 Global land evapotranspiration, ET, has been estimated using multiple data sources, such as satellite observations, in situ measurements, and land surface models, LSMs. This paper presents a new synthesis product of global land ET, combining data from 40 different data sets. The results show that the global average ET is 493 millimeters per year, mm slash year, with a range of 460 to 526 mm slash year. The authors also found that the global average ET decreased significantly from 1989 to 1997, but then increased again from 1997 to 2005. These changes were not observed in other studies, suggesting that the data used in this study may be more accurate than previous studies. This article was authored by B. Mueller, M. Hershey, C. Jimenez, and others.