A line chart displays atmospheric CO2 levels over time using monthly measurements. The visualization is rendered as an SVG within a React application, utilizing D3 v7 methods including `scaleTime`, `scaleLinear`, `line`, and `axisBottom`. Data loaded from a local CSV file includes years, months, and CO2 values, with missing data points filtered out before scaling. The chart updates responsively based on container dimensions, allowing the line to adapt to resizing. Axes are labeled with date and CO2 level measurements.