Here’s what you’ll learn when you read this story:While most estimates place the current human population at around 8.2 billion, a new study suggests we might be vastly underrepresenting rural areas. Homo sapiens is the most successful mammalian species in Earth history, and it’s not even close. Well, with a background in water resource management, Láng-Ritter looked at a different kind of population data gathered from rural dam projects—300 such projects across 35 countries, to be precise. Unlike global population datasets, such local impact statements provide comprehensive, on-the-ground population counts that are not skewed by administrative boundaries. But a few million or even billion would upend our understanding of human occupation on this planet.