How can I interpret changes in emissions year-over-year (YoY) for a single company?

There are many reasons a company’s reported emissions can change year-over-year (YoY), in addition to changes in absolute emissions. It is important to view emissions figures in context of their underlying methodologies, which can be referenced in the Methodology, Change in Calculation Methodology, and Exclusion sections in the Company Profile.

Many companies are using increasingly sophisticated and accurate methodologies to calculate their greenhouse gas emissions. Thus, YoY changes in reported emissions may be due to greater availability of data, more sophisticated calculation methodology, or a greater scope of business operations included in the calculations. Other events, such as mergers and acquisitions, may also result in YoY variances for a given company.