Highlights • The use of liquefied natural gas for heavy-duty vehicles in Canada and BC is investigated. • LNG heavy-duty vehicles in Canada reduce GHG emissions for methane emissions below 13 ${\text{g}}_{\text{C}{\text{H}}_{\text{4}}}\text{/k}{\text{g}}_{\text{LNG}}$. • LNG heavy-duty vehicles in BC reduce GHG emissions for methane emissions below 18 ${\text{g}}_{\text{C}{\text{H}}_{\text{4}}}\text{/k}{\text{g}}_{\text{LNG}}$. • LNG heavy-duty vehicles cannot reduce GHG emissions to meet the 2050 target in Canada and BC.

Abstract This study investigates the greenhouse gas (GHG) emissions from diesel- and liquefied natural gas-fueled (LNG) heavy-duty vehicles (HDVs) in the context of Canada and the province of British Columbia (BC) from 2014 to 2050. HDVs accounted for 18% and 11% of the 2014 GHG emissions from the transportation sector in Canada and BC, respectively. Different scenarios are analyzed using the GHGenius model and recent emissions measurements from LNG HDVs. The low emissions scenario of 1 ${\text{g}}_{\text{C}{\text{H}}_{\text{4}}}\text{/k}{\text{g}}_{\text{LNG}}$ indicates that LNG HDVs could reduce GHG emissions by 22% and 30% in Canada and BC, respectively. Also, the analysis shows that Canada’s and BC’s well-to-wheels (WTW) methane emissions should be maintained below 13 and 18 ${\text{g}}_{\text{C}{\text{H}}_{\text{4}}}\text{/k}{\text{g}}_{\text{LNG}}$ to produce less GHG emissions from LNG HDVs than their diesel counterparts. If WTW methane emissions are maintained at the current estimated rate of 26 ${\text{g}}_{\text{C}{\text{H}}_{\text{4}}}\text{/k}{\text{g}}_{\text{LNG}}$, replacing diesel with LNG in HDVs would change GHG emissions from +1.7% to +24% for Canada, and from −8% to +16% for BC by 2050. Finally, our study indicates that even methane emissions of 1 ${\text{g}}_{\text{C}{\text{H}}_{\text{4}}}\text{/k}{\text{g}}_{\text{LNG}}$ would not be enough to decrease GHG emissions of HDVs by 80% below 2005 levels by 2050 as is the target set by the Government of Canada and BC. However, LNG HDVs do reduce nitrogen oxides and particulate matter emissions. Policy makers could support LNG HDVs for immediate reductions of nitrogen oxides and particulate matter, but should support methane emissions measurements and control campaigns, and other alternative fuels to meet the 80% GHG emission reduction target by 2050.