The World Cities Report 2024: Cities and Climate Action by the UN-Habitat presents a comprehensive analysis of the critical climate challenges facing urban areas globally. Highlighting the role of cities both as contributors to greenhouse gas emissions and as high-risk areas for climate impacts, the report underscores the urgent need for resilient urban infrastructure, targeted investment, and sustainable urban planning to counteract environmental threats.
Key Climate Challenges for Urban Areas
The report paints a stark picture of climate-induced risks for cities. By 2040, urban populations will face significant shifts in temperature, humidity, and climate conditions, impacting billions.
- Temperature Increases: The global urban population, especially in tropical regions, will experience substantial warming, with nearly two billion urban residents projected to see an average temperature increase of 0.5°C. Approximately 36% of urban populations will experience annual temperatures of at least 29°C by 2040.
- Sea-Level Rise: Over 2,000 low-lying coastal cities, home to 1.4 billion people, are predicted to encounter greater exposure to storm surges and rising seas by 2040. This risk escalates as the global mean sea level rises, potentially inundating cities situated less than 5 meters above sea level.
- Flooding and Riverine Floods: The report estimates that by 2030, 14% of urban populations (517 million people) will face riverine flooding, especially in areas with a 100-year flood return period. Compared to rural areas, the rate of urban flood exposure has surged 3.5 times faster since 1975.
Decline of Green Spaces and Rise of Vulnerable Settlements
Urban spaces have seen a sharp reduction in green areas, further amplifying environmental and social problems.
- Green Space Reduction: Between 1990 and 2020, urban green spaces dropped from 19.5% to 13.9%. This reduction limits cities’ natural resilience against extreme weather events and negatively impacts urban biodiversity.
- High-Risk Informal Settlements: Informal settlements, or slums, increase urban vulnerability to climate impacts, as they are often in flood-prone or precarious locations. With limited protective infrastructure and minimal legal recognition, these areas struggle to attract climate-resilient investments, trapping residents in cycles of risk and poverty.
The Investment Gap: Financing Climate Resilience
An alarming financing gap plagues cities’ efforts to build climate-resilient systems.
- Funding Needs: Urban areas need between $4.5 trillion and $5.4 trillion annually for infrastructure projects spanning transport, energy, water, waste, and telecommunications.
- Current Financing Levels: In contrast, recent financing stands at a mere $831 billion annually, covering only a fraction of the required investments. Moreover, adaptation-focused financing reached only $10 billion in 2021-2022, representing just 1% of total urban climate financing.
How Urban Areas Contribute to Global Warming
Urban areas are major contributors to global emissions, primarily due to their high population densities and industrial activities.
- Energy Consumption: Cities contribute to 71-76% of CO2 emissions from global energy use, driven by dense residential, commercial, and industrial sectors that consume vast amounts of energy for heating, cooling, and lighting.
- Industrial and Waste Emissions: Urban industries, especially those reliant on fossil fuels, emit large volumes of greenhouse gases like CO2, methane, and nitrous oxide. Additionally, methane emissions from landfill waste contribute significantly to urban emissions, with a warming potential far surpassing CO2.
- Urban Heat Islands (UHIs): Cities often experience higher temperatures than rural areas due to extensive concrete and asphalt surfaces, which trap heat. This phenomenon exacerbates the severity of heatwaves and can worsen public health risks.
Impacts of Global Warming on Cities
Cities are disproportionately affected by global warming, with consequences ranging from extreme heat to heightened wildfire risk.
- Heatwaves: Rising global temperatures have intensified the frequency and severity of urban heatwaves, with countries like India facing especially severe impacts on public health and energy demand.
- Coastal Flooding: Rising sea levels threaten to inundate low-lying coastal areas, causing displacement and loss of ecosystems. By 2050, 136 major coastal cities could incur annual losses exceeding $1 trillion if adaptive measures aren’t implemented.
- Extended Wildfire Season: Higher temperatures and prolonged droughts have extended wildfire seasons, increasing the frequency and intensity of urban wildfires, especially in areas with abundant flammable vegetation.
UN-Habitat’s Role in Sustainable Urban Development
UN-Habitat, established by the UN General Assembly, is pivotal in promoting sustainable urbanization and addressing the unique challenges posed by climate change in urban areas.
- Mandate and Mission: The organization’s mission is to foster inclusive, safe, resilient, and sustainable cities, aiming to reduce inequality, discrimination, and poverty.
- Strategic Approach: Under its 2020-2023 Strategic Plan, UN-Habitat has adopted a comprehensive, multi-pronged approach to urban issues, encompassing research, policy advice, advocacy, and partnerships with stakeholders.
- Key Functions:
- Think: Conducts research and develops global standards for sustainable urbanization.
- Do: Provides technical assistance to support cities in crisis response and sustainable development.
- Share: Uses outreach to inspire shifts in development strategies and investments.
- Partner: Collaborates with various sectors to address complex urban challenges.
India’s Initiatives for Urban Climate Resilience
India has introduced several programs aimed at curbing climate impacts within urban spaces, enhancing sustainability, and promoting clean energy.
- Smart Cities Mission: Focused on creating sustainable and inclusive urban spaces, this initiative leverages technology to improve infrastructure and public services.
- Atal Mission for Rejuvenation and Urban Transformation (AMRUT): AMRUT targets infrastructure upgrades in water supply, sewage, and green spaces, enhancing the climate resilience of Indian cities.
- Swachh Bharat Mission-Urban: This campaign promotes waste management and sanitation improvements, reducing pollution and fostering cleaner, healthier urban environments.
- FAME India Scheme: The Faster Adoption and Manufacturing of (Hybrid &) Electric Vehicles initiative encourages the transition to electric vehicles, decreasing transportation-related emissions.
- Green Energy Corridor: This project facilitates the integration of renewable energy into India’s urban grids, aiming to reduce the dependence on fossil fuels.
Strategic Path Forward for Climate-Resilient Cities
Given the multifaceted risks posed by climate change, a robust, integrated approach is needed to fortify cities against environmental challenges.
- Resilient Infrastructure: Urban infrastructure contributes to 79% of total emissions yet holds the potential to meet 72% of Sustainable Development Goals (SDGs). Cities must invest in infrastructure capable of withstanding climate shocks while addressing social vulnerabilities.
- Green Energy Transition: Promoting electric vehicles and public transportation electrification can drastically reduce cities’ carbon footprints, aligning with broader goals for cleaner, greener urban mobility.
- Diverse Financing Solutions: To bridge funding gaps, cities should consider innovative financing mechanisms such as green bonds and climate-friendly loans, enabling access to long-term capital for climate resilience projects.
- Urban Carbon Sinks: By implementing green roofs, urban forests, and parks, cities can enhance carbon sequestration, mitigate urban heat islands, and improve residents’ quality of life.
- Circular Waste Management: Effective waste management, including recycling and composting, is crucial to reducing methane emissions from landfills, thereby mitigating urban contributions to climate change.
- Whole-of-Society Approach: Effective climate action requires collaboration across governmental levels and sectors. Coordinated efforts can ensure consistency, inclusivity, and local relevance, enhancing cities’ capacity to adapt to climate challenges.
- Lifestyle and Behavioral Changes: Encouraging eco-friendly practices like carpooling, walking, and biking over private vehicle use can reduce demand for high-emission transportation options, benefiting both the environment and public health.
The World Cities Report 2024 stresses the urgency for cities to tackle climate change impacts through sustainable, resilient urban development. With over 2 billion urban residents facing climate-induced risks by 2040, the report underscores the need for proactive infrastructure investments, innovative financing models, and robust climate adaptation strategies. Addressing these challenges requires a coordinated, inclusive approach that prioritizes local resilience, green energy solutions, and sustainable urban planning.