South Asian perspective on temperature and rainfall extremes: A review

Abstract

Climate change has pushed the natural limits of our environment, creating extreme weather events that are more frequent and more intense in certain locations around the globe. There is evidence of increasing trends in temperature extremes in most countries of South Asia, while in a few regions, temperature extremes have been decreasing. Heatwaves have intensified, which has contributed to accelerating drought and extreme flood events in most South Asian countries. Overall changes in rainfall and temperature have led to alterations in water availability in this region. With few exceptions, the general phenomenon in most South Asian countries is that rainfall intensity has increased, but with a reduced number of wet days. Studies that associate rainfall and temperature in the region of South Asia are scarce and rainfall extremes have been studied more extensively than temperature extremes. In fact, temperature trends are spatially less coherent than rainfall trends in most south Asian countries. It is more likely correlated for the teleconnection and South Asian climate for influencing the temperature and rainfall pattern, rather than any other factors. When it comes to trend estimations, statistical slope detection metrics, such as simple linear regression, have been commonly used to detect and quantify mean trends for countries in the regions of South Asia. However, application lacks in usage of robust nonparametric statistical tests to quantify temperature and rainfall extremes in many countries of South Asia. Statistical downscaling is recommended for better prediction accuracy as well as to find spatial coherence in trends.