Green infrastructure refers to natural or nature-based systems that provide environmental services traditionally delivered by engineered "grey" infrastructure. Examples include: green roofs and rain gardens managing stormwater (instead of pipes and detention ponds), urban tree canopy providing cooling (reducing air conditioning demand), wetlands filtering water (complementing treatment plants), and permeable pavement allowing groundwater recharge. Green infrastructure can be more cost-effective, adaptable, and multi-functional than conventional approaches—a rain garden manages stormwater while providing habitat and neighbourhood beauty. The term also applies broadly to environmentally beneficial infrastructure like renewable energy systems, energy-efficient buildings, and clean transportation. Federal and provincial funding programs increasingly support green infrastructure investments. Municipal climate action plans typically incorporate green infrastructure as both mitigation (reducing emissions) and adaptation (managing climate impacts like increased precipitation and urban heat).