Container ships straddle a fine line between ultra-efficient and ultra-polluters. They can carry thousands of 20-ft containers across thousands of miles of ocean in relatively short time, but they also burn sulfur-laden heavy oil fuels. Each ship can emit over 150,000 tons of CO2 every year, 5,000 tons of sulfur, and other harmful particulates attributed to death and disease along heavily populated coastlines.

A.P. Moller Maersk AS operates the world’s largest container ship fleet. For the first time in 106 years, they lost money due to the economic downturn. How much money? $1.3 billion. Ouch. But they’ve also pledged to reduce their CO2 output by 20% by 2017. How nice would that be?

The Maersk Alabama was a ship captured by Somali pirates last year, which may be why the name is familiar to you. As recently as 2007, many shipping companies were placing orders for huge, $100 million dollar container ships that could hold thousands of containers. In this sense, these ships are incredibly efficient, requiring crews that often number under two-dozen. Sometimes over 1,000 feet long, they are monsters in every sense of the word, especially when it comes to emissions.

Green Car Congress reports that 12% of the world’s shipping fleet is idled right now. Not exactly good for the economy… but better for the environment. But perhaps more importantly, Maersk is also saying that they will cut their CO2 emissions by 20% by 2017. Maersk operates a fleet of over 500 ships, ranging from small boats like the Alabama that can carry a little over 1,000 containers to the Emma, which has an unofficial capacity of about 15,000 containers. If they truly did cut their emissions by 20%, that would be a huge dent in the global emissions equation. They are currently experimenting with a 5-7% biofuel blend. But perhaps even more shocking is their vocal support for a carbon tax on shipping.

I still say bring back sails. But what do I know?

Reprinted with permission from Gas 2.0