Projections of future bioclimatic indicators using bias-corrected CMIP6 models: a case study in a tropical monsoon region

Abstract

This study evaluates the potential impacts of climate change on Bangladesh by analyzing 19 bioclimatic indicators based on temperature and precipitation. Data from 18 bias-corrected CMIP6 global climate models (GCMs) were used, covering four Shared Socioeconomic Pathways (SSPs)—SSP126, SSP245, SSP370, and SSP585—across three future timeframes: near-term (2015–2044), mid-term (2045–2074), and long-term (2075–2100). Under the high-emission SSP585 scenario, average temperatures are projected to rise by up to 3.76 °C, and annual precipitation could increase by 52.6%, reaching up to 3446.38 mm by the end of the century. The maximum temperature (Bio5) could reach 32.91 °C, while the minimum temperature (Bio6) might rise by 4.43 °C, particularly during winter. Precipitation seasonality (Bio15) is projected to increase by as much as 7.9% in the northwest, indicating heightened variability between wet and dry seasons. The diurnal temperature range (Bio2) is expected to decrease by up to − 1.3 °C, signifying reduced nighttime cooling, which could exacerbate heat stress. Significant reductions in temperature seasonality (Bio4) are forecast for the northeast, with notable declines in isothermality (Bio3) under SSP585, pointing to increased climatic extremes. These climatic shifts pose severe risks to agricultural productivity, water resource availability, and biodiversity, particularly in flood-prone regions. The findings highlight the need for urgent adaptation measures, including improved flood management systems, efficient water resource use, and climate-resilient agricultural practices. By providing robust region-specific projections, this study offers critical insights for policymakers and stakeholders to mitigate the adverse effects of climate change and safeguard environmental and economic sustainability in Bangladesh.