I hope this works!
The atmospheric concentration of carbon dioxide, the major greenhouse gas directly affected by human activities, has increased by about 30% since the beginning of the pre- industrial era around 1750 because of the combustion of fossil fuels and changes in land- use practices. During the same period of time human activities have also increased the atmospheric concentrations of other greenhouse gases such as methane and nitrous oxide, and regional pollutants such as sulfate aerosols. Increased atmospheric concentrations of greenhouse gases tend to warm the atmosphere, while increased concentrations of aerosols tend, in some regions, to cool the atmosphere. The Earth's climate, which has been relatively stable during the past 10,000 years is now changing. The Earth's surface temperature this century is as warm or warmer than any other century during the six hundred years; the Earth's surface temperature has increased by about one degree Fahrenheit over the last century; and the last few decades have been the hottest this century. In addition, there is evidence of changes in sea level, glaciers are retreating world-wide, and the incidence of extreme weather events is increasing in some parts of the world. Computational models that take into account the observed increases in the atmospheric concentrations of greenhouse gases and aerosols simulate the observed changes in temperature quite well, suggesting that there is a discernible human influence on the Earth's climate.
Greenhouse gas concentrations are projected to increase significantly during the next century in the absence of policies specifically designed to address the issue of climate change. For example, carbon dioxide emissions are projected to range from 6 to 36 billion tons of carbon per year in the year 2100: compared to current carbon dioxide emissions of 6 billion tons of carbon per year. Climate models project that the global mean surface temperature could increase another 1.5 to 6.5 oF by 2100: a rate significantly faster than observed changes over the last 10,000 years. Sea level is projected to increase by another 15 - 95 cm by 2100.
Black carbon pollution is the release of tiny particles into the air from burning fuel for energy. Air pollution caused by such particulates has been a major problem since the beginning of the industrial revolution and the development of the internal combustion engine . Scientific publications dealing with the analysis of soot and smoke date back as early as 1896. Mankind has become so dependent on the burning of fossil fuels (petroleum products, coal, and natural gas) that the sum total of all combustion-related emissions now constitutes a serious and widespread problem, not only to human health, but also to the entire global environment.
When people think about air pollution, they usually think about smog, acid rain, CFC's, and other forms of outdoor air pollution. But did you know that air pollution also can exist inside homes and other buildings? It can, and every year, the health of many people is affected by chemical substances present in the air within buildings.
Smog is a type of large-scale outdoor pollution. It is caused by chemical reactions between pollutants derived from different sources, primarily automobile exhaust and industrial emissions. Cities are often centers of these types of activities, and many suffer from the effects of smog, especially during the warm months of the year. Additional information about smog and its effects are available from Environment Canada and the Air Quality Management District (AQMD) in southern California.
For each city, the exact causes of pollution may be different. Depending on the geographical location, temperature, wind and weather factors, pollution is dispersed differently. However, sometimes this does not happen and the pollution can build up to dangerous levels. A temperature inversion occurs when air close to the earth is cooler than the air above it. Under these conditions the pollution cannot rise and be dispersed. Cities surrounded by mountains also experience trapping of pollution. Inversion can happen in any season. Winter inversions are likely to cause particulate and cabon monoxide pollution. Summer inversions are more likely to create smog.
Another consequence of outdoor air pollution is acid rain. When a pollutant, such as sulfuric acid combines with droplets of water in the air, the water (or snow) can become acidified . The effects of acid rain on the environment can be very serious. It damages plants by destroying their leaves, it poisons the soil, and it changes the chemistry of lakes and streams. Damage due to acid rain kills trees and harms animals, fish, and other wildlife.
The Greenhouse Effect, also referred to as global warming, is generally believed to come from the build up of carbon dioxide gas in the atmosphere. Carbon dioxide is produced when fuels are burned. Plants convert carbon dioxide back to oxygen, but the release of carbon dioxide from human activities is higher than the world's plants can process. The situation is made worse since many of the earth's forests are being removed, and plant life is being damaged by acid rain. Thus, the amount of carbon dioxide in the air is continuing to increase.

Many people spend large portion of time indoors - as much as 80-90% of their lives. We work, study, eat, drink and sleep in enclosed environments where air circulation may be restricted. For these reasons, some experts feel that more people suffer from the effects of indoor air pollution than outdoor pollution.
There are many sources of indoor air pollution. Tobacco smoke, cooking and heating appliances, and vapors from building materials, paints, furniture, etc. cause pollution inside buildings. Radon is a natural radioactive gas released from the earth, and it can be found concentrated in basements in some parts of the United States. Additional information about the radon problem is available from the USGS and the Minnesota Radon Project.
http://www.lbl.gov/Education/ELSI/pollution-main.html