How sensitive is tropospheric oxidation to anthropogenic emissions?

We use a global chemistry transport model to explore how changes in anthropogenic emissions alter ozone production and tropospheric oxidizing capacity over decadal (1990-2010) and centennial timescales (1900 2100). We find that the spatial extent of O-3 production and loss in the troposphere changes very little despite large projected increases in precursor emissions. While tropospheric OH shows a long-term decrease of only 20% between 1900 and 2100, there are widespread changes in distribution which alter regional oxidation capacity substantially. We show that the remote marine boundary layer remains an important net sink of O-3, as greater production related to increased continental NOx emissions is outweighed by greater O-3 destruction. The critical NOx level required to support net O-3 production doubles between 1900 and 2100, from 28 to 55 pptv on average, preventing any large-scale shift in production regime. Citation: Wild, O., and P. I. Palmer (2008), How sensitive is tropospheric oxidation to anthropogenic emissions?, Geophys. Res. Lett., 35, L22802, doi: 10.1029/2008GL035718.