The Greenhouse effect (I part) class 4th

Industries and wrong human habits are damaging the natural environment.

Because of pollution there are more and more gases in the atmosphere and the Earth's temperature is getting hotter and hotter.  

The effect is similar to a greenhouse, that's why it is called "the greenhouse effect".

The gasses produced by the human activities are entrapping the sun's heat: they let sun's rays pass through and reach the Earth but and let only a minimum amount of them leave.

CARBON DIOXIDE:

http://www.noaa.gov/

It's the most important greenhouse gas.
Almost 6 billion tonnes enter the atmosphere every year.
It comes either from the burning of fossil fuels like coal, gas and oil or the burning of rain forest trees.


CHLORO- FLUORO-CARBONS:

These gasses are in aerosol,sprays, refrigerators, plastic boxes and solvents.
They are very harmful both for human health and the natural environment. 
They are the cause of the depletion the ozone layer.  

Ozone depletion and the ozone hole generated worldwide concern over increased cancer risks and other negative effects. The ozone layer prevents most harmful UVB wavelengths of ultraviolet light (UV light) from passing through the Earth's atmosphere. 


METHANE:
This colorless, odorless gas has huge potential as a fuel, but it also poses a major threat to the climate.
Methane is a natural substance produced through biological routes as well as technological processes or other synthetic means.



NITROUS OXIDE:

Nitrous oxide has significant medical uses, especially in surgery and dentistry, for its anaesthetic and pain reducing effects. Its name "laughing gas" is due to the euphoric effects upon inhaling it. Recently has been found to be a major scavenger of stratospheric ozone,
It is estimated that 30% of the N2O in the atmosphere is the result of human activity, chiefly agriculture.


THE DEPLETION OF THE OZONE LAYERS

Work of Hole Ozone Layer from Tiago Amaral