Impact on Biodiversity — Revision Notes
⚡ 30-Second Revision
- Biodiversity: — Variety of life (genes, species, ecosystems).
- Climate Change Drivers: — GHG emissions, temperature rise, altered precipitation, extreme events.
- Key Impacts: — Habitat loss, range shifts, phenological mismatches, trophic cascades, extinction debt, ocean acidification, coral bleaching, sea-level rise.
- Vulnerable Indian Ecosystems: — Western Ghats, Eastern Himalayas, Sundarbans, Andaman/Lakshadweep coral reefs.
- Legal Frameworks (India): — WPA 1972, BD Act 2002, FRA 2006.
- International Agreements: — CBD (Kunming-Montreal GBF), CITES, Ramsar, Paris Agreement (Art 6.8).
- Conservation Strategies: — Nature-based Solutions (NbS), Ecosystem-based Adaptation (EbA), assisted migration, ex-situ conservation, climate refugia.
- IPCC AR6: — Confirms widespread, rapid impacts, urgent need for mitigation/adaptation.
- Biodiversity-Climate Paradox: — Loss of biodiversity weakens natural climate regulation, accelerating warming.
2-Minute Revision
The impact of climate change on biodiversity is a critical UPSC topic, highlighting how rising global temperatures, altered precipitation, and extreme weather events fundamentally disrupt life on Earth.
At the species level, organisms face physiological stress, forcing them into range shifts towards poles or higher elevations, often leading to habitat fragmentation. Crucially, phenological mismatches occur when the timing of biological events (e.
g., flowering, migration) becomes desynchronized between interacting species, disrupting vital ecological relationships. Ecosystems experience community composition shifts and trophic cascades, leading to the degradation of essential services like water purification and carbon sequestration.
Marine biodiversity is severely threatened by ocean acidification, which harms calcifying organisms, and coral bleaching due to warming waters. India's biodiversity hotspots, such as the Western Ghats and Sundarbans, are particularly vulnerable, facing unique threats like altered monsoons and sea-level rise.
Conservation efforts are evolving to include Nature-based Solutions (NbS) and Ecosystem-based Adaptation (EbA), which leverage healthy ecosystems for both climate mitigation (e.g., carbon sequestration in forests) and adaptation (e.
g., mangroves for coastal protection). Legal frameworks like the Wildlife Protection Act and Biological Diversity Act provide a foundation, but require integration with climate action plans. Understanding this complex interplay, including the 'Biodiversity-Climate Feedback Loop Paradox,' is essential for a holistic UPSC preparation.
5-Minute Revision
The impact of climate change on biodiversity is a profound and accelerating crisis, demanding a comprehensive understanding for UPSC. Climate change, driven by anthropogenic greenhouse gas emissions, manifests through rising temperatures, altered precipitation patterns, and increased frequency of extreme weather events.
These changes directly affect species' physiological processes, pushing many beyond their thermal tolerance limits and forcing them into range shifts towards cooler latitudes or higher elevations. This often leads to habitat fragmentation, reducing genetic diversity and increasing extinction risk.
A key concept is 'phenological mismatch,' where the timing of interdependent biological events (e.g., plant flowering and pollinator emergence) becomes desynchronized, disrupting critical ecological interactions and food webs, potentially leading to 'trophic cascades.
' The concept of 'extinction debt' highlights that past climate impacts have already committed some species to future extinction, even if conditions stabilize.
Marine ecosystems face unique threats: ocean acidification, caused by increased CO2 absorption, impairs calcifying organisms like corals and shellfish, while rising sea temperatures trigger widespread coral bleaching.
Sea-level rise threatens coastal habitats like mangroves and wetlands. In India, iconic ecosystems like the Western Ghats (vulnerable to monsoon shifts), Eastern Himalayas (glacier melt, upward migration), Sundarbans (sea-level rise, cyclones), and Andaman/Lakshadweep coral reefs (bleaching, acidification) are at high risk.
This creates a 'Biodiversity-Climate Feedback Loop Paradox' – biodiversity loss weakens natural climate regulation (e.g., reduced carbon sequestration by forests), which in turn accelerates climate change and further biodiversity decline.
Addressing this requires integrated strategies. Mitigation efforts focus on reducing GHG emissions, often through Nature-based Solutions (NbS) like afforestation and peatland restoration, which also provide biodiversity benefits.
Adaptation strategies aim to help species and ecosystems cope with unavoidable impacts, utilizing Ecosystem-based Adaptation (EbA) such as restoring mangroves for coastal protection or creating wildlife corridors.
Other strategies include assisted migration and ex-situ conservation. India's legal frameworks (Wildlife Protection Act 1972, Biological Diversity Act 2002, Forest Rights Act 2006) provide a foundation, but their effectiveness needs strengthening through explicit climate-biodiversity integration, enhanced funding, and community participation.
International agreements like the Kunming-Montreal Global Biodiversity Framework and the Paris Agreement (especially Article 6.8 on non-market approaches) guide global efforts. For UPSC, linking these scientific impacts, policy responses, and Indian examples is crucial for analytical answers.
Prelims Revision Notes
- Biodiversity Definition: — Genetic, species, and ecosystem diversity. Crucial for ecosystem services.
- Climate Change Mechanisms: — Temperature rise (thermal tolerance), precipitation changes (droughts/floods), extreme events (wildfires, storms), sea-level rise, ocean acidification.
- Species-Level Impacts: — Physiological stress, range shifts (poles/elevations), phenological mismatches (asynchronous timing), reproductive impairment, genetic erosion.
- Ecosystem-Level Impacts: — Community composition shifts, trophic cascades (food web disruption), ecosystem service degradation (carbon sequestration, water regulation, pollination).
- Key Concepts:
* Habitat Fragmentation: Breaking up continuous habitats. * Extinction Debt: Future extinctions from past impacts. * Climate Refugia: Areas stable under climate change. * Nature-based Solutions (NbS): Ecosystem actions for societal challenges (e.g., afforestation, mangrove restoration). * Ecosystem-based Adaptation (EbA): Using ecosystem services for adaptation.
- Vulnerable Indian Ecosystems (Examples):
* Western Ghats: Monsoon variability, temperature rise, endemic species. * Eastern Himalayas: Glacier melt, upward migration, landslides. * Sundarbans: Sea-level rise, cyclones, saltwater intrusion. * Andaman/Lakshadweep Coral Reefs: Ocean warming (bleaching), acidification.
- Indian Legal Frameworks:
* Wildlife Protection Act, 1972: Protected areas, species protection. * Biological Diversity Act, 2002: CBD implementation, ABS, sustainable use. * Forest Rights Act, 2006: Community rights, conservation role.
- International Agreements:
* CBD (Kunming-Montreal GBF): Global targets for biodiversity, climate link. * Paris Agreement (Art 6.8): Non-market approaches, non-carbon benefits. * CITES: Regulates trade in endangered species. * Ramsar Convention: Wetlands of international importance.
- Current Affairs: — IPCC AR6 findings, COP outcomes, India's updated NDCs and NBAP. Focus on recent reports and policy shifts.
- Distinguish: — Mitigation (reducing emissions) vs. Adaptation (adjusting to impacts). Both crucial for biodiversity.
Mains Revision Notes
- Introduction: — Define biodiversity and state climate change as a primary driver of its loss. Emphasize the interconnectedness.
- Mechanisms of Impact: — Detail how temperature, precipitation, extreme events, sea-level rise, and ocean acidification lead to biodiversity loss. Use scientific terms like thermal tolerance, range shifts, phenological mismatches, trophic cascades, and extinction debt.
- Indian Context & Case Studies: — Provide specific, well-articulated examples from India's vulnerable ecosystems (Western Ghats, Eastern Himalayas, Sundarbans, coral reefs). Explain the unique threats and species affected in each.
- The Biodiversity-Climate Feedback Loop Paradox (Vyyuha Analysis): — Explain how biodiversity loss exacerbates climate change (e.g., reduced carbon sinks, weakened coastal protection) and vice-versa, creating a vicious cycle. Argue for integrated solutions.
- Conservation Challenges: — Discuss habitat fragmentation, limited adaptive capacity of species, funding gaps, implementation challenges, and the need for inter-sectoral coordination.
- Emerging Conservation Strategies:
* Nature-based Solutions (NbS) & Ecosystem-based Adaptation (EbA): Define, provide examples (mangrove restoration, agroforestry, watershed management), and discuss their co-benefits for climate and biodiversity. * Assisted Migration & Climate Refugia: Explain these adaptive measures. * Ex-situ Conservation: Role as a last resort.
- Legal and Policy Frameworks (India): — Analyze the strengths and weaknesses of WPA 1972, BD Act 2002, FRA 2006, and National Biodiversity Action Plan. Discuss their relevance and suggest measures for strengthening (e.g., explicit climate integration, funding, community participation, science-policy interface).
- International Cooperation: — Highlight the role of CBD (Kunming-Montreal GBF), Paris Agreement (Art 6.8), and other conventions in guiding national action and fostering global collaboration.
- Conclusion: — Reiterate the urgency of integrated, adaptive, and equitable approaches to safeguard biodiversity for a climate-resilient future. Emphasize the synergy between conservation and sustainable development.
Vyyuha Quick Recall
CLIMATE-BIO for Impact Pathways:
- Coastal Inundation (Sea-level rise)
- Loss of Habitat (Fragmentation, degradation)
- Increased Temperatures (Thermal stress, bleaching)
- Mismatched Phenology (Timing disruptions)
- Acidification of Oceans (Calcifier impacts)
- Trophic Cascades (Food web disruptions)
- Extreme Events (Wildfires, floods, storms)
- Biodiversity Loss (Genetic, species, ecosystem)
- Invasive Species (Increased vulnerability)
- Overexploitation (Exacerbated by climate stress)