The Greenhouse effect is the rise in the temperature of the Earth’s atmosphere due to certain gases like, methane, water vapour, nitrous oxide and carbon dioxide, which trap the energy and heat from the sun. Without these gasses, the heat would escape reducing the temperature of the atmosphere. These gases are commonly known as Greenhouse gases, because they help to maintain the Earth’s average temperature. Simply put, it is a natural process which make the Earth’s atmosphere just right for life forms to flourish.
Greenhouse effect in technical words is defined as the effect produced by certain gases such as carbon dioxide, on a planet’s atmosphere by raising the equilibrium temperature of the surface of the planet,
thus preventing the outward transmission of the long-wave radiation from the surface but permitting the inward transmission of short-wave radiation from the sun to the surface.
If you have ever seen a greenhouse, most of them look like a small glass house used to grow plants, especially in winter. The glass panes of the greenhouse let the light in, but trap the heat and energy, thus keeping the greenhouse warm even in winter, so much so that the atmosphere is warm enough for the plants to grow in winter. The Greenhouse heats up mainly because the sun warms the ground inside, which in turn warms the air above the ground, and this air is stopped from rising and flowing away.
In the Earth’s atmosphere the Greenhouse gases behave similar to the glass panels in a greenhouse. Sunlight penetrates through Earth's atmosphere, passing through the layer of Greenhouse gases. On reaching the Earth's surface, biosphere, water, and land, absorb the sunlight’s heat and energy. Once the energy and heat is absorbed, it returns to the atmosphere. Most of the heat and energy is trapped in the Earth’s atmosphere by the Greenhouse gases, which ultimately results in the Earth to warm up; however some of the heat and energy returns back to space.
Scientists use the term albedo to define the percentage of solar energy reflected back by a surface. Understanding local, regional, and global albedo effects is critical to predicting global climate change.
The Greenhouse effect can also be compared to the inside of a car parked in sunlight, which lets the light in, but traps the heat and energy, keeping the car warm. The Greenhouse effect is very essential, without which the Earth would not be warm enough for humans to survive.
Today, the term, Greenhouse effect mistakenly signifies the unnatural rise in temperature within the planet’s atmosphere due to man-made hazards. If the effect becomes stronger, then the Earth’s atmosphere could become warmer than the average temperature. Even a little excess warming may result in trouble for humans, animals and plants.
In the last few centuries, the human activities have directly or indirectly caused the concentration of the major greenhouse gases to increase. Scientists predict that this increase may enhance the greenhouse effect making the planet warmer. Few researchers estimate that the Earth's average temperature has already risen by 0.3 to 0.6° Celsius. Predictions of future point at an alarming rise to approximate 1 to 3° Celsius higher than today by the middle of the next century.