ETC/ATNI Report 2021/17: Wheat yield loss in 2019 in Europe due to ozone exposure

Tropospheric ozone impacts agricultural crop and timber production, with significant economic effects for the sector. In the early 2000’s the PODy (phytotoxic ozone dose above a threshold y) indicator for calculating this impact was proposed by the expert group IPC-Vegetation working in support of the Air Convention. Within the ETC/ATNI, annual production of PODy maps has started in 2020. In this report we have implemented an impact modelling chain to quantify and monetize the loss in wheat production due to tropospheric ozone exposure for 2019. We also studied the sensitivity of the results to the degree of spatialization of the input data. This study quantifies and monetizes losses of bread wheat production due to tropospheric ozone pollution in 2019 in Europe. It uses the POD6spec methodology and the flux-effect function recommended by the Mapping Manual of the Air Convention. Wheat production data from Eurostat are used together with international wheat prices calculated by dividing the Gross production value of wheat in 2019 by the production quantities, both from FAOSTAT. The study calculates losses in wheat production for a reference case that started from wheat production data at regional level (NUTS 2), geolocated the production at grid level using Corine Landcover, and then calculated impacts at a grid level, before aggregating them at country level. Two sensitivity cases were also studied with degraded geolocation, one of which calculated impacts directly at country level. It was shown that 2019 was a specific year, with low levels of PODy, possibly due to specific meteorological conditions during the accumulation period. Despite this, the reference case shows wheat production losses that reach levels between 8 % and 9 % in five countries and exceed 5 % for seventeen countries. Economic losses amount to several millions of € in the majority of countries. When comparing these results to the two sensitivity cases, on a country level, percentage losses differed up to 2.8 percent. Aggregated at a European level, the differences were less than expected, but this is possibly related the low PODy levels in 2019.