Climate change stems from numerous sources, including accumulation of greenhouse gases in the atmosphere, the burning of coal and fossil fuels and even some natural Earth activities such as volcanic eruptions. Some climate change comes from natural phenomena, including the changing path of Earth's orbit around the sun and extended heating and cooling phases. According to the Environmental Protection Agency, however, human activity, starting in the 20th century, greatly accelerates the rate of climate change.
The Earth's atmosphere contains a delicate balance of gases and particles, including greenhouse gases. The atmosphere requires some greenhouse gases for regulating temperature, weather and water vapor. Human activities such as the operation of power plants and manufacturing plants and burning coal for energy, introduce excessive amounts of carbon dioxide into the atmosphere. This causes a thickening of the lowest level of atmosphere and traps heat. Burning coal also emits high levels of carbon dioxide into the atmosphere. Smoldering coal produces methane too, another gas posing environmental and health risks in large quantities. Nitrous oxide, another gas, enters the atmosphere in excess through large-scale agricultural operations. Release of synthetic compounds, including chlorofluorocarbons and hydro chlorofluorocarbons, interferes with atmospheric activities too. These synthetics change the way sunlight reaches Earth and reflects back into the atmosphere; their congregation thins the ozone layer and lets more heat through.