This visualization displays the Keeling Curve, tracking monthly average atmospheric CO₂ concentrations from NOAA’s Mauna Loa records between 1958 and 1967. The line chart shows a clear upward trend in carbon dioxide levels over time. Using D3 v7, the code employs `scaleLinear`, `extent`, `axisLeft`, `axisBottom`, and `line` to map the data from a CSV file, with a black stroke path representing the average readings and gridlines drawn via tick marks.