Climate change effects on water footprint of crop production: A meta-analysis

• Variation in climatic parameters poses a threat to crop production. • PRISMA was followed in collecting data. • Temperature and rainfall were the two climatic variables considered. • Rainfall had a greater influence on the water footprint. • There was a shift from WF green to more WF blue with time. The impact of climate change on both natural and human systems is becoming increasingly severe. One of the areas that is most affected is agriculture, which is responsible for utilising around 70 % of the planet's freshwater and is also under significant pressure to feed the ever-growing global population. This meta-analysis examined the complex relationships between water footprint and climate change, focusing on the effects of rainfall and temperature changes in different geographical areas. The study used a combination of the following search words: climate change, climate variability, global warming, drought, water footprint, blue water footprint, green water footprint, grey water footprint, crop production, crop yield, crop water footprint, crop water use, water usage, precipitation, rainfall, and temperature. The selection of articles followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram procedure, ultimately including 33 articles that met the study criteria out of the 938 articles initially retrieved. The study's findings indicated that the most influential factors of the water footprint varied globally due to natural and human interference conditions. The findings also indicated that all crops were susceptible to changes in temperatures and rainfall distribution, resulting in a decrease in WF blue , WF grey , and WF total , while WF green increased with increasing rainfall and temperatures. Temperature had a notable effect on the WF blue of crops grown in areas that receive limited rainfall. Future research should conduct a meta-analysis on the uncertainty associated with climate change projections and its implications for estimating the water footprint of crop production.