This is a couple of years old, but I just read about it:
Big polluters: one massive container ship equals 50 million cars
The article focused on sulfur, but according to Wikipeida, "Carbon dioxide emissions from shipping is estimated to be 4 to 5 percent of the global total." [
http://en.wikipedia.org/wiki/Environ...t_of_shipping]
According to the article, cargo ships use the cheapest and dirtiest fuel, so I imagine that they were forced to run cleaner, they would need better fuel, and not only would trade cost more, but the price of fuel would go up.
So, rely on domestic marketing, upgrade the rail system, use electric trains, and power them by burning hippies!
Perfect!
Hippies are a clean fuel, right?
