As we embark on the United Nations ‘decade of action’ (see go.nature.com/2opvyi3) and this week’s UN COP25 Climate Change Conference in Madrid, let’s remember the crucial contribution of groundwater to climate resilience and sustainable development.

Besides sustaining drinking water and ecosystems worldwide, groundwater acts as a subsurface sponge for floods. It is a resource against drought and for natural climate solutions that sequester soil carbon. And it is crucial for sustainable development because it enables food security and lifts rural populations out of poverty.

However, these essential benefits are being undermined by the long-term depletion, contamination and salinization of groundwater (see, for example, I. E. M. de Graaf et al. Nature 574, 90–94; 2019).

In our view, groundwater needs to be monitored and managed with greater rigour on regional and global scales so that it can be used more effectively to boost climate adaptation and sustainable development. As members of a global group of scientists and practitioners, we have issued a call to action to international and national governmental and non-governmental agencies, development organizations, corporations, decision makers and scientists, to ensure that groundwater benefits society now and into the future (see go.nature.com/37gnbtb).