Mitsui O.S.K. Lines, Ltd. (MOL) has successfully completed the first Japanese trial of marine fuel made using cow dung. 

This liquefied methane or "bio-LNG" was used on a 6,455gt cargo vessel called the Ise Mirai which is the first Liquefied Natural Gas (LNG) fuelled ocean cargo vessel in Japan. 

LNG has long been touted as an alternative fuel, and it does reduce CO2 emissions when compared to traditional heavy fuel oils. However, a big issue with the use of LNG is methane slip. This is where unburnt methane escapes into the atmosphere through the funnel. Methane is one of the leading contributors to climate change and is responsible for around 30% of the rise in global temperatures since the industrial revolution.

By utilizing waste to create the bio-LNG rather than natural gas extracted from the earth the total carbon footprint of the process is likely to be reduced significantly. It also prevents large piles of manure from sitting in storage and producing methane as it decomposes. Plus manure can have a very negative effect on the local environment due to the excess nutrients seeping into rivers and lakes. 

Similar technology is already being used for experiments to power tractors, trucks and power for homes. With the infrastructure for LNG already being in place moving to bio-LNG seems like a simple step in the quest to reduce shipping's carbon footprint.