Beating the Heat: A Sustainable Cooling Handbook for Cities is a guide published at COP26. The Cool Coalition, UNEP, RMI, Global Covenant of Mayors for Climate & Energy (GCoM), Mission Innovation, and Clean Cooling Collaborative contributed to its launch. It provides urban planners with a range of proven strategies for cooling cities, along with 80 case studies demonstrating their effectiveness.

It highlights the importance of addressing building emissions, which constitute approximately one-fifth of global emissions. The guide also underscores the impacts of climate change, which are already affecting both rainfed and irrigated production and the environmental consequences of years of unsustainable use. It is a valuable resource for policymakers, researchers, and stakeholders interested in sustainable urban cooling solutions.

Key findings

• Global temperatures are rising: Cities experience amplified heat, known as the urban heat island effect, due to dense infrastructure and reduced green spaces. This can lead to health risks, decreased productivity, and higher energy consumption.
• Sustainable solutions exist: Outlines various strategies, categorized into city-wide, district-level, building-level, and household-level interventions. These include:
  • Urban greening: Increasing vegetation like trees and parks provides shade, reduces air temperature, and improves air quality.
  • Cool roofs and pavements: Reflective surfaces reduce heat absorption and radiation, lowering ambient temperatures.
  • Energy-efficient buildings: Implementing passive cooling techniques like natural ventilation and optimizing building design can reduce cooling energy demand significantly.
  • Behavioral changes: Individual actions like using energy-efficient appliances and adapting clothing choices can contribute to collective cooling efforts.

Overview

1. INTRODUCTION

Begins by emphasizing the crucial need for sustainable urban cooling, notably highlighting the significance of thermal comfort in urban areas, where air temperature and humidity are key factors. Next, it sets the foundation for subsequent in-depth discussions on sustainable cooling strategies. Concurrently, it outlines urban heat’s formidable challenges, asserting cities’ critical role in implementing effective solutions. In addition, the chapter introduces the UNEP Cool Coalition’s framework, which served as a guiding principle in developing this handbook. Ultimately, the goal is to provide a comprehensive overview of sustainable urban cooling techniques suitable for cities or districts in developed and developing countries.

2. WHY A STRATEGIC, WHOLE SYSTEM APPROACH IS KEY TO SUSTAINABLE URBAN COOLING

Explores adopting a comprehensive, strategic approach to achieve sustainable urban cooling. Importantly, it underscores the need for a multi-faceted strategy considering various factors contributing to urban warming. Additionally, it highlights the urgency to address the urban heat island effect, reduce emissions from cooling needs, and ensure fair access to cooling without intensifying local warming.

Emphasizing the importance of a whole-system approach, this concept combines different interventions to accelerate the transition towards sustainable urban cooling. Specifically, it proposes three key steps for cities to implement collectively for effective urban cooling: Firstly, reduce urban-scale heat through heat-resilient planning and infrastructure. Secondly, decrease cooling needs in buildings with energy-efficient and thermally effective building practices. Finally, meet cooling needs in buildings efficiently using optimal cooling technologies and operations. By employing this strategic approach, cities can enhance resource efficiency, reduce energy use, and lower emissions linked to cooling. Consequently, this leads to a more sustainable and resilient urban environment.

3. BARRIERS TO SUSTAINABLE URBAN COOLING AND INTERVENTIONS TO ADDRESS THEM

Addresses the barriers to implementing sustainable urban cooling practices and provides interventions to overcome these challenges. Firstly, it identifies five key barriers that hinder the adoption of holistic and sustainable urban cooling solutions:

1. Lack of Awareness: There is a general lack of awareness among the public, government stakeholders, and the design and construction industry about the causes of urban heat islands and the benefits of sustainable urban cooling.
2. Lack of Supportive Policies and Regulations: Secondly, the absence of supportive policies and regulations hampers the implementation of sustainable urban cooling practices at the city level.
3. Financial Barriers: Financial constraints pose a significant challenge to scaling sustainable urban cooling initiatives, limiting market demand for such practices.
4. Limited Institutional Capacities: Fourthly, cities often face limitations in institutional capacities to plan, implement, and monitor sustainable urban cooling projects effectively.
5. Complexity of the Solution Set: Finally, the complexity of sustainable urban cooling solutions can be overwhelming, making it challenging for cities to identify and implement the most suitable interventions.

The chapter suggests interventions to overcome barriers: raising awareness of sustainable cooling, creating supportive policies, innovating financing mechanisms, improving institutional capacities, and simplifying the implementation of cooling solutions. These strategies can help cities progress towards sustainable, resilient environments.

4. GUIDELINES FOR CITIES FOR DEVELOPING A COOLING ACTION PLAN

Emphasizes the importance of tailoring the plan to each city’s unique context, considering various factors such as environmental attributes, climate conditions, regulatory requirements, and the pace of development. They provide a carefully structured framework for cities to plan and implement sustainable urban cooling initiatives effectively.

1. Integrative Action: Encourage cities to take an integrative approach, carefully considering multiple factors influencing urban cooling. These factors may include building design, infrastructure, and community needs.
2. Flexibility and Adaptability: To accommodate the unique circumstances of each city, it allows for discretion and flexibility in adapting the cooling action plan to suit the city’s priorities, resources available, and data quality.
3. Consistent Framework: It also provides a consistent framework to guide cities in developing a cohesive cooling action plan while accommodating variations in local conditions.
4. Prioritization and Organization: To ensure a synergistic approach to implementation, a framework is offered for prioritizing and organizing interventions to advance sustainable urban cooling.
5. Trigger Points: Lastly, it helps identify trigger points that may catalyze specific interventions within the cooling action plan, such as completing a cooling landscape assessment or adopting building energy codes.

Following these guidelines, cities can develop tailored cooling action plans that address their unique challenges and opportunities. Ultimately, this can foster more sustainable, resilient, and cooler urban environments.

5. CITY’S BASELINE ASSESSMENT AS THE STARTING POINT FOR ACTION

Highlights the importance of conducting a baseline assessment as the initial step in developing a city’s cooling action plan. Notably, the baseline assessment serves as a crucial starting point for understanding the current and future impacts of urban heat and conventional cooling approaches on vulnerable populations, energy systems, emissions, and the city economy.

1. Firstly, establishing the City’s Current Baseline involves understanding the urban heat island effect and its impact on different neighbourhoods.
2. Secondly, assessing At-Risk Populations: Identifying vulnerable communities disproportionately affected by urban heat and lacking access to cooling solutions.
3. Thirdly, evaluating Energy Systems and Emissions requires analyzing the energy consumption patterns related to cooling and assessing the impact of associated emissions.
4. Lastly, understanding Economic Impacts: Involves examining the economic implications of current cooling practices and the potential benefits of transitioning to sustainable urban cooling solutions.

The baseline assessment lays the foundation for developing targeted interventions and strategic goals within the cooling action plan. By thoroughly assessing the city’s current status regarding urban heat and cooling practices, cities can identify priority areas for intervention and establish a roadmap for implementing sustainable urban cooling strategies effectively.

6. HEAT-RESILIENT URBAN DESIGN AND INFRASTRUCTURE

Delves into the critical importance of heat-resilient urban design and infrastructure in mitigating urban heat islands and promoting sustainable urban cooling. Specifically, it emphasizes the role of physical interventions in shaping urban environments to enhance cooling efficiency and reduce heat-related challenges.

1. Physical Interventions: Firstly, it discusses a range of physical interventions that cities can implement to promote cooling. These interventions include optimizing built environment shapes, changing surface compositions, increasing green spaces, and enhancing urban vegetation.
2. Policy and Regulatory Changes: Secondly, it highlights the need for policy and regulatory adjustments, such as land use and zoning regulations, to support heat-resilient urban design and infrastructure.
3. Trade-offs and Considerations: Thirdly, it addresses the trade-offs in implementing cooling interventions, including cost considerations, indoor and outdoor thermal comfort, and equity implications.
4. Community Engagement: Lastly, it emphasizes the importance of engaging communities in the planning and implementing of urban cooling solutions to ensure that interventions align with local priorities and needs.

By adopting heat-resilient urban design and infrastructure strategies, cities can enhance their resilience to heat stress, improve thermal comfort for residents, and reduce energy consumption associated with cooling systems. In conclusion, it underscores the need for a holistic approach that considers physical interventions and policy changes to create sustainable and cool urban environments.

7. DISTRICT COOLING

It focuses on district cooling systems, presenting them as a highly efficient method for cooling services in urban areas. It discusses the significant benefits of district cooling, which essentially involves centralized cooling plants that distribute chilled water to multiple buildings, thereby reducing the need for individual cooling systems in each building.

1. Firstly, in terms of Efficiency and Sustainability, district cooling systems are highlighted for their energy efficiency and sustainability, especially when compared to decentralized systems in individual buildings.
2. Secondly, it emphasizes the role of Public-Private Partnerships, indicating their crucial role in enabling the development and operation of district cooling systems.
3. Subsequently, it touches on the Regulatory Framework. It encourages cities to establish regulatory frameworks that support the implementation of district cooling systems and ensure their efficient operation.
4. Following that, it talks about Planning and Implementation. Guidelines are provided for cities to assess the viability of district cooling, plan for its implementation, and integrate it into urban development projects.
5. Lastly, it discusses the Environmental Benefits. District cooling systems are recognized for their potential to reduce greenhouse gas emissions, improve air quality, and contribute to overall urban sustainability.

By promoting the adoption of district cooling systems, cities can significantly enhance their cooling efficiency, reduce energy consumption, and mitigate the urban heat island effect. It underscores the importance of strategic planning, stakeholder collaboration, and supportive policies in advancing sustainable solutions through district cooling infrastructure.

8 ENERGY-EFFICIENT AND THERMALLY EFFICIENT BUILDINGS

Stresses the role of energy-efficient buildings in mitigating urban heat and promoting sustainable cooling. It discusses passive design strategies, like optimizing insulation, shading, and ventilation, to minimize the need for mechanical cooling. It also advocates for improved building envelopes through efficient insulation and high-performance windows.

Using energy-efficient technologies such as smart HVAC systems and renewable energy sources is explored. The chapter stresses the importance of enforcing building codes that promote energy efficiency in new and existing buildings. It calls for collaboration among architects, developers, and policymakers to prioritize energy-efficient practices. By doing so, cities can reduce energy demand, lower emissions, and increase resilience to heat stress. It concludes by emphasizing the need to incorporate sustainable practices in urban planning for healthier and more environmentally friendly cities.

9 CITIES LEADING BY EXAMPLE

Underscores cities’ pivotal role in leading by example by adopting sustainable practices and policies to mitigate urban heat and promote climate-friendly cooling solutions. It is emphasized that municipal governments must proactively address heat-related challenges and demonstrate leadership in sustainable urban cooling.

1. Regarding Sustainable Procurement and Contracting, cities are encouraged to adopt sustainable procurement practices. This includes setting energy performance thresholds for leased buildings and sourcing services from district cooling providers.
2. On the topic of Building Energy Performance, the importance of setting stringent energy performance requirements for city-owned buildings is highlighted. Implementing energy labels to promote energy efficiency is also proposed.
3. When discussing Innovative Business Models, public-private partnerships and energy services company models are mentioned for cost-effective procurement of efficient cooling equipment and urban transport solutions.
4. In terms of training and outreach, the need to provide training, outreach, and tools to promote behavior change among procurement staff is emphasized. This ensures compliance with sustainable practices.
5. Finally, Monitoring and Evaluation is advocated for continuous compliance monitoring and tracking of impact to drive continuous improvement in sustainable cooling initiatives.

By leading by example, cities can inspire other stakeholders to adopt sustainable practices, reduce energy consumption, and enhance resilience to heat stress. In conclusion, it underscores the importance of city governments in transitioning to sustainable urban cooling solutions and setting a positive example for the broader community.

10 COMMUNITY-CENTRIC INITIATIVES TO ADVANCE HEAT EQUITY AND ACCESS TO COOLING

Concentrates on community-centric initiatives to advance heat equity and improve access to cooling solutions for marginalized communities. Notably, the chapter highlights the necessity of engaging with local communities to ensure that the benefits of cooling are distributed equitably, especially to those most vulnerable to heat-related challenges.

1. Public Cooling Infrastructure: Discusses providing public cooling infrastructure and cooled spaces accessible to heat-vulnerable communities during heatwaves, ensuring their safety and comfort.
2. Nature-Based Solutions: Encourages community partnerships to install nature-based solutions and cool surfaces, which can help reduce urban heat and improve local microclimates.
3. Heat Action Plans: Highlights the importance of developing heat action plans, including heat alert systems and cool roof programs, to protect communities during extreme heat events.
4. Community Engagement: Emphasizes the need for awareness and outreach programs to engage communities in sustainable urban cooling initiatives and empower them to take action to address heat-related challenges.
5. Heat Equity Planning: Advocates for identifying vulnerable communities without access to public cooling infrastructure and developing plans to ensure equitable access to cooling solutions.

By prioritizing community-centric initiatives, cities can address heat equity issues, improve access to cooling resources, and enhance the resilience of marginalized communities to heat stress. In conclusion, it underscores the importance of collaborating with residents, community organizations, and stakeholders to co-create solutions that meet different communities’ needs and priorities.

11 AWARENESS AND CAPACITY-BUILDING TO SUPPORT SUSTAINABLE URBAN COOLING

Focuses on the importance of awareness and capacity-building initiatives to support sustainable urban cooling efforts. It particularly emphasizes the need to raise awareness about the urgency and benefits of sustainable urban cooling and build the necessary capacities among stakeholders to implement cooling solutions effectively.

1. To begin with, Mass Awareness Programs: Discusses the importance of enhancing mass awareness about the benefits of sustainable urban cooling and the urgency of addressing heat-related challenges. Cities are encouraged to utilize various means and scales to reach a broad audience.
2. Secondly, Capacity Assessment: It highlights the significance of assessing the capacities of city authorities and key actors to enforce and implement urban cooling initiatives. Cities must develop the workforce and technical capacities to deliver sustainable cooling solutions.
3. Thirdly, Partnerships and Collaborations: Emphasizes the role of partnerships and collaborations in supporting awareness and capacity-building efforts for sustainable urban cooling. Engaging with stakeholders from various sectors can enhance the effectiveness and reach of these initiatives.
4. Fourthly, Training Programs: It advocates for developing training programs and capacity-building activities to equip stakeholders with the knowledge and skills required to implement sustainable cooling solutions.
5. Lastly, the Phased Approach: Suggests cities expand the scope and reach of awareness and capacity-building programs in phases to ensure sustained engagement and impact.

In conclusion, by investing in awareness and capacity-building initiatives, cities can empower stakeholders, build support for sustainable urban cooling measures, and enhance the overall effectiveness of cooling interventions. The chapter underscores the importance of continuous learning, collaboration, and community engagement in driving the transition towards more sustainable and resilient urban environments.

12 FUNDING AND FINANCING SUSTAINABLE URBAN COOLING INTERVENTIONS

Delves into the critical aspect of funding and financing sustainable urban cooling interventions, emphasizing the importance of identifying and securing financial resources to support the implementation of sustainable cooling solutions in cities.

1. Firstly, it highlights the need for cities to conduct a Funding Landscape Assessment. This task aims to identify potential funding sources for sustainable urban cooling projects and is crucial for understanding available financial resources and debt obligations associated with cooling interventions.
2. Secondly, it views funding and financing as Facilitative Interventions that support the implementation of cooling initiatives. Trigger points for activating funding strategies include completing baseline assessments, cooling action plans, or individual intervention strategies.
3. Thirdly, it emphasizes the importance of Benefits Case Development. This involves demonstrating the return on investment for cities and their citizens by considering the holistic benefits of interventions and their impact on multiple aspects of urban sustainability.
4. Fourthly, it advocates for Cost Optimization. Here, the aim is to leverage funded projects and trigger points to reduce the initial costs of planned interventions.
5. Furthermore, it explores various Funding Sources, including official development assistance, dedicated climate funds, and national- and state-level financing options.
6. Lastly, it considers Revenue Generation opportunities, for instance, through tax-raising authority to fund interventions that benefit the city and gain support from the community.