This scatter-plot matrix compares daily air quality (AQI), temperature, and annual municipal greenhouse gas emissions in San Francisco from 2020 to 2022. Each cell pairs two variables, with points colored by year using `d3.scaleOrdinal` and `d3.schemeCategory10`. The code loads both CSV files via `d3.csv` with `d3.autoType`, then aggregates emissions per fiscal year using `d3.rollup`. Tooltips appear on hover, and linear scales per trait are created with `d3.scaleLinear`.