What is hydrocarbon combustion?

Hydrocarbon combustion involves the burning of a hydrocarbon compound. Hydrocarbon compounds contain only the elements hydrogen and carbon. In order for combustion to take place, oxygen must be present. Since oxygen is a diatomic element in nature and is never found as a single atom, it will be written as O2 in a chemical equation. Hydrocarbon combustion reactions always produce the same two products, CO2 and H2O. Below is an example of this type of reaction.
CH4 + O2 --> CO2 + H2O
The hydrocarbon (CH4) listed in the reaction above is called methane and is a colorless and odorless gas. Methane is the main component found in natural gas, which is a non-renewable energy source. As energy needs around the world increase, methane and other fuels will continue to be used while more research involving renewable methods occurs.
One of the two products produced from a hydrocarbon combustion reactions has created much controversy in the last twenty years. Carbon dioxide is considered a greenhouse gas. Greenhouse gases gather in the atmosphere and act as a blanket around the Earth trapping in heat. These gases cause an overall warming of the planet that may result in changes in water temperature, winds, and seasons.

Definitions of combustion vary somewhat, but when talking about hydrocarbons it is taken to mean a chemical reaction with oxygen that gives off heat and light, i.e. burning something. Combustion requires ignition, or an initial input of energy as heat. Once ignited, the reaction is sustained by the energy released in the reaction.
A hydrocarbon is any chemical compound of carbon and hydrogen. Apart from coal, which is carbon with different levels of contaminants, fossil fuels are hydrocarbons. Methane is the simplest, with the formula CH_4 . Propane is another gaseous hydrocarbon with the chemical formula C_3H_8 . Petroleum as it is extracted from the ground is a mixture of hydrocarbons. The process of refining mostly involves separating these into fractions, which are mixtures of hydrocarbons having certain ranges of properties, such as gasoline, kerosene, diesel, etc. Many of these products are burned as fuel, and the heat energy released is harnessed in different ways.
The products of complete combustion are carbon dioxide and water. A general chemical equation for the combustion of a hydrocarbon is written
C_mH_n + O_2 -> CO_2 + H_2O
Note that this chemical equation is not balanced. The “m” and “n” subscripts indicate that compounds containing different amounts of carbon and hydrogen all combust according to the same pattern.
The carbon dioxide produced in combustion of hydrocarbons is a concern today because it is known to be a “greenhouse gas”—that is, a gas that, in increased concentrations, changes the balance of radiative energy entering and leaving Earth’s atmosphere, causing a net warming of the atmosphere. Methane, which can escape into the atmosphere during extraction of hydrocarbons, is also a greenhouse gas. Concerns about changes in climate caused by atmospheric warming have motivated recent development in energy sources other than hydrocarbon fuels.