1. Increasing amounts of carbon dioxide emitted into the atmosphere from combustion of coal, oil, and natural gas have increased the Earth’s temperature a few degrees since the Industrial Revolution began in England in the 18^th
2. Other greenhouse gases, such as methane, come from wetlands and rice paddies, and they contribute a lot of warming potential.
3. The oceans are warming, acidifying, and expanding, which is leading to sea level rise, declines of coral, and potential flooding of low-lying cities, islands, and coastal regions.
4. Glaciers and massive ice sheets in polar regions are melting, releasing tremendous volumes of fresh water into the oceans, and changing circulation patterns of ocean currents. An example is the Gulf Stream that now keeps Iceland, England, and northern Europe warm, but this may change.
5. Weather patterns are changing toward more or less rainfall; colder or warmer temperatures; more frequent, severe hurricanes; and greater fires and droughts—all depending on geographic region of the Earth and season.

These changes and others have led to local, national, and international efforts to respond in one of more of three ways:

1. Lower our emissions of the gases that cause global warming.
2. Remove them from the atmosphere.
3. Adapt our lifestyles to the changes in climate.