Semiarid ecosystems have a disproportionately large role in the global carbon cycle, driving trends and interannual variability of the global carbon sink . These systems are highly sensitive to annual precipitation and temperature variations  . The positive trend in semiarid regions is consistent with widespread woody encroachment and increased vegetation greenness  driven by CO2 fertilization and rainfall increases , although some trends are complicated by irrigation practices . Increases in temperature and drought diminish this trend through reduced vegetation productivity and increased vegetation mortality  with indications that this trend is declining or reversing in some locations .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report