Answer :
The greenhouse effect is a natural process that warms the Earth's surface. It occurs when certain gases in the atmosphere trap heat from the sun, preventing it from escaping back into space. This trapping of heat is essential for maintaining the Earth's temperature at a level that can support life.
On a molecular level, the greenhouse effect is caused by the interaction of incoming solar radiation with the Earth's surface. When sunlight reaches the Earth, some of it is reflected back into space, while the rest is absorbed and warms the surface. The Earth then radiates heat in the form of infrared radiation.
Greenhouse gases, such as carbon dioxide (CO2), methane (CH4), and water vapor (H2O), are present in the atmosphere. These gases absorb the infrared radiation emitted by the Earth and re-radiate it in all directions, including back towards the Earth's surface. This process effectively traps heat and increases the temperature of the Earth.
In summary:
1. Incoming solar radiation warms the Earth's surface.
2. The Earth radiates heat in the form of infrared radiation.
3. Greenhouse gases in the atmosphere absorb and re-radiate this infrared radiation, trapping heat and warming the Earth.
This mechanism helps regulate the Earth's temperature, but human activities, such as burning fossil fuels and deforestation, have increased the concentration of greenhouse gases in the atmosphere, leading to an enhanced greenhouse effect and global warming.