Calculating your Carbon Footprint
Introduction to Personal Carbon Footprints.
You may have come across the term 'Carbon Footprint.'
Typically "Carbon Footprint" relates to how much greenhouse gasses are emitted during the production and use of a product, like a grocery bag or shoes.
Individuals also have a carbon footprint. Typically it is the amount of greenhouse gases they emit on annual basis and measured in metric tons of carbon emitted per year. It is called carbon footprint because all Greenhouse gasses can be converted to equivalent carbon emissions (technically Carbon dioxide emissions).
Individuals can use carbon footprint calculators to estimate their own emissions. These tools are generally more precise than the basic income-based calculator we mentioned earlier, but they require a bit more time and some calculations. As previously mentioned, the average carbon footprint for a person in the U.S. is approximately 10,000 kilograms annually, or about 30 kilograms daily. Obviously, carbon emissions differ significantly for various reasons. The main reason relates to how much we consume.
Carbon emissions primarily come from the burning of fossil fuels. There are two broad categories of carbon emissions: direct and indirect.
Direct emissions are the fossil-fuel energy (and associated emissions) you purchase and use. This includes the electricity and natural gas used in your home, the gasoline you burn in your vehicle, boat, or lawnmower, and the emissions you create when you fly. For an average person, direct emissions might look like this:
Transportation~4000 kg/yr
Electricity~1300 kg/yr
Natural Gas~2000 kg/yr
Indirect emissions are the emissions from the burning of fossil fuels used to produce the items we consume. Emissions are created during the production of the food you eat, the clothes you wear, and the gadgets and appliances you buy. Emissions are also produced by data centers that function when using social media or streaming services. All the products we buy require fossil fuels in some capacity. Average indirect emissions might look something like this.
Diet~1500 kg/yr
Consumption~1500 kg/yr
This gets us to the total annual carbon footprint for a person of about 10,000 kg/yr (10 metric tons per year) or about 30 kg/day.
For the purists, there is another category of emissions that accounts for about 33% of US emissions. These emissions are for things outside our individual control. They come from our military, healthcare system, construction, schools, government centers, and other sources. If these were considered, per capita emissions in the US would be about 14,000 kg/year.
Calculate your own Carbon Footprint
Some of you may want to calculate your carbon footprint by hand. This involves tracking all of your home energy inputs (gas and electricity), as well as the gasoline used in your car or truck. In addition, you would track all of your purchases. This is cumbersome, but I am aware of several people who enjoy this activity. And yes, they are engineers.
But if you could commit just 30 minutes of your time, we can help you out. To be Climate Responsible requires a little time and effort.
1) What is your annual electric usage. You will need to get this information from your electric company. Typically, it is online. This is reported in kWh per month. You will need to sum the last 12 months. What was the 'highest and lowest monthly. (Estimated time: 4 minutes)
2) What is your annual natural gas usage? You will need to get this information from your gas company. Typically, it is online. This is reported in therms per month. Please sum the last 12 months. What were the highest and lowest monthly? (Estimated time: 4 minutes)
3) What is the average mpg of your vehicle? Newer vehicles report this on the dashboard (skroll through the menu). You can also calculate by tracking mileage and gasoline used (best option) or you can go to epa's fuel economy.gov and look up your make and model of car. Know that HOW you drive can make a big difference. (Estimated time: 4 minutes)
4) How much do you drive? Please track this; don't guess. Two weeks' worth of data is a good start. Day 1. Write down the odometer mileage. Please set a calendar event for 2 weeks from now (Day 14). At the end of Day 14, write down the odometer reading. Subtract Day 14 mileage from Day 1 and divide by 14 to get the average miles per day. {Ideally, track your miles traveled on an annual basis. I check my miles every January 1, then divide by 365 to get my daily average. (Estimated time: 1 minute)
Using a Carbon Footprint Calculator
An easier option is to use a carbon footprint calculator. These calculators all require different inputs, such as miles driven per year, home size, etc. These are still not perfect but get closer to your actual footprint with less work.
There are many calculators available, but I prefer CFCalc because it is the one I created :) And I have verified that the results are reasonable.
When you are comfortable with your annual carbon footprint (kg per year), divide that number by 3650 to get your 10% daily reduction target. You can then move on to Commit Now!