Conclusion

The assessment of land-use changes with carbon dynamics demonstrates the potential of ecologically fragile Western Ghats in mitigating global warming through carbon sequestration. Land-use analysis reveals the loss of evergreen forest cover from 16 to 11% (1985–2018) with the increase in anthropogenic pressure due to unplanned developmental activities. The simulation of likely changes depicts the region will have merely 10% evergreen cover (in protected areas) with agriculture (17%), plantations (40%) and built-up area (5%). The WG forests stores 1.23 MGg of carbon (both above-ground biomass and soil). The annual increment of 37,507.3 Gg highlights the role of forests in lowering carbon at the regional level. The temporal land-use and climate variable responses have revealed reduction in rainy days (4 days) in Kerala and Tamil Nadu parts of WG with the increase in Maharashtra. The regions in 8–12° latitude are experiencing an increase of 0.5–1°C mean temperature. The results indicate that the future trends of deforestation and associated carbon stock loss would induce higher instances of flooding and drought due to changes in the climate. This analysis demonstrates that land-uses (land-cover) in the Western Ghats landscape have played a decisive role in moderating microclimatic conditions over spatial and temporal scales.

Analyses of rainfall dynamics reveal a declining trend in southern Western Ghats, while an increasing trend in the northern Western Ghats. Across the agro-climatic zones at 1 degree latitude, Ghats and the transition zones in the south (Kerala, Tamil Nadu) show a decrease in rainfall ranging between 40 and 650 mm in the century with a decline of rainy days of 5–10 days. In contrast, the north (Maharashtra, Gujarat) showed increasing trends of rainfall ranging from 120 to 430 mm and rainy days by 3–6 days at Ghats and transition zones between Ghats and plains. Similar trend analyses of temperature show an increasing trend in temperatures all across the Western Ghats. Grid-wise analysis at one degree latitude reveals an increasing trend ranging between 0.31°and 1.1°C in the coast. Similar trends are observed in Ghats (0.1–1.0°C) and transition zones (0.1–0.8°C) with the highest changes in the south, followed by the north, while the central Western Ghats showed low variability in the last century.

The reduction in rainfall or rainy days and an increase in temperature (dryness) can affect carbon stock in the region. The farmers of peninsular India would face the threat of food security with erratic monsoon and lack of water. This necessitates immediate implementation of carbon capture (with afforestation of degraded landscapes with native species, regulations of LULC changes) and de-carbonization (through large-scale implementation of renewable and sustainable energy alternatives) through stringent norms toward
(i) protection of ecologically fragile regions,
(ii) dis-incentives for continued higher emissions based on 'polluter pays' principle and
(iii) incentives for reduced emission.
The WG has sequestered carbon worth INR 100 billion ($1.4 billion) at $30 per tonne of carbon. The analysis emphasizes the need for alternate development paradigm with the focus on conservation of ecologically fragile ecosystems considering the ecosystems' pivotal role in carbon capture, de-carbonization, moderating climate, sustaining water and supporting people's livelihood. Policy measures to mitigate global warming necessitates acceleration of de-carbonization measures including
(i) stringent norms for carbon intensity in the industrial processes and transportation sectors,
(ii) implementation of innovative carbon pricing in agreement with the internationally agreed comprehensive pricing mechanisms,
(iii) shift from linear economy to circular economy through stringent regulations on recycling and reduction of wastes, energy and materials efficiency,
(iv) arresting deforestation through stringent regulation on large-scale land-use changes in the ecologically fragile regions.