Ocean Acidification

Brief Context

Context A recent study has revealed that ocean acidification has breached its planetary boundary, posing grave threats to marine ecosystems and global climate stability. What is Ocean Acidification? Ocean acidification refers to the ongoing decrease in the pH of Earth’s oceans, caused by the uptake of carbon dioxide (CO₂) from the atmosphere.

Source Content

Syllabus: GS3/ Environment

Context

• A recent study has revealed that ocean acidification has breached its planetary boundary, posing grave threats to marine ecosystems and global climate stability.

What is Ocean Acidification?

• Ocean acidification refers to the ongoing decrease in the pH of Earth’s oceans, caused by the uptake of carbon dioxide (CO₂) from the atmosphere. 
• When CO₂ dissolves in seawater, it forms carbonic acid, which lowers ocean pH and reduces calcium carbonate levels – essential for many marine organisms.

Planetary Boundary Breach

• Planetary boundaries are thresholds beyond which the Earth’s vital systems may no longer maintain a stable environment.
• The study finds that by 2020, the average global ocean conditions had already fallen 20% below pre-industrial calcium carbonate saturation, crossing the safe threshold for acidification.
• At 200 metres below the surface, 60% of global waters had breached the “safe” limit for acidification.

Impacts of Ocean acidification

• Calcifying Species Affected: Corals, oysters, mussels, and pteropods (sea butterflies) are most vulnerable.
  • Acidification weakens shells and skeletons, reduces reproduction, slows growth, and increases mortality.
• Fisheries and Livelihoods: Decline in fish nursery grounds affects food security and economic stability of coastal communities.
• Tourism Sector: Coral reef degradation affects tourism and recreational diving industries.
• Climate Feedbacks: Damage to ocean ecosystems like plankton may affect carbon sequestration capacity of oceans. This could amplify global warming over time.
• Social impacts: Climate-linked migration and livelihood loss may increase geopolitical tensions. Rising unemployment in coastal sectors may trigger social unrest.

Initiatives to Tackle Ocean Acidification

• Global Ocean Acidification Observing Network (GOA-ON): GOA-ON is a collaborative international network of 367 members from 66 countries, aimed at enhancing the monitoring and understanding of ocean acidification across estuarine, coastal, and open ocean systems.
• UN Decade of Ocean Science for Sustainable Development (2021–2030): Proclaimed in 2017 by the United Nations General Assembly, it aims to reverse the decline the ocean health through;
  • Stimulating scientific research, technological innovation, and policy-relevant knowledge.
  • Supporting countries to achieve SDG-14 (“Life Below Water) and broader climate resilience.
• Intergovernmental Oceanographic Commission (IOC) of UNESCO: Under its Global Ocean Observing System (GOOS), it supports real-time ocean monitoring including pH and CO₂ measurements.
• Blue Carbon Initiatives provides research, policy advice, and financing mechanisms to promote blue carbon strategies globally.
  • Blue Carbon refers to the carbon stored in coastal and marine ecosystems such as mangroves, salt marshes, and seagrasses.

Way Ahead

• Policy and Governance: Mainstream ocean acidification into national climate and ocean policies.
  • Prioritise Marine Spatial Planning and Integrated Coastal Zone Management.
• Local Adaptation and Conservation: Protect and restore resilient ecosystems, such as mangroves and seagrasses.
  • Implement Marine Protected Areas (MPAs) in regions of high vulnerability.

Concluding remarks

• Ocean acidification is not just a marine problem, it is a multi-dimensional crisis affecting biodiversity, economies, food systems, and climate resilience. 
• Its silent but accelerating pace demands urgent and coordinated policy responses globally and nationally.

Source: Guardian