PRESENTATION OUTLINE
The ozones layer
The ozone layer protects all life from the sun's harmful radiation, but human activities have damaged this shield. Such as deforestation, CFCs, fossil fuels and greenhouse gases.
Fossil fuels
Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years.Fossil fuels contain high percentages of carbon and include coal, petroleum, and natural gas.
Burning fossil fuels releases Carbon dioxide into the atmosphere trapping some of the energy that reaches Earth from the sun,preventing it from escaping back into space
Greenhouse gases
The greenhouse effect happens when certain gases known as greenhouse gases collect in Earth’s atmosphere. These gases include carbon dioxide (CO2), methane, nitrous oxide (N2O), fluorinated gases, and ozone.
Greenhouse gases let the sun’s light shine onto the Earth’s surface, but they trap the heat that reflects back up into the atmosphere. In this way, they act like the glass walls of a greenhouse. This greenhouse effect keeps the Earth warm enough to sustain life. Scientists say that without the greenhouse effect, the average temperature of the Earth would drop from 14˚C to as low as –18˚C
