Main gases that affects Air pollution and its results

Main gas is carbon dioxide. Major sources are fossil fuel burning and deforestation. Less developed countries with 80% of world's people are responsible for 35% of carbon dioxide emission but may contribute 50% by 2020. Currently carbon dioxide is responsible for 57% of global warming trend. Sulfur dioxide is another major pollutant of air. It can injure man,plants and materials. These chemicals descend into earth's crest in the form of snow or rain and in dry forms as gases fog and dew or solid particles. But I feel like it affects the plants the most. Trees plays an important role in producing oxygen from carbon dioxide. As long as there are no wood burnt than is produced by the forests, no change in atmospheric CO2 will result. Pollutants that i discussed above can cause direct damage to the leaves of crop plants and trees when they enter leaf pores.
(http://healthandenergy.com/air_pollution_causes.htm)