Heat Island Newsroom
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April 5, 2021 Newsletter
General Heat Islands
- Socioeconomics, the Urban Environment, and the Heat-Health Nexus Researchers in Italy conducted an extensive review of published literature to better understand what determinants drive heat-health vulnerability in relation to the built environment. Their review confirms interactions among physical surroundings, socioeconomic status, and heat-related impacts in urban settings. Yet, the authors find that more research is needed to link heat-health outcomes to built environment characteristics. Simultaneously, the authors underscore that understanding these relationships and creating locally relevant metrics for exposure and sensitivity could be crucial to infrastructure adaptation.
- Cooling Hot Cities by the Numbers Greening and cooling strategies help cities adapt to heat islands, but simulation methods and approaches to identify potential temperature benefits vary. Researchers from multiple universities and organizations reviewed 146 studies from 1987 to 2017 that conducted numeric modeling of urban air temperature reductions from infrastructure interventions. After vetting the studies with the most-robust methods, they find that both cooling and greening strategies result in lower temperatures: reflective coatings or materials offer ≈ 0.4–1.1°F cooling per each 0.10 albedo increase, and that trees yield ≈ 0.5°F cooling per each 0.10 canopy cover increase. Variation among studies may be attributed to underlying physical models. The authors identify a three-part framework for assessing the suitability of a numerical model for a heat mitigation analysis, and include recommendations for design and communication of these heat island reduction studies.
- What Do You Really Think? Perception of Cooling Strategies Among Practitioners Perceptions of heat island cooling strategies and adaptation methods have been overlooked in urban climate research. Researchers from Arizona State University, Stanford University, and the National Asphalt Pavement Association conducted a survey to fill this research gap. Among professional respondents — including government practitioners and researchers — perceptions are largely affected by geographic areas they work in and how familiar respondents are with related building codes and regulations. Academic literature and government reports are the two major information sources for most respondents. The authors identify several opportunities to foster public engagement and proliferate heat island cooling strategies: improve public education on cooling measures, increase communication between researchers and building code writers, and support the spread of trustworthy information on social media platforms.
- New Artificial Intelligence Tool Creates Visualizations of Heat Island Effects Evergreen, a Canadian nonprofit organization, recently created a new tool: Artificial Intelligence (AI) for the Resilient City. This scalable planning and data visualization tool helps municipalities plan for climate impacts and invest effectively for the future. In its initial pilot for Calgary, Alberta, AI for the Resilient City looked at heat islands to map baseline heat island environmental and health impacts, project future levels of heat, and inform heat island policy and planning. The tool is funded by Microsoft’s AI for Earth program.
- New Tree Equity Application Emphasizes Planting in the Most-Needy Areas Trees are sparse in most low-income neighborhoods. Through a newly developed app American Forests seeks to ensure equitable tree planting. This organization created the Tree Equity Score and Analyzer app using a science-based approach to determine opportunities for improving tree canopy cover where it is most needed. The score is based on existing tree canopy cover, population density, income, employment, race, age, and surface temperature. The Tree Equity Score can be used by city staff, community activists, urban foresters, and others to make a strong case for planting trees. Pilot locations included the State of Rhode Island; Maricopa County, AZ; and San Francisco, CA. By 2022, the app will be customized for all urbanized areas of the United States.
- Inequitable Population Exposure to Heat Islands across the United States A multitude of city-level analyses suggest that heat exposure is unequally distributed across demographic or socioeconomic divisions. However, are such disparities prevalent nationwide? A new research paper from authors at Yale University, the University of North Carolina, Arizona State University, and the Data-Driven EnviroLab identifies summer days when heat exposure is at a maximum combined with census tract-level demographic data for the 175 largest urbanized areas in the country. The researchers find that the average person of color lives in a census tract with higher summer daytime heat island intensity than non-Hispanic whites. Similarly, people living in households below the poverty line are subject to higher heat island intensity. The results suggest widespread inequalities in heat exposure by race and ethnicity.
- Reducing Heat Islands through Increased Green Infrastructure Improves City Vitality Researchers from the Curtin University Sustainability Policy Institute conducted a systematic literature review on how green infrastructure and urban design and planning strategies may reduce urban heat and stimulate human activity within cities. The study reports that conventional urban design tends to be harmful to people’s physical and mental health with its reliance on roadways and automobiles, which furthers urban sprawl into natural spaces and increases heat-inducing infrastructure. However, introducing green infrastructure solutions can reduce urban heat and produce functional, comfortable, and attractive urban environments that improve public health. The authors assert that in the wake of COVID-19, opportunities exist to re-assess thermal performance, aesthetics, and how cities establish communities.
- Which Green Infrastructure Solutions Effectively Cool Heat Islands? Researchers from the University of Surrey modeled the impacts of green infrastructure using the Town of Guildford in the United Kingdom as a test case. The work analyzes the heat impacts across scenarios of current vegetative cover, increased green roofs, increased grasslands, increased trees, and a scenario without vegetation cover. Additionally, the researchers compare temperature differences among a central urban area, an urban park, and a suburban residential area. The results show that temperature variations are highly dependent on the type of green infrastructure, waste heat sources (buildings and vehicles), and the percentage of land covered by vegetation. Among all the scenarios, trees produced the greatest estimated temperature benefit. Measurable temperature reductions, up to 1-2°F, may be possible if solutions are implemented city-wide.
- Could Depaving Vacant Properties in Kansas City, MO Create Cool Islands? In a recent publication, University of Kansas researchers investigate the potential impact of converting existing vacant lots in Kansas City, MO, to green spaces for three heat-wave events. The study used vacant property data and identified places with a high fraction of impervious surfaces to determine the most suitable areas for converting vacant lots to green spaces. The study finds that under an aggressive depaving and greening strategy, localized nighttime cooling benefits could reach 1–2°F; more moderate and conservative strategies could still yield small cooling benefits.
- Multi-Decade Review Links Heat Islands and Urban Pollution A researcher from the University of Sydney, Australia, conducted a review of three decades of literature linking heat islands and urban air pollution. Results from 16 countries and 11 climatic zones span topics including the daytime/nighttime variability of heat island-urban pollution interactions, the role of urban form, and the effects of heat island cooling strategies on urban air quality. This review strives to identify strategies that will help governments and urban planners effectively address both heat islands and urban pollution.
Trees and Vegetation
- Nevada Prioritizes Urban Forestry in New Climate Strategy Nevada's newly published State Climate Strategy includes a dedicated element for urban forestry and acknowledges the need for a statewide urban forestry strategy to address the heat island effect. In addition, such a strategy will help the state meet its GHG emissions reduction goals, climate justice objectives, and economic development targets. Statewide action will require expanding the Nevada Division of Forestry’s Urban and Community Forestry Program, revising applicable statutes, and providing support to existing community-based urban forestry efforts.
- Google’s Tree Canopy Lab Maps Trees and Heat in Los Angeles, CA Google recently piloted an interactive mapping and data platform for officials in Los Angeles to explore relationships among the heat index, population density, carbon emissions, and tree coverage. The company’s Tree Canopy Lab uses aerial imagery, three-dimensional digital surface models, and AI to generate maps that support decision-making related to heat island risk. The tool showed that more than 50% of Angelenos live in areas with less than 10% tree canopy coverage and 44% live in areas with extreme heat risk. The Tree Canopy Lab launched with data on Los Angeles, but the program plans to expand to hundreds of locations.
- Climate-Resilient Trees Will Increase the Urban Canopy in Albuquerque, NM In Albuquerque, The Nature Conservancy conducted the Climate Ready Trees project to support adaption to current and future climate impacts, including an amplified heat island effect. The project developed a curated list of well-adapted tree species that will serve as a guideline to increase the diversity and resiliency of Albuquerque’s community forest. Featured trees are scored based on temperature tolerance, drought tolerance, and soil textures. The report also identifies six common tree planting location types and the ideal tree characteristics to succeed in each location – information broadly applicable to the U.S. Southwest. Pursuing the project’s findings will support Albuquerque’s goal to plant 100,000 trees by 2030 and to increase the tree canopy in the city.
- Denver, CO, to Fight Heat with More Trees Denver is emerging as one of the country’s most “impervious” or paved-over cities. Just 8% of Denver’s 155 square miles has been designated as parkland, compared with 23% in San Diego, CA; and 15% in Minneapolis, MN; according to data from the Trust for Public Land. This pattern has measurable heat island effects, with one analysis estimating that during the summer, some areas are 12°F hotter than areas with established vegetation. Establishing new greenspace has proved difficult. Using $1 million in funding, Denver Parks and Recreation is planning to bolster tree planting in existing parks, dense downtown areas, and “low equity” neighborhoods.
December 14, 2020 Newsletter
General Heat Islands
- New Reports Emphasize Disparities in Access to Cooling Parks and Schoolyards The Trust for Public Land recently released two new resources: School’s Out and The Heat Is On. The Heat Is On investigates how race and income relate to access to parks. On average, communities within a 10-minute walking access are cooler than those that lack such access to a park by as much as 6 degrees. Parks serving primarily non-White populations are, on average, half the size of parks that serve majority-White populations and nearly five times more crowded. School’s Out analyzes the millions of students impacted by heat islands around the United States. The report finds that nationwide, 36% of the Nation’s 50.8 million public school students attend school in a heat island, and there is a strong correlation between populations with low income and schools being situated in heat islands. The report recommends opening schoolyards to the public during non-school hours to increase national access to parks and green areas.
- Campaign Maps Ambient Heat across 13 U.S. Cities For a third summer, the National Oceanic and Atmospheric Administration’s (NOAA’s) National Integrated Heat Health Information System (NIHHIS) and Climate Adaptation Planning and Analytics (CAPA) Strategies continued their Heat Watch program, which engages local organizations and community members in a data collection process and returns high-resolution spatial descriptions of urban heat. Thirteen U.S. cities (identified with blue circles in the map) conducted campaigns in summer 2020, in which local volunteers collected ambient temperature and humidity measurements three times in a single, hot day. In total, over 380 volunteers drove and biked 176 hour-long routes and collected nearly 1.2 million unique measurements of heat, helping to inform area-wide models of temperature and heat index. The next steps span validating the data with local communities; examining overlays with sociodemographic information, land-use and land-cover variables, and historical housing practices; and incorporating the data into ongoing planning efforts such as vulnerability assessments and active transportation plans. The NIHHIS/CAPA team is working to grow their network of over 30 campaign cities. NIHHIS is accepting applications for 2021 urban heat island mapping campaigns. Applications are due January 8, 2021.
- Cambridge, MA, Resilience Plan Tracks Albedo Changes to Reduce Heat Island Effects With support from Thriving Earth Exchange, researchers from the National Aeronautics and Space Administration’s DEVELOP program and Hunter College partnered with Cambridge’s Community Development Department to devise rooftop albedo detection methods and track heat island reductions within the citywide Climate Change Preparedness & Resilience (CCPR) Plan. Specifically, the team worked to devise a replicable, practical, affordable, and consistent methodology to track changes in albedo over time to determine whether the city is successfully reducing its heat island effect. A pilot of the approach indicated that rooftop albedo has increased since 2010 – likely attributable to the increasing availability of higher-albedo roofing materials and the overall trend of green building design. This project expands the city’s capacity to manage heat island effects, along with changes to urban forest canopy and pervious/impervious cover. To ensure that the CCPR Plan is effective, the city is applying benchmarks that would signal the need for future adjustment of heat island cooling strategies.
- Massachusetts Awards Heat Island Reduction Grants to Four Communities The Massachusetts Municipal Vulnerability Preparedness Program recently awarded a series of grants to identify climate hazards, develop strategies to improve resilience, and implement priority actions around the state. Four awards target heat island planning and identification of cooling actions. Boston, MA, was awarded $280,000 to fund a Heat Resilience Planning Study that will focus on “hot spots.” This effort, part of Climate Ready Boston, will develop heat-mitigation scenarios in partnership with communities facing disproportionate effects of urban heat risk – compounded by social inequity. Chelsea, MA, was awarded $262,000 for an Urban Heat Island Mitigation Project. Cambridge, MA, and Metro Mayors were awarded $268,000 for the Building Resilience to Climate Driven Heat in Metro Boston project. Arlington, MA, was awarded $186,000 for the Wicked Hot Mystic project.
- Recent Developments in Designing and Developing Cool Materials In a recent Renewable Energy journal article, researchers reviewed progress on the design, development, and implementation of cooling materials – exhibiting low and very-low surface temperatures. This review presents recent technological advances around natural, light color, infrared reflective, phase change, thermochromic, fluorescent, photonic, and plasmonic materials. The authors found that innovations in photonic materials show enormous cooling potential at a reasonable price, and that photonic materials may play a key role in future cooling strategies. While more research into cooling materials is needed, the results demonstrate that innovative materials can exhibit sub-ambient surface temperatures and contribute greatly to alleviate urban overheating.
- Can Planting Trees Make a City More Equitable? The Trillion Trees Initiative, launched by American Forests, brings together businesses, nongovernmental organizations, and cities to commit to planting urban trees. Through this initiative, partners have committed to conserve, restore, or grow 855 million trees as a means to encourage reforestation, improve air quality, promote urban cooling, sequester carbon, and improve “tree equity.” Participating entities submit annual data about their forestry practices, and how the planted trees meet both climate change and community engagement goals. Alongside this effort, American Forests is developing a national tree equity score that factors in the heat island effect and neighborhood income levels so cities may use it to inform their work. Cities involved in this initiative include Boise, ID; Dallas, TX; Detroit, MI; and Tucson, AZ; among others.
Green Roofs and Walls
- Can Green Walls Cool Urban Heat? University of Antwerp researchers reviewed recent green wall literature to understand how green walls might be applied to improve urban resilience. The literature shows green walls are a resource to decrease temperatures in urban environments and reduce the heat island effect through increased shading, evapotranspiration, insulation, and ventilation. Green walls lower indoor air and ambient air temperatures, increase thermal comfort for residents, and reduce energy demands for additional cooling. The researchers found that urban green infrastructure, including the use of vertical green walls, may be an effective strategy for cooling at building and street levels; and that shading was the most important factor for cooling.
- Cooling Strategies Likely Have Heat Health Benefits for Los Angeles, CA Recent work from researchers at Arizona State University and Applied Climatologists explores two historical extreme heat events in Los Angeles, and the potential for increasing vegetative cover and albedo to reduce total exposure to dangerously hot conditions. For each heat event, the researchers conducted atmospheric model simulations for a control case and four levels of increased albedo and vegetative cover. Accounting for both indirect cooling effects associated with neighborhood implementation of cooling strategies and the direct effects of high-albedo roofing, the researchers developed occupant heat exposure and mortality profiles. The results suggest that improvements in indoor thermal conditions could be associated with a sizable health benefit, signaling a need for large-scale implementation of cooling strategies.
Trees and Vegetation
- Environmental Justice Project Aims to Grow Tree Canopy in Underserved Communities Vibrant Cities Lab – a partnership among the U.S. Forest Service, American Forests, and the National Association of Regional Councils – completed the three-year Growing Tree Canopy through Environmental Justice project focused on delivering in-depth community engagement with tree canopy in the Anacostia watershed located in Prince George’s County, MD. Key accomplishments include the Chesapeake Tree Canopy Management Strategy; the creation of a cross-boundary partnership to achieve tree canopy and community engagement goals; and the development of five case studies featuring environmental justice, community engagement, tree planting, and stewardship projects. Each of the case studies in Baltimore, MD; Detroit, MI; Oakland, CA; Portland, OR; and NJ provides an overall context for the implemented projects and lessons learned. The Detroit and NJ case studies cite the heat island effect as a motivation for efforts to increase coverage in neighborhoods with disproportionately low tree canopy.
- Vegetation Drives Microclimate Variability in the Salt Lake Valley University of Utah researchers found that land cover characteristics drive changes in spatial and temporal temperature variability. The researchers collected data from 60 sensors in 5 urban parks and surrounding neighborhoods in Utah’s semi-arid Salt Lake Valley. Tree shading was associated with higher temperature variability during the day, while turfgrass cover was associated with higher temperature variability at night. Both trees and turfgrass had cooling benefits, suggesting that mixed tree and grass landscapes may be effective in alleviating the heat island effect in semi-arid urban settings.
August 25, 2020 Newsletter
Please Share! Cool Your Community Social Media Toolkit We are launching Cool Your Community – a social media toolkit from the U.S. EPA Heat Island Reduction Program to increase awareness of heat islands, share information on heat island cooling strategies, and encourage individuals to adopt these strategies. We have developed messages and graphics, freely available in English and Spanish, for communities, local governments, organizations, and individuals to share with their networks. The messages focus on the benefits of cool roofs, trees and vegetation, heat equity, heat vulnerability, and more. We encourage you to share them directly with your program’s stakeholders by posting them on your social media accounts, or by letting your stakeholders know about the toolkit through a newsletter or email announcement.
Webcast Recording Available! Equity in Action: Heat Planning in Greater Phoenix This June webcast covered how The Nature Conservancy Arizona, Arizona State University, the Maricopa County Department of Public Health, and other partners developed the Heat Action Planning Guide for Neighborhoods of Greater Phoenix. The partners worked directly with community members using a participatory process to identify challenges and create community-driven solutions to mitigate and adapt to future heat. Specific cooling solutions include revitalizing vacant lots with trees and vegetation, and increasing shade along transit routes and at bus stops. This process was designed to develop awareness, increase social cohesion, and foster action in underrepresented communities. This team’s work was also featured in the Washington Post.
Local and tribal governments are doing the hard work of implementing energy and environmental programs on a community level that reduce air pollution, improve air quality, lower energy costs, support local economic development, improve public health, and increase energy system reliability. Our six-step guide is designed to help local and tribal governments plan, implement, and evaluate new or existing energy or environmental projects. It is intended for small and medium-sized communities and tribes, but may also be relevant for larger jurisdictions or states. Local Action Framework: A Guide to Help Communities Achieve Energy and Environmental Goals
General Heat Islands
Dallas, TX Comprehensive Plan Sets Ambitious Heat Island Reduction Targets Following the 2017 Dallas Urban Heat Management study, the city’s newest comprehensive plan includes a series of goals to protect and enhance its ecosystems, trees, and green spaces, particularly for vulnerable populations, which will, in turn, improve public health. The plan targets reducing the local heat island index 20% by 2030, 50% by 2040, and 75% by 2050. The plan’s cooling strategies include ongoing efforts to increase the city’s tree canopy, install cool roofs, institute urban greening requirements for new developments, transform vacant lots into pocket parks and gardens, and create green corridors – a city-wide network of urban trails that link neighborhoods with transportation hubs and economic centers.
Online Map Depicts Heat Island Intensity and “Disparity” Variables Side-by-Side Students and researchers from several universities launched the interactive Surface Urban Heat Island (SUHI) Disparity Explorer. For major metropolitan centers across the United States and Puerto Rico, it depicts SUHI intensities for day, night, summer, and winter, alongside socioeconomic variables such as race and income. A draft manuscript provides supporting documentation.
New Tool Estimates Urban Heat Adaptation Benefits The C40 Cool Cities Network developed a downloadable Excel-based tool to support city planners and designers in quantifying health outcomes such as heat-related illnesses and deaths, environmental outcomes such as heat island reductions, and associated economic benefits. With the tool, users can calculate benefits brought about by specific parks and green infrastructure, water bodies such as rivers and lakes, and cool and vegetative surfaces. This information could be used to formulate adaptation investments and prioritize actions.
What is the True Value of Trees, Cool Roofs, and Other Cooling Strategies? Researchers from the Global Cool Cities Alliance and The Nature Conservancy published a research article earlier this year highlighting the economic benefits associated with heat island cooling strategies. This research captures several benefits of heat mitigation: improved energy efficiency, worker productivity, air quality, health, and equity. Using standard cost-benefit tests, it finds that adaption of these strategies has been slower than their economic potential. Such cost-benefit tests could inform program design.
Use of Collaborative Decision-Making Frameworks in Heat Response Planning Using the test case of Chatham County, GA researchers explored if the collaborative, multi-stakeholder frameworks of coproduction – an iterative process between science and decision-making fields to develop research questions and methods – and geodesign – a collaborative pathway among landscape architects, planners, and others for plan conception and evaluation – supported heat response planning decision-making. The work included a variety of collaborative methods such as the use of workshops, focus groups, and geodesign drafting software across stakeholders and key informants in multiple fields: planning, public engagement, natural resources, public health, and meteorology. Two workgroups identified and narrowed a series of actions, policies, and projects centered on county-wide green infrastructure and social vulnerability. The researchers concluded that co-production and geodesign frameworks promoted synergist heat response action plans.
- Primer on Passive Heat Islands Reduction Measures The World Bank’s Energy Sector Management Assistance Program primer covers solutions that cities can take to reduce excess heat and the benefits of these solutions. Specific passive cooling strategies include reflective surfaces such as cool roofs, walls, and pavements; permeable infrastructure such as green roofs, green walls, permeable pavements, trees, and parks; water infrastructure; urban design; and reducing waste heat from air conditioners, transit vehicles, and industry. The primer features several policy options for implementing such measures, including awareness-raising activities, incentives, and mandates. Case studies feature Toronto, ON and Washington, DC, among others.
Phoenix, AZ Launches Cool Pavement Pilot This summer the Phoenix Street Transportation Department selected nine locations as part of a new cool pavement pilot project. The city will test if a specific pavement coating treatment is effective at reducing temperatures by engaging Arizona State University researchers to take measurements throughout the coming years. The pilot will uncover if the treatment is durable and helps cool the heat island effect.
In a report for 2019, Denver details the progress of its 2018 green building ordinance. The ordinance applies to new and re-roofed buildings over 25,000 square feet and requires installation of a cool roof in addition to one of several “green” options: installing a green roof/green space, funding it elsewhere, meeting green building certification standards, installing renewable energy, or undertaking energy efficiency. Since the ordinance took effect, Denver issued 65 project permits. The report presents breakdowns of green building options across 51 of these projects. Denver touts that these projects are using less energy, adding more green space, and contributing less to the urban heat island effect, among other environmental benefits. Results are In for Year One of Denver, CO's Green Building Ordinance
What Incentives Promote Green Roofs and Walls? In a journal article published in Land Use Policy, researchers reviewed municipality incentive policies that promote the installation of green roofs and walls. Such cooling strategies are used to alleviate multiple impacts of urban development; but with high upfront costs, incentives are one way to promote and facilitate their adoption. The results, covering 113 cities, show that incentive policies fall into 6 categories: tax breaks, financing, permitting, sustainability certification, requirements, and administrative processes. Green roof incentives are mainly concentrated in Europe and North America, and no exclusive green walls policies exist.
Philadelphia, PA Assesses How Increased Tree Canopy Might Benefit Public HealthGreenworks Philadelphia aims to increase tree cover across the city by the year 2025. In a published assessment, researchers used multiple tree canopy scenarios in both lower and higher socioeconomic areas to estimate preventable annual premature deaths associated with physical and mental health benefits of greenspace. Results indicate a low scenario with a 5% increase in tree canopy could reduce 302 yearly deaths. Achieving an ambitious 30% tree canopy coverage could reduce 403 yearly deaths (with a value of nearly $3.9 billion associated with avoided deaths).
Interactive Heat & Health Tracker This summer the Centers for Disease Control and Prevention (CDC) created a new Heat & Health Tracker to provide local heat and health information so communities can be better prepared for responding to extreme heat events. This tracker relies on data such as current, historical, and future projected temperatures; heat-related health effects (e.g., emergency department visits, deaths); population characteristics; and community characteristics (e.g., land cover). The tracker's features allow users to search for information by county or Zip code to create custom maps, view data snapshots, and access guidance and resources from CDC and other credible sources.
Heat-Related U.S. Deaths A newly released article from CDC researchers summarizes heat-related death data for the United States from 2004 to 2018. The researchers reported 10,527 heat-related deaths in that time period, an average of 702 per year. These numbers include deaths where heat was the underlying or contributing cause. The article highlights the need for preparedness and response initiatives that limit exposure to extreme heat, including coordinated approaches such as surveillance, heat response planning, communication and education activities, and operation of cooling centers.
COVID-19 News and Resources
- COVID-19 and Cooling Centers (CDC)
- Heat and COVID-19 Information Series (Global Heat Health Information Network)
- Coronavirus Makes Cooling Centers Risky, Just as Scorching Weather Hits (New York Times)
- Will Summer Kill Coronavirus? Cities Fear Heat Waves Will Quickly Become Deadly (Washington Post)
- Cities Brace for 'Collision Course' of Summer Heat Waves and COVID-19 (National Public Radio)
- Roadmap for Cities to Address Dangerous Heat during the COVID-19 Pandemic (Global Cool Cities Alliance, Society of Behavioral Medicine)
Trees and Vegetation
The Urban Land Institute’s report Pavement-to-Parks: Transforming Spaces for Cars into Places for People highlights the role of depaving as an opportunity to promote community connection, improve park access, and enhance environmental sustainability – including cooling heat islands. Many cities dedicate land to automobile storage and transport, including parking lots and garages, roadways, and spaces beneath highway overpasses; however, such spaces could be transformed into parks. This report presents 15 project examples and 4 programmatic examples from cities that have converted or enhanced spaces to support recreation, sustainability, and neighborhood revitalization. Pavement to Parks Report Features Many Benefits of Depaving
How Urban Trees Affect Human Health A cohort of U.S. and Canadian researchers published a comprehensive review of existing literature on the health impacts of urban trees. The review process screened several thousand articles, ultimately narrowing to 201 relevant studies. These studies address three broad categories of health benefits associated with trees: (1) reducing harm, including benefits such as reducing air pollution and heat exposure; (2) building capacities, including benefits such as improving birth outcomes and active living; and (3) restoring capacities, including benefits such as improving mental health and relieving stress. The review points to why urban planners and managers should promote trees and urban forestry as measures to protect public health.
Measuring Microclimates in Atlanta, GA At the Georgia Institute of Technology campus in Atlanta, researchers monitored 37 sites spanning built and vegetated environments to identify the distribution and intensity of the surface heat island. Heat island intensities were tracked with levels of tree canopy and landscaping. Vegetated sites had lower temperatures than impervious sites by up to 6.8°F. This method could be applied elsewhere to understand differential heat island intensities and inform cooling strategies.