Determine your current energy usage.

Local utilities should have records of how much electricity was generated from which sources.  Try to find similar data for all sectors you've included in your scope (see "Choose Your Goals," earlier).

Ideally, obtain a few years of data, since weather and other factors can affect one year's energy usage.

Anchorage had prepared a couple of recent reports.  One, by Deerstone Consulting in May 2017, was entitled, Anchorage Energy Landscape and Opportunities Analysis, and the other, Municipality of Anchorage Greenhouse Gas Emissions Inventory.

This information was very valuable in giving us a baseline understanding of how much energy was being used by which sources.  Additionally, the US Energy Information Administration provides valuable information about each state's energy usage.  States also track energy usage, such as Alaska's Greenhouse Gas Inventory.  If you're using end-use energy statistics, realize that is less than energy generated.  There are inefficiencies in power plants as well as losses in electrical lines.  Find out the appropriate factors so you're using the amount of energy generated.

Convert energy into tons of carbon dioxide.

If your goal is to align your community with the 1.5, 1.75, or 2.0 degree C warming recommendations of the UN, you'll need to know how much carbon dioxide you're emitting, so you can evaluate possible reduction pathways.

Once you know how much energy is being consumed by various sources, the US EIA makes it easy to calculate the tonnage of greenhouse gases produced, using these factors. 

Note that some sites refer to tons of carbon, while others refer to tons of carbon dioxide.  If you're planning on reducing emissions based on percentages, it doesn't matter whether you use tons of carbon or tons of carbon dioxide, as long as you're consistent.  To convert between the two, there are 44 tons of carbon dioxide per 12 tons of carbon (same US EIA source as above).