From Monsoon Stability to Climatic Extremes: A Geographical Analysis of Rising Heatwaves and Cloudbursts in India under Climate Change

Abstract

India's climate is undergoing a profound structural transformation, moving from the relatively predictable monsoon rhythms that have anchored subcontinental agriculture for millennia toward an era of intensifying extremes. This systematic review and meta-analysis synthesises 47 peer-reviewed studies published between 2017 and 2026 to examine the geographical, agricultural, hydrological, and socio-environmental dimensions of two dominant extreme event types: heatwaves and cloudbursts. Drawing on data from Scopus, Web of Science, ScienceDirect, SpringerLink, and Google Scholar, the review applies PRISMA-compliant screening and quantitative pooling of effect sizes across regional and thematic strata.

Meta-analytic estimates reveal that heatwave frequency has increased by approximately 2.3 events per decade (95% CI: ±0.8) across the Indo-Gangetic Plains and Peninsular India, while mean maximum temperature trends reach +0.62°C per decade (±0.18). Extreme rainfall intensity has risen by 8.4% per decade (±2.9%), with cloudburst frequencies in the Himalayan region increasing by 1.8 events per decade (±0.9). Agricultural losses are quantified at −4.7% kharif yield and −5.9% rabi wheat yield per degree Celsius of warming, with compounding effects from erratic monsoon onset and flash flood damage. The synthesis identifies critical data gaps, particularly for the North-East and semi-arid regions, and underscores regional imbalances in observational infrastructure. The paper concludes with policy-relevant recommendations spanning climate adaptation, disaster risk reduction, and agricultural resilience, alongside a structured framework for improving the academic impact of future studies in this domain.