proposed heavy-duty vehicle and engine greenhouse gas emission regulations available in english and french 116 pages . greenhouse gases ghgs are primary contributors to climate change. the most significant sources of ghg emissions are anthropogenic mostly as a result of combustion of fossil fuels. the emissions of ghgs have been increasing significantly since the industrial revolution and this trend is likely to continue if no action is taken. transportation is one of the largest sources of ghg emissions in canada accounting for about 28 of total emissions in 2009. heavy-duty vehicles accounted for around 7 of total ghg emissions or 24 of transportation emissions. accordingly taking action to reduce emissions from new on-road heavy-duty vehicles is an essential element of the government of canadas strategy to reduce air pollutant and ghg emissions to protect the environment and the health of canadians. the objective of the proposed heavy-duty vehicles greenhouse gas emission regulations the proposed regulations under cepa 1999 is to reduce ghg emissions by establishing mandatory ghg emission standards for new on-road heavy-duty vehicles and engines of the 2014 and later model years that are aligned with u.s. standards. the development of common north america standards will provide a level playing field that will lead north american manufacturers to produce more advanced vehicles which enhances their competitiveness. the proposed regulations would introduce progressively more stringent ghg emission standards for new on-road heavy-duty vehicles and engines that would align with the national ghg emission standards and test procedures of the united states environmental protection agency for the 2014 and later model years. the proposed regulations would apply to companies manufacturing and importing new on-road heavy-duty vehicles and engines for the purpose of sale into canada. it would reduce greenhouse gas emissions from the whole range of new on-road heavy-duty vehicles from full-size pick-u trucks and vans to road tractors i.e. semi trucks and buses as well as a wide variety of vocational vehicles such as freight delivery service cement garbage and dum trucks. the standards in the proposed regulations would address emissions of co2 n2o and ch4 from heavy-duty vehicles and engines and would also include measures to require reductions in leakage of the hydrofluorocarbon refrigerant used in cabin air-conditioning systems. the proposed regulations also include provisions that establish compliance flexibilities designed to provide appropriate lead-time for technological improvements and a smooth transition to a more stringent regulatory program. these flexibilities include a co2 credit system for generating banking and trading emission credits that could be used to offset any emission deficits incurred. credits would be obtained by companies whose fleet emission levels fall below the applicable standard while deficits would be incurred by companies whose fleet emissions exceed the applicable standard. flexibilities also include additional credits for vehicles with advanced and innovative technology vehicles. companies would also be required to submit annual reports and to maintain records relating to the ghg emission performance of their fleets.