This example visualizes global population distribution by rendering sized circles for cities with populations exceeding 50,000. The visualization uses a natural Earth projection via `d3.geoNaturalEarth1` and `d3.geoPath` to draw countries, graticules, and interiors from World Atlas TopoJSON data. City positions are projected from latitude and longitude coordinates, with circle radii scaled by population using `d3.scaleSqrt`. The React component fetches city data from a Simplemaps World Cities CSV.