Enhanced weather extremes and climatic stresses in the last four decades and future predictions urging mangrove restoration and resilient agriculture in the Sundarban, India

Abstract

Climate change–induced phenomena, including rising sea levels and extreme weather events like floods and drought, are significantly affecting the Sundarban mangrove ecosystems. This study investigates trends in nine temperature and eight precipitation extreme weather indices for the Indian-Sundarban region using daily historical weather data (1982–2017) and the RClimDex graphical interface. Future climate projections were generated using statistical downscaling of an ensemble mean from 19 general circulation models under Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 scenarios. The results indicate significant change over the past four decades, including increased annual mean minimum temperatures, reduced cool nights, more warm nights, fewer cool days, and a decreased diurnal temperature range. Precipitation trends show a rise in heavy rainy days, along with longer consecutive dry and wet periods. Future projections reveal a consistent increase in annual rainfall under RCP 4.5 (0.3–3.8%) and RCP 8.5 (3.0–6.3%), alongside a gradual increase in mean temperatures under RCP 4.5 (up to 1.2 °C for minimum and 1.3 °C for maximum temperature) and sharper increases under RCP 8.5 (up to 2.9 °C for minimum and 3.0 °C for maximum temperatures). These trends highlight the escalating risks to Sundarban mangroves, which are critical for protecting the mainland from flooding, tidal waves, cyclones, and coastal erosion. Enhanced extreme events, such as increased flooding and droughts, underscore the urgent need for robust conservation measures, including mangrove restoration and climate-resilient agriculture. Linking adaptation and mitigation strategies with a strong policy framework is essential to safeguard the Sundarban ecosystem and its vital services.