How is the growing population currently being affected, and how will it be impacted in the future by climate change-induced compound extreme events? This study delves into exposure of the Indian population to compound precipitation-temperature extremes, specifically hot-dry and hot-wet extremes. The study reveals an increase of over 10 million person-years of exposure across various regions in India. In densely populated areas, the increase in hot-wet extremes has been more pronounced compared to hot-dry extremes, a trend that is expected to persist into the future. The research identifies the Indo-Gangetic plain and southern coastal areas as future hotspots.
India being world’s most populous country and sixth most vulnerable to climate extremes, faces escalating climate challenges. The country’s reliance on rain-fed agriculture intensifies the repercussions of increasingly frequent dry spells and heavy rainfalls, a result of erratic precipitation patterns observed since the beginning of the 21st century. Further exacerbating the crisis, India has been warming steadily since the 1980s. This rise in temperatures has led to a spike in heatwaves, causing substantial human fatalities and posing serious threats to health, agriculture, and natural ecosystems. The simultaneous or successive occurrence of these temperature and precipitation extremes, known as compound extremes, poses a greater societal and environmental risk as compared to their individual occurrence.
The journal paper titled “Population Exposure to Compound Precipitation-Temperature Extremes in the Past and Future Climate across India”, authored by Prof. Rajib Maity, Department of Civil Engineering, IIT Kharagpur; Prof. Harald Kunstmann, Institute of Meteorology and Climate Research (IMK-IFU), Karlsruhe Institute of Technology, Garmisch-Partenkirchen, Germany and Ms. Subhasmita Dash, Research Scholar, IIT Kharagpur provides a comprehensive analysis of the impact of climate change on the Indian population through the lens of compound extremes. The research, published in Journal of Hydrometeorology under the American Meteorological Society, delves into the increasing number of compound extremes events due to climate change and their societal consequences in terms of population exposure.
The study specifically focuses on compound precipitation-temperature extremes (hot-dry and hot-wet) across India, a region characterized by a wide variety of climatic regimes and significant variation in population density. Utilizing a copula-based statistical approach, the researchers evaluated changes in population exposure to these compound extremes in the past i.e. 1981-2020 and project future changes for the periods 2021-2060 (near future) and 2061-2100 (far future), under different future warming and socioeconomic development scenarios.
In recent years, from 2001 to 2020, India has experienced a notable increase in both hot-dry and hot-wet extreme weather events, surpassing the frequencies observed in earlier decades. The study highlights that densely populated regions in India are expected to experience more adversity due to the hot-wet extremes in the future as compared to the hot-dry extremes. Considering both hot-wet and hot-dry extremes, the influence of climate is identified as the predominant factor towards the increase in exposure. This emphasizes the crucial role that climate change plays in amplifying the population exposure to compound extremes in a warmer future. Regions like the Indo-Gangetic Plain and the southern coastal areas are identified as future hotspots with maximum increases in exposure under projected warming and population scenarios.
This study explores the population exposure to an increasing number of hydroclimatic extreme events owing to the warming climate. It is well agreed that the extreme events are increasing in terms of frequency as well as intensity due to climate change and that the exposure to compound extreme events (concurrent occurrence of two or more extreme phenomena) affects population, ecosystems, and a variety of socioeconomic aspects more adversely. The results indicate an increase of more than 10 million person-year exposure from the compound extremes across many regions of the country, considering both near and far future periods. The increase is as much as sixfold in many parts of the country, including the Indo-Gangetic Plain and southernmost coastal regions, identified as the future hotspots with the maximum increase in exposure under all the projected warming and population scenarios. The study helps to identify the regions that may need greater attention based on the risks of population exposure to compound extremes in a warmer future. It underscores the critical need to confront climate-related challenges arising from increasing exposure to compound extremes in India.
Prof. Rajib Maity Ms. Subhasmita Dash
Department of Civil Engineering Research Scholar
IIT Kharagpur IIT Kharagpur
Publication:
https://www.uni-augsburg.de/en/campusleben/neuigkeiten/2024/04/15/climate-hotspots-in-india/
Inputs By : Prof. Rajib Maity, Department of Civil Engineering, IIT Kharagpur
Email: rajib@civil.iitkgp.ac.in
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