Shown here are four representations chemists use for methane. In the colored models, carbon is light gray and hydrogen is white. Click on image for full size (33 Kb GIF) Windows to the Universe original artwork by Randy Russell.

Methane is gas that is found in small quantities in Earth's atmosphere. Methane is the simplest hydrocarbon, consisting of one carbon atom and four hydrogen atoms. Methane is a powerful greenhouse gas.

Methane is flammable, and is used as a fuel worldwide. It is a principal component of natural gas. Burning methane in the presence of oxygen releases carbon dioxide and water vapor:

CH₄ + 2 O₂ → CO₂ + 2 H₂O

Although the concentration of methane in Earth's atmosphere is small (around 1.8 parts per million), it is an important greenhouse gas because it is such a potent heat absorber. The concentration of methane in our atmosphere has risen by about 150% since 1750, apparently largely due to human activities. Methane accounts for about 20% of the heating effects by all of the greenhouse gases combined. Both natural and human sources supply methane to Earth's atmosphere.

Major natural sources of methane include emissions from wetlands and oceans, and from the digestive processes of termites. Sources related to human activities include rice production, landfills, raising cattle and other ruminant animals (cow burps!), and energy generation.

Here are four different ways chemists use to show a molecule of methane. In the colored molecule models, carbon is light gray and hydrogen is white. Click on image for full size (33 Kb GIF) Windows to the Universe original artwork by Randy Russell.

Methane is a kind of gas. There is a small amount of methane in the air you breathe. A methane molecule has carbon and hydrogen atoms in it.

Methane is a greenhouse gas. That means it helps make Earth warm. But if there was too much methane, that could make our planet too warm.

Where does the methane in Earth's atmosphere come from? Cow burps, for one place! Farming rice also puts methane into the air. Some methane also comes from garbage dumps. Termites make lots of methane, too. Swamps also make methane.

Methane can burn. It is used as a fuel. It is one of the main gases in natural gas. The heat in your home might be from natural gas. Methane is called a hydrocarbon because it has hydrogen and carbon atoms in it.

Here are four different ways chemists use to show a molecule of methane. In the colored molecule models, carbon is light gray and hydrogen is white. Click on image for full size (33 Kb GIF) Windows to the Universe original artwork by Randy Russell.

Methane is a kind of gas. There is a small amount of methane in the air you breathe. A methane molecule has carbon and hydrogen atoms in it.

Methane is a greenhouse gas. That means it helps make Earth warm. But if there was too much methane, that could make our planet too warm.

Where does the methane in Earth's atmosphere come from? Cow burps, for one place! Farming rice also puts methane into the air. Some methane also comes from garbage dumps. Termites make lots of methane, too. Swamps also make methane.

Methane can burn. It is used as a fuel. It is one of the main gases in natural gas. The heat in your home might be from natural gas. Methane is called a hydrocarbon because it has hydrogen and carbon atoms in it.