If there were one image that summed up stereotypes of Americans, it would be a picture of a morbidly obese white person in a fast food restaurant’s drive-through lane while driving a full-size SUV. The American being obese and eating McDonald’s is important for the caricature, but driving a full-size SUV without any other passengers is just as important. Americans, after all, aren’t only supposedly lovers of unhealthy foods and excessive girth; they also supposedly don’t mind destroying the planet with their cartoonishly large and inefficient forms of transportation.

It was the same story not too long ago when gas prices dropped to historic lows, and sales of SUVs and trucks jumped back up. Many comments were made and stories were written about how shortsighted Americans are and how foolish we are to sacrifice the planet just because of cheap gas prices. Especially considering that a lot of trucks now get the kind of gas mileage that 10 years ago was associated with family sedans, is it really fair to put so much blame on American drivers for pollution? If not, are there other areas that would yield better results if they received just as much attention and criticism?

Digging into data on sources of pollution, it quickly became apparent that thoroughly investigating every single source would require far more time than I had available and would result in a research paper, not an article. One transportation-related source of pollution did stand out, and it’s definitely worth paying attention to. That source? Container ships.

Considering the amount of cargo a single container ship can hold and how quickly it can move that cargo around the world, modern cargo ships are pretty miraculous. Sure, planes can transport cargo as well, but the amount of cargo a container ship can carry makes it much more efficient. Just because container ships are considered efficient for the amount of cargo they can carry doesn’t mean they sail the oceans while spouting rainbows and fairy dust. On the contrary, container ships are major polluters.

How exactly does container ship pollution compare to car pollution? The Guardian reports that based on the engines and fuel used in 2009, just 15 of the world’s largest container ships emit as much pollution as every single car in the world. With more than 760 million cars in the world and at least 90,000 cargo ships, that means cargo ships pollute at the same level as 4,560,000,000,000 cars. Even if smaller ships pollute much less than the largest ones, cutting that total number by half would still leave container ships polluting on the level of 2,280,000,000,000 cars. If every single person on the planet owned and drove two cars, the level of pollution wouldn’t even touch those levels of emissions.

The biggest problem is the type of fuel that container ships burn. Extremely low quality diesel known as “bunker fuel” or “fuel oil” is used to power the diesel engines in container ships, and while it’s the most cost-effective fuel available, it’s so noxious that several countries have instituted buffer zones. Inside those zones, container ships are required to burn cleaner fuel to cut down on the pollution that is released in the air. That fuel is more expensive, but it also cuts pollutants dramatically. Sulfur, for instance, is reduced by 98%, and particulate matter is reduced by 85%.

Simply eliminating container ships would be impractical and irrational, but considering there are 90,000 of them running 24 hours a day, 280 days a year, reducing emissions in container ships would likely have a pretty high “bang per buck” factor. Mandating the use of higher quality fuel would increase the cost of shipping, but it would reduce air pollution on a scale that an extra 10 or 20 miles per gallon per car wouldn’t even touch. Considering the amount of cargo carried on each ship, there would likely only come with a negligible increase in cost per item. Then again, when the price of oil begins to increase more quickly, the cost of shipping those items is going to rise no matter what.

Then again, what if cargo ships didn’t have to run on fossil fuel at all? Nuclear power is incredibly efficient, and the U.S. Navy has at least 200 nuclear ships. Building new ships or overhauling old ships would cost a huge amount of money, but it would also lead to a major reduction in use of fossil fuels. It’s unfortunate, but any transition away from fossil fuel is going to be quite expensive.

Then again, switching container ships to nuclear power would be more of an investment than a true cost. In the long run, when fossil fuel is no longer available, having a shipping fleet that no longer uses fossil fuel would be a huge advantage. In the short run, though, nuclear power is cheaper than diesel power. One paper places the cost to operate a nuclear ship at one-sixth that of a diesel ship. Even if nuclear power hasn’t gotten any cheaper since then, investing in converting commercial ships wouldn’t cost nearly as much as it might initially appear.

Getting back to cars: Even if worldwide car pollution is dwarfed by container ship pollution, it doesn’t necessarily mean there’s no point in buying an efficient vehicle or exploring the possibility of buying an electric car. At the most basic level, if a more fuel-efficient car can do what you need it to do, but $50 worth of gas gets you twice as far, that extra money can be put toward more fun things. Plus, depending on how much you spend on gas for your daily commute, leasing an electric car could turn out to almost be free.

We might not know exactly when it will happen, but eventually the cost of finding and extracting new oil will become too high to justify its use as fuel. When that happens, if viable alternative fuels haven’t been developed, that’s going to go very poorly. Caring about the future and the preservation of the planet is important, but maybe it’s time to walk back the rhetoric a little bit. After all, that Suburban driver isn’t exactly single-handedly responsible for destroying the environment.

Check out Autos Cheat Sheet on Facebook
Follow Collin on Twitter @CS_CollinW