# Calculating emissions from the project

​​​​​​Every project needs to take into account emissions that arise from running it (see Part 4, Division 4 in the method). This is to ensure these emissions are included in calculations that determine net CO2-e abatement for a reporting period and crediting period.​

### What’s CO2-e?

CO2-e expresses the warming effect of different greenhouse gases as an equivalent amount of carbon dioxide. It is the amount of carbon dioxide that would give the same warming effect as each greenhouse gas that is emitted or stored by an activity. For example, methane (CH4) has a Global warming potential (GWP) of 25, which means 1 tonne of CH4 is 25 tonnes of CO2-e.

Only those greenhouse gases from emissions sources outlined in Section 46 are included when calculating CO2-e for a soil carbon project.

For each CEA, identify which emissions sources listed in Sections 67–71 are relevant to your project. Use the equation trees in Figure 6 to calculate project emissions from livestock, synthetic fertiliser, lime, crop residues and irrigation energy use. If the project is a sustainable intensification project and irrigation is chosen as the management action, calculation of irrigation energy use is compulsory (Section 71).​

#### Figure 6: Equation trees for calculating total emissions during the project reporting period for each carbon estimation area​ (click image to enlarge)

The equation tree in Figure 6 shows how to calculate total emissions during the project reporting period for each CEA.
You must calculate project emissions from livestock, synthetic fertiliser, lime, crop residues and irrigation energy use. An individual equation tree for each emission source, in Figure 6, steps through the calculations. Equation numbers are at the top left of each box.
A summary of the required equations and the relevant sections of the method is given below.
• Livestock emissions: Equations LS7–LS9, Section 67
• Synthetic fertiliser emissions: Equations SF4–SF7, Section 68
• Lime emissions: Equations L1–L2, Section 69
• Crop residue emissions: Equations R6–R10, Section 70
• Irrigation energy use: Equations I1–I2, Section 71
Data needed to complete the sequence of equations are drawn from a number of sources. Some data come from the National Greenhouse and Energy Reporting Regulations, some are already available for you in the methodology determination, and others are drawn from the National Inventory Report 2013 and from data you will produce as a result of running your project.​