The earliest source of the dispersal of opinions between different ESG rating agencies is most likely the identification of ESG factors.
Identification of ESG factors (A): Different rating agencies may prioritize and identify different ESG factors based on their proprietary methodologies, resulting in variation from the outset. This initial step influences the entire rating process as it determines which aspects of ESG will be assessed.
Determination of weighting and scoring methodologies (B): Although critical, discrepancies in weighting and scoring methodologies come after the identification of ESG factors. These methodologies vary based on the initial set of factors considered important by each agency.
Gathering of a set of data points for the identified ESG indicators (C): This step involves data collection based on the previously identified factors and methodologies. Differences in data sources and quality further contribute to variation, but the foundational divergence starts with factor identification.
Reference:
CFA ESG Investing Principles
MSCI ESG Ratings Methodology (June 2022)

Stewardship codes were first developed with a focus onpublic equity investments, where investors havevoting rights and shareholder engagement opportunities. Over time, stewardship expectations have expanded to include other asset classes, but public equities remain the core area of engagement and governance focus.
"Stewardship codes... tend to reveal an initial focus in practice on public equity investment. The stewardship thought process both by regulators and by investors is most developed in public equities." This reflects the strong tradition ofshareholder activismandproxy votingin public markets, which provide direct mechanisms for investors to influence corporate behavior.

According to the McKinsey framework, the element of sustainable investing that is allocated to the investment dimension of tools and processes is integration with investment teams.
Investment Integration: This involves embedding ESG factors into the traditional investment process, ensuring that ESG considerations are integrated into all stages of investment analysis and decision-making.
Collaboration with Investment Teams: Effective ESG integration requires close collaboration between ESG specialists and traditional investment teams. This ensures that ESG insights are incorporated into portfolio construction, risk assessment, and performance evaluation.
Tools and Processes: Integration with investment teams involves developing tools and processes that facilitate the incorporation of ESG data and analysis into investment workflows. This includes ESG scoring models, data analytics platforms, and reporting frameworks.
Reference:
MSCI ESG Ratings Methodology (2022) - Highlights the importance of integrating ESG factors with investment teams to enhance decision-making.
ESG-Ratings-Methodology-Exec-Summary (2022) - Discusses the role of integration in sustainable investing frameworks, emphasizing tools and processes.

Transition bondsare designed to help high-emitting or "brown" industries shift toward lower-carbon or more sustainable practices. These bonds provide capital for companies that are not yet green but are working to reduce their environmental footprint.
"Transition bonds allow financing of activities by companies that may be carbon-intensive today, but are on a credible path to lower emissions. They are often used in sectors like steel or oil & gas." This distinguishes transition bonds from social bonds (focused on social outcomes) and SDG-linked bonds (which are broader and not specific to "brown" industries).

p 1: Definitions and Concepts
Blue Bond: A bond specifically designed to support marine and ocean-based projects, such as sustainable fisheries, coral reef restoration, and wastewater treatment to protect water resources.
Green Bond: A bond issued to raise funds for new and existing projects with environmental benefits, including renewable energy projects like solar farms, wind energy, and other sustainability projects.
Transition Bond: A bond issued to support companies in transitioning their operations towards more sustainable practices. These bonds often support companies that are moving from high carbon-intensive activities to lower carbon-intensive practices.
Step 2: Characteristics and Use Cases
Blue Bond: Focuses on aquatic ecosystems.
Green Bond: Focuses on a wide range of environmental projects, including renewable energy, energy efficiency, sustainable agriculture, and pollution prevention.
Transition Bond: Typically used by companies in carbon-intensive industries to finance their transition to greener operations.
Step 3: Application to Solar Farm Financing
A bond issued to finance the construction of a solar farm falls under the category of a green bond. This is because:
Solar farms are renewable energy projects.
Green bonds are specifically designed to fund projects that provide clear environmental benefits.
Step 4: Verification with ESG Investing Reference
Green bonds are explicitly used to finance projects that have positive environmental impacts, such as renewable energy projects. As per ESG investing documents: "Green bonds support projects with environmental benefits, including renewable energy projects such as solar and wind farms".
Conclusion: A bond issued to finance the construction of a solar farm is an example of a green bond due to its environmental benefits and alignment with sustainable finance principles.