Global warming refers to an average increase in the Earth's temperature, which in turn causes changes in climate. A warmer Earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans. When scientists talk about the issue of climate change, their concern is about global warming caused by human activities. An examination of surface temperature records shows there has been a gradual increase in average temperatures around the world over the past century. Once, all climate changes occurred naturally.

However, during the Industrial Revolution, we began altering our climate and environment through agricultural and industrial practices. The Industrial Revolution was a time when people began using machines to make life easier. It started more than 200 years ago and changed the way humans live. Before the Industrial Revolution, human activity released very few gases into the atmosphere, but now through population growth, fossil fuel burning, and deforestation, we are affecting the mixture of gases in the atmosphere. Since the Industrial Revolution, the need for energy to run machines has steadily increased...

While some degree of warming can be explained by natural processes, such as geologic cycles, volcanic eruptions and cosmic intrusions (asteroids), it is argued that human activities that produce greenhouse gases and alter the earth's surface may be causing an acceleration of the warming process. Energy that makes cars run and much of the energy used to light and heat our homes, comes from fuels like coal and oil - fossil fuels. Burning these fuels releases greenhouse gases. We send greenhouse gases into the air when we watch television or listen to a stereo.

By using the air conditioner, microwave, washing machine, or hair dryer we are helping to send greenhouse gases into the air. To perform many of these functions, you need to use electricity. Electricity comes from power plants. Most power plants use coal and oil to make electricity.

Burning coal and oil produces greenhouse gases. Greenhouse gases (G HGs) are chemicals and materials present in the earth's atmosphere that have certain radiation blocking properties. Radiation emitted from the sun travels toward earth. When it reaches the earth's atmosphere a portion of it is reflected back into space, a portion of it is absorbed as it passes through the atmosphere, and a portion of it makes it through the atmosphere to the earth's surface. The radiation that reaches the earth's surface is then either absorbed by surface materials, or reflected off the surface and back toward space.

As the radiation leaves the earth it must again pass through the atmosphere, where a portion of it is again absorbed. This energy that is trapped in the atmosphere creates a kind of insulation around the earth, causing the earth's temperatures to be higher than they otherwise would. These materials in the atmosphere that absorb the sun's radiation are called greenhouse gases. The main greenhouse gases are water vapor (responsible for around 90% of radiation absorption), carbon dioxide, nitrous oxide, and methane.

These gases have both natural and anthropogenic (human) sources. The trash that we send to landfills produces the greenhouse gas called methane. Methane is also produced by the animals we raise for dairy and meat products and when we take coal out of the ground. Automobiles and factories are adding greenhouse gases to the atmosphere. According to the Intergovernmental Panel on Climate Control (IPCC), greenhouse gases will continue to rise, mainly due to human activity. The rise in greenhouse gases will then cause significant global warming.

IPCC has declared that "global warming during this century will likely be accompanied by a variety of changes in regional climates. The warming will probably be greater over land than ocean, and regional climates will probably become more variable. Other possible effects include rainfall in the tropics, decreasing rainfall at multitudes, continued thinning of polar sea ice, and more frequent and intense EL Nino events." The amount of global warming is uncertain due to our limited knowledge of how the climate system works as well as our uncertainty in future greenhouse emissions. There really is no way to predict all of the effects that global warming will have on the earth. Again, some projections include a partial melting of glaciers and the polar ice caps, which would cause the sea level to rise and create havoc for coastal communities (including NYC) and island nations. Other predictions include an alteration in the kinds and amounts of vegetation (including agricultural crops) that could be supported by the new climate, again, an increase in extreme weather events (droughts, floods and storms), and the destruction of fragile ecosystems that depend on particular temperatures and climatic conditions for their survival..