NCB Report 2025 Highlights Carbon Uptake Potential of Concrete in India

Overview

The Global Cement and Concrete Association (GCCA) India, in collaboration with the National Council for Cement and Building Materials (NCB), released a groundbreaking report titled "Carbon Uptake by Concrete" on the 63rd Foundation Day of NCB, celebrated on 26th December 2025. This study challenges conventional perceptions of concrete as merely a carbon emitter.

Key Findings

• Concrete absorbs atmospheric CO₂ throughout its lifecycle through natural carbonation
• Acts as a passive carbon sink, particularly effective under Indian climatic conditions
• The cement sector contributes approximately 7% of total global anthropogenic CO₂ emissions
• Despite emissions, concrete's carbon absorption capacity is significantly underreported

Carbonation Process Explained

• Atmospheric Interaction: CO₂ from air penetrates concrete surfaces over time
• Chemical Reaction: CO₂ reacts with calcium hydroxide (Ca(OH)₂) in concrete
• Calcium Carbonate Formation: Produces calcium carbonate (CaCO₃), effectively sequestering carbon
• Lifelong Process: Continues throughout the structure's operational life and beyond

Report Recommendations

• Accurate Carbon Accounting: Develop precise methods to measure concrete's carbon absorption
• Improve Data Quality: Enhance robustness of data collection on concrete usage and exposure conditions
• Refine Estimation Methods: Create India-specific models for national carbon inventories
• Policy Integration: Recognize concrete's role in sustainable construction policies

Industry Context

Classified as a hard-to-abate industry, the cement sector faces unique decarbonization challenges. This report offers a nuanced perspective by highlighting concrete's dual role. Under Indian climatic conditions—characterized by high temperatures and humidity—carbonation occurs more rapidly, making Indian concrete structures particularly effective carbon sinks.