What is Greenhouse Effect?
The greenhouse effect is the process thanks to which Earth has a higher temperature than it would have without it. The gases that radiate heat also known as greenhouse gases absorb the energy radiated out by the Earth and reflect a part of it back to Earth. Of all the energy that the Earth receives from the Sun, a part of it around 26% is reflected back to space by the atmosphere and clouds. Some part of it is absorbed by the atmosphere, around 19%. The rest hits the ground and heats the surface of the Earth. This absorbed energy is radiated out of the earth in the form of Infrared Waves. These IR waves warm the atmosphere above the Earth. The atmosphere again radiates this energy it received from the Earth both upwards and downwards. The energy sent downwards results in a higher equilibrium temperature that if greenhouse gases were absent. This greenhouse effect is essential to supporting life on Earth. The greenhouse gases responsible for the greenhouse effect are:
The excessive burning of fossil fuels such as petrol, coal etc have resulted in an increase in the amount of greenhouse gases in the atmosphere resulting in a phenomenon known as Global Warming. This is an increase in the ambient temperature of Earth which will negatively affect life on Earth.
How do we know?
If an ideal black body were at the same distance from the Sun as Earth, its temperature would be 5.3oC. However, Earth reflects 30% of this energy back into space. Including this in the calculation for the temperature of Earth gives is an answer of -18oC. As we can clearly see, this is far from true. The average temperature is a whopping 33oC higher at 15oC. This difference in ambient temperature is caused by greenhouse gases.
Global Warming and the Greenhouse Effect
Global Warming refers to the increasing temperature of the Earth’s climate system and its related effects. Scientific evidence has conclusively proven that the Earth’s temperature is in fact rising and has risen by 0.85oC. This has impact has effected different regions differently. The effects include rising sea levels, retreating glaciers, loss of sea ice in the poles, warming global temperatures, changing precipitation, expansion of deserts etc. This raises significant threats for humans such as food security from decreasing crop yields, submergence of low lying area due to the rising sea. To prevent irreversible damage to the delicate ecosystems on Earth, scientists have decided that the global warming should be limited to a maximum of 2.0oC relative to pre-industrial levels. Greenhouse effect plays an important role in the rising temperature. And hence to restrict global warming we need to limit the greenhouse effect and the gaseous emissions that cause greenhouse effect.
Fourteen of the fifteen years in the 21st century have been the hottest years on record with constant occurrences of extreme weather, cyclones, droughts, floods etc. All these events are some way or the other have an association with the greenhouse effect and global warming. Learn more on how you can help reduce the carbon footprint, Byju’s The Learning App. Join us and Fall in love with Learning.
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