Environmental problems

I think the melting of the ice caps is are povoked by man, because the planet's temperature is rising year after year by the greenhouse effect. The emission of the Co2 (carbonic gas) is   provoked by factories, cars, bus , the fire of the forest, and others facts such as deforestation that increases the greenhouse effect. It is very difficult for the man to find a solution, because economical problems may arise whether the world  if we decrease the industrial production, knowing that the world is on in crisis.

melting ... is provoked

buses, or busses. Both are correct, but "buses" is better.

forest fires

other facts that increase.

You have written a true and thoughtful paragraph. Your English has become excellent.

in addition to christine comments:

CO2 ( carbon dioxide ) emission by factories, cras, buses, forest fires etc contributes to and increases the greenhouse effect.

Great work! I'm not entirely sure what you were trying to express in the last sentence, but I did the best I could. 

I think the melting of the ice caps is caused (or exacerbated) by man, because the planet's temperature is rising year after year by the greenhouse effect. The emission of the CO2 (carbon Dioxide) produced by factories, cars, bus, buring of  the forests, and others factors such as deforestation that increase the greenhouse effect. It is very difficult for man to find a solution because economic problems may arise whether the world decreases the industrial productionor not, knowing that the world is in crisis.

Using the in front of CO2 is appropriate because you qualified it by specifying that it was the CO2 "produced by factories". If you were speaking of CO2 in general, then you wouldn't use "the" in front of it.