Greenhouse Gas Emissions Inventories

Greenhouse gas emissions inventories are like financial statements or bathroom scales. You check on them regularly to see whether you are making progress.

An inventory shows how much global overheating pollution you are putting into the air. The global overheating pollution is greenhouse gases. You get an inventory every year or two and see how much your emissions have gone down.

Greenhouse gas inventories also guide you to what you should do. If you have too much money going out, you can look at your bank statement to see where the money is going out. Too much going out to buy drinks on the weekend? Are repairs on your car costing more than replacing it? As you see where the money is going, you get ideas about how to adjust your life. It’s the same with greenhouse gas emissions. Are most of your emissions from burning gasoline in cars and trucks? Are emissions mostly from people burning natural gas to heat their homes? Are methane emissions a big deal? Should you start by tending to the health of your cattle to cut down on cattle gas (burps)? (Some places do.) How about refrigerants? The fluid gases that are pumped around refrigerating units are greenhouse gases if they leak out. Big deal? Little deal?

Worldwide and in the U.S., the biggest deal is burning fossil fuels -- gasoline, natural gas, and coal. Chances are good that your community does not burn coal, and that your community's biggest emissions come from gasoline and natural gas.

To know about your specific city, you need a greenhouse gas emissions inventory to tell you how much in greenhouse gases are released by each activity and in each location.

You can imagine a smoky city, like London during the Great Smog of 1952. For five days, the smog in London was so thick, you couldn’t see the end of the block and the sun could not shine through. The toxic air killed about 4,000 people. You would not want that to continue, so you ask, “Where is all this smoke coming from?” And “How much is coming from each source?” A greenhouse gas emissions inventory answers the same questions for greenhouse gases.

Winging It vs Standard Procedures

Imagine you go to a new doctor who puts their stethoscope on your wrist, rather than your back and chest. “Yeah, I like to check pulses on the wrist. I have a better idea than the way most doctors listen to your chest.” Good idea? Bad idea? Probably you don’t want to stick with that doctor. You might like them to take the standard measures and then add their special innovations. But you don’t want their creativity without the standard procedures.

It is the same with greenhouse gas emissions. There are standard procedures for looking for and counting emissions. Each place is different. Ideally, the inventory you get provides the results of standard measurement procedures and also accounts for the specifics of your particular place.

Standard procedures have been specified by the United Nations, by the EPA, and by Arizona State University. There are other specifications of standard inventory procedures. Altogether, there are about 10 widely recognized standard procedures, and all provide roughly the same guidance.