Policy impact assessment

The agricultural and horticultural industry operates within a complex system, in which a wide range of operational and environmental factors co-exist and interact with each other, such that even seemingly minor changes can have far reaching effects. Consequently, all changes must be assessed with great care to ensure that they are both liable to result in the required benefits (which are generally indirect benefits) and kept under constant review in light of our current scientific understanding.

AERU is at the forefront of agri-environmental policy impact assessment (ex-ante and ex-post), and has been involved in a number of projects that have took a holistic approach to the determination the impacts (both positive and negative) of a wide range of initiatives that have sought to induce environmental improvements. This includes those related to non-point source water pollution, greenhouse gas emissions and biodiversity.

Skills and services encompass the following:

Ex-ante assessment of policy options
Ex-post assessment of existing policy

Projects

Publications

Tzilivakis, J., Lewis, K.A., Kennedy, M.C., Ridley, L. & Garthwaite, D.G. (2026). The UK pesticide load indicator: development toward a policy tool. Journal of Environmental Science and Health, Part B: 1-18. [DOI].
Tzilivakis, J., Warner, D., Green, A., & Lewis, K.A. (2021). A broad-scale spatial analysis of the environmental benefits of fertiliser closed periods implemented under the Nitrates Directive in Europe. Journal of Environmental Management, 299: 113674. DOI.
Warner, D.J., Tzilivakis, J., Green, A. and Lewis, K.A. (2020). Establishing a field-based evidence base for the impact of agri-environment options on soil carbon and climate change mitigation – phase 1. Final Report. Work package number: ECM50416. Evidence Programme Reference number: RP04176. Natural England.
Warner, D.J., Tzilivakis, J., Green, A. and Lewis, K.A. (2020). Establishing a field-based evidence base for the impact of agri-environment options on soil carbon and climate change mitigation – phase 2. Final Report. Work package number: ECM50416. Evidence Programme Reference number: RP04176. Natural England.
Tzilivakis, J., Green, A., Warner, D.J and Lewis, K.A. (2020) Identification of approaches and measures in action programmes under Directive 91/676/EEC. Final report. Report prepared for Directorate-General Environment, European Commission, for project ENV.D.1/SER/2018/0017 by the Agriculture and Environment Research Unit (AERU), University of Hertfordshire, United Kingdom. [Download].
Warner, D.J., Tzilivakis, J., Green, A., Charlton, D. & Lewis, K.A. (2019). Determining the climate change mitigation potential of Countryside Stewardship. World Journal of Agriculture and Soil Science Change, 1(2), DOI
Tzilivakis, J., Warner, D., Green, A. & Lewis, K. (2019). Spatial analysis of the benefits and burdens of Ecological Focus Areas for water-related ecosystem services vulnerable to climate change in Europe. Mitig. Adapt. Strateg. Glob. Change, 24(2): 205-233. DOI
Lewis, K.A., Tzilivakis, J., Warner, D.J. & Green, A. (2018). Agri-environmental Management in Europe: Sustainable Challenges and Solutions - From Policy Interventions to Practical Farm Management. 5m Publishing, Sheffield, UK. ISBN: 1912178443
Warner, D., Tzilivakis, J., Green, A. & Lewis, K. (2017). Ecological Focus Areas and beneficial insect (Coleoptera: Carabidae) conservation for pest control: habitat suitability and farm specific factors. In: G. Begg, F. Bianchi, N. Birch, B. Gerowitt, J. Holland, D. Lupi, C. Moonen, M. Ramsden & P. van Rijn (Eds.), Proceedings of the 7th IOBC-WPRS Working Group meeting on Landscape Management for Functional Biodiversity (IOBC-WPRS Bulletin vol. 122). Dundee (Scotland, UK), 29-31 March, 6-10.
Angileri, V., Fasbender, D., Van Eupen, C., Tzilivakis, J., Warner, D., Devos, W., Loudjani, P., Paracchini, M-L. and Terres, J-M. (2017). Using the Ecological Focus Area (EFA) calculator to assess the potential impact of EFA implementation on biodiversity and ecosystem services. European Commission, Joint Research Centre (JRC) Technical Report. DOI: 10.2788/20041.
Warner, D., Tzilivakis, J., Green, A. & Lewis, K. (2017). Prioritising agri-environment options for greenhouse gas mitigation. International Journal of Climate Change Strategies and Management, 9(1): 104-122. DOI
Tzilivakis, J., Warner, D.J., Green, A. & Lewis, K.A. (2017). Spatial and temporal variability of greenhouse gas emissions from rural development land use operations. Mitigation and Adaptation Strategies for Global Change, 22(3): 447-467. DOI
Warner, D.J., Tzilivakis, J., Green, A. & Lewis, K.A. (2016). Rural Development Program measures on cultivated land in Europe to mitigate greenhouse gas emissions – regional “hotspots” and priority measures. Carbon Management, 7(3-4): 205-219. DOI
Tzilivakis, J., Warner, D., Green, A. & Lewis, K.A. (2015). Adapting to climate change: Assessing the vulnerability of ecosystem services in Europe in the context of rural development. Mitigation and Adaptation Strategies for Global Change, 20(4): 547-572. DOI
Warner, D.J., Tzilivakis, J., Green, A., Slater, R.I.J. & Lewis, K.A. (2013). Measuring the Extent to Which Greenhouse Gas Emission Savings Achieved by Environmental Stewardship are Displaced On-farm - Natural England Report NECR121. Natural England, York, UK.
Tzilivakis, J., Lewis, K., Green, A., Warner, D., Fialkiewicz, W., Olearczyk, D., Bordet, C. & Langevin, B. (2013). Optimal Design of Climate Change Policies Through the EU's Rural Development Policy: Final Report to the European Commission. European Commission, Brussels.
Lewis, K.A., Green, A., Tzilivakis, J. & Warner, D.J. (2010). The contribution of UK farm assurance schemes to environmental policy: Research Update Brief. University of Hertfordshire, Hatfield, UK
Lewis, K.A., Green, A., Tzilivakis, J. & Warner, D.J. (2010). The contribution of UK farm assurance schemes towards desirable environmental policy outcomes. International Journal of Agricultural Sustainability, 8(4): 237–249. DOI
Lewis K.A., Tzilivakis J, Green, A., Warner, D.J. & Coles A.J. (2008) Farm Assurance Schemes – Can they improve farming standards? British Food Journal 110(11), 1088-1105.
Warner, D.J. and Lewis, K.A. (2008) The impact on greenhouse gas emissions of the revised Action Programme for Nitrate Vulnerable Zones: Final Report for Project WT0757NVZ. Department for Environment, Food and Rural Affairs (Defra).
Tzilivakis, J., Lewis K.A., Green, A., Warner, D.J. and Calvert, A. (2002) Priorities for the Environmental Protection of Soil. R&D Project Record P5-055 for the Environment Agency.
Tzilivakis, J., Broom, C., Lewis, K.A., Tucker, P., Drummond, C. & Cook, R. (1999). A strategic environmental assessment method for agricultural policy in the UK. Land Use Policy 16, 223-234.
Lewis, K.A., Newbold, M.J. & Thomas, M.R. (1998). Pesticide policies, practices and initiatives - can the UK's know-how be transferred to Chile? International Conference on Pesticide use in Developing Countries: Impact on health and the environment, Costa Rica February 1998.
Tzilivakis, J., Broom, C.E. & Lewis, K.A. (1997). In search of sustainable CAP: Assessing the environmental impacts of agricultural policy. European Environment Conference, September 1997, Leeds.