GREENHOUSE effect. We have to stop it. And we have to start NOW.

125.000 years ago in Europe there were lions and elephants; at that time the temperatures were 3 Celsius degrees higher than today and forests covered Greenland. 
Soon, it may be 3 degrees hotter again but this time the change isn't happening naturally. 
This all is happening because of pollution...and it is happening very quickly. 

Pollution sends 4 main "greenhouse gases" into the atmosphere. They are: 
- Carbon dioxide (CO2)
- CFC (chloro-fluoro-carbons)
- Methane 
- Nitrous oxide 

CO2 is the most important greenhouse gas and it causes half of this problem. Nearly 6 billion tonnes of it enter the atmosphere every year from the burning of fossil fuels (coal, gas and oil). An extra 1,5 billion tonnes each year come from the burning of rainforest trees; normally, trees absorb CO2 but there are less day by day. 
Methane and Nitrous oxide come from fertilizers, cow's stomachs and rubbish. 
CFC are very dangerous, each one can trap 10.000 time more heat than an atom of CO2...and they don't just stay in the atmosphere, they destroy the ozone layer! 

The greenhouse effect causes enormous damage to the earth and its inhabitants: the sun's rays reflected on earth can't easily get out of the atmosphere, causing a rise in the level of temperatures; this provokes the melting of the perennial ice, causing a rise in the sea levels and the desertification of lots of areas of the planet. The oceans' temperature increase causes always more frequent devastating atmospheric phenomena. The knock-on effects produced are dreadful. 

So...HOW CAN WE STOP IT? 

- Stop using fossil fuels 

- Preserve rainforests beacuse the earth needs more trees, not fewer

- Use renewable energy, now at 20%. To slow down the greenhouse effect that number must rise to 50% in the next 15 years

- Totally ban CFCs in all the countries of the world

(Thanks to Lorenzo S. for helping me writing this post)