A world map highlights the top 10 countries by CO2 emissions, with those nations filled in green while others remain gray. Country names appear at geographic centroids, and hovering over a highlighted country displays its total emissions in million metric tons. The visualization uses D3's `geoNaturalEarth1` projection and `geoPath` to render SVG paths from GeoJSON features, with `geoCentroid` positioning labels and `geoGraticule` available for optional outlines.