Why Website Carbon Emissions Matter in 2026 The internet accounts for approximately 3.7% of global greenhouse gas emissions — comparable to the aviation industry. As the EU Green Claims Directive, CSRD and consumer expectations push companies toward measurable sustainability commitments, adding a carbon footprint badge to your website is both a technical and marketing move. How Website Carbon is Calculated The calculation methodology used by most tools follows the Sustainable Web Design (SWD) model v4, which considers: Data transfer per page view (measured in MB) Grid carbon intensity (gCO₂/kWh, varies by country and CDN location) Device energy (estimated from transfer volume) Network infrastructure energy The standard formula yields a result in grams of CO₂ per page view. A lean page (under 500KB) typically produces 0.1–0.3g CO₂/visit. A bloated page (>3MB) can reach 1.5–2.5g.…