5. Conclusions

The report summarises the potential direct and indirect impact of climate change on the risk assessment of plant protection products.

Regarding the experimental studies, concerns were raised that extended drought and more frequent flooding of soils may impact the microbial communities in the soil or sediment. Therefore, specific care should be taken when soil or sediment samples are taken for laboratory tests. Also, the terrestrial field dissipation studies may be impacted by these events and an increased risk of invalid results from field studies was identified.

The main impact was identified in the area of environmental fate modelling. In the relevant environmental fate models and scenarios outdated weather data is used (mainly derived from time series between year 1970 – 2000). An impact analysis showed that the effect of increased temperature and changes in rainfall patterns potentially lead to decreased leaching of pesticides to groundwater (calculated for the Hamburg scenario with FOCUS PELMO). Other publications based on leaching calculations with MACRO show slight increases in leaching concentrations and with FOCUS surface water calculations increases or decreases in surface water concentrations depending on the application timing.

Indirect factors such as shifts in agronomic dates (emergence and harvest dates, dates when BBCH stages are reached), an increased use of plant protection products due to warmer and wetter conditions and an increased pest pressure, or an extension of agricultural land further north into potentially vulnerable areas could have a larger impact on the fate of plant protection products than the outdated climate data of the models.

At the same time, it is expected that new management practices will become more important. This may include precision farming techniques like application via drones and spot applications, and mitigation options such as micro dams or conservation tillage.

For Ecotoxicology it is concluded that testing guidelines should be reviewed to evaluate if the environmental parameters in these guidelines are still relevant and conservative or would need to be updated. The aquatic and terrestrial indicator species may react differently to changed temperature conditions. It needs to be evaluated if the indicator species are still appropriate considering changing environmental conditions. A change in environmental conditions could mean a change in timings of food item availability, shifts in diets and ultimately have an impact on growth and reproduction of the non-target organisms. An evaluation should be made of the impact on focal and indicator species, of a potential shift in the timings of when a BBCH stage of a crop is reached.

It further is concluded that changes in the environmental parameter and modelling input may have a significant impact on the aquatic and terrestrial risk assessment. An impact assessment should be conducted when environmental fate or ecotoxicological parameters or processes are changed to be aware of the impact on the risk assessment.

The following work packages were identified based on the action points described in the different sections (EFT = Environmental fate studies; MOD = Environmental fate modelling; ECO = Ecotoxicology; CHE = Chemistry):

ID	Title	Priority	Description
EFT 1	Guidance review for terrestrial field dissipation studies	1	Literature review to be performed to evaluate in detail the impact of drought and flooding on soil microbial communities Guidance for terrestrial field dissipation studies should be reviewed in terms of how to deal with extended drought or flooding, to avoid the increasing risk of invalid results or how the results of affected trials can be interpreted for the risk assessment
MOD 1	Update of weather files	1	Update climate data and irrigation schedules used in models for environmental risk assessment to new time series. Contact SDLM working group for input. Develop process on how to update and distribute climate data regularly (every 5-10 years) for relevant models and scenarios to stakeholders. Initiate discussions with model developers if sub-daily precipitation data can be used. Availability of weather data of e.g. hourly resolution or options of temporal rainfall disaggregation needs to be checked. Impact assessment on PEC groundwater and surface water calculations.
MOD 2	Re-evaluation of relevance of FOCUS crops and scenarios	1	Member states to re-evaluate spatial extent of FOCUS groundwater and surface water scenarios and to re-define relevancy of scenarios for their national risk assessment. Contact SDLM working group for input. Member states to re-evaluate if further FOCUS scenarios, FOCUS crops, or combinations of both need to be defined to cover all major agricultural areas and to avoid increased necessity to use surrogate crops Development of guidance on how to select surrogate crops for those scenarios which are not defined for FOCUS crops
MOD 3	Re-definition of agronomic dates and practices	1	Update of agronomic dates in FOCUS and national scenarios (especially emergence and harvest dates of FOCUS crops) and BBCH – date relationships in AppDate and for national scenarios in Myrbeck (1998) Develop regulatory framework for precision farming techniques. Detailed guidance and implementation in FOCUS models is required (e.g. new application types, drift curves, mitigation options in SWAN and VFSmod)
ECO 1	Testing guidelines	1	Identify if the 'indicator' species being tested are still appropriate considering the changing environmental conditions. Evaluate if the study designs are still representative of the changing environmental conditions. Establish if the current indicator species can tolerate a change in the study design parameters.
CHE 1	Temperature selection for shelf-life testing	1	Review of relevant temperature ranges for shelf-life test. Potentially introduction of new temperature ranges for Southern Europe

Table 5: Suggested Priority 1 work packages

ID	Title	Priority	Description
EFT 2	Guidance development for soil sampling	2	Guidance on sampling timing should be developed to ensure that microbially active soils are taken which are not influenced by drought or flood periods or include how the results of affected studies can be interpreted for the risk assessment.
MOD 4	Literature reviews	2	Literature review of worst-case runoff and drainage entries to re-evaluate conservatism of STEP2 entries in light of increased rainfall intensities and update in FOCUS surface water repair. Literature research and discussion with SDLM working group on expected development of soil organic carbon content and soil pH values is recommended to decide if current scenarios cover future developments conservatively or if updates in soil data would be necessary
MOD 5	Definition of BBCH-date relationship	2	Development of a flexible approach of defining BBCH-date relationships with field data (or crop modelling
ECO 2	Risk assessment considerations	2	An evaluation should be made to see if the toxicity endpoints are still the appropriate parameters The impact of climate change on biodiversity from a regulatory ecotoxicology point of view should be evaluated: landscape change, movement of mobile organisms, ecosystems and their services, etc. An evaluation should be made of the impact on focal and indicator species by shifts in BBCH timings It is recommended that an evaluation is made on the impact of a change in ‘target pest’ on off-field habitats and recolonisation.

Table 6: Suggested Priority 2 work packages

ID	Title	Priority	Description
MOD 6	Discussions on implementation of climate projections	3	Initiate discussions on European level (EFSA, EU-PARC project) if in an updated future risk assessment scheme climate projection could and should be implemented instead of past weather data

Table 7: Suggested Priority 3 work packages