1. Air pollution and climate change Short lived climate forcers Øystein Hov

2. Is it useful to control short-lived climate forcers?

3. UNEP and WMO 2011 – Integrated Assessment of Black Carbon and Tropospheric Ozone: Summary for Decision Makers. Temperature evolution for the scenarios

4. Methane measures suggested to be effective

5. Black Carbon Measures suggested to be effective

6. Global benefits from full implementation of identified measures in 2050/2030 compared to reference scenario UNEP and WMO 2011 – Integrated Assessment of Black Carbon and Tropospheric Ozone: Summary for Decision Makers.

7. Can we trust in these results? Emission scenario uncertainty? Impact calculation uncertainty Black Carbon forcing range assumed 0.3-0.6 Wm -2 (being on the high side of model results) Estimated RF effect of the CH4 & BC measures O 3 0.18 / CH 4 0.21 / BC 0.14 Wm -2 Only two models used (GISS, ECHAM) and simplified temperature response function

8. Meteorologisk Institutt met.no Contributions from European countries to Arctic pollution (2006)‏ Secondary inorganic aerosols: SO4, NO3, NH4 Primary PM25

9. AMAP Assessment 2006: Acidifying pollutants, Arctic haze, and acidification in the Arctic www.amap.no BC north of the Polar Circle 1991-2001 average

10. Impact on instantaneous forcing of 1 kt BC Source: EMEP/MSC-W, UniOslo, IIASA Instantaneous forcing over

12. Surface temperature response to forcings by natural factors, anthropogenic GHGs and anthropogenic aerosols NorESM (→ GFCS via downscaling) All forcings Anthropogenic GHG Natural (Solar + volcanoes) Anthropogenic Aerosols global Arctic S/N the fourth decade ahead Hawkins and Sutton BAMS 2009

13. IPCC AR4 (2007) projected surface temperature changes 2090-2099 relative to 1980-1999 (multi-AOGCM average projection A1B SRES scenario) Climate reanalysis and projections