Our Environment — BIOLOGY STD 6 — Question

About one-third of the solar energy that reaches earth is reflected back by the atmosphere directly. The rest two-third reaches the earth’s surface and heats it However, to maintain the energy balance, the earth radiates back the heat. This radiated heat is absorbed by some gases and water vapour in the atmosphere and reflected back to the earth to keep it warm. This is called the greenhouse effect and the gases that trap earth’s radiation are called greenhouse gases.