Urban Biodiversity Under Threat: Preserving Green Spaces for Sustainable Cities

Urban Biodiversity Under Threat: Preserving Green Spaces for Sustainable Cities

Syllabus

GS 3: Environment

Why in the News?

International Day for Biological Diversity, observed on May 22, 2025, focuses on “Harmony with Nature and Sustainable Development,” highlighting the urgent need to protect urban biodiversity and urban green spaces amid rapid urbanization.

Introduction

• Biodiversity is essential for human well-being, ecological balance, and sustainable urban living. Urban ecology plays a crucial role in maintaining biodiversity in cities and promoting green space sustainable development.
• With nearly 25% of species facing extinction, cities must prioritize nature and biodiversity conservation. Understanding why conserve biodiversity is crucial for urban planners and policymakers.
• Green spaces, including tree cover and restored waterbodies, can significantly improve health, climate resilience, and liveability in urban areas, making biodiversity conservation a civic necessity and highlighting the importance of green plants in ecosystems.

Understanding Biodiversity and Its Global Importance

Definition of Biodiversity

Biodiversity refers to the variety and variability of all living organisms on Earth. It includes plants, animals, fungi, and microorganisms, forming the foundation of urban wildlife and ecosystem services in cities. Adaptive management approaches are crucial for maintaining this diversity in urban environments.

Why It Matters

• Biodiversity supports life systems that provide food, water, clean air, climate regulation, and disease control. This underscores why we must conserve biodiversity in urban environments.
• Global Concern: Currently, about 25% of species are under threat of extinction, raising alarms worldwide and emphasizing the need for urban habitat restoration.

International Day for Biological Diversity

• Observed on: May 22 every year.
• Theme for 2024: “Harmony with nature and sustainable development”.
• Purpose of the Date: This date marks the adoption of the text of the Convention on Biological Diversity (CBD) on May 22, 1992.

Kunming-Montreal Global Biodiversity Framework (GBF)

• Origin: Developed under the CBD.
• Vision: To conserve and manage 30% of global terrestrial and marine biodiversity by 2030, including urban ecosystems and biodiversity hotspots.

Key Focus Areas

• Four Goals and 23 Targets.
• Target 12: Emphasizes enhancing green spaces and blue spaces in urban planning.
• Link to SDG 11: Aligns with the United Nations Sustainable Development Goal to make cities inclusive, safe, resilient, and sustainable.

Threats to Urban Biodiversity

• Unplanned Development: Rapid and unregulated urban growth has led to the destruction of ecosystems and wildlife habitats.
• Human Greed: Encroachment, pollution, and negligence contribute to biodiversity loss in urban spaces, highlighting the critical role of humans in biodiversity conservation.

Need for Green Spaces in Cities

• Urban Population Surge: Nearly 50% of the global population lives in cities, expected to reach 70% by 2050.
• Demand for Space: Urban areas face competing demands for housing, infrastructure, transport, but urban green spaces and city parks must not be compromised.
• Urban biodiversity must be prioritized for long-term well-being and sustainable urban development.

Benefits of Urban Biodiversity

Health Benefits

• Urban Forests and Green Spaces
  • Provide food, water, and fiber.
  • Help reduce the urban heat island effect.
  • Aid in flood control, water conservation, and pollution reduction.
• Pollution Control
  • Absorb suspended particulate matter and carbon dust.
  • Tree belts (10m wide) can reduce noise pollution by 5 decibels.
• Climate Regulation
  • In Frankfurt, green spaces lowered city temperatures by 3.5°C and increased humidity by 5%.
  • Mental Well-being: Parks and gardens offer recreational and spiritual spaces amidst concrete landscapes.
• Air Quality Improvement: Green spaces contribute significantly to air quality improvement through filtration and carbon sequestration.
• Green Roofs: Implementing green roofs can further enhance urban biodiversity and provide additional ecosystem services. Adaptive management strategies can optimize their performance over time.

Economic Benefits

• Valuation by Experts
  • Theodore Endreny estimated the annual value of urban trees in megacities at around $967,000 (~₹8 crore) per square kilometer, highlighting the importance of urban forests and green infrastructure.
• Action Points
  • Preserve existing greenery.
  • Create new green spaces and parks.
  • Develop tree-lined roads and protect natural water bodies.
  • Improve community health through green infrastructure and ecosystem services.
  • Implement adaptive management approaches for effective biodiversity conservation in urban areas.

Urban Forest Cover in Indian Cities

• Forest Survey of India Findings
  • Average forest cover in leading cities is only 10.26%.
  • Mumbai:43%
  • New Delhi & Hyderabad:6%
• Bengaluru:85%
• Chennai:66%
• Ahmedabad:27%
• Recent Losses (2021–2023)
  • Chennai: Lost 2.6 sq. km of forest.
  • Hyderabad: Lost 1.6 sq. km.

GBF’s Urban Planning Guidance

• Urban Planners’ Tools
  • Use GBF to enhance green and blue areas.
  • Promote ecological connectivity and human well-being through green corridors.
  • Support native species and natural habitats.
  • Implement adaptive management approaches for effective biodiversity conservation in urban areas.
  • Integrate green infrastructure solutions into urban planning and development.

3-30-300 Rule by UN Habitat

• What It Means
  • Every home, office, or school should view at least three mature trees.
  • Neighbourhoods should have a minimum of 30% tree canopy cover.
  • A public green space of 0.5–1 hectare should be within a 300-metre walk or cycle ride from all homes.

City Biodiversity Index (CBI)

• Purpose: Evaluates the biodiversity status of a city, serving as an urban biodiversity index.
• Three Core Parameters:
  • Extent of native biodiversity.
  • Ecosystem services provided.
  • Biodiversity governance.
• ICLEI’s Role: Developed CBI using 23 indicators for Indian cities like Kochi, Gangtok, and Nagpur.
• Next Step: Based on CBI, cities prepare a Local Biodiversity Strategy and Action Plan (LBSAP).

Successful Models of Urban Greening

Chennai’s Koyambedu Market

• Greening Initiative (2021)
  • Led by Care Earth Trust with CMDA funding.
• Outcomes in 2 Years
  • 141 higher plant species (39 families, 106 genera).
  • Attracted 35 bird and 27 butterfly species, key bioindicators of ecological health.

Chennai’s Million Tree Plan

• Prepared by Care Earth Trust (2018)
  • For Greater Chennai Corporation.
  • Target: Plant one million native trees in 5 years.

Madras Race Club Transformation

• Project Aim: Turn land at Guindy into a lake to recharge groundwater and enhance ecosystem services.

Threats to Waterbodies in Indian Cities

• Urban Encroachments:
  • Encroachments and real estate expansion have destroyed many waterbodies.
  • Examples: Chennai and Bengaluru lost vital wetlands.
• Pallikaranai Marsh Restoration:
  • Once used as a dump yard.
  • Now declared a reserved forest and Ramsar site, showcasing successful habitat restoration.
• Need for Restoration
  • Clean waterbodies by preventing garbage dumping.
  • Treat sewage using conventional or nature-based solutions.
  • Grant legal protection to remaining lakes and wetlands.
  • Apply adaptive management strategies to maintain and improve urban water bodies.

Role of Residential and Rooftop Gardening

Disappearance of Trees

• Traditional home gardens with mango, jackfruit, and coconut trees are vanishing due to high-rise buildings.

Policy Suggestion

• GCC should mandate five tree plantings in plots over 2,400 sq. ft.

Green Roofs and Community Gardens

• Promote roof and kitchen gardens to grow greens and medicinal plants.
• Boosts biodiversity and public health.
• Green roofs contribute to urban green infrastructure and ecosystem services.
• Green roofs can aid in stormwater management, carbon sequestration, and air quality improvement.
• Implement adaptive management techniques to optimize the performance of green roofs over time.

Legal and Civic Action for Biodiversity

Strict Enforcement Needed

• City officials must penalize biodiversity destruction and pollution.

Supreme Court’s Intervention

• Criticized destruction of trees in Hyderabad’s Kancha Gachibowli for IT infrastructure.

Guiding Principle

• Development must not come at the cost of biodiversity.

Community Involvement and Mass Movement

• Need for Collective Action
  • Involve resident welfare associations, NGOs, and corporates.
  • Mobilize public awareness and engagement.
  • Make urban biodiversity conservation a citywide movement.
  • Promote urban agriculture as part of green space initiatives.
  • Encourage the implementation of green infrastructure in residential and commercial buildings.
  • Foster adaptive management practices at the community level for sustainable urban ecosystems.

Conclusion

Urban biodiversity is vital for sustainable cities and urban sustainability. Preserving green spaces ensures better health, climate resilience, and economic value. Collective action, inclusive planning, and strict enforcement can create a harmonious future with nature. Sustainable urban development and climate change adaptation rely on effective biodiversity conservation in cities. By prioritizing urban ecology and green infrastructure, we can enhance ecosystem services and create more livable, resilient urban environments. The multifunctionality of green spaces in providing ecosystem services, supporting urban wildlife, and improving air quality underscores the importance of adaptive management approaches in urban biodiversity conservation. As we strive to create sustainable cities, the conservation and expansion of green spaces, including innovative solutions like green roofs, must remain at the forefront of our efforts to ensure a balanced coexistence between urban development and nature.

Source

The Hindu

Mains Practice Question

Discuss the role of green and blue spaces in ensuring urban biodiversity and sustainable development. How can cities implement effective green infrastructure to enhance ecosystem services and promote ecological resilience?