Understanding implications of climate change and socio-economic development for the water-energy-food nexus: A meta-regression analysis

In recent years, the impacts of climate change and socio-economic development on the water-energy-food nexus have been a hot topic. Forecasting future food and energy production and water withdrawal trends under a range of climate and socio-economic scenarios is a critical step for formulating agricultural, industrial, and environmental policy. However, published studies are imprecise due to the complexity of the changeable environment and nexus system. Here we conducted a systematic review and meta-analysis based on 97 studies (1253 observations) published before September 2021 to evaluate the effects of climate change factors on food yield and irrigation water, as well as the influence of socioeconomic development on energy production and water withdrawal. The study shows that the most serious impact of climate change on food yield occurred under the RCP8.5 scenario, with an average decrease of 1.73%, 4.17% and 4.56% in the 2020s, 2050s, and 2080s, respectively. Similar to the prediction of food yield, the irrigation water requirement of food production under the influence of climate change in the RCP8.5 scenario (12.22-18.01%) is higher than that in RCP4.5 and RCP2.6. Under the five socio-economic future scenarios, the average energy generation is projected to increase from 77.41 EJ (2010) to 334.11 EJ (2100). Water withdrawals for electricity generation range from 347 km3 (SSP1) to 1263 km3 (SSP5). Population and GDP were significantly and positively correlated with power generation and water withdrawal (P < 0.001). To some extent, increases in CO2 concentration and precipitation could compensate for the negative impact of rising temperatures on food yield. Climate change, as well as economic and social growth, will provide substantial challenges to the future water-energy-food nexus. In particular, the water resource risk at its core will create significant uncertainty in the future water-energy-food nexus. To ensure the security and stability of the nexus, we advocate for quick adoption of innovative technologies as well as a multi-sectoral, coordinated strategy for adaptation. We believe that the findings of this paper will provide effective and reliable data support for future policy formulation.