The quantification of carbon dioxide emissions is a topic of great relevance, but a fundamental question often remains unanswered: is a ton of CO2 identical worldwide, regardless of countries and industrial sectors? This question, while seemingly trivial, is the core of every carbon accounting process.

This holds true for both national inventories developed in accordance with the requirements of the Conferences of the Parties (COP) of the UNFCCC, and for the measurement of greenhouse gas (GHG) emissions of companies, which are increasingly common in the voluntary market. The so-called carbon footprints summarize all direct and indirect greenhouse gas emissions into a single unit of carbon dioxide equivalent (CO2e). Organizations calculate the impact of their production and operations to understand their baseline emission values and responsibly plan decarbonization pathways.

The importance of having standardized methodologies for quantifying GHG emissions cannot be underestimated. These help companies monitor improvements over time and assess their positioning regarding climate risk in relation to competing entities. In this regard, the International Organization for Standardization (ISO) has developed, since 2006, a package of voluntary standards covering all dimensions of carbon accounting. This includes product and organizational carbon footprints, the measurement of emission reductions through projects, verification and accreditation procedures, as well as defining the necessary competencies for verifiers. Among the topics addressed, there is also carbon neutrality and the Net Zero standard, which is currently under development.

To maintain their relevance, the standards are updated over time to stay aligned with the evolution of the international regulatory landscape and the new market needs. For example, at the time of the first revision of the ISO GHG package, the Kyoto Protocol had not yet been ratified, whereas today we operate in a context defined by complex regulations, both national and regional, such as those signed under the Paris Agreement or the European Green Deal.

Moreover, the needs of businesses are continually evolving. A significant change has occurred in the revision of standards dedicated to product and organizational carbon footprints, initiated to respond to the changing needs of companies. Initially, these standards were used separately, depending on whether the aim was to reduce the impacts of individual products or to implement strategies at the corporate level. It is becoming increasingly clear, however, that the complex pathways to decarbonization require an integrated approach that combines product and organizational policies.

ISO working groups dealing with carbon footprints are therefore collaborating synergistically, aiming to maximize the interconnections between standards related to products and those concerning organizations. This translates into common structures and indexes, as well as identical textual passages on crucial aspects, such as the quantification of biogenic emissions or emissions related to electricity consumption.

However, there is a critical issue that ISO has not yet managed to resolve: the lesser dissemination of its standards compared to the GHG Protocol. A key factor is that the GHG Protocol standards are offered for free, unlike ISO standards, which require a purchase. Additionally, the process of developing the GHG Protocol is less complex in terms of managing consensus at the international level.

The support from the private sector also contributes to highlighting the differences between these two approaches. A notable case is the significant funding received by the GHG Protocol, which underscores interest in voluntary standardization, but also raises questions about potential conflicts of interest from large companies in defining the requirements of the standards.

Although the cost of individual standards does not represent an absolute barrier for small and medium-sized enterprises, it remains a significant barrier to accessing knowledge, thus limiting their ability to engage effectively with these standards.