The concept of "carbon footprint" originates from the "Ecological Footprint (EF)". It refers to the total greenhouse gas (GHG) emissions from human production and consumption activities, expressed in carbon dioxide equivalent (CO₂e).
Compared to single carbon dioxide emissions, carbon footprint assesses the direct and indirect GHG emissions of a research object throughout its life cycle using the Life Cycle Assessment (LCA) method. For the same object, the calculation of carbon footprint is far more complex and extensive than that of carbon emissions alone.
To address this calculation challenge, SKYCO2 has invested significant efforts since 2021 in independently developing the carbon footprint module within its "CLIMATE VERITAS" system. Recently, we have received numerous inquiries about carbon footprint software. Therefore, we decided to integrate profound insights from the actual development process to provide a comprehensive and thorough explanation for everyone.
This article series will be divided into three parts, exploring relevant topics one by one.

In fact, there are two commonly used methods for product carbon footprint calculation: the LCA method and the Input-Output (IO) method.
The Input-Output (IO) method allocates carbon footprints to products according to their prices based on economic input-output models. Due to its simplicity, this method is often used for Scope 3 calculations. However, it fails to reflect product-specific characteristics, making it unsuitable for enterprises' carbon reduction management and highlighting the low-carbon value of products.
In contrast, the LCA method considers all processes of a product's life cycle from production to disposal. It quantitatively calculates and evaluates the product's resource consumption, energy use, and emissions, summarizing all involved processes as much as possible. Nevertheless, this method also has drawbacks: it may omit certain processes and involves a cumbersome calculation process.

Some may ask why the emission factor method is not mentioned. In fact, if we could establish enough "activity data * emission factor" processes that connect various unit processes—enabling traceability of the entire product life cycle down to elementary flows (unprocessed natural resources and directly emitted pollutants/waste without further treatment)—the emission factor method would essentially be the LCA method.
However, such an LCA method would seem very simple initially, requiring only the input of enterprise activity data. But in the later stage, achieving layer-by-layer traceability would require establishing extremely complex reference relationships. Without such traceability, as factors like technology, time, and geographical location change—coupled with changes in references—emission factors would become increasingly chaotic and difficult to maintain over time.
These are the reasons why LCA software is widely used for product carbon footprint calculation.

By establishing unit processes, LCA software defines the input-output relationships between product flows and elementary flows, sets reference relationships among unit processes, and integrates the parsing and referencing of external databases. This enables effective linkage of tens of thousands of data entries from upstream and downstream enterprises. Once these interconnections are established, the need for "emission factors" becomes less critical.
In fact, LCA software is not solely used for carbon footprint calculation. The carbon footprint (climate change) indicator is just one of dozens of product environmental assessment indicators covered by the Environmental Footprint (EF). Therefore, using emission factors for a complete LCA would require maintaining tens of times more emission factors than are needed for carbon footprint calculation alone.

In summary, LCA software is essential for product carbon footprint calculation due to its accuracy and efficiency. Through LCA software, we can comprehensively and accurately assess the GHG emissions of products throughout their life cycles, providing strong support for enterprises' carbon reduction management and highlighting the low-carbon value of their products.
In the subsequent articles, we will delve into the behind-the-scenes stories and unique advantages of SKYCO2's independently developed LCA software, "CLIMATE VERITAS".