Quantifying the impact of climate change on evapotranspiration is necessary for devising accurate water and energy budgets in light of global warming. Nevertheless, in the Middle East and North Africa (MENA), little has been done to bridge this gap. This study, then, implements Penman and Budyko approaches to climatic data retrieved from the sixth phase of the Coupled Model Intercomparison Project (CMIP6) to assess evapotranspiration and water availability evolutions through the twenty-first century. Outcomes reveal that the MENA region is indeed vulnerable to a surge in temperature, which can increase evapotranspiration losses and decrease water availability. Under the shared socioeconomic pathway (SSP2-4.5), the potential evapotranspiration (PET) has been projected to increase throughout the MENA region by up to 0.37 mm per year during the middle of the twenty-first century (2021–2050) and by up to 0.51 mm per year during the end of the twenty-first century (2071–2100). Meanwhile, the actual evapotranspiration (AET) has been projected to increase by up to 0.3 (~0.2) mm per year before 2050 (2100). The trends in both projections (PET and AET) are exaggerated under SSP5-8.5. The analysis predicted a shortage of water availability (precipitation—AET), which is alarming for most MENA regions. Relative to the reference period (1981–2010), the decline in annual water availability would reach 26 (62) mm by 2100 under SSP2-4.5 (SSP5-8.5). The rise in temperatures appears to be the principal reason for MENA and water availability responses. This study’s outcomes can facilitate accurate and realistic predictions related to evapotranspiration and water availability, which are key elements in not only managing water resources but also in devising effective climate change mitigation and adaptation plans.

鉴于全球变暖，量化气候变化对蒸散的影响对于制定准确的水和能源预算是必要的。然而，在中东和北非 (MENA)，几乎没有采取任何措施来弥合这一差距。然后，这项研究对从耦合模型比对项目 (CMIP6) 第六阶段检索到的气候数据实施 Penman 和 Budyko 方法，以评估整个 21 世纪的蒸散量和可用水量的演变。结果表明，中东和北非地区确实很容易受到温度升高的影响，这会增加蒸散损失并减少可用水量。在共享社会经济路径 (SSP2-4.5) 下，预计整个 MENA 地区的潜在蒸散量 (PET) 将增加多达 0。二十一世纪中叶（2021-2050）每年增加 37 毫米，二十一世纪末（2071-2100）每年增加 0.51 毫米。同时，预计实际蒸散量 (AET) 在 2050 年 (2100) 之前每年将增加 0.3 (~0.2) 毫米。在 SSP5-8.5 下，两种预测（PET 和 AET）的趋势都被夸大了。该分析预测水资源供应短缺（降水 - AET），这对大多数 MENA 地区来说是令人担忧的。相对于参考期（1981-2010 年），到 2100 年，在 SSP2-4.5 (SSP5-8.5) 下，年可用水量将下降 26 (62) 毫米。温度升高似乎是 MENA 和水资源可用性响应的主要原因。这项研究的结果可以促进与蒸发蒸腾和可用水量相关的准确和现实的预测，