This line chart displays CO2 emissions over the years, using a smooth curve to connect data points from a CSV dataset. The visualization uses D3 v5's `scaleLinear`, `axisBottom`, `axisLeft`, and `line` with `curveBasis` to render the chart as an SVG. A maroon line path and styled axis labels with gridlines are included. The code loads data via `csv` from a gist, formats numeric fields, and appends axes, labels, and a title within a group element.