The GHG Protocol is an organisation which develops GHG accounting standards. Standardised emissions accounting is important in developing accurate GHG inventories (carbon footprints) across bodies that can be compared to one another.
The organisation has established a global, standardized framework for measuring and managing emissions. The GHG Protocol Corporate Accounting and Reporting Standard makes it possible to compare emissions from private and public sector operations, value chains, products, cities, and policies.
Businesses will typically use the GHG Protocol Corporate Accounting and Reporting Standard when accounting for their own emissions
The Standard helps companies and other organizations to identify, calculate, and report GHG emissions. It is designed to set the standard for accurate, complete, consistent, relevant and transparent accounting and reporting of GHG emissions by companies and organizations. 
The Standard covers the setting of organisational and operational boundaries, tracking emissions over time, and reporting emissions. It provides guidance on GHG accounting and reporting principles, business goals and inventory design, managing inventory quality, accounting for GHG reductions, verification of GHG emissions, and setting a GHG target.
2. Emission ‘scopes’
The GHG Protocol Corporate Standard is the source of the widely-used emission scoping system. This classifies a company’s GHG emissions into three ‘scopes’.
Scope 1 emissions are direct emissions from owned or controlled sources.
Scope 2 emissions are indirect emissions from the generation of purchased energy.
Scope 3 emissions are all indirect emissions (not included in scope 2) that occur in the value chain of the reporting company, including both upstream and downstream emissions. 
3. Value chain emissions
Most large companies report on the emissions from their direct operations (scopes 1 and 2).
Emissions along the value chain often represent a company’s biggest greenhouse gas impacts. For example, Kraft Foods found that value chain emissions comprise more than 90 percent of the company’s total emissions.
Developing a full GHG emissions inventory – incorporating corporate-level scope 1, scope 2, and scope 3 emissions – enables companies to understand their full value chain emissions and to focus on measures that will produce the largest reductions in GHGs.
4. Second edition
The GHG Protocol: Corporate Accounting and Reporting Standard was revised after a two-year multi-stakeholder dialogue. The new edition is designed to improve the rigour quality, and user-friendliness of the first edition.
The new Standard covers the accounting and reporting of the six greenhouse gases covered by the United Nations Framework Convention on Climate Change.
5. Scope 3 standards
The GHG Protocol Corporate Value Chain (Scope 3) Standard and GHG Protocol Product Standard both take a value chain or life cycle approach to GHG accounting. The Corporate Value Chain (Scope 3) Standard accounts for emissions at the corporate level, while the Product Standard accounts for emissions at the individual product level. Together with the GHG Protocol Corporate Standard, the three standards provide a comprehensive approach to value chain GHG measurement and management.
6. Additional services
In addition to accounting and reporting standards, the GHG Protocol provides sector guidance, calculation tools and training.
The organisation also provides webinar, e-learning and in-person training and capacity-building support on its standards and tools. When sector guidance, product rules, or tools conform with GHG Protocol Standards, the organisations responsible can apply to be registered on the ‘Built on GHG Protocol’ scheme.
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