This area chart visualizes world population growth from 1800 through 2015, using a filled path to emphasize the magnitude of increase over time. The chart employs `d3.area()` with a `curveBasis` smoothing, while `d3.scaleTime` and `d3.scaleLinear` handle the axes. Data loads from a CSV via `d3.csv`, with SVG rendering and custom axis formatting that converts billions to "B" labels.