by Betsy Herbert
published in the Santa Cruz Sentinel 8/14/2014
If you’re watching your greenhouse gas (GHG) emissions, it’s clear that riding a bike, walking, skateboarding, using a ZipCar or taking the bus are all better choices than driving a personal vehicle . . . at least for shorter trips.
Apparently, choosing alternative travel modes for shorter trips is having an effect on the country’s driving habits. Nationwide, our non-highway vehicle trips consumed 39% less fuel in 2012 than they did in 2004, according to a 2014 U.S. Department of Transportation study. Total miles driven nationwide has also dropped some 5% since its peak in 2006. This national trend is influenced by the increasing costs of owning a car and especially by the transportation choices of Millennials, people born between 1983 and 2000, according to nonprofit U.S. PIRG.
What are our alternatives for long-distance travel? I’m planning a big trip next year and, like a growing number of travelers, I’m considering the environmental impacts of my travel choices. Sure, long-distance travel presents other potential environmental impacts, but fossil fuel burning (which produces lots of GHGs) is a major one.
You can compare the GHG emissions of different modes of transportation by using an on-line GHG emissions calculator. I compared emissions for two different legs of my trip; one across the country and one across the Atlantic ocean.
For a cross-country trip from San Francisco to New York City, I used the calculator on the CarbonFootprint.com website to estimate and compare a single passenger’s GHG emissions from a one-way trip by rail, motorcoach, car and air.
The results showed that trains have the lowest emissions for a cross-country trip. By rail, a single passenger’s share of GHG emissions was calculated at 0.06 metric tons. By motorcoach, GHG emissions increase to 0.14 metric tons. On a non-stop flight, a single passenger’s share of GHG emissions shoots up to 0.84 metric tons. By car, a solo driver emits a whopping 1.4 metric tons of GHGs, but this number decreases by adding passengers. (This calculator bases car emissions on your particular vehicle year, make and model.)
For a transatlantic trip, your choices are limited to ship and air. There aren’t many websites that offer GHG emissions calculators for cruise ships. I used the CleanerClimate.com calculator to determine that a single passenger’s share of GHG emissions from a 7-night transatlantic cruise (New York to Southampton, England) is 1.96 metric tons, compared to a single passenger’s share of GHG emissions from a nonstop flight of 1.25 metric tons.
Factors other than GHG emissions obviously influence one’s choice of transportation for long-distance travel, including ticket cost, timing, and personal health and safety. There are also other environmental impacts to consider. According to Richard Hammond, the Guardian's green travel columnist, cruise ships have issues. "Quite aside from the carbon emissions, there is a high cost to the ocean. The cruise industry has a poor record in terms of waste water treatment and disposal, and therefore it has to clean up its act if it is to be considered as an environmentally friendly means of travel,” he writes.
Once it has calculated your trip’s GHG emissions, an on-line calculator will usually recommend a tax deductible donation, estimated to offset the carbon footprint of your trip. For example, to offset the GHG emissions of a one-way nonstop flight across the country, the Terrapass.com website suggests donating $11.95 to any of its projects designed to reduce GHGs and produce renewable energy. Check whichever website you use to ensure that its projects are verified by an independent and accredited third party accounting firm.