Global water data: A newly endangered species

Water science finds itself at an interesting and critical crossroads. Sophisticated atmospheric modeling, remote sensing, and Internet‐based exchange of data enable exciting new synergies to develop among scientists, policy‐makers, and the private sector. Paradoxically we find it evermore difficult to validate products from these high‐technology tools and to exploit their full potential due to a severe and sustained decline in available hydrologic data sets.