Before discussing the concept of global warming we have to understand some basic terminology which acts like basic building blocks.
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| Global Warming |
Weather is defined as local atmospheric activity over a brief period of time (hours, days or months). It is the degree of atmosphere being hot, cold, dry, calm or cloudy.
Climate is defined as the weather average over a large area on a longer time scale of (years, decades, century). It includes average temperature, wind pattern and precipitation.
climate is majorly depends on two factors one is incoming energy from sun in the form of radiation (mainly infrared), and atmospheric properties i.e. absorption, reflection and radiation from earth surface.
There is one term we frequently heard about is climate change lets explain it in simple fashion suppose we took an average of temperature and precipitation and it shows change in average, so we call it climate change.
Difference between Weather vs Climate
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Short (hours, days, month)
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Long (years, decades, century)
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Atmosphere, land, water bodies
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Greenhouse gases:
Greenhouse gases mainly responsible for heat trapping/absorption and if this heat trapping takes place in earth atmosphere which increase the earth atmosphere temperature is known as greenhouse effect. Greenhouse effect is very much required for our survival because without GHGs the earth atmosphere temperature may be reaches to the -10℃ .
- water vapour (most abundant and most contributing in heat trapping)
- N2O (nitrous oxide also known as laughing gas)
- SF6 (sulphur hexafluoride)
- NF3 (nitrogen trifluoride)
- soot particles (unburnt hydrocarbon particles)
Global Warming:
UV is completely reflected back by the stratospheric ozone (also known as good ozone since it protects us from harmful UV radiation) hence only visible region and infrared reaches to the earth atmosphere (atmosphere consist of dust particles, GHGs, O2, N2, water vapour and atmospheric ozone).
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| Global Warming |
After passing through earth atmosphere UV radiations reaches the earth surface where all the surface phenomena occurs i.e. absorption, reflection and refraction. After getting heat exchange trough fastest mode of heat transfer (radiation) the Earth will emit long wavelength radiation and infrared radiation.
As these radiation will go into earth atmosphere, atmosphere will not allow these radiation to go out i.e. it behaves as opaque for long wavelength radiation instead the GHGs absorb these radiation. Hence as the amount of GHGs will increases more absorption of such radiation occurs hence the earth atmosphere becomes more warmer.
Impacts of Global warming:
- Increase in GHGs cause Increase in average global temp.
- Melting of arctic glaciers, increase the water level in see which causes submergence of islands
- Loss of wildlife and biodiversity like plants, fishes, coral reefs etc.
- Cause of climate change, change in wind pattern due to this frequent flood, drought, cyclones, hurricanes, tornadoes occurs it is also the major cause of migration of people.
- Melting of Himalayan glacier increase which cause increase in river discharge, causes soil erosion, causes increase in silt deposition in river bed, causes increases in floods.
Latest example of impact:
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