This workshop was presented at the EcoMobility World Festival in Johannesburg, South Africa. The workshop was also part of the CCAC Urban Bus Fleets project, which is aimed at supporting cities in shifting new bus purchases to engines that achieve the lowest technically feasible black carbon emissions matched by current fuel quality, and to make a public commitment to shift all new bus purchases to soot-free engines by a target date.

Besides contributing to climate change, motor traffic causes air pollution and respiratory diseases. 3.7 million people die annually worldwide from transport-related emissions such as PM2.5 and PM10 alone. The Clean Bus Fleets workshop, organised by the C40 cities in partnership with the city of Joburg, CCAC and the ICCT, focused on the impact on the public and the environment of vehicles powered by fuels with high soot emissions. Participants also discussed strategies to reduce traffic congestion while creating new income sources for the cities.

While diesel fuel is high on soot (also called black carbon) particles, clean bus fleets offer the largest opportunity to drastically reduce the levels of pollution in major cities. Diesel engines are therefore the primary target for reducing transportation-related black carbon emissions since they account for more than 95 percent of black carbon in this sector (Ray Minjares, Soot free urban buses, Ecomobility World Festival Technical Papers, 2015). Around 56% of G20 nations have already required soot-free diesel engines for their bus fleets, explained Raj Minares, ICCT. Finally, Bus Rapid Transit (BRT) is being rapidly taken up in cities and provides an immense opportunity to shift the diesel powering the buses to soot free fuels offering huge benefits to health and the environment.