Chemical weathering occurs more rapidly in warm, wet climates, and mechanical weathering occurs more in cold climates. Mechanical weathering occurs more rapidly in warm, wet climates, and chemical weathering occurs more in cold climates. Ice wedging is common in Earth's Polar Regions and mid latitudes, and also at higher elevations, such as in the mountains. Abrasion is another form of mechanical weathering. In abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a mountainside or cliff.