation of cooling centers in Maricopa County, Arizona. Weather,
Climate, and Society, 9(1): 7180.
L. Keith, S. Meerow & T. Wagner
2050003-22
J. of Extr. Even. Downloaded from www.worldscientific.com
by 72.217.50.169 on 11/24/20. Re-use and distribution is strictly not permitted, except for Open Access articles.
Bernard, SM and McGeehin MA (2004). Municipal heat wave response plans. American
Journal of Public Health, 94(9): 15201522.
Bolitho, A and Miller F (2017). Heat as emergency, heat as chronic stress: Policy and
institutional responses to vulnerability to extreme heat. Local Environment, 22(6):
682698.
Bouchama, A, Dehbi M, Mohamed G, Matthies F, Shoukri M and Menne B (2007).
Prognostic factors in heat wave Related deaths. Archives of Internal Medicine,
167(20): 21702176.
Campbell, S (1996). Green cities, growing cities, just cities?: Urban planning and the
contradictions of sustainable development. Journal of the American Planning
Association, 62(3): 296312.
Chow, WTL, Chuang WC and Gober P (2012). Vulnerability to extreme heat in metro-
politan phoenix: Spatial, temporal, and demographic dimensions. Professional
Geographer, 64(2): 286302.
Corburn, J (2007). Reconnecting with our roots: American urban planning and public
health in the twenty-rst century. Urban Affairs Review, 42(5): 688713.
Corburn, J (2009). Cities, climate change and urban heat island mitigation: Localising
global environmental science. Urban Studies, 46(2): 413427.
Coseo, P and Larsen L (2014). How factors of land use/land cover, building conguration,
and adjacent heat sources and sinks explain Urban Heat Islands in Chicago. Land-
scape and Urban Planning, 125: 117129.
CRED (2011). 2010 Disaster in Numbers.
DIppoliti, D, Michelozzi P, Marino C, DeDonato F, Menne B, Katsouyanni K, Kirch-
mayer U, Analitis A, Medina-Ramón M, Paldy A, Atkinson R, Kovats S, Bisanti L,
Schneider A, Lefranc A, Iñiguez C and Perucci CA (2010). The impact of heat waves
on mortality in 9 European cities: Results from the EuroHEAT project. Environ-
mental Health: A Global Access Science Source, 9(1): 19.
Davis, RE, Knappenberger PC, Michaels PJ and Novicoff WM (2003). Changing heat-
related mortality in the United States. Environmental Health Perspectives, 111(14):
17121718.
Dhalluin, A and Bozonnet E (2015). Urban heat islands and sensitive building design
A study in some French citiescontext. Sustainable Cities and Society, 19: 292299.
Dobney, K, Baker CJ, Chapman L and Quinn AD (2010). The future cost to the United
Kingdoms railway network of heat-related delays and buckles caused by the pre-
dicted increase in high summer temperatures owing to climate change. Proceedings
of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid
Transit, 224(1): 2534.
Donner, J, Sprondel NF and Köppel J (2017). Climate change adaptation to heat risk at the
local level: A Bayesian network analysis of local land-use plan implementation.
Journal of Environmental Assessment Policy and Management, 19(2): 129.
Downes, NK and Storch H (2014). Current constraints and future directions for risk
adapted land-use planning practices in the high-density Asian setting of Ho Chi
Minh City. Planning Practice and Research, 29(3): 220237.
EPA (2006). Excessive Heat Events Guidebook in Brief.
Golany, G (1983). Design for Arid Regions. Van Nostrand Reinhold Company.
Planning for Extreme Heat
2050003-23
J. of Extr. Even. Downloaded from www.worldscientific.com
by 72.217.50.169 on 11/24/20. Re-use and distribution is strictly not permitted, except for Open Access articles.
Golden, JS (2004). The built environment induced urban heat island effect in rapidly
urbanizing arid regions A sustainable urban engineering complexity. Environ-
mental Sciences, 1(4): 321349.
Good, EJ (2016). An in situ-based analysis of the relationship between land surface skin
and screen-level air temperatures. Journal of Geophysical Research: Atmospheres,
121(15): 88018819.
Guhathakurta, S and Gober P (2007). The impact of the Phoenix urban heat Island
on residential water use. Journal of the American Planning Association, 73(3):
317329.
Guindon, SM and Nirupama N (2015). Reducing risk from urban heat island effects in
cities. Natural Hazards, 77(2): 823831.
Hamilton, IG, Davies M and Gauthier S (2010). Londons urban heat island: A multi-
scaled assessment framework. Proceedings of the Institution of Civil Engineers,
166(3): 3334.
Hansen, A, Bi P, Nitschke M, Ryan P, Pisaniello D and Tucker G (2008). The effect of
heat waves on mental health in a temperate Australian City. Environmental Health
Perspectives, 116(10): 13691375.
Hatuka, T and Saaroni H (2014). The need for advocating regional human comfort design
codes for public spaces: A case study of a Mediterranean urban park. Landscape
Research, 39(3): 287304.
Hatvani-Kovacs, G, Bush J, ShariE and Boland J (2018). Policy recommendations to
increase urban heat stress resilience. Urban Climate, 25: 5163.
Hebbert, M and Mackillop F (2013). Urban climatology applied to urban planning: A
postwar knowledge circulation failure. International Journal of Urban and Regional
Research, 37(5): 15421558.
Hondula, DM, Davis RE, Saha MV, Wegner CR and Veazey LM (2015). Geographic
dimensions of heat-related mortality in seven U.S. cities. Environmental Research,
138: 439452.
Howard, L (1818). The Climate of London: Deduced from Meteorological Observations,
Made in the Metropolis, and at Various Places around it, 2nd edn., Vol. 1 (Harvey
and Darton, London), p. 348.
Icaza, LE, Van Den Dobbelsteen A and Van Der Hoeven F (2016). Integrating urban heat
assessment in urban plans. Sustainability, 8(4): 320.
IPCC (2014). Climate Change 2014 Synthesis Report Summary Chapter for Policymakers.
Jenkins, K, Gilbey M, Hall J, Glenis V and Kilsby C (2014). Implications of climate
change for thermal discomfort on underground railways. Transportation Research
Part D: Transport and Environment, 30: 19.
Kaiser, EJ and Godschalk DR (1995). Twentieth century land use planning: A Stalwart
family tree. Journal of the American Planning Association, 61(3): 365385.
Kaloustian, N, Bitar H and Diab Y (2016). Urban heat island and urban planning in Beirut.
Procedia Engineering, 169, 7279.
Kingsborough, A, Jenkins K and Hall JW (2017). Development and appraisal of long-term
adaptation pathways for managing heat-risk in London. Climate Risk Management,
16: 7392.
L. Keith, S. Meerow & T. Wagner
2050003-24
J. of Extr. Even. Downloaded from www.worldscientific.com
by 72.217.50.169 on 11/24/20. Re-use and distribution is strictly not permitted, except for Open Access articles.
Kleerekoper, L, Van Esch M and Salcedo TB (2012). How to make a city climate-proof,
addressing the urban heat island effect. Resources, Conservation and Recycling, 64:
3038.
Klok, L and Kluck J (2018) Reasons to adapt to urban heat (in the Netherlands). Urban
Climate, 23: 342351.
Koop, SHA, Koetsier L, Doornhof A, Reinstra O, Van Leeuwen CJ, Brouwer S, Dieperink
C and Driessen PPJ (2017). Assessing the governance capacity of cities to address
challenges of water, waste, and climate change. Water Resources Management,
31(11): 34273443.
Kovats, RS and Hajat S (2008). Heat stress and public health: A critical review. Annual
Review of Public Health, 29(1): 4155.
Lambert-Habib, ML, Hidalgo J, Fedele C, Lemonsu A and Bernard C (2013). How is
climatic adaptation taken into account by legal tools? Introduction of water and
vegetation by French town planning documents. Urban Climate,4:1634.
Levy, JM (2016). Contemporary Urban Planning. Taylor & Francis.
Long, J and Rice JL (2019). From sustainable urbanism to climate urbanism. Urban
Studies, 56(5): 9921008.
Lu, P, Shen YT and Lin TH (2017). Environmental risks or costs? Exploring ooding and
the urban heat Island effect in planning for policymaking: A case study in the
Southern Taiwan Science Park. Sustainability, 9(12): 2239.
Luber, G and McGeehin M (2008). Climate change and extreme heat events. American
Journal of Preventive Medicine, 35(5): 429435.
Magli, S, Lodi C, Lombroso L, Muscio A and Teggi S (2015). Analysis of the urban heat
island effects on building energy consumption. International Journal of Energy and
Environmental Engineering, 6(1): 9199.
Mahlkow, N and Donner J (2017). From planning to implementation? The role of climate
change adaptation plans to tackle heat stress: A case study of Berlin, Germany.
Journal of Planning Education and Research, 37(4): 385396.
Mahlkow, N, Lakes T, Donner J, Köppel J and Schreurs M (2016). Developing storylines
for urban climate governance by using constellation analysis Insights from a case
study in Berlin, Germany. Urban Climate, 17: 266283.
Meerow, S and Woodruff S (2019). Seven principles for strong climate change planning.
Journal of the American Planning Association, 86(1): 3946.
Mees, HL, Driessen PP and Runhaar HA (2015). Coolgovernance of a hotclimate
issue: Public and private responsibilities for the protection of vulnerable citizens
against extreme heat. Regional Environmental Change, 15(6): 10651079.
Memon, RA, Leung DYC and Chunho L (2008). A review on the generation, determi-
nation and mitigation of urban heat island. Journal of Environmental Sciences, 20(1):
120128.
Morawetz, UB and Koemle DBA (2017). Contingent valuation of measures against urban
heat: Limitations of a frequently used method. Journal of Urban Planning and
Development, 143(3): 111.
Nordgren, J, Stults M and Meerow S (2016). Supporting local climate change adaptation:
Where we are and where we need to go. Environmental Science & Policy, 66:
344352.
Planning for Extreme Heat
2050003-25
J. of Extr. Even. Downloaded from www.worldscientific.com
by 72.217.50.169 on 11/24/20. Re-use and distribution is strictly not permitted, except for Open Access articles.
ONeill, MS, Carter R, Kish JK, Gronlund CJ, White-Newsome JL, Manarolla X, Zano-
betti A and Schwartz JD (2009). Preventing heat-related morbidity and mortality:
New approaches in a changing climate. Maturitas, 64(2): 98103.
Oke, TR (1973). City size and the urban heat island. Atmospheric Environment, 7(8):
769779.
Pal, JS and Eltahir EAB (2016). Future temperature in southwest Asia projected to exceed
a threshold for human adaptability. Nature Climate Change, 6(2): 197200.
Plate, EJ (2002). Flood risk and ood management. Journal of Hydrology, 267(12): 211.
Quattrochi, DA, Luvall JC, Rickman DL, Estes Jr MG, Laymon CA and Howell BF
(2000). A decision support information system for urban landscape management
using thermal infrared data. Photogrammetric Engineering and Remote Sensing,66
(10): 11951207.
Reid, CE, ONeill MS, Gronlund CJ, Brines SJ, Brown DG, Diez-Roux AV and Schwartz J
(2009). Mapping community determinants of heat vulnerability. Environmental
Health Perspectives, 117(11): 17301736.
Richardson, GRA, Otero J, Lebedeva J and Chan CF (2009). Developing climate change
adaptation strategies: A risk assessment and planning tool for urban heat islands in
Montreal. Canadian Journal of Urban Research, 18(1): 7493.
Robine, JM, Cheung SLK, Le Roy S, Van Oyen H, Grifths C, Michel JP and Herrmann
FR (2008). Death toll exceeded 70,000 in Europe during the summer of 2003.
Comptes Rendus Biologies, 331(2): 171178.
Runhaar, H et al. (2012). Adaptation to climate change-related risks in Dutch urban areas:
Stimuli and barriers. Regional Environmental Change, 12(4): 777790.
Sailor, D, Shepherd M, Sheridan S, Stone B, Kalkstein L, Russell A, ... Andersen T
(2016). Improving heat-related health outcomes in an urban environment with sci-
ence-based policy. Sustainability, 8(10): 113.
Sampson, NR, Gronlund CJ, Buxton MA, Catalano L, White-Newsome JL, Conlon KC,
ONeill MS, McCormick S and Parker EA (2013). Staying cool in a changing
climate: Reaching vulnerable populations during heat events. Global Environmental
Change, 23(2): 475484.
Santamouris, M, Cartalis C, Synnefa A and Kolokotsa D (2015). On the impact of urban
heat island and global warming on the power demand and electricity consumption of
buildings A review. Energy and Buildings, 98, 119124.
Schanze, J (2007). Flood risk management A basic framework. In: Flood Risk Man-
agement: Hazards, Vulnerability and Mitigation Measures. Netherlands: Springer,
pp. 120.
Schlosberg, D and Collins LB (2014). From environmental to climate justice: Climate
change and the discourse of environmental justice. Wiley Interdisciplinary Reviews:
Climate Change, 5(3): 359374.
Shi, L, Chu E, Anguelovski I, Aylett A, Debats J, Goh K, Schenk T, Seto KC, Dodman D,
Roberts D, Roberts JT and VanDeveer SD (2016). Roadmap towards justice in urban
climate adaptation research. Nature Climate Change, 6(2): 131137.
Solecki, WD, Rosenzweig C, Parshall L, Pope G, Clark M, Cox J and Wiencke M (2005).
Mitigation of the heat island effect in urban New Jersey. Environmental Hazards,
6(1): 3949.
L. Keith, S. Meerow & T. Wagner
2050003-26
J. of Extr. Even. Downloaded from www.worldscientific.com
by 72.217.50.169 on 11/24/20. Re-use and distribution is strictly not permitted, except for Open Access articles.
Stone Jr B (2005). Urban heat and air pollution: An emerging role for planners in the
climate change debate. Journal of the American Planning Association, 71(1): 1325.
Stone Jr B, Vargo J, Liu P, Hu Y and Russell A (2013). Climate change adaptation through
urban heat management in Atlanta, Georgia. Environmental Science & Technology,
47(14): 77807786.
Stone, B and Rodgers MO (2001). Urban form and thermal efciency: How the design of
cities inuences the urban heat island effect. Journal of the American Planning
Association, 67(2): 186198.
Tollefson, J (2018). China declared largest source of research articles. Nature, 553(7689):
390.
Vek Alp, A (1991). Vernacular climate control in desert architecture. Energy and
Buildings, 16(34): 809815.
Watts, N, Amann M, Arnell N, Ayeb-Karlsson S, Belesova K, Berry H, Bouley T, Boykoff
M, Byass P, Cai W, Campbell-Lendrum D, Chamber J, Daly M, Dasandi N, Davies
M, Depoux A, Dominguez-Salas P, Drummond P, Ebi KL, Ekins P, Montoya LF,
Fischer H, Georgeson L, Grace D, Graham H, Hamilton I, Peña SH, Hess J, Kelman
I, Kiesewetter G, Kjellstrom T, Kniveton D, Lemke B, Liang L, Lott M, Lowe R,
Sewe MO, Martinez-Urtaza J, Maslin M, McAllister L, Mikhaylov SJ, Milner J,
Moradi-Lakeh M, Morrissey K, Murray K, Nilsson M, Neville T, Oreszcyn T, Ow
F, Pearman O, Pencheon D, Pye S, Rabbaniha M, Robinson E, Rocklöv J, Saxer O,
Schütte S, Semenza JC, Shumake-Guillemot J, Steinbach R, Tabatabaei M, Tomei J,
Trinanes J, Wheeler N, Wilkinson P, Gong P, Montgomery H and Costello A (2018).
The 2018 report of the Lancet Countdown on health and climate change: Shaping the
health of nations for centuries to come. The Lancet, 392(10163): 24792514.
Wilhelmi, OV and Hayden MH (2010). Connecting people and place: A new framework
for reducing urban vulnerability to extreme heat. Environmental Research Letters,
5(1): 014021.
Xiao, Y and Watson M (2017). Guidance on conducting a systematic literature review.
Journal of Planning Education and Research, 39(1), 93112.
Zaidi, RZ and Pelling M (2015). Institutionally congured risk: Assessing urban
resilience and disaster risk reduction to heat wave risk in London. Urban Studies,
52(7): 12181233.
Zander, KK, Botzen WJW, Oppermann E, Kjellstrom T and Garnett ST (2015). Heat stress
causes substantial labour productivity loss in Australia. Nature Climate Change,
5(7): 647651.
Planning for Extreme Heat
2050003-27
J. of Extr. Even. Downloaded from www.worldscientific.com
by 72.217.50.169 on 11/24/20. Re-use and distribution is strictly not permitted, except for Open Access articles.
... There were no clear patterns among plans that did not mention heat. However, a recent national survey found that small and mid-sized cities were less likely to have planning staff devoted to heat (Keith et al 2020). Our study only examined large cities, so we were unable to confirm disparities based on city-size. ...
... If heat was framed as a particular problem, the two most prevalent heat framings in our study were UHI and EHE, in alignment with peer reviewed literature recently summarized by Keith et al (2020). Scientific perspectives are shifting, for instance, skepticism that UHI is relevant to local planning compared to paradigms such as Local Climate Zones that take into account a variety of land morphology features (Stewart and Oke 2012, Martilli et al 2020, Venter et al 2021, Turner et al 2022, Wang 2022. ...
... UHI, on the other hand, was associated with hard interventions but not soft, and appeared in most general plans (more often than EHE). This finding supports the observation that two, distinct heat governance systems emerge-heatas-hazard and heat-as-land-planning-that emphasize acute and chronic aspects of heat separately (Keith et al 2020). This finding underscores the need for integrated planning across the two domains . ...
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Heat has become a central concern for cities everywhere, but heat governance has historically lagged behind other climate change hazards. This study examines 175 municipal plans from the 50 most populous cities in the United States to understand which aspects of urban heat are included or not in city plans and what factors explain inclusion. We find that a majority of plans mention heat, but few include strategies to address it and even fewer cite sources of information. The term “Extreme Heat Event” (EHE) is significantly more likely to be paired with institutional actions as a part of hazard planning, while “Urban Heat Island” (UHI) is more likely to be paired with green and grey infrastructure interventions as a part of general planning. Disparity and thermal comfort framings are not significantly related to any solutions and are used least. Plan type, followed by environmental networks (e.g, C40, Urban Sustainability Directors Network, Rockefeller 100 Resilient Cities), explain variation in plan content; social and environmental context do not. Findings point to the emergence of two independent heat governance systems, EHE and UHI, and several gaps in heat planning: integration, specificity, solutions, disparity, economy, and thermal comfort.
... Despite the growing threat of heat, effective approaches to alleviate urban heat do exist. These include risk mitigation strategies designed to facilitate institutional response during extreme heat events, such as heat alerts, as well as strategies that focus on reducing urban temperatures through measures such as increasing vegetative cover and nature-based solutions, improving building standards, and increasing access to air conditioning (Escobedo et al., 2019;Keith et al., 2020). Air conditioning access is an effective approach for regulating heat and subsequently protecting health, but it is not a sustainable practice in its current form because it generates climatechanging emissions and is often prohibitively costly for lowincome households (Barreca et al., 2016). ...
... Air conditioning access is an effective approach for regulating heat and subsequently protecting health, but it is not a sustainable practice in its current form because it generates climatechanging emissions and is often prohibitively costly for lowincome households (Barreca et al., 2016). Tree planting is a welldocumented heat mitigation strategy that has received increased investment in a growing number of cities around the world (Keith et al., 2020;Esperon-Rodriguez et al., 2022). Investments to increase UTC are understood to provide a range of co-benefits to urban communities such as: reduced urban heat through shading and evapotranspiration; reduced energy demand; carbon sequestration; improved air quality; improved water quality and supply through stormwater runoff management; provision of wildlife habitat; enhanced community cohesion; and improved human health and wellbeing (United States Environmental Protection Agency, 2011;Escobedo et al., 2019). ...
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Extreme heat in the United States is a leading cause of weather-related deaths, disproportionately affecting low-income communities of color who tend to live in substandard housing with limited indoor cooling and fewer trees. Trees in cities have been documented to improve public health in many ways and provide climate regulating ecosystem services via shading, absorbing, and transpiring heat, measurably reducing heat-related illnesses and deaths. Advancing “urban forest equity” by planting trees in marginalized neighborhoods is acknowledged as a climate health equity strategy. But information is lacking about the efficacy of tree planting programs in advancing urban forest equity and public wellbeing. There is a need for frameworks to address the mismatch between policy goals, governance, resources, and community desires on how to green marginalized neighborhoods for public health improvement—especially in water-scarce environments. Prior studies have used environmental management-based approaches to evaluate planting programs, but few have focused on equity and health outcomes. We adapted a theory-based, multi-dimensional socio-ecological systems (SES) framework regularly used in the public health field to evaluate the Tree Ambassador, or Promotor Forestal , program in Los Angeles, US. The program is modeled after the community health worker model—where frontline health workers are trusted community members. It aims to address urban forest equity and wellbeing by training, supporting, and compensating residents to organize their communities. We use focus groups, surveys, and ethnographic methods to develop our SES model of community-based tree stewardship. The model elucidates how interacting dimensions—from individual to society level—drive urban forest equity and related public health outcomes. We then present an alternative framework, adding temporal and spatial factors to these dimensions. Evaluation results and our SES model highlight drivers aiding or hindering program trainees in organizing communities, including access to properties, perceptions about irrigation responsibilities, and lack of trust in local government. We also find that as trainee experience increases, measures including self- and collective efficacy and trust in their neighbors increase. Findings can inform urban forestry policy, planning, and management actions at the government and non-profit levels that aim to increase tree cover and reduce heat exposure in marginalized communities.
... Such environmental injustice amplifies inequities, including inequitable exposure to extreme heat and limited resources to deal with such exposures (Hoffman's, 2017;Hoffman et al., 2020;Hsu et al., 2021). While the body of literature on extreme heat and health continues to grow alongside global temperatures, there's more to do to raise awareness and to substantively adjust public investments to be more inclusive of heat mitigation and adaptation strategies (Keith et al., 2019). ...
... Although flooding continues to demand attention and resources due to its visibility in, and impact on, communities, and due to the inertia of systems such as disaster declarations, funding pathways and technical expertise siloes, extreme heat now has resonance due to these types of collaborations (Keith et al., 2019). The efforts to date demonstrate that cities need not choose between addressing flooding and addressing extreme heat. ...
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After centuries of adapting to coastal living, increases in stormwater and tidal flooding events, along with projected sea level rise, led Charleston, South Carolina, USA to define flooding as an existential threat to the city. With billions of planned flood management projects underway, and additional billions of federal disaster flood recovery funds allocated to the State of South Carolina, the Governor's office established a South Carolina Office of Resilience in September 2020, with a focus on water management. The City of Charleston developed its own Flooding and Sea Level Rise Strategy. Simultaneously, the fourth National Climate Assessment pointed to heat health risks and projected costs of lost labor productivity concentrated in the Southeast, yet local recognition of heat as an equivalent threat to flooding was not apparent. Although Charleston's All Hazards Vulnerability Assessment included extreme heat as a significant hazard, without a group focused on heat, ongoing work in the city continued to prioritize water management as annual flood events rapidly escalated. This narrow adaptation framing was further solidified as funding focused on flood recovery and adaptation and technical experts worked within water-related boundaries. These interacting forces led to Hazard Bias, an inherent organizational process of reinforcing focus on a single hazard in the context of compound, complex hazard risks. To adapt to increasing heat, Charleston will need to raise compound risk awareness and adjust its capital investments in resilience to be inclusive of heat mitigation and adaptation as well as water. Yet in 2020 Charleston lacked basic urban heat data, technical expertise, and a strong source of motivation to develop a prioritization approach for recognizing multiple risks and complementary adaptation opportunities in those investments. Recognizing the inherent bias, a new coalition of heat researchers, practitioners, and health experts launched a tripartite heat-health research program and spurred the development of a new heat network in Charleston. The network reduced hazard bias by raising heat-health risk awareness and by intervening in adaptation planning to broaden water-only considerations to be inclusive of water AND heat. This paper provides a detailed case study how the intersections of multiple networks, messengers, and messages contributed to broadening the local resilience agenda from a “hazard bias” and how the lessons learned during this transformative process further reveal health inequities.
... and potential mitigation strategies. Similarly, maps made from satellite-derived T s are often used as a guide for planning heat mitigation strategies by decision makers (Keith et al., 2019). However, T a is more relevant for heat exposure than T s , but is difficult to measure in cities due to the dearth of standard weather stations and hard to model due to multiple confounding factors (Hardin et al., 2018;Ho et al., 2016;Muller et al., 2013;Stone et al., 2019). ...
Article
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Surface temperature is often used to examine heat exposure in multi‐city studies and for informing urban heat mitigation efforts due to scarcity of urban air temperature measurements. Cities also have lower relative humidity, traditionally not accounted for in large‐scale observational urban heat risk assessments. Here, using crowdsourced measurements from over 40,000 weather stations in ≈600 urban clusters in Europe, we show the moderating effect of this urbanization‐induced humidity reduction on outdoor heat stress during the 2019 heatwave. We demonstrate that daytime differences in heat index between urban clusters and their surroundings are weak, and associations of this urban‐rural difference with background climate, generally examined from the surface temperature perspective, are diminished due to moisture feedbacks. We also examine the spatial variability of surface temperature, air temperature, and heat index within these clusters—relevant for detecting hotspots and potential disparities in heat exposure—and find that surface temperature is a poor proxy for the intra‐urban distribution of heat index during daytime. Finally, urban vegetation shows much weaker (∼1/6th as strong) associations with heat index than with surface temperature, which has broad implications for optimizing urban heat stress mitigation strategies. These findings are valid for operational metrics of heat stress for shaded conditions (apparent temperature and humidex), thermodynamic proxies (wet‐bulb temperature), and empirical heat indices. Based on this large‐scale empirical evidence, surface temperature, used due to the lack of better alternatives, may not be suitable for accurately informing heat mitigation strategies within and across cities, necessitating more urban‐scale observations and better urban‐resolving models.
... While public sector leaders are in many cases detecting problems related to urban overheating, and indicating that those problems are crossing thresholds for concern and response needs, tackling urban overheating remains a relatively new challenge for traditional governance actors. As such, ambiguity regarding responsibility and accountability structures, access to financial, human, and regulatory resources, and a legacy of institutional nonattention to problems associated with urban overheating are hindrances to successful implementation that many actors have yet to overcome (Keith et al., 2019). While preferred models for urban overheating governance have not yet been clearly articulated, it is clear that any contemporary models are relatively immature compared with those established for other chronic environmental hazards, including air pollution (e.g., strong national to local regulatory structures, financial incentives, and explicitly named responsible governance institutions) (Keith et al., 2021) and noise (e.g., local regulatory structures and workplace protections). ...
Article
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Urban overheating, driven by global climate change and urban development, is a major contemporary challenge that substantially impacts urban livability and sustainability. Overheating represents a multifaceted threat to the well‐being, performance, and health of individuals as well as the energy efficiency and economy of cities, and it is influenced by complex interactions between building, city, and global scale climates. In recent decades, extensive discipline‐specific research has characterized urban heat and assessed its implications on human life, including ongoing efforts to bridge neighboring disciplines. The research horizon now encompasses complex problems involving a wide range of disciplines, and therefore comprehensive and integrated assessments are needed that address such interdisciplinarity. Here, our objective is to go beyond a review of existing literature and instead provide a broad overview and integrated assessments of urban overheating, defining holistic pathways for addressing the impacts on human life. We (a) detail the characterization of heat hazards and exposure across different scales and in various disciplines, (b) identify individual sensitivities to urban overheating that increase vulnerability and cause adverse impacts in different populations, (c) elaborate on adaptive capacities that individuals and cities can adopt, (d) document the impacts of urban overheating on health and energy, and (e) discuss frontiers of theoretical and applied urban climatology, built environment design, and governance toward reduction of heat exposure and vulnerability at various scales. The most critical challenges in future research and application are identified, targeting both the gaps and the need for greater integration in overheating assessments.
... Despite a growing awareness of health and mortality effects of heat waves, planning for extreme heat by local governments is far from a universal practice (Keith, Meerow, & Wagner, 2019). The majority of surveyed urban planners are concerned about heat, however they perceive the lack of human and capital resources to be major barriers in heat resilience planning . ...
Article
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While recognition of the dangers of extreme heat in cities continues to grow, heat resilience remains a relatively new area of urban planning. One barrier to the creation and successful implementation of neighborhood-scale heat resilience plans has been a lack of reliable strategies for resident engagement. In this research, the authors designed a two-week summer STEM module for youth ages 12 to 14 in Roanoke, Virginia in the Southeastern United States. Participants collected and analyzed temperature and thermal comfort data of varying types, including from infrared thermal cameras and point sensors, handheld weather sensors, drones, and satellites, vehicle traverses, and student peer interviews. Based on primary data gathered during the program, we offer insights that may assist planners seeking to engage residents in neighborhood-scale heat resilience planning efforts. These lessons include recognizing: (1) the problem of heat in neighborhoods and the social justice aspects of heat distribution may not be immediately apparent to residents; (2) a need to shift perceived responsibility of heat exposure from the personal and home-based to include the social and landscape-based; (3) the inextricability of solutions for thermal comfort from general issues of safety and comfort in neighborhoods; and (4) that smart city technologies and high resolution data are helpful “hooks” to engagement, but may be insufficient for shifting perception of heat as something that can be mitigated through decisions about the built environment.
... This framing may require that city officials adjust their assessment methods to better account for how to assess heat as an experiential hazard to inform a greater understanding of that hazard for plans and actions (Hamstead and Coseo, 2019). Many existing policies may only assess simple metrics (e.g., surface and air temperature) to document existing thermal conditions that are then extrapolated into loose proxies for how communities may or may not experience and manage heat as a risk (Dare, 2019;Hamstead and Coseo, 2019;Keith et al., 2019). Dare (2019) also found that many policies to reduce heat favor "visible" strategies (e.g., street tree planting) that may leave out "less visible" but important experiential strategies (e.g., improved transit service, support for utility bills) that could be better accounted for if residents are included in assessments and planning procedures (Guardaro et al., 2020). ...
Article
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Designing cities for thermal comfort is an important priority in a warming and urbanizing world. As temperatures in cities continue to break extreme heat records, it is necessary to develop and test new approaches capable of tracking human thermal sensations influenced by microclimate conditions, complex urban geometries, and individual characteristics in dynamic settings. Thermal walks are a promising novel research method to address this gap. During a thermal walk in Phoenix, Arizona, USA, we examined relationships between the built environment, microclimate, and subjective thermal judgments across a downtown city neighborhood slated for redevelopment. Subjects equipped with GPS devices participated in a 1-hour walk on a hot sunny day and recorded their experience in a field guide. Microclimate measurements were simultaneously collected using the mobile human-biometeorological instrument platform MaRTy. Results revealed significant differences in physiologically equivalent temperature (PET) and modified physiologically equivalent temperature (mPET) and between street segments with more than 18 °C (25 °C mPET) between the maximum and minimum values. Wider range of mPET values reflected the inclusion of individual level data into the model. Streets with higher sky view factor (SVF) and east-west orientation showed a higher PET and mPET overall. Furthermore, we showed evidence of thermal alliesthesia, the pleasure resulting from slight changes in microclimate conditions. Participants' sense of pleasure was related to the mean PET of the segment they just walked, with linear regression explaining over 60% of the variability. We also showed that estimated percent shade was significantly correlated with SVF, PET, mPET, and pleasure, indicating that participants could sense minor changes in microclimate and perceived shade as pleasant. Although generalization of results is limited by a low sample size, findings of this study improve the understanding of dynamic thermal comfort in complex urban environments and highlight the value of thermal walks as a robust research method.
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Urban overheating is an increasing threat to people, infrastructure, and the environment. Common mitigation strategies, such as green infrastructure, face space limitations in current car-centric cities. In 2020, the City of Phoenix, Arizona, piloted a “cool pavement” program using a solar reflective pavement (RP) seal on 58 km of residential streets. Comprehensive micrometeorological observations were used to evaluate the cooling potential of the RP based on three heat exposure metrics––surface, air, and mean radiant temperatures––across three residential RP-treated and untreated neighborhoods. In addition, the solar reflectivity of RP was observed over seven months across eight residential neighborhoods. Results are synthesized with the literature to provide context-based RP implementation guidelines to mitigate urban overheating where common strategies cannot be applied. The three most important contextual factors to consider for effective RP implementation include urban location, background climate type, and heat metric of interest.
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Planning is a highly political activity. It is immersed in politics and inseparable from the law. Urban and regional planning decisions often involve large sums of money, both public and private, with the potential to deliver large benefits to some and losses to others. Contemporary Urban Planning, 11e provides students with an unvarnished and in-depth introduction to the historic, economic, political, legal, ideological, and environmental factors affecting urban planning today, and emphasizes the importance of considering who wins and who loses in planning decision making. The extensively revised and updated 11th edition of this beloved text tackles the most pressing recent issues in urban development-including the major turn toward reurbanization, Affordable Housing and the particular housing needs of an aging population, new developments in public transportation planning, policy, and technology, standards for "green" buildings, the second Obama administration's environmental policy and energy planning, as well as the rapidly growing and critical field of planning for natural catastrophes. Contemporary Urban Planning is an essential resource for students, city planners, and all who are concerned with the nature of contemporary urban development problems.