• Range in projections of near-term AQ (surface O3 and PM2.5)
is driven primarily by emissions rather than by climate change
• Globally, warming decreases background surface O3 but
high CH4 (RCP8.5) can offset this decrease
• Higher surface temperatures in polluted regions will trigger
feedbacks in local chemistry and emissions, increasing peak
levels of O3 and PM2.5
• For PM2.5,climate change may alter natural aerosol sources
and wet removal, but no confidence level is attached to the
overall impact