Containing global warming has become one of humanity's greatest challenges. No wonder many companies are committed to reduce, and better than that, to zero emission of gases that cause the greenhouse effect. The first step for the strategy to be successful is to monitor CO2 emissions based on an understanding of the impact that the company's activities can generate throughout its production process as well as on its surroundings.

These emissions are classified according to the GHG Protocol (Greenhouse Gas Control) in scopes 1, 2 and 3. According to the protocol, scopes 1 and 2 are mandatory for companies that are to adhere to the measurement. The third is voluntary – as well as the most difficult to be monitored. Understand the differences:

Scope 1 emissions

These are emissions released into the atmosphere as a direct result of the company's own operations. All fuels that produce greenhouse gas emissions must be included in scope 1, the combustion of vehicles owned or controlled by the company, for example.

Scope 2 emissions

These are indirect emissions from electricity purchased for the company's own use. That is, all greenhouse gas emissions into the atmosphere from the consumption of electricity, steam, heat, and cooling are part of this scope.

Scope 3 emissions

These are all indirect emissions not included in scope 2 that occur in the company's value chain. In other words, these are emissions linked to the company's operations, such as purchased raw material, business trips and employee displacement, waste disposal, transport, and distribution.

While Scope 3 is not mandatory, for many companies most of the greenhouse gas emissions and cost-saving opportunities are outside their operations. Therefore, when measuring Scope 3 emissions, organizations may:

• Assess where the emission “hotspots” are in their supply chain.
• Identify resource and energy risks in their supply chain.
• Identify which suppliers are leaders and which are laggards in terms of sustainability performance
• Identify energy efficiency and cost reduction opportunities in their supply chain.
• Engage suppliers and help them implement sustainability initiatives.
• Improve energy efficiency of their products.
• Engage positively with employees to reduce emissions from business travel to employee commuting.

The  GHG Protocol website has a report in several languages, including Portuguese, with the requirements that companies must follow to prepare an inventory from the seven greenhouse gases covered by the Kyoto Protocol.