Oceans of Opportunity: Carbon Capture for Net-Zero India

Climate change has emerged as one of the most pressing challenges of our time, significantly driven by the emission of greenhouse gases (GHGs) like carbon dioxide (CO₂), nitrous oxide (N₂O), and methane. India finds itself in a critical position as the third-largest emitter of CO₂ globally, contributing approximately 2.6 gigatonnes annually. CO₂ concentrations have surged by over 32% since the Industrial Revolution, raising concerns about the severe environmental repercussions. The alarming 2018 IPCC Report cautions that if global warming continues unabated, it could surpass 1.5°C by 2040, leading to catastrophic sea-level rises and biodiversity loss. To combat this, significant measures are required, including a 45% reduction in emissions by 2030 and achieving net-zero emissions by 2050. Notably, India has committed to halving its CO₂ emissions by 2050 and setting a net-zero target by 2070.

Beneath the Surface: Techniques for Ocean-Based Carbon Capture

As the world grapples with climate change, Carbon Capture, Utilisation, and Storage (CCUS) and Carbon Dioxide Removal (CDR) technologies are becoming critical solutions alongside energy efficiency and renewable resources. CDR focuses on removing existing CO₂ from the atmosphere or oceans, while CCUS captures carbon emissions from industrial sources and power plants, pushing it into innovative uses or storage solutions.

Effective deployment of CCUS and CDR could potentially absorb up to 14% of CO₂ by 2060, stabilizing concentrations around 450 ppm by 2100. According to NITI Aayog, these technologies could also foster economic growth by creating 8-10 million full-time jobs by 2050.

“Researchers and companies are increasingly exploring ways to harness the ocean’s natural chemical and biological processes to absorb and store CO₂.”

The Blue Shift in CCUS: Approaches to Ocean-Based CCUS

CCUS technologies utilize various methods, including biological, geological, and ocean-based sequestration. While land-based strategies like reforestation show promise, the ocean—covering 70% of the planet—represents the largest carbon sink. It holds about 50 times more carbon than the atmosphere and 16 times more than terrestrial storage. The ocean’s potential as a carbon repository offers a strategic pathway to global decarbonization.

Innovators are increasingly looking toward these natural oceanic processes to capture and store CO₂ effectively.

Ocean-based Negative Emission Techniques

Ocean-based sequestration presents unique advantages, utilizing low temperatures and high pressure to stabilize CO₂ in liquid form, significantly minimizing leakage risks. The deep-sea environment also reduces the chances of groundwater contamination, making this method scalable without overwhelming land-based infrastructures. Key ocean-based Negative Emission Techniques (NETs) include:

• Ocean Alkalinity Enhancement (OAE): Involves adding pulverized minerals like lime to increase seawater alkalinity, accelerating CO₂ absorption from the atmosphere.

• Electrochemical Seawater Processing: Uses electric currents to treat seawater, enabling the extraction of valuable minerals while producing hydrogen and oxygen.

• Biological Carbon Capture: Leverages marine ecosystems to utilize photosynthesis for transferring carbon from the surface to the deep sea, facilitating long-term carbon storage.

• Ocean Fertilization: Involves adding micronutrients to promote phytoplankton growth, which in turn enhances deep-ocean carbon retention.

• Marine Protected Areas: Vital habitats like mangroves and coral reefs serve as significant carbon sinks, supporting biodiversity and delivering additional ecological benefits.

Leveraging India’s Potential for Ocean-based CCUS

India’s extensive coastline of over 11,000 km and approximately 2 million sq. km of Exclusive Economic Zones (EEZ) present significant opportunities for ocean-based CCUS. Techniques like OAE promise durable carbon storage, with lifespans extending up to 100,000 years. Remarkably, the cultivation of seaweed could lead to annual carbon captures of 0.6 gigatonnes, potentially reaching 1 gigatonne with supplementary ocean fertilization efforts.

Moreover, the repurposed CO₂ can find applications across various industries, including food and beverage, healthcare, biofuels, and construction materials. However, scaling up seaweed farming—a requirement of 64% increase—will be crucial to achieving these targets by 2030.

“Global interest in ocean-based NETs is growing. Most nations have included CDR in their long-term climate strategies under the United Nations Framework Convention on Climate Change.”

Global Efforts in Ocean-based CCUS: From Startups to National Initiatives

As awareness of ocean-based NETs increases, countries like the US and Japan are amplifying their focus on CDR techniques. Initiatives such as the US Department of Energy’s Carbon Negative Shot aim to reduce CDR costs to approximately $100 per net ton of CO₂ by 2030. Funding opportunities from programs like Horizon Europe encourage seaweed cultivation techniques and electrochemical processes.

A plethora of startups are innovating in ocean-based carbon solutions. For example, Amsterdam-based Brineworks employs electrolysis for CO₂ extraction from seawater, while companies such as SeaO2 and Captura utilize electrodialysis for CO₂ capture, further bolstered by ocean reabsorption capabilities.

Advancing Research and Development for Scalable Ocean CCUS Solutions

India’s journey toward ocean-based CDR (OCDR) is fraught with challenges including scale-up difficulties, technological readiness levels, and environmental impacts. Limited information on the efficiency and potential of these newer methods necessitates robust research and development efforts.

Central to this endeavor should be the National Mission on Ocean-Based CCUS, which must focus on innovation, safety, and thorough techno-economic evaluations. Increasing the country’s investment in research and development from below 1% of GDP to 2-3% will be essential for improving technological readiness and overall effectiveness.

Fostering Technology and Innovation to Advance Ocean-Based CCUS

To transition OCDR technologies from the lab to scalable applications, both public and private sectors must encourage support for advanced monitoring technologies. High-precision sensors and underwater vehicles capable of monitoring seawater chemistry are fundamental for effective implementation.

Key government ministries like the Ministry of Earth Sciences and the Ministry of Environment, Forest and Climate Change must drive policies aimed at improving collaboration between research institutions and industry stakeholders, thus facilitating the innovation landscape.

Strengthening Standard Regulatory and Monitoring Systems

A robust, standardized Measurement, Reporting, and Verification (MRV) framework is essential for transparent carbon accounting in CCUS. By supporting studies on variables that impact carbon sequestration, such as seawater chemistry and ocean dynamics, India can enhance its regulatory efforts. Institutions tasked with monitoring, like the Voluntary Carbon Market Integrity Initiative, should work alongside government bodies to ensure rigor and compliance.

Empowering Coastal Community Engagement in Ocean CCUS Efforts

Engaging coastal communities in CCUS strategies is vital for successful implementation. Policy frameworks should promote a bottom-up approach, ensuring that local voices are integrated into planning and benefit-sharing concepts. Skill development initiatives tailored to local contexts can empower communities, especially leveraging the involvement of women in activities like offshore algae cultivation.

Towards a Net Zero Blue Economy

Ocean-based CCUS stands as a crucial avenue for India to approach its ambitious net-zero targets by 2070. While global efforts are ramping up, India must shift its policies to incorporate CCUS into a broader climate strategy. This technology offers the potential for new economic opportunities in green fuels, bio-based materials, and carbon credits, directly contributing to sustainable growth and the envisioned blue economy.

Poornima V B is a Research Intern at the Observer Research Foundation.