This report assesses progress in 2018 toward implementing the Climate and Clean Air Coalition's (CCAC) global strategy to introduce low-sulfur fuels and cleaner diesel vehicles. The rapid reduction of diesel black carbon emissions is one element of a strategy proposed to reduce near-term climate warming by an average of 0.5°C over 25 years. To achieve this target, emissions of black carbon from all sectors must fall to 75% below 2010 levels by 2030. The Heavy-Duty Vehicles (HDV) Initiative of the CCAC released its global strategy in 2016 with the aim for all countries to implement vehicle emissions and fuel quality requirements equivalent to Euro 4/IV by 2025 and Euro 6/VI by 2030. This study finds that this strategy can reduce diesel black carbon emissions to 88% below 2010 levels by 2040 but that higher ambition—equal to Euro 4/IV implementation by 2021 and Euro 6/VI no later than 2025—is necessary to meet the emissions reduction and temperature targets.
Researchers estimate that diesel engines accounted for 88% of black carbon (BC) emissions from road transport in 2010. Diesel on-road vehicles are a particularly good target for emissions control given their disproportionate contribution to impacts on climate and health, the existence of clear and cost-effective technology pathways for achieving substantial emissions reductions, and the joint benefits of reductions for climate, health, and agriculture. “Soot-free” engines—or those equivalent to or better than Euro VI for HDVs, Euro 5b for light-duty vehicles (LDVs), or any policies that explicitly require the installation of a diesel particulate filter (DPF)—are capable of reducing exhaust emissions of diesel BC by 99% compared with older-technology engines.
This study finds that in 2018, 40% of new heavy-duty diesel vehicles (HDDVs) sold worldwide are equipped with DPFs. This share is projected to grow to 50% in 2021 after adopted Euro VI-equivalent standards have gone into force in India and Mexico. If China and Brazil introduce Euro VI-equivalent standards, the share of new HDDVs with DPFs would increase to 70%. Policies adopted as of May 2018 are projected to reduce global BC emissions from diesel road transport by 37% by 2040, equivalent to 40% below 2010 levels. Implementation of the Global Sulfur Strategy could reduce BC emissions to 88% below 2010 levels in 2040.
With the adoption of soot-free standards forthcoming in the largest vehicle markets, the remaining countries without such standards will account for 30% of new HDDV sales spanning more than 150 national jurisdictions. Harmonization of such policies across trade blocs will remain an important strategy to deliver more rapid progress than if each country were to develop regulations individually. Extending support for tightened standards to a short list of populous countries could also have an outsized impact on the global BC emissions trajectory.