ateam - Potsdam Institute for Climate Impact Research

ATEAM final report Section 5 and 6 (2001-2004) 15
The variation in temperature and precipitation between scenarios and the variation between the
seasons increase significantly in the second half of the 21 st century. The variations between the climate
models is different between the scenarios. For the high emission scenario A1f, the variation between
climate models is approximately equally high as the variation between climate projection for all other
emission scenarios (Figure 3).
A Tyndall working paper on the methodology and results has been published by Mitchell et al.(2004)
and will be split into two parts for submission to peer-reviewed journals. Furthermore, the paper by
Erhard et al. which is currently being prepared for the ATEAM special issue will deal with the climate
scenarios in some detail (see Annex 2).
6.2.1.3 Land use change scenarios
Future land uses were constructed for the high priority scenarios given in Table 2 and for A2 CGCM2
and A2 CSIRO2 (medium priority), based on an interpretation of the four SRES marker scenarios. The
interpretation was undertaken by first defining the range of drivers that will affect different land use types
within Europe: urban, agriculture (cropland, grassland and biofuels), forestry and designated areas.
The approach recognises three levels in the derivation of land use scenarios that move from qualitative
descriptions of global socio-economic storylines, over European sector driving forces (see Table 3), to
quantitative projections of regional land use change. For each land use category the methodology
broadly followed the same steps. First an assessment was made of the total area requirement (quantity)
of each land use, as a function of changes in the relevant drivers. This was based on outputs from the
global scale IMAGE 2.2 Integrated Assessment Model on commodity demands at the European scale
(IMAGE team, 2001). Second, scenario-specific spatial allocation rules were developed and applied to
locate these land use quantities in geographic space across Europe. Third and finally, the scenarios of
the broad land use types were post-processed to maintain the land use constant in designated areas
(for conservation or recreation goals). This approach was implemented using a range of techniques that
were specific to each land use, including reviews of the literature, expert judgement, and modelling.
Widespread consultation was undertaken with other experts in this field, as well as with stakeholders.
For a detailed description of the methodology refer to Rounsevell et al. 2003. (A summary of the
European land use change scenarios – version 2.0, pp. 38. Report, see Annex 2). The land use
scenarios reflect changes both in the physical environment (climate change) with concurrent changes in
socio-economic factors. The result is an original dataset and maps of Europe for each scenario and for
each land use type.
European level sectoral driving forces
Sector-specific driving forces for Europe for each land use type were developed from the global level
driving forces taken from IMAGE 2.2 (see above). This was based on an interpretation of the SRES
narrative storylines for the European region using, where appropriate, knowledge of past and present
European and national policy. For some land use types (e.g. forestry, protected areas), it was necessary
to identify distinct regional trends in driving forces based on countries or country groups. The regional
trends themselves may also differ between scenarios. An important aspect of the European level
qualitative descriptions was to provide a check of internal consistency between each of the land use
sectors and storylines. In this way, the assumptions that were used, for example, for urban land use
were not in conflict with those for agriculture. A summary of the European level qualitative descriptions
is given in Table 3.