A new study from the International Council on Clean Transportation (ICCT) estimates that ships in the Great Lakes-St. Lawrence Seaway (GL-SLS) consumed more than 500,000 tons of fuel and emitted more than 1.6 million tons (Mt) of CO2 in 2019. The new, wide-ranging emissions inventory for 2019 also shows that ships flagged to the United States and Canada were together responsible for nearly 80% of total CO2 emissions, each about 40%.