period of cooling across most regions, followed by warming towards the end of the century (as a result the ensemble projections shown exhibit a smaller warming rate during the first couple of decades). The projected changes in precipitation are equally inconsistent across models. While the GFDL and CCC models predict drier conditions across most regions, the remaining models show significant relative increase in precipitation and are regionally more differentiated. These uncertainties about the evolution of the climate in the coming decades necessitate the evaluation of climate change impacts on cropland patterns across a range of different climate scenarios and are further elaborated on in the next section.

# **_5.2 Projected changes in croplands_**

The results presented above illustrate the discrepancies that exist across a variety of cropland models (CRMs), on the one hand, and across a range of climate models (AOGCMs), on the other. To characterize cropping pattern changes in Africa, this section evaluates the impact of climate change on croplands across the range of projections made by various models.

Table 5 shows relative changes in cropland area compared to current cropland patterns predicted by the ensemble average of seven AOGCMs. To do this, the unweighted mean of climate model projections was used to parameterize each of the six croplands models (column headers) and predict changes in cropland area for 2010–2039, 2040–2069 and 2070– 2099 in each region and for the continent as a whole (rows). The right-most column shows the average impact across all CRMs. As far as the aggregate cropland area in Africa is concerned, different CRMs reveal a somewhat heterogeneous pattern, with some models showing increases and others showing decreases. However, towards the later periods of the century, most models agree on significant losses of cropland area across the continent. Considering the average change predicted by all CRMs, croplands are expected to decrease by 4.3% during the first 30-year period, and by 9.4% and 18.3% by the middle and end of the century.

A more detailed look at the contribution of each sub-region to this overall pattern reveals that the highest relative loss is likely to occur in the northern and eastern part of the continent, whereas the western part (western Sahel) may experience increases in cropland share according to some CRMs. Again, while the earlier decades reveal heterogeneous patterns across the region, the later part of the period is characterized by losses of croplands in practically all sub-regions, with some cropland losses exceeding 30% in parts of the continent.

Table 6 shows a similar summary of regional cropland area changes for AOGCMs throughout the century. That is, the mean cropland density based on all six CRMs was used to evaluate changes in cropland area for each climate model across the various sub-regions. With the exception of the CCC model, all models show substantial losses in cropland area in the national aggregate and increasing cropland area losses towards the end of the century. Similar to the comparison of CRMs, the comparison of AOGCMs shows the strongest and most consistent loss of cropland in the northern and eastern part of the continent and gains of cropland area in western and southern Africa during the first period. However, this intermittent increase in cropland area is offset later in the century. Note that the last column in Table 6 is identical to the last column in Table 5 and shows the average change in cropland areas across all AOGCMs and CRMs. It is important to note that the positive relative effects 11