Abstract:

This report assesses global progress in 2019 toward reducing black carbon emissions from diesel on-road light-duty and heavy-duty vehicles. As of July 2019, 39 countries have implemented “soot-free” standards for new heavy-duty diesel engines that achieve a 99% or greater reduction in black carbon emissions compared with older-technology diesel engines. Five countries have adopted such standards for implementation before 2025, and at least six countries are planning to complete the transition to ultralow-sulfur diesel. The authors estimate that currently adopted policies will reduce global on-road diesel black carbon emissions to 40% below 2010 levels by 2030. A 75% reduction in global on-road diesel black carbon emissions is achievable by 2030, but only if virtually all countries implement soot-free standards in the 2020 to 2025 time frame. Adhering to this timeline could avoid roughly $1 trillion (U.S.) in cumulative societal costs over the next decade.