Energy efficiency can reduce both indoor and outdoor concentrations of air pollutants. By doing so, energy efficiency drives a range of economic, environmental and health benefits associated with local air quality.
The energy system contributes vitally to economic and social progress around the world, but the associated emissions and negative side effects are costly. Air pollution is one of the world’s single biggest environmental risks to human health, with one in nine deaths linked to poor indoor or outdoor air quality. The World Health Organization (WHO) estimates that 92% of the world’s population lives in locations where local air pollution exceeds WHO limits.
Transport was responsible for 28% of total final consumption of energy globally in 2016, and more than 90% of transport energy use depends on oil products (Energy Efficiency 2017). Since the majority of transport emissions are discharged at street level often within densely populated cities, improvements in transport efficiency can, therefore, have a significant impact on air pollution and on human health. In 2016, mandatory vehicle fuel efficiency standards covered nearly 30% of all energy use within transport. In 2015, the total energy savings from these standards was 2.4 million barrels of oil per day, however, there is still significant room for improvement (Energy Efficiency 2017).
In China, air pollution has been a particularly serious issue, due to the rapid increase in the number of motor vehicles and the large share of coal-based electricity generation. More than two million premature deaths annually are attributed to outdoor and indoor air pollution in China. For the average Chinese citizen, air pollution shortens life expectancy by approximately 2 years. In France, air pollution costs the country nearly USD 110 billion per year according to a 2015 French Senate inquiry, with transport, heating, and agriculture being the largest contributing factors. The French public health agency estimates that 48 000 deaths per year in France are due to fine particle pollution, mainly from vehicle exhausts (Pascal et al., 2016).
Energy efficiency has played a huge role in China’s improvements in energy intensity, leading to savings of 11% of total primary energy supply between 2000 and 2014, and an avoided 1.2 gigatonnes of CO2 emissions in 2014. These gains in efficiency, and subsequent reductions in air pollution from energy generation and transport, have been made through mandatory energy savings programmes in industry, a building retrofit, and heat-metering reform programme, and the use of standards for personal vehicles (Energy Efficiency 2016).
Introducing or increasing mandatory vehicle efficiency standards is an effective way to reduce pollution within cities. Despite representing 43% of total oil consumption for road transport, only four countries currently regulate the energy efficiency of heavy-duty vehicles (Energy Efficiency 2017) The US Clean Air Act from 1970 continues to deliver reductions in air pollution through stringent vehicle emission standards and for every USD 1 spent on reducing emissions, the return on investment is calculated to be USD 9 in benefits to public health, environmental improvements, productivity and consumer savings (US EPA).
There has been a rapid uptake of electric vehicles, with 2 million vehicles worldwide in 2016, which may further accelerate with recent policy announcements to phase out the sale of gasoline or diesel vehicles, however, at present these vehicles represent just 0.2% of the light duty vehicles currently on the road worldwide (Energy Efficiency 2017). The replacement of conventional vehicles with electric ones can reduce local urban air pollution and electric two-wheelers and vehicles are more efficient than their conventional counterparts, however, the source of electricity must be taken into account in an overall assessment of the impact on air pollution.
Mandatory building standards and retrofits that reduce the energy consumption within buildings can greatly improve the efficiency of heating and cooling systems within a home, commercial or public building. It is important for energy efficiency retrofits that reduce heat loss through increasing the air-tightness of a building to address the need for properly designed and adequate ventilation to protect the health of building occupant (Hamilton et al., 2015).
Scaling up the use of energy efficient appliances and lighting reduces the demand for electricity generation, and therefore reduces air pollution. Reducing the cost of operating cooking, lighting and heating appliances and equipment within the home can help facilitate the switch from less efficient, high polluting fuels, such as biomass or kerosene, still used by 2.7 billion people around the world for cooking and/or lighting, and greatly reduce both indoor and outdoor air pollution.