Assessing Effects of Climate Change on Air Quality in the Netherlands

Abstract

Concentration maps of pollutants over the Netherlands, using model calculations and measurements, are reported annually at a resolution of 1 × 1km2 for policy makers. Each year these maps are presented for the preceding year and for future years (i.e. 2030, 2035, 2040), based on scenarios. Maps for the future years require emission scenarios as well as meteorological data consistent with climate change scenarios. We present and apply two different approaches currently considered to assess effects of climate change on air quality in the Netherlands. The first approach utilizes the OPS model, a source-receptor model combining a Gaussian plume model for the local dispersion with a Lagrangian trajectory model for long range transport. The OPS model is driven with yearly specific meteorological fields based upon measurements provided by the Royal Netherlands Meteorological Institute (KNMI). Output from climate models cannot be used yet in this model. Here we present a way in which specific climatological fields of past years, based on observations, can be used for the scenario runs for future years. A comparison with the method currently used (i.e., using meteorological data from 2005 to 2014) reveals limited mean climatic effects on air quality, but with potentially relevant spatial patterns. The second approach is using the EMEP4NL model, with one-way nested horizontal grids to the EMEP/MSC-W model, to calculate concentrations and depositions over The Netherlands at high resolution. This model is driven by hourly meteorological data from the WRF model. If the latter model is being nudged with output of a climate change scenario (HadGEM2-ES RCP8.5 in this study), one gets high resolution meteorology fields, which are used directly for EMEP4NL runs. We present results for a 2050–2059 climate and compare these with a recent period (2008–2017) for the summer period (JJA).