As global food demand rises, urban agriculture models, such as vertical and terrace farming, have gained traction, especially amid crises like the Ukraine war and COVID-19 pandemic. Climate change remains the most significant threat to global food security. According to the latest FAO analysis, which encompasses assessments from 1990 to 2023, approximately 40% of economic losses resulting from climate-related hazards, including droughts and floods, have impacted the agriculture sector. This has reduced yields, increased production costs, and worsened food insecurity, affecting millions. Urban gardens offer a solution, enhancing food resilience. A systematic PRISMA-based review analyzed studies from Scopus and reports from organizations like the FAO. Over 3329 documents were reviewed. Publications on food resilience grew by 50% in four years, with the US leading with 700 projects. Agricultural and biological sciences dominate research (45%). Urban gardens focus on educating communities about food security and improving food systems. Mobile gardens with portable labs maximize urban spaces, turning rooftops and terraces into productive areas. These initiatives empower communities to grow food, promote nutrition education, and foster social connections. Urban gardens, though not fully sustainable, as they can consume up to 35% more energy per kg of food than optimized traditional farms and generate a 20–40% higher carbon footprint if using imported substrates or plastics, are key for resilient food systems, yielding up to 20 kg/m²/year, reducing transport emissions by 68% (vs. 2400 km supply chains), and using 90% less water than conventional agriculture.

The global interest in utilizing waste from agro–industrial processes through the implementation of clean technologies is rapidly increasing. This study evaluates the technical, economic, and environmental feasibility of valorizing regional agro–industrial residues in Santander, Colombia, specifically coffee mucilage, cocoa mucilage, and pig manure, using integrated biorefinery scenarios. Modernizing these processes is essential given a theoretical energy potential of 75,000 TJ/year, which could generate up to 20,833 GWh/year. Three biorefinery scenarios were designed and simulated using Aspen Plus^® to produce bio-hydrogen, methane, and methanol. The total plant capacity was established at 31.7 t/day, distributed according to regional biomass availability: 4.62 t/day of cocoa mucilage, 1.83 t/day of coffee mucilage, and 25.25 t/day of pig manure. The technical results for Scenario 1 indicated a reformed H₂ production of 0.15 t/day with an associated preheating energy requirement of 193,365 kJ/h. Environmental impact assessment using the ReCiPe 2015 Midpoint methodology identified Scenario 3 as having the lowest direct CO₂ mass flow (9.28 t/day) due to carbon consumption during methanol synthesis. However, Scenario 1 reported a CO₂ equivalent (CO₂e) of 194.37 t/day, reflecting indirect emissions from thermal and energy requirements. Economic analysis, validated through engineering cost references, demonstrated that while Scenario 3 offers a diverse product portfolio, it is currently not cost-effective as the production costs exceed the total expected income. Consequently, Scenario 2 is identified as the most balanced alternative for the Santander context, offering a sustainable compromise between technical efficiency, environmental mitigation, and economic viability.

The environmental performance of chitosan production is evaluated through a rigorous computational comparison between traditional thermochemical deacetylation and innovative green synthesis pathways utilizing Deep Eutectic Solvents (DES). Implementation of the Waste Reduction (WAR) algorithm facilitates the quantification of the Potential Environmental Impact (PEI) across eight toxicological and ecotoxicological categories, providing a systematic benchmark for process sustainability. While the conventional route, characterized by the intensive consumption of HCl and NaOH, generates a substantial environmental burden of 1.37 × 10⁷ PEI/ton, the optimized green architecture leveraging a choline chloride:ethylene glycol (ChCl:EG) system achieves a radical reduction to 2.25 × 10⁴ PEI/ton. This 99.8% decrease in PEI is primarily driven by the mitigation of Human Toxicity Potential (HTP) and Acidification Potential (AP) through the substitution of corrosive mineral acids and volatile organics with biodegradable, low-vapor-pressure alternatives. These findings substantiate the integration of DES-mediated biorefineries as a high-efficiency strategy for the valorization of marine waste into high-purity biopolymers, aligning with the requirements for industrial process intensification and circular bioeconomy standards.