IMO emissions report raises new concerns about methane slip

A recent report from the International Maritime Organization (IMO) reveals that global shipping emissions increased nearly 10 percent from 2012 to 2018, with the industry facing a growing challenge concerning methane slip.

- Tom Ewing

In July, the IMO released the fourth version of “Reduction of GHG Emissions from Ships.” At 577 pages, it’s hard to overstate the report’s scope and detail. The big picture: Total shipping emissions rose from 977 million tons in 2012 to 1.07 billion tons in 2018, a 9.6 percent increase, mostly carbon dioxide (CO2). The industry’s share of global greenhouse gas emissions increased from 2.76 percent in 2012 to 2.89 percent in 2018.

Maritime carbon intensity improved between 2012 and 2018, the IMO report stated. However, the reduction has not been constant, and it has slowed since 2015.

One of the most troubling aspects of the report is the increase in methane emissions. Methane, the primary component of natural gas, has 86 times the climate impact of CO2 over a 20-year period, according to the Intergovernmental Panel on Climate Change. In ships, the use of liquefied natural gas (LNG) increased by about 30 percent from 2012 to 2018. During that same time, methane emissions increased by more than 150 percent.