The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere.

1. Green House Effect

2. Greenhouse Effect:
• The greenhouse effect is the process by which radiation from a planet's
atmosphere warms the planet's surface to a temperature above what it would
be without its atmosphere.
• Joseph Fourier discover the “Green house effect”.
• The term “Greenhouse” was first used by Nils Gustaf Ekholm in 1901.

3. Explanation:
 Light from sun contains thermal radiations(IR) of long wavelength as well
as UV radiations of short wavelength. Glass and polythene sheets allow
only radiations of short wavelength to pass through. Thus a greenhouse
becomes a heat trap. Radiations from Sun pass easily through glass and
warms the objects in greenhouse. These objects and plants give out
radiations of longer wavelengths. Glass do not allow them to escape out
and are reflected back in greenhouse. This maintains the inside
temperature of greenhouse.
 Greenhouse promises the better growth of plants.

4. The Greenhouse Effect on Earth:
• The greenhouse effect is a natural process that warms the Earth’s surface.
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.

5. Greenhouse Gases:
• A greenhouse gas is a gas that absorbs and emits radiant energy within the
thermal infrared range. Greenhouse gases cause the greenhouse effect.
• In order, the most abundant greenhouse gases in Earth's atmosphere are:
 Water vapor
 Carbon dioxide
 Methane
 Nitrous oxide
 Ozone
 Chlorofluorocarbons (CFCs)
 Hydro fluorocarbons (HCFCs and HFCs)

6. Can we survive without greenhouse effect??
• Greenhouse gases in the air, mainly carbon dioxide, methane and water
vapour , trap radiation from the Sun and act like a thermal blanket around the
planet. Without greenhouse gases, the average temperature of Earth's surface
would be about −18 °C (0 °F), rather than the present average of 15 °C (59
°F).So Life as we know it would not be able to survive without greenhouse
effect.

7. Contt..
• Human activities over the last 100 years, particularly the burning of fossil
fuels, have caused a rapid increase in carbon dioxide and other greenhouse
gases in the atmosphere. Before the industrial age, these gases had remained
at near stable concentrations for thousands of years.
• The rapid warming observed since the 1970s has occurred in a period when
the increase in greenhouse gases has dominated over all other factors.

8. Causes of greenhouse effect:
• Burning of fossil fuels.
• Deforestation.
• Increase in population.
• Farming.
• Industrial Waste and landfills.
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9. How greenhouse effect humans:
 Wildfires ,in turn leads to deforestation. Since trees absorbs much of the
excess carbon dioxide from atmosphere ,fewer trees means higher level of
greenhouse gases in atmosphere –thus perpetuating the cycle in which
warmer temperature wreak atmosphere havoc.
 Human activities, mainly the burning of fossil fuels and clearing of forests,
have strengthened the “greenhouse effect” and caused “global warming”.

10. Global Warming:
Increase in average temperature of earth by trapping more heat due to greenhouse effect
is known as “global warming”.
How Global warming is affecting our Earth:
 Melting glaciers, early snowmelt, and severe droughts will cause more dramatic
water shortages and increase the risk of wildfires.
 Rising sea levels will lead to coastal flooding.
 Forests, farms, and cities will face troublesome new pests, heat waves, heavy
downpours.
 Disruption of habitats could drive many plant and animal species to extinction.

11. Ways to reduce greenhouse effect and global warming:
1. Reduce, Reuse, Recycle
2. Use Less Heat and Air Conditioning
3. Use the "Off" Switch
4. Plant a Tree
5. Buy Energy-Efficient Products
6. Drive Less and Drive Smart
7. Replace Your Light Bulbs
8. Encourage Others to Conserve

12. Thankyou