Portfolio Carbon Intensity Calculator

Weighted average carbon intensity answers a narrow question: how carbon-efficient are the companies a portfolio holds, relative to the revenue they generate. Each holding contributes its own intensity, Scope 1 plus Scope 2 emissions in tonnes CO2e divided by revenue in millions of dollars, multiplied by its share of portfolio market value. Normalizing by revenue rather than by absolute emissions is what allows a small specialty chemicals firm and a large software firm to be compared on the same axis, and it is why WACI can be computed for a portfolio without knowing anything about ownership percentages. Attributed or financed emissions answer a different question - the absolute tonnes an investor is accountable for - and require the ownership share, which is why the two metrics can move in opposite directions. Magnitudes depend heavily on the denominator convention, so figures are only comparable within a consistent methodology; broad developed-market equity benchmarks are frequently quoted in the range of roughly 100 to 200 tonnes CO2e per million dollars of revenue, with utilities, cement, steel and oil and gas dominating the total while contributing a modest share of market value. Four structural weaknesses deserve attention. Revenue is the denominator, so a company can appear to decarbonize purely through price inflation or growth. Scope 3 is usually excluded despite often exceeding 80 percent of a value chain footprint. Coverage is incomplete, and missing issuers are filled with sector-average estimates. Finally the metric is backward-looking and says nothing about a company's transition plan, so it is normally paired with forward-looking scenario analysis and implied temperature rise measures.

Portfolio-level carbon measurement became possible only after corporate emissions disclosure became routine. The Carbon Disclosure Project, founded in London in 2000 and now known simply as CDP, began sending standardized emissions questionnaires to listed companies on behalf of institutional investors, and Trucost, established the same year, pioneered modelled estimates for the many firms that did not respond. The Greenhouse Gas Protocol, developed from 1998 by the World Resources Institute and the World Business Council for Sustainable Development, supplied the Scope 1, 2 and 3 boundaries that make any such aggregation coherent. Investor commitments followed in 2014 with the Montreal Carbon Pledge and the Portfolio Decarbonization Coalition, both convened around the UN-supported Principles for Responsible Investment, which pushed asset owners to measure and publish portfolio footprints. The decisive step was institutional: the Financial Stability Board created the Task Force on Climate-related Financial Disclosures in December 2015 under the chairmanship of Michael Bloomberg, and its June 2017 final recommendations named weighted average carbon intensity as the cross-sector metric asset managers and asset owners should report, which is why WACI rather than any competing formulation became standard. The Partnership for Carbon Accounting Financials, started in 2015 by Dutch financial institutions, published its Global GHG Accounting and Reporting Standard for the Financial Industry in 2020 to standardize financed emissions across asset classes, and the International Sustainability Standards Board absorbed the TCFD recommendations into IFRS S2 in 2023.