Impacts of climate change on agro-climatic suitability of major food crops in Ghana

climatic conditions to 17% under RCP2.6 (39861 km2) and RCP8.5 (40875 km2), with a con- current reduction in areas that are moderately suitable for just one crop as these become less (Fig 4B and 4C and Table 5). We assessed the suitability of dual crops under current and projected climatic conditions through pairwise combinations of suitability maps (Fig 6). Areas with a highest suitability of dual crops are 5.5% (13175 km2) for maize and groundnuts, 5.4% (12837 km2) for cassava and sorghum and 5.2% (12499 km2) for maize and cassava (Figs 6 and 7 and S2 Table); all other combinations are below 5%. Except for cassava and groundnut, all suitability combinations of crops are projected to decrease for the areas where both crops currently have the high suitabil- ity class. Concurrently, the areas where a more crops will be moderate and marginal or mar- ginal for both crops will increase for both RCP2.6 and RCP8.5 (Fig 7). Although the results show on dual crop suitability vary across the country, aggregated results show the most com- mon suitability under climate change will be sorghum and groundnuts for the northern parts and cassava and groundnuts for the southern parts of Ghana. The least potential dual Fig 4. Assessment of changes in suitability according to the applied GCMs and RCP for (a) maize (b) sorghum, (c) cassava and (d) groundnuts in Ghana. https://doi.org/10.1371/journal.pone.0229881.g004 Table 4. Mean percentage changes in area suitable for each suitability class under climate change for maize, sorghum, cassava and groundnuts.

Crop Maize Sorghum Cassava Groundnut Suitability RCP2.6 RCP8.5 RCP2.6 RCP8.5 RCP2.6 RCP8.5 RCP2.6 RCP8.5 Limited -10.6 -8.2 -11.8 -9.4 -3.7 -2.8 -7.6 -7.1 Marginal 8.1 6.6 12.1 12.7 5.2 4.2 11 4.5 Moderate 14.4 15.5 9.3 9.7 5.6 8.2 0.4 2.1 Optimal -11.9 -14.0 -9.7 -13.1 -7.2 -9.6 -3.8 0.4 https://doi.org/10.1371/journal.pone.0229881.t004 PLOS ONE Climate change and food crops suitability in Ghana PLOS ONE | https://doi.org/10.1371/journal.pone.0229881 June 29, 2020 11 / 21