- Short-lived climate pollutants
- Our work
- Our partners
- Resources for action
- News & Events
- The Coalition
Urban bus activity is projected to soar by nearly 50 percent by 2030. Given that diesel engines are responsible for about a quarter of the black carbon emitted by the transportation sector, that could mean an additional 26,000 tonnes of black carbon.
These dangerous toxins will be particularly concentrated in cities in the global south, where a lack of engine and fuel regulations paired with limited access to clean technology and densely packed roads mean that out-of-date heavy duty vehicles are spewing dangerous amounts of toxins into the air.
Black carbon contributes to harmful air pollution around the world, a scourge responsible for about seven million premature deaths every year. In cities where these emissions are particularly dense, diesel exhaust can be responsible for 70 percent of residents’ risk of exposure to air toxins. On top of that, it’s also a short-lived climate pollutant, which means that it increases the rate of climate change in the near-term.
Soot-free buses are a vital alternative. These vehicles are made up of a fuel and engine combination that meets Euro VI emissions standards, which can be an electric bus, a bus that uses compressed natural gas, or a Euro VI engine or an older one with a filter. The important part is that it stays under a strictly limited amount of emissions. Less than 20 percent of buses sold around the world currently meet these standards.
The Soot-Free Urban Bus Fleet project, led by the CCAC along with C40 Cities, the International Council on Clean Transportation (ICCT), and UN Environment Programme targets cities with populations over 3 million that would benefit from support in converting to soot-free technology. The programme is currently targeting 20 cities in different countries— eleven of them CCAC member countries.
“The CCAC and other partners helped bring fuel standards into the limelight,” said Jane Akumu, the Africa focal point at the UN Environment Programme for promoting cleaner mobility programmes. “In some African, Asian, and Central American countries, fuel standards were not a priority but by focusing on the air quality impacts and especially the health impacts, these discussions have really come to the forefront.”
An important target of these efforts are industry manufacturers, without whom cities have no access to soot-free technology.
In 2017, the bus manufacturers BYD, Cummins, Scania and Volvo Buses all committed to ensure that soot-free engine technology would be available in 20 of the cities targeted by the Soot-Free Urban Bus Fleet Project. They also committed to making public the number of soot-free buses that are sold each year.
“The added value of the CCAC work is to be able to bridge the knowledge gap between what is happening on the ground at a city level with the headquarters for these big companies,” said Francisco Posada Sanchez, a Senior Researcher at The International Council on Clean Transportation.
Since then, ICCT has continued to facilitate conversations with bus manufacturers and city governments, with a particular focus on buses in Asia given that they are large distributors across the global south.
These conversations play an important role in linking industry and city governments. Bus company Scania has committed to slashing CO2 emissions by 50 percent by 2025 and Volvo has committed to having net-zero emissions by 2050. Today, in 14 of the partner cities there are now soot-free products available, paving the way for more soot-free vehicles.
Manufacturers often perceive large swaths of the global south, particularly Africa, as entirely being a Euro 2 market, without realizing there’s an appetite for cleaner technology. This can mean, in some cases, that they end up nudging city governments in a particular direction.
“The value of the CCAC, UNEP, ICCT and others is to educate the decision-makers in these countries, as well as the local distributors of buses and the headquarters of those companies to help them connect the dots,” said Sanchez. “We can help show them that Jakarta in Indonesia, Johannesburg in South Africa, Lagos in Nigeria, Addis Ababa in Ethiopia, and Nairobi in Kenya are cities that might not be on their radar but that are very ready to convert to something cleaner.”
The efforts to target manufacturers are complemented with a variety of efforts on the ground in global south cities, which can include knowledge exchange workshops, training, and regional meetings.
The partnership has had standout successes in South America, which now has over 1,500 electric buses operating, making it the biggest electric bus fleets outside of China.
A variety of successes within cities have also occurred, such as in 2017 which Sao Paulo approved a proposed amendment to their Climate Change Law which would require the city’s bus fleet to be 100 percent fossil free by 2037 and for 90 percent of particulate matter emissions to be reduced by 90 percent.
Santiago became the first Latin American city to adopt Euro VI standards for its public transportation, which helped pave the way for electric buses. The city had over 400 electric buses in 2020 and expects its entire bus fleet to be electric by 2035. This work has contributed to a dramatic drop of 27.6 percent in particulate matter emissions.
But growing progress is also being made across Africa where, in 2020, Economic Community of West African States (ECOWAS) announced they were adopting a comprehensive set of regulations for introducing cleaner fuels and vehicles in the region.
“Soot free buses are very, very important for West Africa. We can’t go backwards, we have to follow the trends and the current trend is to move to cleaner and greener mobility,” said Yssoufou Cisse, the Secretary General of UATP, the Africa Division of the International Association of Public Transport. “We can’t continue developing non-clean transport. We have to encourage our governments to put all efforts towards cleaner transport.”
Cisse adds that a major challenge for Africa is the fact that 80 percent of public transport is still informal but that there is nonetheless an appetite for this change.
The CCAC supported a sub-regional meeting with 15 ECOWAS countries at the end of May 2021. This knowledge-sharing workshop included a presentation of best practices and examples of soot free bus progress across Asia and Latin America. It also included a training component to better equip ECOWAS leaders to make the same changes. The event was hybrid, partially in person and partially digital, for leaders to learn more about how to implement soot-free buses.
A consultant was also hired to conduct a cost-benefit analysis of soot-free buses in Dakar and analyze financing possibilities for making the city’s bus fleet soot-free. A feasibility study was also completed in Lagos. Both studies were done in partnership with the city’s transport authorities.
The progress in Dakar has helped motivate the government to make potentially significant changes. The city government has received World Bank funding to develop bus corridors and they've exploring the option of making one of those corridors electric, dependent on availability of funds. Dakar also plans to operate 380 Compressed Natural Gas buses by 2023 and a total of 930 by 2032, and hopes to have 144 LFP battery buses in the upcoming years, adds Cisse.
The partnership has also made inroads into East Africa, including by supporting the Kenyan government to integrate the benefits of soot-free buses into their Nationally Determined Contributions, or their international commitment towards climate change mitigation. The city of Nairobi also did a cost-benefit analysis on implementing electric buses in the city.
The partnership is also supporting Dar es Salaam in Tanzania on how to procure soot-free buses and develop standards, work that is expected to be finalized this year.
“When we first started having conversations about the need for soot-free buses, many government regulators would say that they were focusing on the infrastructure itself, such as the roads, but not on the buses,” said Akumu. “Now, they’re much more likely to say that you also need to look at buses to make sure they’re as clean and efficient as possible, because the CCAC’s support has really helped bring it into focus.”
Our Expert Assistance is a no-cost service that connects you to an extensive network of professionals for consultation and advice on a range of short-lived climate pollution issues and policies.
Experts will provide guidance on technological options, mitigation measures (like those carried out by our initiatives), funding opportunities, application of measurement tools, and policy development.