Dynamics and future projections of Indian forest carbon stocks under different emission pathways using CMIP6 and LPJ-GUESS

Abstract Forests are integral to the global carbon cycle, acting as major carbon sinks, though their capacity can be altered by climate and land use changes. India has a diverse forest ecosystem, but the dynamics and changes in its carbon stocks under a changing climate are not well understood. This study investigates the regional and temporal changes in vegetation carbon biomass (VCB) within Indian forests by assessing changes across the recent past (1960–2020), near-term (2021–2040), mid-term (2041–2060), and long-term (2081–2100) using the LPJ-GUESS Ver.4.1.1 dynamic global vegetation model, forced with climate data from CMIP6 future climate projection. Our results indicate an overall rise in carbon stock across India’s forests leading to a 35%, 62%, and 97% rise by 2100, under low, medium and high emissions, with the scenario trajectories diverging clearly by 2050. Desert and semi-arid regions have a substantial increase in forest VCB under high emissions, followed by the Trans-Himalaya, Gangetic Plain, Deccan Peninsula, and Northeast India in the long term (2081–2100), compared with historical simulations. Meanwhile, the Himalayas and Western Ghats have a comparatively lower increase. VCB trends are positively associated with temperature and precipitation, intensifying after 2040. Climate sensitivity and Granger causality analyses highlight that precipitation variability has a stronger national-scale impact on VCB, while temperature effects vary by region. The precipitation influence typically lags by ∼2 years under low-medium emissions and by ∼4 years under high emissions, while temperature shows a more consistent ∼2 year lag. This study underscores the need for regionally tailored climate strategies and offers insights to guide future climate action, mitigation planning, and environmental sustainability.