Air pollution and climate change Short lived climate forcers Øystein Hov

Is it useful to control short-lived climate forcers?

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

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 Wm -2 (being on the high side of model results) Estimated RF effect of the CH4 & BC measures O / CH / BC 0.14 Wm -2 Only two models used (GISS, ECHAM) and simplified temperature response function

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

AMAP Assessment 2006: Acidifying pollutants, Arctic haze, and acidification in the Arctic BC north of the Polar Circle average

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

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

IPCC AR4 (2007) projected surface temperature changes relative to (multi-AOGCM average projection A1B SRES scenario) Climate reanalysis and projections