Western Ghats could become India's major carbon sink by century-end
What's the story
A recent study by the Indian Institute of Tropical Meteorology (IITM), Pune, has revealed that the Western Ghats could emerge as one of India's major natural carbon sinks by the end of this century. The research has been published in the International Journal of Climatology. It examines Gross Primary Productivity (GPP), the amount of carbon dioxide absorbed by plants during photosynthesis, using advanced CMIP6 Earth System Models under a high-emission climate scenario.
Productivity increase
Vegetation productivity on the rise
The study found that India's vegetation productivity has been on the rise for the last three decades and is expected to continue doing so until 2100. The Western Ghats, Western Himalayas, and Northeast India are expected to see the biggest future gains. This suggests these regions could play an increasingly important role in carbon dioxide removal from the atmosphere.
Driving factors
Not all good news
Dr. Smrati Gupta said, "The increase in GPP is mainly driven by rising atmospheric carbon dioxide, which enhances photosynthesis, along with projected increases in rainfall over many parts of India." However, she cautioned that this doesn't mean climate change is good for forests as higher temperatures continue to suppress plant productivity during warmer years by increasing heat and moisture stress.
Climate impact
Complex interactions
The study also found that while increased rainfall generally supports vegetation growth, temperature extremes have the opposite effect. After removing long-term climate trends, researchers observed that rainfall anomalies boosted plant productivity, whereas unusually warm conditions reduced it. Dr. Yogesh K Tiwari, corresponding author of the study, said "ecosystems respond differently to rainfall and temperature," highlighting the complexity of these interactions in climate change scenarios.
Model shortcomings
Model limitations
The study also points out the limitations of current climate models. While they capture long-term trends well, they underestimate GPP's overall magnitude compared to satellite observations and flux tower measurements. The researchers stress that improving the representation of hydroclimatic processes and biosphere-atmosphere interactions is crucial for more accurate projections of carbon storage and ecosystem responses in monsoon-dependent regions like India.
Mitigation impact
Implications for climate policy
The study's findings have major implications for India's climate mitigation and carbon budgeting efforts. Forests and other terrestrial ecosystems absorb a large portion of the country's carbon emissions. However, while stronger natural carbon sinks could aid these efforts, the study warns that increased carbon uptake alone cannot counterbalance the broader ecological impacts of climate change.