Environmental Engineering Reference
In-Depth Information
6.2 A Methodology for Determining the Impact of
Climate Change on Ozone Level in an Urban Area
Martin Cope, Sunhee Lee, Bill Physick, Debbie Abbs, Kim Nguyen,
and John McGregor
Centre for Australian Weather and Climate Research, Private Bag No. 1 Aspendale Victoria,
Australia 3195
Abstract
In this paper we present a methodology that has been used to give an
insight into the impact of climate change on ozone levels in Sydney in 20 and 50
years time. The methodology comprises a dynamical downscaling system which
takes 200 km resolution global climate simulations and through a two stage
process, generates 3 km resolution mesoscale meteorological and trace gas
concentration fields over populated areas.
The system was assessed for Sydney and was found to perform well in the
prediction of the historical ozone climatology, mesoscale meteorology and peak
ozone concentrations. The system was used to downscale an A2 climate scenario
for 2021-2030 and 2051-2060. Although the simulated ozone climatology did not
change significantly, increases in ambient temperature and the resultant increases
in ozone precursor concentrations and photochemical transformation rates lead to
increases in the frequency and magnitude of peak ozone concentrations and health
impacts.
The tools that were developed and assessed in this project are intended to
provide a capability which can aid policy makers in formulating long term air
pollution policies where the impact of climate change has to be considered.
However, when applied for this purpose, it is recommended that the system be
operated in an ensemble mode whereby a range of model projections are generated
and an estimate of likelihood can be calculated. It is further recommended that the
system be enhanced to consider the formation and fate of fine particles (primary
and secondary) as this air pollutant is generally considered to cause the largest air
quality related health impacts in Australia.
Keywords
Climate change, ozone projection, dynamic downscaling system, IPCC-A2
scenario
