From 10-13 January, 2012 the Helmholtz-Centre for Environmental Research - UFZ in Leipzig hosted the first LIAISE Winter School on "Tools and Modelling for Impact Assessment". 18 participants from eleven different countries discussed on tool use, modelling approaches, policy assessment and sustainability. Lecturers and tutors from within and beyond the LIAISE Network of Excellence gave interdisciplinary insights into different approaches to policy assessment.

As a starting point for the Winter School Sabine Weiland (FU Berlin) gave a general introduction on policy assessment and sustainability. The subsequent sessions were dedicated to tools and tool applications in different areas: Stefan Reis (CEH) introduced the APIS tool, which is applied in modelling air pollution. Multifunctional land use and the role of impact assessments in this area has been the topic of Katharina Helmings (ZALF) presentation. Alena Bleicher, Matthias Gross, Stephan Bartke (UFZ) and Max Morio (U Tübingen) showcased how to develop a tool for an integrated assessment in the case of revitalizing contaminated areas. Dagmar Haase (UFZ) presented in a hands-on application session a tool developed to enable users to assess future scenarios by using multi criteria analysis. Ullrich Lorenz (German Environment Agency) showed how the approach of qualitative modelling can help to support decisions of policy makers. The case of modelling climate policies was part of Bert Saveyns (IPTS) presentation. Pieter Valkering (U Maastricht) played an interactive game on water management with the participants.

A number of sessions also focussed on issues of impact assessment. Eleftheria Vasileidaou (U Amsterdam) drew attention to the interconnection between stakeholders and tool developers. Manuel Winograd (EEA) shared his practical experiences in making appropriate impact assessments for sustainable decisions.

This LIAISE Winter School was kindly supported by The Integrated Assessment Society (TIAS).