Global warming certainly does exist and has since the first atmosphere formed on Earth. Some global warming has always been present and prevents the Earth from radiating energy back into space at the same rate it receives energy from the sun. When global warming is discussed in science and politics, it is often called anthropogenic, or "human-caused," global warming. This has also been demonstrated to exist.Continue Reading
The sun radiates a known amount of energy in the direction of Earth. If none of this energy was retained, the Earth's temperature would be beneath the freezing point of water. Some global warming has always been present and is caused by airborne molecules such as water vapor, carbon dioxide and methane.
Since the Industrial Revolution began in the late 18th century, the atmospheric concentrations of these gases have been increasing. The burning of wood, coal, natural gas and petroleum liberates large quantities of greenhouse gases that enter the atmosphere. These gases build up and trap more of the Sun's energy in the lower atmosphere, thus raising the climatic temperature.
Where legitimate controversy exists is in the severity and potential impact of this warming effect. That the effect itself exists is beyond reasonable doubt, though it is often questioned by non-scientists in public debates.Learn more about Human Impact