Editor's note: This article has been updated to reflect that black carbon is not a greenhouse gas. 

Of the many risks posed by climate change, the effects on human health are particularly significant—and people are already experiencing their impact. The rise in global mean temperatures, coupled with changes in the distribution of water, are currently leading to an increase in vector- and water-borne diseases, which will affect people in regions like the Western Pacific, where malaria and dengue are a particular threat. Climate change is also affecting global food security, which can result in new illnesses driven by hunger and malnutrition. And the increase in intensity and frequency of extreme-weather events like 2014’s Typhoon Hagupit in the Philippines or Tropical Storm Erika that swamped Dominica in August 2015, will lead to even more weather-related fatalities, as well as an upsurge in communicable diseases, as natural disasters overwhelm resources, infrastructure, and disaster-preparedness systems—particularly in developing countries.

And these are just the health effects that result from climate change. Many of the greenhouse gases and other substances that cause climate change are also culprits when it comes to human-health threats—creating air pollution that drives premature deaths and severe health issues. Black carbon, a major emission from the transport industry, is one such substance.

Despite the importance of this issue, black carbon has largely been ignored in the major discussions about climate action, although the public sector is increasing its demands for solutions. For business, there is an opportunity to develop innovative solutions for low-emissions transport that benefits the climate, human health, and the economy.  

The Climate, Health, and Economic Costs of Black Carbon

Black carbon falls into a class of what are known as “short-lived climate pollutants,” or greenhouse gases and other substances that don’t last long in the atmosphere but nonetheless wreak havoc on our climate. Among all of the contributors to climate change, short-lived climate pollutants like black carbon pose the biggest threats to public health.

Black carbon, which is emitted during fuel combustion, is estimated to be the second-most significant anthropogenic emission to contribute to climate change, after carbon dioxide. It has a unique ability to both increase global and regional temperatures and reduce the cooling effect of large reflective surfaces like glaciers. Indeed, over a 100-year period, black carbon has the potential to trap 900 times more heat in the atmosphere than carbon dioxide.

The impact of black carbon on mortality and human health is also considerable. Black carbon is a component of PM2.5, fine particles that, by entering and remaining inside the lung, can cause premature mortality, cardiovascular and respiratory diseases, and birth defects. According to the World Health Organization (WHO), 3.7 million premature deaths resulted from outdoor air pollution in 2014—88 percent of which occurred in low- and middle-income countries where older engines and dirtier fuels tend to be more prevalent, and where the number of vehicles on the road is rising. China is particularly vulnerable, with an estimated 4,000 daily deaths that can be attributed to poor air quality. Even the United States faces up to 4,300 additional premature deaths per year from air pollution if regulatory and demographic conditions remain constant.

The economic costs of the public health challenges stemming from black carbon are also significant. In Europe, deaths from air pollution cost the economy more than US$1.4 trillion, which amounts to almost 2 percent of the global economy. For the entire OECD region, this figure is estimated to be US$3.5 trillion. Black carbon accounts for about half of these impacts.

Cities and Transportation: The Problem and the Solution

The impacts of black carbon are most acute in major cities, especially in the developing world, where more than 90 percent of air pollution derives from transportation—including passenger cars, public-transit vehicles, or light- and heavy-duty vehicle trucks. This makes the transportation industry the single most important actor in reducing the climate, health, and economic impacts caused by black carbon. As concern for human health continues to take center stage, the transport sector faces a serious risk if it does not act in concert with the public sector to reduce emissions. 

Given the role of transportation in black carbon, the industry has a significant opportunity to act. But this requires public- and private-sector investment and stronger policies. At the global level, governments must continue to uphold strong policy frameworks on transport emissions, including strict vehicle standards. At the local level, policies must respond to specific population needs, and policymakers must seek collaboration with private companies, which can act as service providers, technology innovators, or investors.

The private and public sectors can consider, for instance, partnerships to monitor and evaluate emissions reductions. The largest bus company in Russia’s Murmansk region has developed a reporting protocol to understand whether its upgraded fleet is helping the company meet its goals of cutting emissions and costs, improving passengers’ health, and strengthening the company’s market position.

Another example of such collaboration is in Dubai, where the French emissions-monitoring company NUMTECH mapped air quality across the entire city, taking transport and industry into account. The city of Dubai commissioned the modeling, which was carried out in partnership with Airparif, Enviro Solutions, and CTI-Chuden.

Three Opportunities for Public-Private Sector Collaboration

Already, there is significant action underway at the local level. This activity falls into three broad categories that should be replicated elsewhere:

  • Transport demand management: Various economic instruments, such as parking management and congestion pricing, combined with regulatory instruments, such as restrictions on traffic and vehicle ownership, can help cities create more efficient transport systems and encourage people to shift to public transit. In Beijing, parking management has also led to increased social equity, and in London, the introduction of a congestion charge in 2003 led to reduced congestion and pollution.
    Car manufacturers should offer input on these policies, which will affect their business models, due to possible restrictions on vehicle ownership and requirements for new product types that have lower emissions.
    These changes also offer the private sector opportunities: Public-transit systems are likely to adopt innovative proposals from private-sector providers. Consider, for instance, that the total bus stock in 2010 was approximately 16 million units—a figure that is expected to rise to around 18 million units by 2020 and 20 million units by 2030. Currently, about 17 percent of all buses are purchased for use in China, which is developing new transport and clean air policies.
  • Technologies and standards: National and city governments are starting to introduce stricter emission standards for all kinds of vehicles, especially for those with diesel engines. Efficient technologies such as “green” tires, diesel-particulate filters, hybrids, and electric vehicles can also mitigate vehicle emissions. Jakarta is investigating refinery upgrades to improve fuel quality as well as vehicle-emissions standards, which includes partnering with companies such as Sinopec, Saudi Aramco, and JX Nippon Oil and Energy. California, which has enforced black carbon regulations and diesel-engine emissions since the late 1960s, has reduced black carbon by 90 percent over the past 45 years. At the national level, the United States recently adopted emissions standards for heavy-duty diesel road vehicles to reduce emissions and tackle energy dependency.  
  • Transit-oriented development and public transport: A particularly relevant trend in the era of megacities is transit-oriented development, which integrates urban and transport planning to manage land resources more efficiently. Cities are attracted to public-private partnerships because private-sector management of these systems can reduce costs. In these partnerships, the city or local authority defines the outcomes, and the private contractor is responsible for achieving them within a defined budget.

Successful approaches can also combine these actions. For instance, Mexico City has reduced private-vehicle use by expanding sustainable transport options such as bus rapid transit and public bike-share, as well as prioritizing pedestrians and cyclists in its new mobility law. The city also launched a real-time monitoring program to track black carbon concentrations in five parts of the city. City officials mandated the removal of lead from the city’s gasoline supply, retrofitted existing automobiles with catalytic converters, and created legislation to require vehicle manufacturers to put catalytic converters into cars from the outset. These projects relied on a partnership with the private sector.

This kind of public-private collaboration is also happening at scale. For instance, the Climate and Clean Air Coalition’s Heavy-Duty Diesel Vehicle Initiative brings together multiple stakeholders to catalyze major reductions in black carbon through the adoption of clean fuel and vehicle regulations and supporting policies, with a focus on diesel engines in all economic sectors. To date, it has provided support to programs in Bangladesh, Chile, Colombia, Ethiopia, Ghana, Jordan, Kenya, Mexico, Paraguay, Peru, Sweden, and Uruguay.

It is clear that addressing black carbon can generate positive outcomes beyond just reducing the impact of climate change. Health and economic benefits also await if industry and policymakers work together to address this short-lived climate pollutant. 

This article was originally published as an issue brief with The Climate Group, one of our co-founding partners at We Mean Business. That article includes a foreword from Climate and Clean Air Coalition Head Helena Molin Valdes.