This visualization displays global population estimates for 2018 using circles positioned at country centroids on a natural Earth projection, rendered as an SVG. It uses `d3.geoPath` for map geography, `d3.geoCentroid` for circle placement, and `d3.scaleSqrt` to encode population via circle area. The code loads UN population data from a CSV and country boundaries from a TopoJSON file, styling countries and circles with CSS. A legend shows size scaling, and missing data is highlighted in red. Interactivity includes hover highlighting and zooming via `d3.zoom`.