Your Kitchen Carbon Footprint & What You Can Do
A recent study by the University of Michigan produced some interesting data about the amount of U.S. annual C02 emissions that are attributable to food selection and preparation.
The average U.S. household is responsible for total of about 48 tons of C02 every year. Some of this is from direct energy use, such as home heating, or driving. Some is due to indirect energy use, such as the energy needed to manufacture and ship the products that we buy.
Let's focus on the kitchen: What we choose to eat, and how we choose to cook it.
How We Cook:
A modern electric oven used to bake or roast a meal will require about 2.4 kilowatt-hours (kwh) of electricity. Each kwh, on average will cause the emission of 1.6 lbs of C02 from the utility that produces it.
This is a national average. It is higher for a coal-fired utility and lower for a utility that uses natural gas, wind, or hydroelectric generation. That means that a typical meal prepared in an electric oven is responsible for about 3.9 lbs of C02.
Natural gas heat is measured in therms. The therm equivalent for the same amount of heat used in the electric oven example above is .112 therms. This equates to 1.3 lbs of C02 to cook the same meal.
To get a single C02 estimate for a U.S. kitchen, let's look at oven ownership. As of 2014, the # of gas ovens in the U.S. stood at
35 million, while there were 56 million electric ovens. Or, the U.S. oven distribution was 38.5% gas and 61.5% electric.
Applying those percentages to the amount of C02 produced by either source in a typical meal prep, we get an average "C02 per meal" of 2.9 lbs. Assuming the oven is used once a day gives us an annual total of just over 1000 lbs, or half a ton.
If you are one of the almost 2/3 that uses an electric oven, the annual C02 result is about 1400 lbs.
That is about the same amount of C02 as produced by a 1200 mile car trip for the average U.S. household, or roughly 1700 car-miles for the electric oven majority.
Using a solar powered oven instead of your kitchen oven just three times a week could save the C02 equivalent of driving a car 750 miles each year. This doesn't include the significant savings in the summer from less need to cool your kitchen while cooking.
Substituting a light meal that doesn't require heating once a week, especially in the summer, can be very enjoyable.
I particularly enjoy cutting into a loaf of nice French bread, with a bit of cheese, and some fresh fruit (paired with a nice bottle of wine) on a warm summer evening.
Each time you do something like this instead of cooking reduces your C02 footprint by about 250lbs.
What We Eat:
Many people assume that the largest part of their "dietary carbon footprint" is related to how they cook their food.
The reality is, that WHAT you eat has a much larger carbon impact than HOW you cook it. The good news is, you have a lot more options for adjusting what you eat than how you cook.
The chart below shows the amount of C02 production in lbs that results from consuming one pound of each of a variety of foods. As you can see, some types of food are much more carbon-intensive than others.
As mentioned in the University of Michigan study, meat products have much larger carbon footprints than plant products because of the significant carbon footprint of raising and feeding the animals, and then processing them into the nice packages you buy at the store.
The Michigan study had a few seemingly easy to follow suggestions for reducing your dietary carbon footprint:
- Eating locally grown food could save the greenhouse gas equivalent of driving a car 1000 miles
- Substituting a vegetarian meal for just one meat-based meal per week could save 1160 car-miles of C02 emissions.
- Substituting chicken for beef for one year could save 880 car-miles of C02 emissions.
- Organically grown foods require 30-50% less energy.