• Once you know the energy consumption, you can calculate greenhouse gas emissions associated with them by applying greenhouse gas emission coefficients to the energy consumption. There is a different coefficient for each energy source; these can be obtained from the Energy Information Administration (EIA). Since power delivered to a community may have been generated with varying amounts of different energy sources, the coefficients will differ between cities. For initial estimates, the EIA provides electrical supply coefficients by state. If you want a more accurate baseline, consult your the electrical utility or state energy office. 
• Estimate any other direct greenhouse gas emissions, such as landfill gas or waste incineration. The method to estimate these will be specific to each type of facility or activity.

There are a number of greenhouse gas emissions inventory tools and reports available, many of which include basic data on emissions coefficients for energy sources. Where the staff’s capacity to run detailed studies is limited, local governments can hire consultants to carry out emissions inventories and baselines, supported by municipal data.

The above methods do not take into account construction-related emissions, only operations. Generally, determining construction emissions is more complex, and the contribution to overall emissions is typically less than for operations.

Once you have an energy and greenhouse gas baseline, you can use it to identify “hot spots,” or systems or sectors that have the most noticeable energy waste or greenhouse gas emissions. This helps you focus on making changes where they will have the greatest effect.

To understand the changes over time, you can normalize the numbers - i.e. convert them to per-unit measures. For example, the baseline could indicate greenhouse gas emissions per resident served or volume of wastewater treated. Then, your results wouldn’t be clouded by changes in the population and you could account for increases or decreases in wastewater due to successful demand management programs. Essentially, the energy and greenhouse gas emissions baseline contains your very first measurements for sustainable infrastructure.