Transcript: Earth’s atmosphere is unique within the solar system mostly because of the nitrogen and oxygen that form the bulk of the Earth’s atmosphere: 75 percent nitrogen, 20 percent oxygen, plus carbon dioxide, argon, water vapor and other trace gasses. The weather on the Earth is generated in the lowest part of the atmosphere, called the troposphere, at a distance of up to 10 miles from the Earth's surface or 50,000 feet. The Earth's weather is caused primarily by convection patterns, the rising and falling of parcels of air caused by energy from the Sun either directly on to the atmosphere or Sun’s energy absorbed by the Earth and then reradiated into the atmosphere. Convection plus the Earth's rotation gives the large scale weather patterns well known to all of us. Earth’s atmosphere in the last two centuries has started to be altered in its chemical composition in subtle but not negligible ways, like human industrial activity. The biggest consequences here are pollution which increases the components of nitrogen dioxide, sulfur dioxide, and sulfuric acid, the pollution of the ozone layer, the removal of a small isotope of oxygen called ozone leading to the increase in the ultraviolet radiation that reaches the Earth's surface, and deforestation which reduces the amount of oxygen and increases the carbon dioxide concentration in the atmosphere.