The relative importance of climate, disturbance  and plant feedbacks in shaping present and future savanna distribution varies between continents , which makes projections of changing the biome extent challenging . It has been shown that simulation studies that do not account for CO2 interactions but only consider climate change impacts do not realistically capture the future distribution of savannas  . Due to the continued strong effect of CO2 on tree and shrub-to-grass ratios in future, models suggest a loss of savanna extent and conversion into closed canopy forest/thicket and an expansion of savanna-type vegetation into arid grasslands . In arid savannas and their interface to grasslands, survival of woody vegetation  will depend on their capacity to survive potentially more severe and frequent droughts . Across a range of models, for RCP4.5 future climate change and CO2 concentrations, savanna expanse declines by around 50%  by 2070 in Africa and South America, 25% in Asia and with small changes in Australia . Future fire-spread is expected to be reduced with increased woody dominance , feeding back to further increase tree-to-grass ratios .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report