Air pollution and climate change Short lived climate

Air pollution and climate change Short lived climate forcers Øystein Hov

Is it useful to control short-lived climate forcers?

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

Methane measures suggested to be effective

Black Carbon Measures suggested to be effective

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.

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 CH 4 & 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

Contributions from European countries to Arctic pollution (2006) Primary PM 25 Secondary inorganic aerosols: SO 4, NO 3, NH 4 Meteorologisk Institutt met. no

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

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

Surface temperature response to forcings by natural factors, anthropogenic GHGs and anthropogenic aerosols Nor. ESM (→ GFCS via downscaling) global Arctic All forcings Anthropogenic GHG Natural (Solar + volcanoes) Anthropogenic Aerosols S/N the fourth decade ahead Hawkins and Sutton BAMS 2009

Climate reanalysis and projections IPCC AR 4 (2007) projected surface temperature changes 2090 -2099 relative to 1980 -1999 (multi-AOGCM average projection A 1 B SRES scenario)