What serves as a standard of comparison to evaluate the effect of the independent variable on the dependent variable

a warm, wet climate will produce the highest rate of weathering. the warmer a climate is, the more types of vegetation it will have and the greater the rate of biological weathering (figure below). this happens because plants and bacteria grow and multiply faster in warmer temperatures.

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%