The significance of the water cycle in environmental science lies in its role in regulating climate, supporting life, and driving biogeochemical processes. The cycle consists of evaporation, condensation, precipitation, and infiltration, continuously recycling water through the atmosphere, land, and oceans. It ensures the availability of fresh water for ecosystems, agriculture, and human consumption. Understanding the water cycle is critical for addressing issues like water scarcity, pollution, and climate change impacts on water resources.