Traveling Sustainably: Plains, Trains, Automobiles, Scooters & Bikes [Part 2]

Destination: San Francisco, CA
Departure: Atlanta, GA
Distance: ~2,500 mi

CO2  Emissions

While CO2 is not the only greenhouse gas, it is the largest in quantity in our atmosphere and most widely tracked.  

 Let's say I double my calorie intake for the trip because I'm using more calories and exercise makes me hungry.  I would increase from 1,500 to 3,000 calories per day.  I estimate that 10 % of my calories come from dairy, and the remaining are equally divided among protein, grains, vegetables, and fruit.   Using estimates from Planet Green (where grains, fruit, and veggies emit about 3-4 g CO2 per equivalent calorie, red meat 11, fish 8, dairy 6.5, and poultry 6) and assuming I alternate between meats to average 8 g CO2 per equivalent calorie for protein, I can calculate:

1,500 * [(.1 * 6.5) dairy + (.225 * 8) protein + (.675 * 3.5) grains/fruit/veg] = 8.7 additional kg of CO2

If I bicycled an average of 80 miles a day, the trip would take 32 days and my additional CO2 impact would be  278.4 kg (613.8 lbs) more than my normal use.

Using estimates and data by Matthew McDermott, I created this graph:

The Prius assumes 4 passengers and the Car assumes 1 passenger and 22 MPG, to create a picture of the best and worst case scenario for a car.  A Scoot is a rechargeable, single-passenger electric scooter.  Looks like the electric scooter wins again!

Infrastructure

When considering the environmental impact of traveling, one has to consider the setup necessary to make that trip possible. For example, the materials to make the car, the road, and parking lots. This can be said for trains and planes too, which do have a higher cost of infrastructure per passenger, as suggested in this Slate.com article.  NewScientist.com notes that "more than half of the life-cycle emissions from rail come not from the engines' exhausts, but infrastructure development, such as station building and track laying, and providing power to stations, lit parking lots and escalators." Even electric scooters use roads, have to be charged every 30-65 miles, need replacement batteries, and only last an average of 10 years with "normal" use.

When it comes to infrastructure, bikes are the clear winner. They take fewer materials and energy to build, operate, and maintain and can be ridden without roads.  Plus, they're really fun!


Conclusion

Though a bike or electric scooter are by far the slowest options available for cross-country travel, they are the most preferable if I want to minimize the cost to the environment. As a bike lover, I choose to plan a self-propelled trip and keep a more sustainable diet on the trip to balance the carbon and fossil fuel cost of my extra food intake.