Impact of Climate Change on Summertime Air Quality in the Netherlands

Abstract

Air quality depends both on the emission of air pollutants and on local meteorological conditions. Climate change could therefore affect air quality on local to global scales through changes in meteorology. This study aims to determine the regional impact of climate change on summertime air quality for the Netherlands and to compare it to the effect of air pollutant emission reductions. The focus is on changes in ozone, fine particulate matter, and ammonia concentrations.

By nudging a weather model (WRF) with the output of a high climate change scenario (HadGEM2-ES RCP8.5), high resolution meteorology fields are obtained for a recent (2008-2017) and future (2050-2059) climate. It is shown that in this scenario climate change leads to a 2.5-fold increase in the number of stagnant days and to an increase in the daytime mixing layer height in the simulated summer period.

Simulations are performed with these two meteorological datasets and two emission datasets. The emissions are based on reported air pollutant emissions from 2008-2017 and on a maximum feasible reduction scenario for 2050 (ECLIPSE V6b MFR). Different combinations of the meteorology and emissions are then used as input for a nested chemical transport model (EMEP4NL). For a high future climate change scenario the simulations show an increase of 11% in the daily maximum 8-hour mean of ozone and a decrease of 6% in daily mean ammonia and of 25% in daily mean fine particulate matter concentrations in the Netherlands. Emission reduction measures alone lead to a decrease of 20% in ammonia and of 48% in fine particulate matter concentrations and to a shift in the ozone formation regime and local increases of ozone in urban areas. The combination of climate change and emission reduction measures reinforces the reductions in ammonia (-28%) and fine particulate matter (-59%) concentrations. For ozone, climate change has a detrimental effect on the benefit of emission reduction measures, but emission reduction measures half the mean effect of climate change on ozone concentrations in the Netherlands.