Terrestrial biosphere water balance analysis: a mathematical model to predict the impacts of climate change on net water budget on global scale

Abstract

The industrial revolution triggered increased greenhouse gas emissions, disrupting the water cycle, and raising global temperatures by 2°C. This shift has induced extreme weather, rising sea levels, altered precipitation, and high evaporation rate. Since agriculture, soil, and health of ecosystems are impacted adaptation and mitigation strategies are crucial. To investigate net water budget (NWB) changes in ecosystems, this study employed the Multi-Source Weighted-Ensemble Precipitation (MSWEP) dataset to assess NWB distribution. Global Land Evaporation Amsterdam Model (GLEAM) database analyzes global land evaporation, revealing a gradual NWB increase since 1980 with sporadic drops during severe droughts. Positive shifts are noted in tropics and mountains, while Egypt, Iraq, Russia, Canada, and Australia suffer declines. NWB variability is the highest in the tropics, temperate, and cold regions, necessitating adaptable water management. Coefficient of variation identifies sensitive zones like tropical and transition climate areas. Latitudinal NWB trends show rising inputs and outputs. Most affected is the "First Tropical Lowland Rain Forest" biome, experiencing significant shifts since 2000 due to input and climate changes. The tropics and transition zones of boreal and temperate climate zones have high sensitivity to NWB change, which is attributed to their unique climatic conditions and ecological characteristics. The sensitivity of most continents is also approximately 40%. The change in the latitudinal average of the NWB between 1980 and 2015 is significant, with inputs and outputs in the NWB increasing over time.