I used a carbon dioxide calculator to see how much I generate per year. I was so surprised to the number when I saw the result, 25 tons per year! I noticed the great portion of carbon dioxide I generate is on home energy (heating and cooling).
One thing I did not pay too much attention before is that whether you eat organic food or not also contribute to the carbon emissions. The reason for this is because organic farms use natural methods to growing vegetables and rising animals while conventional farms use pesticide and other chemicals. For instance, GWP shows that the manufacturing of pesticide contributes 3% of the 100-year Global Warming from crops.
Also, shop local food can also reduce footprint since importing food need transportation which considered to be a greate contributor in general. Because food transportation over long distance also generate considerable amount of carbon dioxide through car emissions. Moreover, transportation by air generate 50 times more CO2 than sea shipping. The fact is sea shipping is much slower than air which may influence the freshness of the food. Therefore, the more fresh food we wan to get from importing, the more pollution caused.
The difference of average distance from farms to market depends on its in terminal market or farmers market is huge. U.S. Department of Agriculture find that the average transportation for apples in terminal market is about 2400km (1500miles), however, its only around 160 km(100 miles) for farmers market.
Suppose using a heavy duty truck for transportation, the CO2 emission we can avoid by shopping in farmers market would be:
110g x (2400km – 160km) = 246,400g = 246 tons
Suppose using a airfare for transportation, the CO2 emission we can avoid would be:
500g x (2400km – 160km) = 1,120,000g = 1,120 tons
See those number, and consider how much we generate per year. Therefore, if local food supply can meet all our needs, it is definitely more sustainable to shop in the local farmers market due to fewer transportation emissions.
Resources:
http://www.cuesa.org/learn/how-far-does-your-food-travel-get-your-plate
http://timeforchange.org/co2-emissions-shipping-goods
I know what you mean, it would be more precise to calculate how many carbon emission per pound of apple caused and then determine which can save more. For your question, I believe the second one would cause more emission. However, in the case of my post, the problem I was expecting to talk about is only comparing between transporting goods from local or from farther area to the markets, because no matter where they are come from, individuals all need to, no matter drive or what, to purchase them(regardless the quantity).
You might want to think about the “last mile problem”. Per unit weight of apples, which causes more carbon dioxide emissions: shipping 40 tons of them 2000 miles to the supermarket by truck, or my driving 2 miles in my Prius to pick up a 2-pound bag?
Your observations are quite interesting! Supporting the local business as a way to reduce our carbon footprint is definitely a new angle to deal with the problem. I felt the same approach could be applied to our campus. If our campus dining halls use more of the local products, and more students choose to eat on campus, the carbon footprint in our school would decrease as well!
Not only would we be helping to reduce the carbon footprint by shopping in local farmers markets but we would also be supporting small businesses and stimulating our local economy! Even if we can only buy our food from these farmers markets a few months out of the year, like in central PA we could still be saving 123 tons of carbon emissions. 110g x (2400km – 160km) = 246,400g = 246/2 = 123 tons. (6 months out of the year!) What if we take into consideration the carbon emissions we could save if we got things from other states rather than importing from Mexico or any other places when we couldn’t get them locally? We need to start helping our farmers out who take care of us so well and our earth with our carbon footprint!