Abstract:

Groundwater is increasingly important for agricultural and domestic purposes. It is a key resource for achieving the United Nations’ Sustainable Development Goals. The quantity and quality of groundwater can be directly or indirectly affected by climate change. The IPCC Sixth Assessment Report (AR6) provides a new understanding of trends in groundwater on a global and regional scale in the past and for the future. The results show that: (1) Groundwater storage has declined in many parts of the world, most notably since the beginning of the 21st century, due to the intensification of groundwater-fed irrigation; (2) Groundwater abstraction is projected to further increase in the future with climate change, including the withdrawals from non-renewable groundwater in major aquifers worldwide; (3) Across the tropics and semi-arid regions, intensification of precipitation is projected to increase due to climate change, and this may increase episodic recharge of groundwater; while in higher altitudes, warmer climates may have led to reduced spring-time recharge due to reduced duration and snowmelt discharges. Stepwise ecological restoration in degraded groundwater areas is an important measure to combat climate change and ensure water security.

Key words: IPCC AR6, Groundwater, Climate change, Groundwater depletion, Stepwise ecological restoration