The Science

The Greenhouse Effect

The greebhouse effect is a natural process, which heats the surface of the earth. When the energy of the sun reaches the atmosphere of the earth, some of it is sent back into the space and the rest is absorbed and re-radiated by greenhouse
gases.

Here is how it works step by step.

1. Solar Radiation: Energy from the sun reaches the earth's atmosphere.
2. Reflection: Some of this energy is reflected back into space by clouds and the atmosphere.
3. Absorption: The rest of the energy is absorbed by the earth's surface
4. Re-radiation: The earth radiates this heat back towards space, but greenhouse gases trap some of it, heating the planet up.

Greenhouse gases consist of water vapour, carbon dioxide, methane, nitrous oxide and ozone. When the Sun's energy reaches the Earth's atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.

Scientific Evidence

• Ice core samples indicate that there is an increase in levels of carbon dioxide than it was 800,000 years ago.


• Since the end of the 19th century, the average global temperature has risen by approximately 1.1°C.


• The oceans have taken in much of this added heat with the upper 100 meters registering higher than 0.33°C since 1969.

NASA's Crucial Signs

NASA said that the average surface temperature in the planet has been increasing by 2° Fahrenheit since the late 19th century which mostly has been caused by the increased release of carbon dioxide and other manmade emission into the atmosphere.