Future exacerbation of hot and dry summer monsoon extremes in India

Abstract

Summer monsoon (June-September) precipitation is crucial for agricultural activities in India. Extremes during the monsoon season can have deleterious effects on water availability and agriculture in the region. Here, we show that hot and dry extremes during the summer monsoon season significantly impact food production in India and find that they tend to occur during El Nino years during the observed record of 1951-2018. We then use an ensemble of climate simulations for the historic (1971-2000) and future (2006-2100) that capture this coupling between El Nino and the Indian monsoon to show that the frequency of concurrent hot and dry extremes increases by a factor of 1.5 under continued greenhouse warming during the 21st century. Despite projections of summer monsoon intensification on the order of similar to 10%, the rise in surface air temperatures as well as increase in rainfall variability contributes to more severe hot and dry monsoon extremes over India, thereby posing a substantial challenge to future food security in India.