Could the Seas Turn the Tide in Our Fight Against Climate Change?

Could the Seas Turn the Tide in Our Fight Against Climate Change?

Sub : Env

Sec: Climate change

Why in News

• With climate change intensifying and traditional land-based carbon capture approaches nearing saturation, focus is shifting to marine carbon dioxide removal (mCDR). The ocean, as a critical carbon sink, is being explored for its immense potential to combat global warming.

About Marine Carbon Dioxide Removal (mCDR):

• Marine Carbon Dioxide Removal (mCDR) involves engineering the marine environment to enhance the ocean’s capacity to absorb and store carbon dioxide (CO₂).
• The process is gaining attention as a complement to reducing emissions, aiming to help achieve net-zero targets by utilizing the vast carbon sink potential of oceans.
• Biotic (Nature-Based) Approaches: Utilizes ecosystems such as mangroves, seagrasses, and macroalgae for carbon capture.
• Abiotic (Engineered) Approaches: Employs physical or chemical interventions like Ocean Alkalinity Enhancement (OAE). Adds alkaline materials to seawater to lock CO₂ in dissolved inorganic forms.
• Below are key aspects of mCDR summarized in concise points:
• Biological Carbon Pump: Enhancing natural processes like phytoplankton photosynthesis, where carbon is absorbed and sequestered in deep-sea sediments for centuries​.
• Iron Fertilization: Adding iron to nutrient-limited areas to boost phytoplankton growth. Risks include harmful algal blooms and ecological imbalances​.
• Artificial Upwelling: Bringing nutrient-rich deep waters to the surface to stimulate phytoplankton activity. Challenges include energy demands and potential disruption of marine ecosystems​.
• Alkalinity Enhancement: Introducing minerals like limestone to increase ocean alkalinity and improve CO₂ absorption​.
• Seaweed Cultivation: Farming large-scale seaweed to capture CO₂ via photosynthesis. Some biomass is harvested, while the rest sinks, storing carbon long-term​.
• Indian Ocean Potential: Holds promise for deep carbon burial, potentially capturing 25–40% of marine CO₂ emissions.
• Global Carbon Budget: At the current rate, the remaining 570 billion tonnes of CO₂ budget will be exhausted by 2031. Marine interventions could delay this timeline, aiding the transition to net-zero emissions by 2050.