Dropping diesel would slash marine CO2: Blue Sky

More than two-thirds of CO2 emissions from certain types of vessels would be eliminated if the North American shipping industry replaced burning diesel with an alternative marine fuel such as bio-LNG, methanol, ammonia or hydrogen, according to a recent study by the Blue Sky Maritime Coalition (BSMC).

That estimate is included in a BSMC report that found that certain types of North American waterborne transportation vessels generated about 66mn t of CO2 emissions in 2018.

The study estimates that 47mn t of that 2018 total could be attributed to fuel consumed by ships like offshore support vessels, accounting for 29pc of the 47mn t number, and inland tug and pushboat vessels.

The other 19mn t were emissions from North American ports such as Houston, New York/New Jersey and Los Angeles.

According to BSMC, the waterborne fleet covered by the study could achieve net-zero CO2 emissions by 2050 if it replaced fossil fuels with an alternative marine fuel. Other methods such as carbon capture could also be used to achieve this goal, BSMC said, but replacing the type of fuel burned would be the best option for achieving net-zero emissions.

"Having a complete view of the North American maritime industry's carbon footprint helps us better understand the sum of the challenge ahead of us and the solutions needed to address those challenges," BSMC chief executive David Cummins said.

Production of the alternative marine fuel must also be emission-free in order to reach net-zero CO2 emission targets, BSMC said. It could either come from a renewable source that can be easily produced or by using carbon capture technology to store those emissions.

The study is an analysis of vessel characteristics and inventory from the US Army Corp of Engineers' Institute for Water Resources. It looks at the data from 2018, which was the most recent information available at the time the group began its research, BSMC said. It said the 2018 emissions figures can serve as a baseline for today.

The study focuses on emissions from ship movements at inland and coastal waterways in the US and Canada. It does not include internationally flagged vessels traveling to or from North America.

BSMC is a US and Canadian shipping association that aims to accelerate developing zero-emission vessels, among other goals. Its members include Shell, US shipowner Crowley and Canadian firm Groupe Desgagnes.

By Luis Gronda