What is required when reporting under the GHG Protocol?

The correct choice emphasizes the requirement to use metric tonnes as a unit of measure when reporting under the GHG Protocol. The GHG Protocol is a globally recognized framework that provides standards and guidance for companies and organizations to measure and manage their greenhouse gas emissions.

Using metric tonnes allows for a standardized, quantifiable understanding of emissions that can be compared across different entities, facilitating better analysis and reporting. This standardization is crucial for organizations aiming to assess their environmental impact accurately and make meaningful reductions in greenhouse gas emissions.

In contrast, the other options do not align with the GHG Protocol's requirements. Reporting only in dollars or employing local currency would not convey the actual volume of emissions and could lead to ambiguity in understanding environmental impact. Focusing solely on qualitative assessments would lack the rigor of quantitative data needed for accountability and transparency in emissions reporting.