University of Bath

I-SEE Seminar 'Do health co-benefits compensate the economic costs of the Paris climate agreement?'

There are significant gains for climate action, which are independent of any future reductions of damages from climate change.

11 Dec 20184.30pm
11 Dec 20185.45pm

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.

Afternoon tea will be served in the Wessex Restaurant 16:00-16:25