In 2012 alone, Latin America saw 131,000 preventable air pollution-related deaths. To reduce emissions and improve air quality, it’s essential that public transit fleets—like buses—become more fuel-efficient. Adopting cleaner fuels—like natural gas or low-sulfur diesel—and upgrading to technologies that produce fewer toxic emissions are two strategies for better fuel efficiency that cities should consider pursuing in the fight for clean air.

On March 27, 2015, the C40 Latin American Mayors Forum brought clean bus fleets to the focus of its agenda. Buenos Aires hosted the Forum, and more than 15 Latin American city leaders attended. The Forum brought significant advances for climate change mitigation efforts in Latin America, producing the Clean Bus Declaration of Intent, which urges cities to opt for “low and ultimately zero emissions buses.” The Declaration sets overall clean bus targets in participating cities and a common foundation for prioritizing more sustainable methods of clean fleet financing.

In order to ensure the Declaration’s success and maximize emissions reductions, city leaders should consider this agreement a starting step and continue to explore other low-cost strategies—like route optimization—for reducing emissions.

Targets and financing are just the first step

The Declaration sets targets for implementing cleaner buses: signatory cities have agreed to have clean buses comprise 28 percent of their overall fleet by 2020. In order to determine targets for each participating city, decision-makers will need to carefully analyze local context, because some technology and fuels combinations are more efficient in certain settings—like hybrid buses in dense cities, where frequent acceleration and braking is necessary. In terms of setting targets, Rio offers a good example. The city categorized its emissions using the Greenhouse Gas Protocol for Cities (GPC) and streamlined efforts across the waste and transportation sectors to achieve its target of reducing carbon emissions by 20 percent.

In order to achieve the targets outlined in the Declaration, it’s critical that cities have access to good sources of funding. While the Declaration primarily acts as a target-setting pledge for more eco-friendly buses, it also encourages cities to explore new sources of clean fleet funding, such as global manufacturers and multilateral development banks.

Financing is an important issue for ensuring the financial sustainability of clean fleets, because if adopting clean technologies and fuels is costly, operators might pass these costs on to riders in the form of high ticket prices. This detracts from the ultimate goal of creating affordable public transit. Two promising ways of financing clean fleets are subsidies and climate finance funds. Subsidies can help finance additional capital costs and can be implemented as pilot programs to help operators understand the costs and savings of clean fuels and technologies. Climate finance funds offer another approach. For instance, Climate Funds Update outlines the numerous funds available to cities, and Climate Investment Fund financially supports emissions reductions in emerging economies.

Moving forward with low-cost strategies for reducing emissions

Beyond the targets and financing options for clean fleets outlined in the Declaration, there are many other affordable strategies available to city leaders for reducing emissions that utilize existing resources. For instance, route optimization—redesigning bus routes to be more efficient—has the potential to cut emissions in half in Brasília, Brazil. These impacts build on reductions from city’s clean bus rapid transit (BRT) system without requiring additional costly investment.

Similarly, there’s significant potential for Querétaro, México to cut its emissions by bus reorganization—maximizing the value of each individual bus through efficient route design and phasing out older, less environmentally friendly buses. Along with a move to BRT, bus reorganization was shown to eliminate at least 85 percent of carbon dioxide emissions in the city.

Finally, driver training can be an effective method for reducing emissions, as certain driving techniques are more fuel-efficient than others. One example comes from a driver training course offered by EMBARQ India and with the support of FedEx. Not only did this program provide drivers with a better understanding of how fuel efficiency and driving behavior are interconnected, it also helped create fuel efficiency targets for everyday operations.

Paving the way to the Paris climate talks

Air quality in metropolitan areas ebbs and flows as mobility habits change. The Clean Bus Declaration takes a critical—and commendable—stance encouraging greener transit options in Latin American cities. This puts participating cities in a promising position for the COP21 climate talks in Paris this December, demonstrating initiative to address both public transit emissions and local air quality for healthier, cleaner communities.

We look forward to witnessing the tangible change that the Clean Bus Declaration will create, as well as the many possible next steps that bus agencies can take to reduce emissions and support low-carbon cities.