The Nilgiri Biosphere Reserve, spread across Tamil Nadu, Kerala, and Karnataka, is a region with high biological and cultural diversity. It is home to over 20 indigenous communities and thousands of species of flora and fauna, many of which are endemic to the region. However, the Reserve’s socio-ecological landscape faces severe threats from climate change. Local cultural knowledge on adaptation and resilience is a crucial tool to help address these threats; unfortunately, climate change research has not adequately represented this knowledge, and the region lacks adequate climate monitoring infrastructure.

Climatic and anthropogenic factors, such as erratic rainfall trends, extreme events, gradual temperature rise, irregular construction activities by humans, and a decrease in natural forest cover, have disrupted the long-term patterns of the biosphere. These disruptions have resulted in an overall reduction in annual rainfall; while extreme rainfall events have led to soil erosion, reduced land fertility, and lower vegetation yield. In 2019, the Avalanche and Emerald Valley regions of the Reserve received an unprecedented 900-millimeter (mm) rainfall within 24 hours. It broke the record for the highest rainfall in Tamil Nadu, by nearly twice the amount, and for over 4 days, the region experienced close to 2,500 mm of rainfall. Consequently, the increased frequency of extreme weather events, including floods, droughts, and landslides, is affecting both the people and nature in the region. Moreover, the gradual temperature increase has negatively impacted endemic species such as Anaphalis neelgerryana, Helichrysum wightii, and Andropogon polyptychus. To add to this, activities such as clearing grasslands for tea plantations, and introduction of exotic plant species for fuelwood, paper production, and other purposes has already been a major contributor behind reduction in the nature area of the biosphere reserve and threatened the natural habitats of local fauna, including the Nilgiri Tahr.

The region is also home to the endangered shola forest-grassland mosaic ecosystem, which has been severely impacted by landscape changes since the nineteenth century, affecting indigenous people’s traditional livelihoods and life choices. The shola-grassland mosaic ecosystem, growing along the folds and valleys of the Nilgiri mountains and harboring several endemic and rare species of flora and fauna, is at risk of habitat loss and destruction. The montane grasslands cover larger portions of the mountains, mainly where shola forests do not exist. Together, the shola-grassland mosaic ecosystem is highly efficient in absorbing and slowly releasing high rainfall throughout the year, contributing to the formation of perennial streams. However, even this resilient ecology cannot withstand the tremendously high amounts of rainfall the region is experiencing due to worsening climate change, leading to ecosystem collapse.

While conservationists and activists are fighting to protect forests and wilderness areas from deforestation, mining, and diversion to other projects; the indigenous communities in the region have managed to sustain some of their traditional socio-ecological landscape management practices. Their role in supporting the long-term sustainability of the shola-grassland mosaic is crucial for conserving this endangered and highly biodiverse ecosystem while preserving their unique indigenous culture. Unfortunately, this local knowledge, as well as related practices that could help adapt and cope with climate change and its impacts are not being adequately recognised in climate change research; moreover, there is a lack of proper infrastructure for monitoring climate conditions in the area.