<human>:  What are the major factors that affect global climate change?
<bot>: The major factors that affect global climate change are greenhouse gas emissions, changes in solar activity, and changes in land use. Greenhouse gas emissions, such as carbon dioxide, methane, and nitrous oxides, trap heat in the atmosphere and cause the Earth’s temperature to rise. Changes in solar activity are changes in the energy radiating from the sun, warming or cooling the Earth. Changes in land use, such as deforestation, can also affect climate by altering the amount of CO2 and other heat-trapping gases in the atmosphere.