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.1 Energy efficiency can reduce both indoor and outdoor concentrations of air pollutants. In 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. Scaling up the use of energy efficient appliances and lighting reduces the demand for electricity generation, and therefore reduces air pollution. Mandatory building standards and retrofits that reduce the energy consumption within buildings can also greatly reduce the need for power generation. Similarly, improvements in the efficiency of industrial sites can lead to significant reductions in emissions from fossil fuel based power generation (including at the level of industrial facilities).

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.2 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.2

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.2 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.3

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.2 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.

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 enquiry, with transport, heating and agriculture being the largest contributing factors.4 The French public health agency estimates that 48 000 deaths per year in France are due to fine particle pollution, mainly from vehicle exhausts.5

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.6