1. Evaluating Societal Impacts Related to Air Quality and Climate Thanks to many colleagues, especially Greg Faluvegi & Yunha Lee Drew Shindell Nicholas School of the Environment Duke University

2. Comparing impacts & robustness PollutantClimate DamagesHealth DamagesAg Damages CO 2 Very large (certain)NoneMedium SO 2 Opposite (global)Very largeOpposite* HFCs Large (very likely)NoneVery Large MethaneLarge (certain)MediumLarge BC+Moderate and/orVery largeVery Large large uncertainty How to decide what is best to do where?

3. Lock in new CO 2 - intenstive capital stock Reduce SO 2 and NO x (both with net cooling effects) Avoiding Pitfalls

4. Currently... To get the most out of labour, capital, and other resources, countires need to allocate them efficiently across different sectors of the economy, and to achieve this, product prices need to reflect not only the cost of supplying those products, but also any environmental costs of using them. We think prices paid by users of energy, or energy-related products, need to reflect the full range of environmental costs (air pollution, road traffic congestion…), not just global warming. International Monetary Fund Director Christine Lagarde, 2015

5. Currently... Obama Administration executive order for all federal agencies to include Social Cost of Carbon (SCC) analysis: “intended to include (but not limited to) changes in net agricultural productivity, human health, property damages from increased flood risk, and the value of ecosystem services due to climate change.” EU has the Emissions Trading System All impacts assumed proportional to global mean annual average radiative forcing or temperature change Air Quality falls under a variety of rules, costs typically analyzed for major legislation

6. Develop a broader Social Cost that includes impacts on human health, agriculture, etc. via climate & air quality; includes all the key pollutants causing both problems Model response to emissions of one pollutant at a time Climate impacts of pollutants other than carbon dioxide Same valuation methodology for air quality and climate (similar work for methane/ozone/health in Sarofim, Waldhoff & Anenberg, Environ. Res. Econ., 2015) Valuing Emissions: Social Cost of Atmospheric Release (SCAR)

7. Valuing Clean Air Generation costs from US Energy Information Administration, 2012 Shindell, Climatic Change, 2015

8. Policy Benefits: US Clean Energy & Transportation Consistent with 2°C Shindell et al., Nature Climate Change, 2016

9. Policy Benefits: US Clean Energy: Avoids ~175,000 premature deaths by 2030 (-50%/+450%; ~80% PM 2.5, 20% O 3 ) Clean Transportation: ~120,000 lives by 2030 (-36%/+360%; ~66% PM2.5, 33% O3)

10. Policy Benefits: US Implementation costs ~$100-210B (2030 economy-wide) Shindell et al., Nature Climate Change, 2016

11. How Well do we Know the Values Shindell, Climatic Change, 2015

12. How Well do we Know the Values Kasoar et al., ACPD, 2016

13. Need to define broad targets (e.g. UN Sustainable Development Goals) Need to relate specific actions to broad targets (wider metrics) Need to target efforts to improve quantification of key sources of uncertainty influencing valuation How can policy & research maximize societal benefits?