How land-based moss could cool, decarbonize Saudi cities

RIYADH: Saudi cities are exploring water-wise tools to cut heat, clean air, and capture carbon on hardscapes where trees cannot easily grow.

Land-based moss — able to dry out and revive with just a trace of moisture — offers a low-maintenance, climate-active layer for facades and roofs that aligns with Vision 2030’s Quality of Life goals and the Circular Carbon Economy approach.

“Moss can switch off and on with moisture — exactly what harsh climates demand,” Joshua Van Alstine, co-founder of the Saudi Arabian Botanical Society, told Arab News.

He explained that when integrated into facades, rooftops, and green walls, moss can lower surface and ambient temperatures while passively trapping particulate matter and heavy metals, contributing to energy savings and cleaner air in dense districts.

Ahmed Al‑Jameel, an energy and climate policy expert, told Arab News: “Trees are the lungs; moss can be the skin — covering walls, bridges, and courtyards where trees can’t grow, adding a layer of cooling and carbon capture that complements tree-planting.”