This visualization presents the weekly mean atmospheric CO2 concentration measured at Mauna Loa, alongside historical comparisons from one and ten years prior. The chart displays the raw weekly data points as a time series, with the increase in CO2 since 1800 also visible. It uses D3.js to render the plot, reading from the NOAA ESRL data files. The visualization directly shows the rising trend of CO2 levels, emphasizing the long-term increase and seasonal cycles through the direct plotting of the dataset values.