The document defines various terms related to environmental science and climate change. It provides definitions for terms such as ammonia, avalanches, biodiversity, coal, cryosphere, desertification, dump, electricity, fossil fuel, geothermal energy, hail, hydropower, ice, melt, non-renewable energy, photosynthesis, pollution, radiation, recycling, reforestation, respiration, sink, solar radiation, sulfur dioxide, troposphere, ultraviolet radiation, wastewater, water vapor, weather, and wind energy.