Hydrogels for Climate Change Mitigation: Applications in Water Harvesting, Passive Cooling, and Environmental Solutions.

Climate change presents significant global challenges, with rising temperatures, extreme weather events, and degrading ecosystems threatening both human societies and the environment. The increasing intensity of these climatic effects demands innovative approaches to adaptation and mitigation. Hydrogels, three-dimensional networks of crosslinked polymers with water absorption and retention properties, have become viable multipurpose materials for climate solutions in response to these pressing issues. This review examines four primary applications of hydrogels as climate technologies: atmospheric water harvesting, passive cooling, soil health enhancement, and energy conservation. These materials address climate challenges through their unique properties including high water absorption capacity, stimuli-responsive behavior, and biocompatibility. By effectively capturing moisture, hydrogel-based devices provide sustainable freshwater production in areas with limited water resources. For thermal management, they offer passive cooling through evaporative processes, reducing energy consumption compared to conventional air conditioning systems. Superabsorbent hydrogels in agriculture help drought-resistant crop development in arid areas and improve soil water retention. Smart windows with thermochromic hydrogels allow for passive energy savings by dynamically modulating the sun's light without the need for additional electricity. Through integrated deployment techniques, biodegradable formulations from sustainable sources handle various climate issues while ensuring environmental compatibility.