Container ship photo: Daniel Ramirez; airliner photo: Bob MacInnes
Two things which I think are worth keeping front and center when discussing how we wean ourselves off our petroleum addiction: Travel between nations is good; trade between nations is good. It's easy to point out specific incidences where less-than-savory outcomes resulted from trade and travel, but on the whole both are beneficial for human culture. What we need to address is how are we going to move our goods and ourselves around in less energy intensive ways, so that both are less harmful to the planet (and therefore ourselves). When should be shipping things by ship; when should we be traveling by airplane; how should we be prioritizing these; and, would simply slowing down our travel and shipment of goods be a useful part of the solution?
There are two broad aspects of this that need to be considered. One is technological--what technologies offer solutions to long-distance intercontinental and transoceanic transportation in ways that don't use fossil fuels (or as many) and with low or no carbon emissions? Let's leave that to other posts in this Minus Oil series. What I'm most concerned at the moment is thinking conceptually about how to do this.
photo: Beatrice Murch via flickr
Modern Ships Are Really Efficient, But Still Highly Polluting
Moving either people or goods by ship is far more efficient on a per unit basis than sending the same things by plane or truck.
Bearing out this efficiency, using carbon emissions as proxy for fuel consumption, analysis of the carbon footprint of wine, sent by either ship, airplane, or truck, shows that a bottle of wine sent from Chile to Los Angeles by ship, a distance of about 5,500 miles, actually has lower embodied emissions than one produced a few hundred miles north in Napa or Sonoma and driven down by truck. The Chilean wine likely took more in days to arrive than what it took the Napa wine in hours, however.
That said, modern shipping is highly polluting enterprise--even if the slowness and efficiency still takes it ahead of other transportation methods. The fuel used is a far cry dirtier than the stuff that you pump into your car's gas tank. In fact commercial shipping as a whole produces an estimated 2.2 million pounds of particulate air pollution each year. That's equal to the particulate pollution of half of all the cars in the world. About 70% of it also occurs within 250 miles of coastlines, causing significant health problems.
From super-slow-steaming--resulting in cruising speeds for container ships lower than those of the fastest sail-powered merchant ships of the 19th century--to augmenting engines with kite sails, there are many novel ways to address both fuel consumption in pollution of modern shipping.
But if we are to really reduce our oil usage--either by choice or by necessity, let's not forget that even the IEA and the US military actively discuss peak oil supply constraints as being very real issues, not just something that survivalists and neo-luddite hippies are obsessed with--if we really want to make strides in cutting back on petroleum consumption, whether increased fuel efficiency and kite sails are enough to keep global shipping steaming along at current levels is an open-ended question.
photo: Retromoderns via flickr
Air Travel Consumes Lots of Fuel, Emits Tons of Greenhouse Gases
For most TreeHugger readers it's probably common knowledge that air travel and air shipment is hugely energy intensive and a big source of carbon emissions in their daily lives--even if in the scheme of all the world, global aviation is under 5% of greenhouse gas emissions, albeit a growing portion of those.
Again using emissions as proxy for fuel consumption and environmental impact, if you've adopted a vegetarian diet to lower your carbon footprint, those savings were just cancelled out by that flight to Europe you just took, or that cross-country flight. Which isn't to say going veg isn't a good thing, just that six hours sitting on an airplane had similar environmental impact to all your previous meat-eating.
It's also worth noting that while air travel consumes tons of fuel (literally), going from New York to Los Angeles by yourself in a car getting current average fuel efficiency (mid 20s mpg) doesn't have that much lower emissions--though in actual driving time it's about 48 hours for driving versus 6 for flying. Again, speed is directly related to fuel consumption.
As with shipping, there are plenty of technological ways to reduce oil consumption with aviation--from aviation biofuels, to more efficient plane designs and flying formations, even more niche use of blimps where speed isn't prioritized--but many of these are decades from widespread commercial implementation, and even then there's the very real chance that they will not be enough to keep global aviation aloft at current scale in a world with constrained and more expensive petroleum supplies.Twitter and Facebook.
More Minus Oil:
Want to Kick Our Oil Addiction? Let's Get Our Priorities Straight First
Do We Really All Have To Live Like New Yorkers? Does Density Matter?
Moving Beyond Oil: Restoring Meaning to the Word 'Necessity'