The global Hg flux from natural sources is poorly known. We present data on Hg levels in volcanic fumaroles that, in combination with sulfur analyses and published SO 2 flux data, lead to new global Hg flux estimates. The volcanogenic Hg flux from passively degassing volcanoes is small (30 Mg Hg/yr). The flux from erupting volcanoes is much larger but less well constrained; we estimate it at about 800 Mg/yr. These data are interpreted as evidence for early Hg degassing from magmas. Geothermal sources contribute roughly 60 Mg/yr Hg to the atmosphere, an estimate based on average Hg contents of hot springs and global convective heat transport. Total natural Hg emissions from land amount to 1290 Mg/yr, including a revised soil vapor flux of 400 Mg/yr. Estimates of anthropogenic contributions to the atmospheric Hg budget vary between 3000 and 11 500 Mg/yr and are substantial compared to our natural Hg flux estimate.