Assessing Regional-Scale Heterogeneity in Blue–green Water Availability under the 1.58c Global Warming Scenario
Department of Science and Technology, Ministry of Science and Technology, India, Grant None
Abstract
The 2015 Paris Agreement outlined limiting global warming to 1.58C relative to the preindustrial levels, ne-cessitating the development of regional climate adaptation strategies. This requires a comprehensive understanding of how the 1.58C rise in global temperature would translate across different regions. However, its implications on critical agricultural components, particularly blue and green water, remains understudied. This study investigates these changes using a rice-growing semiarid region in central India. the aim of this study is to initiate a discussion on the regional response of blue–green water at specific warming levels. using different global climate models (GCMs) and shared socioeconomic pathways (SSPs), the study estimated the time frame for reaching the 1.58C warming level and subsequently investigated changes in regional precipitation, temperature, surface runoff, and blue–green water. the results reveal projected reduc-tions in precipitation and surface runoff by approximately 5%–15% and 10%–35%, respectively, along with decrease in green and blue water by approximately 12%–1% and 40%–10%, respectively, across different GCMs and SSPs. These findings highlight 1) the susceptibility of blue–green water to the 1.58C global warming level, 2) the narrow time frame available for the region to develop the adaptive strategies, 3) the influence of warm semiarid climate on the blue–green water dynamics, and 4) the uncertainty associated with regional assessment of a specific warming level. This study provides new insights for shaping food security strategies over highly vulnerable semiarid regions and is expected to serve as a refer-ence for other regional blue/green water assessment studies.
