Future Local Ground‐Level Ozone in the European Area From Statistical Downscaling Projections Considering Climate and Emission Changes

Abstract

AbstractGround‐level ozone is a major air pollutant harmful to human health. In the scope of climate change, it is essential to provide high‐quality local‐scale assessments of the anticipated changes for public health and policy interventions. Assessments and projections of ground‐level ozone usually rely on numerical modeling, but statistical approaches are also available. The present study enhances the validity of statistical downscaling by taking climate change as well as air pollution changes into account. Besides considering meteorological predictors such as air temperature, short‐wave radiation, humidity, and wind, ozone trends from changes in precursor emissions were included in the statistical models. Meteorological and ozone predictor information extracted from reanalysis data for the observational period and output of seven Earth System Models (ESMs) for the projection periods were used, with three of them having interactive chemical modeling, while the other four used prescribed ozone changes. Ground‐level ozone, more precisely daily maximum 8‐hr running means (MDA8) as well as daily maximum 1‐hr values (MDA1), at 798 measurement stations across the European area in the “ozone season” from April to September were assessed. Results depended strongly on whether only meteorological information or additional information about emission changes were considered. As a general picture under the consideration of climate and emission changes, decreasing ground‐level ozone concentrations were projected under the moderate SSP2‐4.5 scenario, while for the more pessimistic scenario SSP3‐7.0 increasing ozone concentrations over Europe, especially at the end of the 21st century, were assessed.