The objective of the present paper is to use CLIMEX software to project how climate change might impact the future distribution of date palm ('Phoenix dactylifera' L.) in Iran. Although the outputs of this software are only based on the response of a species to climate, the CLIMEX results were refined in the present study using two non-climatic parameters: (a) the location of soils containing suitable physicochemical properties and (b) the spatial distribution of soil types having suitable soil taxonomy for dates, as unsuitable soil types impose problems in air permeability, hydraulic conductivity and root development. Here, two different Global climate models (GCMs), CSIRO-Mk3.0 (CS) and MIROC-H (MR), were employed with the A2 emission scenario to model the potential date palm distribution under current and future climates in Iran for the years 2030, 2050, 2070 and 2100. The results showed that only c. 0.30 of the area identified as suitable by CLIMEX will actually be suitable for date palm cultivation: the rest of the area comprises soil types that are not favourable for date palm cultivation. Moreover, the refined outputs indicate that the total area suitable for date palm cultivation will increase to 31.3 million ha by 2100, compared with 4.8 million ha for current date palm cultivation. The present results also indicate that only heat stress will have an impact on date palm distribution in Iran by 2100, with the areas currently impacted by cold stress diminishing by 2100.

This study set out to model potential date palm distribution under current and future climate scenarios using an emission scenario, in conjunction with two different global climate models (GCMs): CSIRO-Mk3.0 (CS), and MIROC-H (MR), and to refine results based on suitability under four nonclimatic parameters. Areas containing suitable physicochemical soil properties and suitable soil taxonomy, together with land slopes of less than 10° and suitable land uses for date palm ('Phoenix dactylifera') were selected as appropriate refining tools to ensure the CLIMEX results were accurate and robust. Results showed that large regions of Iran are projected as likely to become climatically suitable for date palm cultivation based on the projected scenarios for the years 2030, 2050, 2070, and 2100. The study also showed CLIMEX outputs merit refinement by nonclimatic parameters and that the incremental introduction of each additional parameter decreased the disagreement between GCMs. Furthermore, the study indicated that the least amount of disagreement in terms of areas conducive to date palm cultivation resulted from CS and MR GCMs when the locations of suitable physicochemical soil properties and soil taxonomy were used as refinement tools.

Climate is changing and, as a consequence, some areas that are climatically suitable for date palm ('Phoenix dactylifera' L.) cultivation at the present time will become unsuitable in the future. In contrast, some areas that are unsuitable under the current climate will become suitable in the future. Consequently, countries that are dependent on date fruit export will experience economic decline, while other countries' economies could improve. Knowledge of the likely potential distribution of this economically important crop under current and future climate scenarios will be useful in planning better strategies to manage such issues. This study used CLIMEX to estimate potential date palm distribution under current and future climate models by using one emission scenario (A2) with two different global climate models (GCMs), CSIRO-Mk3.0 (CS) and MIROC-H (MR). The results indicate that in North Africa, many areas with a suitable climate for this species are projected to become climatically unsuitable by 2100. In North and South America, locations such as south-eastern Bolivia and northern Venezuela will become climatically more suitable. By 2070, Saudi Arabia, Iraq and western Iran are projected to have a reduction in climate suitability. The results indicate that cold and dry stresses will play an important role in date palm distribution in the future. These results can inform strategic planning by government and agricultural organizations by identifying new areas in which to cultivate this economically important crop in the future and those areas that will need greater attention due to becoming marginal regions for continued date palm cultivation.

One consequence of climate change is change in the phenology and distribution of plants, including the date palm ('Phoenix dactylifera' L.). Date palm, as a crop specifically adapted to arid conditions in desert oases and to very high temperatures, may be dramatically affected by climate changes. Some areas that are climatically suitable for date palm growth at the present time will become climatically unsuitable in the future, while other areas that are unsuitable under current climate will become suitable in the future. This study used CLIMEX to estimate potential date palm distribution under current and future climate scenarios using one emission scenario (A2) with two different global climate models (GCMs), CSIRO-Mk3.0 (CS) and MIROC-H (MR). The results of this study indicated that Saudi Arabia, Iraq and Iran are most affected countries as a result of climate change. In Saudi Arabia, 129 million ha (68%) of currently suitable area is projected to become unsuitable by 2100. However, this is based on climate modelling alone. The actual decrease in area may be much smaller when abiotic and other factors are taken into account. On the other hand, 13 million ha (33%) of currently unsuitable area is projected to become suitable by 2100 in Iran. Additionally, by 2050, Israel, Jordan and western Syria will become climatically more suitable. Cold and heat stresses will play a significant role in date palm distribution in the future. These results can inform strategic planning by government and agricultural organizations to identify areas for cultivation of this profitable crop in the future, and to address those areas that will need greater attention because they are becoming marginal regions for date palm cultivation.