Response of summer vegetation in Mongolia to the range of future climate conditions projected by CMIP3 Models: Study using a simple scaling method

Abstract

In Mongolia, drought is one of the most serious meteorological disasters, causing large direct and indirect livestock losses. In this study, we assessed the influence of climate change on future drought risk in Mongolia by simulating vegetation processes. Our simulation considered uncertainty in future climate projection by running offline a modified version of the process-based vegetation model Sim-CYCLE, forced by adjusted climate projection data with a simple scaling method. The scaling factors representing each of the 24 Phase 3 Coupled Model Intercomparison Project (CMIP3) models were obtained from the magnitude of the changes in summer temperature and precipitation from 1940-59 to 2080-99, and multiplied by the projection of MIROC3.2 mediumresolution version, one of the CMIP3 participants. We analyzed the Special Report on Emissions Scenarios (SRES) A1B and A2 scenarios, and the results showed a robust increase in the future August leaf area index (LAI), which is the indicator of summer drought and also the most important variable in estimating livestock loss by winter disasters, and a decrease in the drought (low LAI) frequency across the range of all CMIP3 models under both scenarios.