Explain why earth's temperature is directly affected by the amount of greenhouse gases in the atmosphere.

Earth's temperature depends on the balance between energy entering and leaving the planet’s system. When incoming energy from the sun is absorbed by the Earth system, Earth warms. When the sun’s energy is reflected back into space, Earth avoids warming. When absorbed energy is released back into space, Earth cools. Many factors, both natural and human, can cause changes in Earth’s energy balance, including:

These factors have caused Earth’s climate to change many times.

well the answer is 2!