Authors: Assistant Professor Ajay Kumar
Abstract: The accelerating rise in atmospheric carbon dioxide (CO₂) concentrations has intensified efforts to enhance terrestrial carbon sinks, particularly through strategic deployment of C₃ and C₄ photosynthetic pathways. This study synthesizes current knowledge on the carbon sequestration potential of C₃ plants, which benefit markedly from CO₂ enrichment but suffer from photorespiration and nutrient constraints, and C₄ plants, which maintain efficiency under heat, drought, and low CO₂ conditions due to their biochemical CO₂-concentrating mechanism. We review field-based flux measurements, remote sensing classification, and genome-scale metabolic models to quantify net primary production responses, soil carbon inputs, and distributional shifts under projected climate scenarios. Findings indicate that C₃ afforestation can maximize sequestration in temperate regions when nutrient limitations are managed, while C₄ bioenergy crops offer robust carbon capture and water-use advantages in warmer, water-limited biomes. We recommend region-specific species selection, integrated methodological frameworks combining eddy-covariance, high-resolution imagery, and mechanistic models, and exploration of synthetic biology and machine-learning tools to refine sequestration estimates. This comprehensive approach informs land-management and policy strategies aimed at mitigating climate change through optimized carbon-negative land uses.
