On css.ch, advertising and tracking add ≈ 2,038 g CO₂ per million pageviews (39 g from ad-serving alone) — 0.4× the index average, cleaner than 47% of the sites we measure.
Ad-relevant
2038
g CO₂ / 1M pageviews
Ad-serving only
39
g CO₂ / 1M pageviews
24
kg CO₂ / year at 1M pageviews per month
47
% cleaner than the DACH index
98
% of the footprint is tracking overhead, not ad-serving
Measured on the live electricity grid from public page-load data — an estimate of a site's ad-tech architecture, not a measured campaign figure. See the methodology →