The Boring Billion

There is a mid-Proterozoic stretch of Earth’s history (roughly 1.9–0.9 Ga) called, non-affectionately, the “boring billion”. The moniker was first inspired several decades ago by the apparent absence of any significant carbon isotope anomalies and was linked to the relatively “boring” interval in between Earth’s broadly two-step pattern in atmospheric oxygenation. However, in light of (i) the original evidence coming from a relatively stable carbon cycles, (ii) the souring over time of the non-flattering term “boring billion” and (iii) the more recent additional clues coming from solid and deep Earth too, we suggest a rebranding to the term the “Balanced Billion”. The first benefit of this change is that it circumvents the subjectivity of what is “boring” as well as the strawman argument used repeatedly in the literature and news media that a new discovery overturns what had previously been thought to be a boring interval. The second, more important benefit of this renaming is that it is not only better marketing but also potentially a more accurate reflection of Earth system processes during the peculiar time—not only the balanced carbon cycle, but also balanced mantle convection and a constant daylength.