Students from around the world calculated their class mean and standard deviations for their footprints and posted them on our world map.
Do you see differences across the globe? If so, why do you think those differences exist?
Did you use the calculator to try to reduce your footprint down to the average from a citizen of another country? What changes would you have to make to lower your footprint in this way? Are you going to try and take some of these actions in your daily life?
Student Footprints >
Plane vs Car: Which is really better for the planet?
From comparing with other students, it seems like plane flights heavily impact the size of carbon footprints in the calculator, while the same distance by car does not make as large of a difference. This result surprised me, so I decided to look into it.
The average plane (out of US airlines) holds about 200 passengers and emits about 24 kg of carbon dioxide per mile. The average car in the US has a fuel efficiency of about 9.4 liters per 100km and emits about 2.3 kg of carbon dioxide per liter of fuel.
So if I traveled 2,000 km by plane (200 passengers), it would emit 48,000 kg of carbon dioxide, which is 240 kg per passenger. But if I traveled the same distance by car (9.4 liters per 100km), I alone would be emitting 489.3 kg of carbon dioxide. This is not even close to the result the carbon footprint calculator gave for these values.
I think understanding this inaccuracy in the calculator is important in properly evaluating our carbon footprints and considering what the best long-distance travel option is for the environment.
Sources:
https://www3.epa.gov/fuele conomy/fetrends/1975-2014/420s14001.pdf
http://blueskymodel.org/air-mile
http://www.eia.gov/tools/faqs/faq.cfm?id=307&t=10
(I converted the values I got from these sources to metric)
I think that you do have a very good point but that it may be quite conditional. In this hypothetical situation, you are (I am assuming) riding in your car by yourself. If you take, say, three other passengers in your car, wouldn't your collective CO2 emissions remain 489.3 kg whereas if you four were taking a plane your collective emissions would be 960 kg?
Wow! I noticed the same thing. This also caused me to rethink my travel methods. After reading your post, I decided to research more about this and found an article comparing the two. It gives a couple different views. Like your post, it described how although planes emit a lot of carbon dioxide, it ended up being reasonable once divided among each passenger. The article also said this about cars and encouraged carpooling and using more fuel-efficient cars. In addition, the article also noted the other emissions by planes that contribute to the greenhouse effect. By the end of the article, the factors varied for choosing the best travel method for reducing my carbon footprint; Fuel efficiency, the number of people travelling in the same vehicle, and the distance needing to be traveled are just some of the factors.
I do agree with you that the inaccuracy of the carbon footprint calculator is important to note when comparing your travel options.
I would like to know your thoughts on the better mode of transportation. Which option would reduce your carbon footprint more? Do you think the other emissions from the plane outweigh the other factors? What about car emissions? Do you have any thoughts on other factors?
Source: http://www.yaleclimateconnections.org/2 … s-driving/
@Alex G you are correct in that I did not consider the best option for traveling in groups of two or more people. I agree that, in that case, traveling by car does seem to result in less CO2 emissions than by plane. So, depending on the fuel efficiency of the car and the number of passengers, cars can be the better option for the planet.
@Emma T, I think the better mode of transportation if you are traveling alone is definitely a plane, but if you are travelling with one or more other people it varies depending on the fuel efficiency of the car and the number of passengers. When I say "better" I mean it will reduce the size of your carbon footprint more. By "other emissions" I am guessing you mean the total CO2 emissions by the plane without dividing by passenger. In that case, no I do not think that the total emissions make the plane a worse option because if all the passengers drove individually the same distance as the plane, that large total would be doubled. As far as cars go, I would say the total emissions sometimes can make it the worse option, and sometimes ca n make it the best option for the reasons I discussed earlier. Another factor to make note of is the type of fuel used. I don't know about plane fuels, but with cars the CO2 emissions can be more or less depending on whether or not they contain ethanol and whether or not diesel fuel is used. This definitely comes into play when larger vehicles such as buses are driven.