Soil, water, wind, and ice erosion are natural processes that shape the Earth's surface over time. Soil erosion occurs when bare soil is exposed to wind and rain, transporting soil particles to other locations. It is worsened by human activities like tilling, overgrazing, deforestation, and fertilizer use. Water erosion displaces soil particles through rainfall, rivers, and freeze/thaw cycles. Wind erosion blows soil particles away, especially in drylands, and can carry pollutants. Glacial erosion rapidly wears away rock through the motion of glaciers and meltwater streams.