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Global-level warming largely influences drought dynamics. Therefore, a robust drought projection is critical to support sustainable development under a future warming climate, especially at the regional level (i.e., South Asia). Encouraged by the Paris Agreement, this study investigates the changes in the intensity, area, and duration of future droughts under 1.5 °C, 2.0 °C, 3.0 °C, and 4.0 °C global warming levels over South Asia. In this regard, seven global climate model outputs under seven newly designed climate change scenarios (SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP4-3.4, SSP4-6.0, and SSP5-8.5) from the sixth phase of the Coupled Model Intercomparison Project (CMIP6) are used. The standardized precipitation evapotranspiration index (SPEI), self-calibrating Palmer drought severity index (scPDSI), and intensity-area-duration (IAD) method are adopted to characterize drought. Drought events are identified considering an area coverage greater than 50,000 km2 for predefined drought durations of 3- (short-term), 6- (medium-term), and 12-month (long-term). A significant drying trend is seen and tested against the two-sample t -test. Notably, to represent the more concrete picture of changes in drought characteristics, the results based on two indices (SPEI and scPDSI) are combined (average) in this paper. The results reveal that droughts with higher-intensity, and long-term duration will increase with continued warming. As drought features, the number of long-term droughts will increase by 21.5% (highest), and the leading area coverage is also estimated (>7%) for long-term drought at higher warming (i.e.4.0 °C) than the reference period (1995–2014). Furthermore, drought events with large-area (>3 × 105 km2) coverage are projected to become more frequent. For drought severity, extreme drought events and associated area coverage are more likely to unfold over the region. However, overall drought conditions are inclined to worsen under higher warming, especially 4.0 °C warming. Importantly, for global warming targets set by the Paris Agreement (1.5 °C and 2.0 °C), drought conditions will be more acute at 2.0 °C than at 1.5 °C. Spatially, a significant drying trend is mainly observed in the western part of South Asia (Southwest-Northwest) according to both drought metrics (SPEI and scPDSI). Notably, NW will experience acute droughts under all warming levels. Droughts in this region will be mainly influenced by the combined effect of decreasing precipitation and escalated evapotranspiration. As global warming increases, a significant increase in PET and temperature is found over South Asia. In addition, the model evaluation shows that the CMIP6-Global climate models (GCMs) are capable of satisfactorily reproducing climate variables and drought events in South Asia. However, our study's findings strongly support the execution of the Paris Agreement target and provide a scientific basis for articulating drought adaptation measures at the regional scale, especially in South Asia. • Intensity-Area-Duration approach is used to analyze future drought over South Asia for 1.5oC - 4.0oC warming. • The modified Penman-Monteith method (considering CO 2) are adopted to estimate PET. • Overall drought conditions will worsen under 4.0oC warming. • The Northwest of South Asia is inclined to be affected by intense drought in the future. [ABSTRACT FROM AUTHOR]

In this paper, future drought characteristics (frequency, duration and intensity) over China are analysed by using four climate models from CMIP6 under the seven SSP-RCP (shared socioeconomic pathway-representative concentration pathway) scenarios (SSP119, SSP126, SSP434, SSP245, SSP460, SSP370, and SSP585) for three defined periods of 2021–2040 (near-term), 2041–2060 (mid-term) and 2081–2100 (long-term). The corresponding four climate models output from CMIP5 are also used to conduct a comparison analysis between CMIP5 and CMIP6 to address the improvements added to CMIP6 in terms of drought identification. The drought characteristics are identified by applying the standardized precipitation-evapotranspiration index (SPEI) at a 12-month timescale and run theory. The results show that CMIP6 has a robust capability to capture historical (1986–2005) drought characteristics. For the future period of 2021–2040, the decrease in precipitation and increase in potential evapotranspiration will lead to continuous dry conditions in the upper and middle Yangtze River basin and eastern Pearl River basin. Relative to the reference period, drought events will be more frequent and severe with longer durations in the Northwest River basins and middle Yangtze River basin. Furthermore, higher emissions signify a greater increase in drought frequency and intensity in the long-term period. Except for the SSP585 scenario, the lower emission scenario corresponds to the higher drought duration soon and in the mid-21st century (2021–2060). This finding is regarded as a "strange phenomenon", which cannot be detected by the previous CMIP5-based emission scenarios (RCP2.6, RCP4.5 and the unlikely pathway RCP8.5). Therefore, additional "possible future"-based scenarios (SSP119, SSP126, SSP434, SSP245, SSP460, and SSP370) should be included in extreme climate studies, especially for the near future and mid-21st century. Notably, compared with CMIP5, the reduced biases in drought characteristics are more likely associated with improvements in the representation of physical processes in climate models from CMIP6. The results of this study could provide a basis for the development of drought adaptation measures over China. • Latest CMIP6 climate models and seven SSP-RCP scenarios are used to analyze the possible changes in droughts over China. • More robust projections will be presented by CMIP6 than CMIP5, due to the better representations in physical processes. • The higher emission signifies shorter drought duration, lower precipitation and PET in mid-21st century over China. [ABSTRACT FROM AUTHOR]