An international regulatory body is set to finalize decarbonization guidelines for about 50,000 commercial vessels across the world later this month, but liquefied natural gas (LNG) ship owners are not waiting to upgrade their fleets.

LNG carrier owners are already searching for ways to comply with the coming International Maritime Organization (IMO) decarbonization rules, which take effect in 2023. The IMO’s decarbonization strategy requires a 40% reduction over 2008 levels in carbon dioxide (CO2) emissions from the shipping industry by 2030 and a 70% reduction in 2050. 

Finnish technology group Wärtsillä Corp., a major supplier of equipment for LNG carriers, has seen an “exponential increase” in customer inquiries about compliance with the rules, said the company’s...