While the co-benefits from addressing both climate change and air pollution related problems have been clearly recognized, there is not much evidence comparing the mitigation costs and economic benefits of air pollution reduction for alternative approaches for meeting greenhouse gas targets. This study analyses the extent to which health co-benefits would compensate the mitigation cost of achieving the targets of the Paris Agreement (2ºC and 1·5ºC) under different scenarios where the emissions abatement effort is shared between countries according to three established equity criteria.
Methods: An integrated assessment model (GCAM) was used to investigate the emission (greenhouse gases and air pollutants) pathways and abatement costs of a set of scenarios. The resulting emissions pathways were transferred to an air quality model (TM5-FASST) to estimate the concentrations of particulate matter (PM2·5) and ozone in the atmosphere and the associated premature deaths and levels of morbidity. These health impacts were then monetized and compared with the mitigation costs both global and regionally. The analysis looks forward to 2050 following the SSP2 socioeconomic narrative.
The health co-benefits significantly outweigh the policy cost of achieving the target for almost all the central scenarios analyzed. In some of the mitigation strategies, the co-benefits are double the costs at a global level. The ratio of health co-benefit to mitigation cost ranges from 1·4 to 2·45 depending on the scenario. At the regional level the costs of reducing greenhouse gas emissions could be compensated with the health co-benefits alone for China and India, while in the European Union and USA the proportion they cover varies but can be significant (7-84% and 10-41%, respectively). A sensitivity analysis shows that, even when the analysis is developed taking the lower bound of the most influential variable (Value of Statistical Life, VSL), the health co-benefits are very close to the mitigation costs (covering 70 to 122%, depending on the scenario). Finally, the study shows that the extra effort of trying to pursue the 1·5ºC objective instead of the 2ºC would generate a substantial net benefit in India (3·28-8·4 trillion US$) and China (0 ·27-2 ·31 trillion US$).
There are significant gains for climate action, which are independent of any future reductions of damages from climate change. Some countries like China and India could justify stringent mitigation efforts just by including health co-benefits in the analysis. The results also indicate that the statement in the Paris Agreement to “pursue efforts” to limit temperature increase to 1·5ºC would make economic sense in some scenarios and countries if health co-benefits are considered.
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Speaker profiles
Professor Anil Markandya graduated from the London School of Economics with a Master of Science in Econometrics in 1968 and was awarded his Ph.D. from the same institution on the Economics of the Environment in 1976. He has held academic positions at the universities of Princeton and Harvard in the US and at University College London and Bath University in the UK. He was a lead author for Chapters of the 3rd and 4th IPCC Assessment Reports on Climate Change, which were awarded a share of the Nobel Peace in 2007. He was a Lead Author for the 5th Assessment Report, the last published IPCC Report. In 2008 he was nominated by Cambridge University as one of the top 50 contributors to thinking on sustainability in the world. In 2012 he was elected the President of the European Association of Environmental and Resource Economics and in 2013 he became a member of the Scientific Council of the European Environment Agency.