The Role of Health Co-Benefits in Assessing Climate Mitigation Costs. Increasing Ambition to Act on Climate Change.

Abstract

Increasing the action to act on climate change and increasing the ambitions to do so, is an important issue in current policy debates. Governments are lacking behind their climate goals and it becomes difficult to achieve a 1.5˚C pathway by the end of the century (Climate Action Tracker, 2019; IPCC, 2018a). In this thesis, an indicator was analyzed which could incentivize policymakers to increase their climate mitigation ambition. This thesis identified the emission levels at net-zero economic costs when including health co-benefits from reduced air pollution for China and India in 2030. The indicator was further used to determine reductions in the total abatement costs coming from health co-benefits. The analysis is based on an extensive data collection of co-benefit values and emission trajectories with consistent mitigation cost estimates from two different integrated assessment models IMAGE and POLES. To identify the emission levels at net-zero costs for a 1.5˚C pathway in 2030, the monetized co-benefits were implemented in a Marginal Abatement Cost Curve. The identified emission level ranges from 2.9 to 7.2 GtCO2 for China and from 0.7 to 1.3 GtCO2 for India. The results illustrate the number of emissions that can be achieved at net-zero cost when accounting for health co-benefits from reduced air pollution. For both countries, these emission levels make up over 50% of the total emissions gap in 2030. Illustrating these emission levels besides the reductions of total mitigation costs is an additional dimension to incentivize and inform governments. Limitations in data characteristics on cost estimates for co-benefits and IAMs for 2030 reduced the persuasiveness of the results. Using co-benefits as an additional dimension to assess the effects of implementing local mitigation measures could increase the usability of the indicator. Using measure specific cost estimates could further increase the usefulness of the indicator for advising policymakers. Yet, the results show for both countries the significant effect just the inclusion of health co-benefits can have on the required mitigation costs. Climate change demands action and co-benefits can incentivize that.