This time-series chart displays San Francisco’s community-wide greenhouse gas emissions from 1990 onward, grouped by sector (such as Buildings, Transportation, and Municipal) with each trend drawn as a separate colored line. Data is aggregated by summing the Emissions_mtCO2e column by sector and year from a CSV file. The visualization uses D3 v7’s `d3.rollups`, `d3.scaleLinear`, and `d3.line` with monotone X interpolation, while color comes from the ColorBrewer Set2 palette via `d3.scaleOrdinal`. An interactive tooltip, built with D3’s selection API, appears on mouse events but is not configured to follow the mouse.