An Overview of Climate Change Over South Asia: Observations, Projections, and Recent Advances

South Asia is among the most populous regions of the earth, which houses fast-developing economies. The unique geographical settings and socioeconomic–demographic structure of the region make it highly vulnerable to the risks posed by climate change, as documented by several comprehensive scientific research reports. Human-induced climate change signatures have already been noted in the form of increasing extremes (e.g., cyclones, droughts, floods, heatwaves, thunderstorms, etc.), rising sea levels, and changing monsoon patterns over the region. South Asia and surrounding regions have already been subjected to the effects of climate change, which has mostly been non-uniform in time and space. Though considerable progress has been made toward understanding the science of climate change, regional climate change consequences are still not well understood and limited by sparse observational networks and inadequate knowledge of region-specific physical processes, often leading to large spread and uncertainties in model projections. Based on the available literature, the chapter presents an overview of the past, present, and future projections of climate over South Asia. Recent advances in observations and dedicated regional and earth system modeling activities over the region are also discussed alongside other emerging methodologies and tools, which can lead to the overall improvement in understanding of physical processes. We discuss the studies that have been carried out in the past and also the prospective gap areas that can be pursued in the future through the use of a combined framework of modern observation–modeling–analysis techniques.