ABSTRACT1) IIASA 'current legislation' (CLE), where current air quality legislation around the world is implemented; 2) IIASA 'maximum feasible reduction' (MFR), in which all currently available technologies are applied to achieve maximum emission reductions; and 3) the IPCC-SRES A2 scenario, which was used as a high emission estimate in the last IPCC assessment report. While increases in NO 2 and ozone are calculated when using the CLE scenario, reductions are seen for the MFR scenario. In the SRES A2 case, increases in NO 2 are largest, locally leading to ozone reductions at the surface resulting from titration effects. The model calculations suggest that air Terr. Atmos. Ocean. Sci., Vol. 18, No. 3, August 2007 476 quality problems will be severely aggravated over Southeast and East Asia if current legislation is not attained.