Worldwide, woody cover is increasing in savannas , as a result of interactions of elevated CO2 and altered fire and herbivory impacts, some of which stems from LULCC  . In some regions, altered climate may also contribute . Elevated CO2 benefits plants with C3 photosynthesis , more than C4 species . Increases in woody vegetation in grassy ecosystems could provide some carbon increase  , but is expected to decrease biodiversity  and water availability  and alter ecosystem services like grazing and wood provision  .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report