This visualization reproduces the Keeling Curve, showing the rise in atmospheric CO₂ concentration from 1958 onward. The chart displays monthly average measurements as a black line over time, with a time-based x-axis and a linear y-axis for CO₂ levels. The data comes from NOAA's Global Monitoring Laboratory. The code uses d3.scaleTime, d3.scaleLinear, d3.line, d3.timeParse, and d3.csvParse within a standard d3.v7 framework to load, parse, and render the time-series line chart. Axes are drawn using d3.axisLeft and d3.axisBottom.