UPSC Mains Answer: Assess the impact of global warming on coral life system with examples.

Difficulty Level: Medium

Pre-requisite: Foundational understanding of coral reef biology (symbiotic relationship with zooxanthellae), the greenhouse effect, and the carbon cycle. Familiarity with key climate change reports (e.g., IPCC) and global environmental agreements (e.g., Paris Agreement)

Sub-category: Geography (Environmental Ecology, Biodiversity, and Climate Change)

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Global warming poses an existential threat to coral reef ecosystems, which are among the most biodiverse habitats on Earth. Rising sea temperatures, primarily driven by anthropogenic greenhouse gas emissions, induce coral bleaching—a phenomenon where corals expel symbiotic algae (zooxanthellae) due to thermal stress, leading to starvation and death. For instance, the Great Barrier Reef has experienced mass bleaching events in 2016, 2017, and 2020, with over 50% of its corals lost since 1995. Additionally, ocean acidification, caused by elevated CO₂ levels, weakens coral skeletons by reducing carbonate ion availability, hindering reef growth. The 2019 IPCC report highlights that even a 1.5°C temperature rise could destroy 70-90% of tropical corals. Beyond ecological losses, global warming disrupts coastal protection, fisheries, and tourism economies reliant on coral reefs. Mitigation strategies, such as reducing carbon emissions, establishing marine protected areas, and promoting coral restoration projects (e.g., Australia’s Reef Restoration and Adaptation Program), are critical to safeguarding these fragile ecosystems for future generations.