awesome sky

Cleaner air from climate policy could save two million lives every year

Savings from reduced air pollution outweigh the cost of climate policy through to 2050

A study published in Nature Climate Change estimates that climate policy could save millions of lives every year by cutting air pollution. The health benefits would outweigh the cost of cutting greenhouse gas emissions.

The research team, led by Dr Jason West at the University of North Carolina, used the latest data on the health impacts of fine particle and ozone pollution to model two scenarios: one with strong global action to limit greenhouse gas concentrations to 525ppm by 2100, and one with no climate action. The climate action scenario entailed a shift away from using fossil fuels, which are the main source of air pollution, by cutting energy demand and switching to nuclear and renewable energy (mainly wind) and biofuels.

They found that the scenario with strong climate action led to half a million fewer premature deaths from air pollution globally every year by 2030, rising to 1.3 million in 2050 and over 2 million by 2100. The model included the impacts of fine particles on lung cancer and cardiopulmonary disease, and the effect of ozone on respiratory problems.

The health benefits are worth between $50 and $380 for every ton of carbon dioxide removed – which is more than the cost of cutting carbon emissions in 2030 and 2050, and within the lower part of the range of cost estimates in 2100.

The health benefits were strongest in the densely populated regions of East and South Asia, North America and Europe, especially in highly polluted parts of Asia. In 2030, two thirds of the global benefits occurred in China, and in East Asia the benefits were 10 to 70 times greater than the costs of cutting greenhouse gas emissions.

By linking a model of the global atmosphere with a model of energy economics, the team were able to account for a number of factors not included in earlier assessments. They included the effect of long range transport of pollution, the growth in ozone pollution due to methane emissions and the impact of climate change itself on air pollution (such as increased ozone production in hotter, sunnier conditions). They also used a higher monetary value for the loss of a human life in future years, as a result of economic growth, and took account of increasing population and susceptibility to pollution. Together with the use of updated values for the health impacts of air pollution, this resulted in higher estimates of co-benefits than those produced by previous studies.

However, the study did not include the health benefits for children and adults under the age of 30, the benefit of avoided illness (rather than premature death) due to air pollution, or the effect of climate policy on indoor air pollution from stoves in developing countries. Inclusion of these effects could result in even higher estimates of the benefits of climate policy for human health.

Co-benefits of mitigating global greenhouse gas emissions for future air quality and human health (2013) J. Jason West, Steven J. Smith, Raquel A. Silva, et al., Nature Climate Change 3, 885–889 doi:10.1038/nclimate2009