Potential for urban agriculture: Expert insights on sustainable development goals and future challenges

Urban agriculture globally contributes to addressing the urgent challenges of urbanization and growing food demand. Various environmental, economic, and social benefits can be achieved by integrating food production systems such as indoor farms, greenhouses, and gardens within cities. As of now, studies on sustainability performances of urban agricultural food production – including innovative indoor farming – are lacking. In our study, we considered a visionary scenario of progressing urban agriculture towards achieving 30 % urban food self-sufficiency and, based on this scenario, conducted a Delphi survey to collect and discuss expert opinions on the (potential) contributions of urban agriculture to achieve selected Sustainable Development Goal (SDG) targets. We argue that expert consensus can indicate the direction of development within the urban agricultural sector at the global scale, although perceived trends and impacts may vary depending on context and location. Based on opinions of 108 participating experts, SDG 7.2 Increase share of renewable energies was identified as key challenge within urban food systems, and targets of SDGs 2 Zero Hunger , 12 Responsible consumption and production , and 15 Life on land were identified as important pull-factors for sustainable urban development. Greenhouses are expected to produce most urban food, while indoor farms are particularly valued for addressing environmental targets. Gardens are perceived to provide most social benefits. Experts further consented that none of the evaluated targets will be met by the SDGs' official timeline of 2030, outlining developmental barriers such as high energy use and lack of regulations and public policies addressing innovative agricultural systems. Going forward, experts' predominantly optimistic perceptions on urban agriculture need to be quantitatively substantiated. Yet, from our study we already derived actionable measures that should be taken by different stakeholders to successfully and timely advance sustainable urban development.