Analysis of Liquefied Natural Gas as a Marine Fuel in the United States

New report from Ocean Conservancy explores the risks of LNG as a fuel choice

International and domestic shipping is responsible for emissions of more than 1 billion metric tonnes of greenhouse gases (GHGs) every year. In July 2023, the International Maritime Organization (IMO) set a goal of reaching net-zero greenhouse gas emissions from international shipping by 2050. Without a major transition to near-zero and zero-emission energy, the latest IMO analysis projects emissions to either stay flat or increase, and ultimately miss the projected IMO goals by 2050.

Liquified natural gas (LNG) is a growing fuel choice for marine transportation, as it has negligible sulfur content and supports low sulfur oxide (SOx) emissions as required by international regulations beginning in 2020. LNG also has reduced CO2 emissions compared to traditional heavy fuel oils, is cheaper than alternative fuels derived from renewable energies, and it has been promoted as a “transition fuel” that will enable the sector to move away from traditional heavy fuel oils. However, LNG is not a low greenhouse gas fuel and is not a climate solution for shipping. LNG is almost entirely composed of methane—a potent greenhouse gas. Methane is as high as 30 times more potent than carbon dioxide (CO2) as a greenhouse gas over a 100-year timeframe; and more than 82 times more potent than CO2 in the near-term.

In addition to the global warming implications of LNG, its production and use can also harm human health and perpetuate environmental injustices. For example, methane emissions from increased LNG consumption can increase background ozone concentrations, which can harm human health at ground level.

Analysis of Liquefied Natural Gas as a Marine Fuel in the United States aims to give the reader a detailed review of the existing literature on LNG as a marine fuel, including:

• Discussion of policies and regulations
• LNG engine technologies and emissions
• The global and U.S. LNG vessel fleets
• Production, import and export of LNG
• Health and equity impacts of LNG

A summary of the highlights of this analysis can be found here.