Appendix B – Greenhouse gas (GHG) inventory project
Boundary setting
Aligned with the GHG Protocol, BDO uses the operational control approach, under which we accounted for 100% of the GHG emissions from operations over which we have control. Operational control is defined as situations and areas where the organization has the authority to introduce and implement operating policies at the worksites. This approach is consistent with the current accounting and reporting practices of many companies that report on emissions from their facilities.
Our carbon footprint reporting period runs from Jan. 1 to Dec. 31, which aligns with our financial reporting period. For 2025, we continued reporting our GHG emissions to align with the calendar year.
Principles of reporting
We follow best practice reporting principles for the calculations, as laid out by the World Resources Institute (WRI):
- Relevance
- Completeness
- Consistency
- Transparency
- Accuracy
BDO's GHG calculation is aligned with the methodology outlined in the GHG Protocol. The completion of our carbon footprint report for Scope 1, Scope 2, and Scope 3 emissions involved applying reasonable assumptions where direct data was unavailable.
Global warming potential (GWP)
In line with best practices in organizational GHG accounting and WRI, we have included greenhouse gases (per Kyoto Protocol) where applicable and material. GWPs are factors describing the radiative impact of one unit of a specific greenhouse gas relative to one unit of carbon dioxide. These factors are used in GHG accounting to convert individual greenhouse gas emission totals into a single standardized unit useful for comparison: carbon dioxide equivalent.
BDO's 2025 GHG calculations were completed in accordance with the 100-year time-horizon GWP values from the Intergovernmental Panel on Climate Change's Fifth Assessment Report (2014). While more recent assessment reports are available, BDO continues to use the Fifth Assessment Report to support consistency in year-over-year reporting and plans to revisit the GWP values used as rebaselining needs arise.
Scope 1: Direct GHG emissions
BDO has natural gas Scope 1 emissions. There are no other substantive fuels (directly combusted) emitted by our worksites. We estimated refrigerants and other fugitive emissions to be negligible/immaterial.
Scope 2: Indirect GHG emissions
Our Scope 2 emissions include purchased electricity and steam. We made improvements in the data collection process and continue to employ extrapolation methods in our calculation for worksites with unavailable data.
Since no renewable energy or Renewable Energy Certificates (RECs) were purchased in 2025, there is no difference between our location-based and market-based Scope 2 emissions. Therefore, both reporting methods result in the same emissions values.
Scope 3: Other indirect GHG emissions
We used the spend-based method to estimate emissions associated with categories 1, 2, 3, and 5.
- Category 1: Purchased goods and services
- Category 2: Capital goods
- Category 3: Fuel and energy-related activities
- Category 5: Waste generated in operations
To estimate emissions from the spend data, we used emission factors from the environmentally extended input-output (EEIO) method, sourced from the Cornerstone Sustainability Data Initiative – Supply Chain Greenhouse Gas Emission Factors v1.4.0 NAICS-6 Datasets and adjusted them for appropriate foreign exchange and inflation rates (i.e., the consumer price index).
BDO GHG rebaseline approach
As we continue refining our data collection process and improving the quality of our data and estimates, we are aligning with the SBTi's rebaselining policy, which requires organizations to recalculate their base year emissions when significant changes occur, such as:
- Structural changes in the firm.
- Changes in the calculation methodology or improvements in the accuracy of emission factors and activity data that result in improved accuracy and have a significant impact on the base year estimates.
- Discovery of material errors.
In line with this guidance, BDO will recalculate its base-year emissions (rebaseline) when structural, methodological, data-related, or other significant changes result in a cumulative change of 5% or more in total base-year emissions. We continue to monitor operational changes across the firm and maintain a log of emissions-related impacts to determine whether the recalculation process is triggered. Following the December 2024 business announcement involving 21 BDO Canada offices, BDO assessed the emissions-related impact of this operational change and determined that it did not exceed the 5% threshold for recalculating base year emissions.”