At Plan A, our carbon accountant experts research and review emission factors and other conversion factors within our methodology to improve their precision and accuracy. This ensures your emission calculations are as accurate as possible.
Updated emission factors are regularly released by governmental agencies, or published in scientific journals. As our understanding of the underlying mechanisms grows, the accuracy and precision of our models improve — and the resulting emissions may change.
It is important to note that carbon accounting is a complex science, and like all scientific models, its results depend on a range of uncertainties. As your activity data is combined with data on, for example, average employee behaviour or average industrial processes and emission factors of multiple different greenhouse gases, the uncertainties aggregate and multiply.
The emissions reported are, in fact, the mean or median on a probability density function as illustrated below.
We are committed to ensuring transparency around changes in our methodologies so that you can easily understand your emission results. As per our data update policy, we will proactively email you when changes in emission factors occur, and you can track all changes in our release notes.