Question:
How does the Greenhouse effect keep the surface atmosphere of Earth warm?

Answer: When solar radiation reaches Earth, it does so largely in the visible light spectrum. This visble light largely passes through the atmosphere and reaches Earth's surface, where it gets absorbed by the land and water. When the Earth's surface reradiates the energy, it does so largely in the infrared spectrum. However, greenhouse gases like carbon dioxide and methane preferentially absorb the infrared radiation leaving Earth's surface, causing the atmosphere to warm.