Weathering breaks down rocks into sediment through mechanical or chemical processes. Mechanical weathering physically breaks rocks into fragments through forces like wind, water, plant roots, or ice wedging. Chemical weathering uses chemical reactions to dissolve or change minerals, often involving carbonic acid, plant acids, or oxidation when iron is exposed to oxygen. The rates of mechanical versus chemical weathering depend on climate, with mechanical weathering dominating in cold climates and chemical weathering faster in warm, wet climates.