Comment in 2024

Water commons are water resources collectively managed and utilized by communities as common property to support their food security, traditions, and livelihoods. Water commons are under increasing pressure of acquisition, privatization, and grabbing. This Comment analytically defines the water commons, examines their vulnerability to grabbing, and discusses the associated water justice and environmental implications.

Research on the ecological impacts of drought has predominantly focused on the scarcity of water supply, often overlooking divergent ecosystem water demands across vegetation types, regions, and time. These diverse ecosystem water demands need to be incorporated into an effective ecological drought monitoring and assessment framework.

Rivers carry large quantities of carbon and form an important link between terrestrial, marine and atmospheric biogeochemical cycles, yet our observations of river carbon are severely limited. Here we provide a blueprint to build a global River Observation System that would improve our ability to observe and predict changes in this crucial piece of the global carbon cycle.

Earth system model projections of vegetation–climate feedback frequently depend on inaccurate values of evaporation sensitivity to vegetation changes, potentially resulting in misleading conclusions. A promising avenue involves improving the transpiration partitioning parameterizations and incorporating groundwater connections to refine the modelled sensitivity.

With rapidly increasing urbanization, a substantial portion of global freshwater is used for the manufacture of construction materials, such as steel and cement. This threatens to intensify competition over the allocation of blue water (from lakes, rivers and aquifers). However, much less attention has been paid to the virtual water content of materials, and the water–materials nexus.