Hydrocarbons make up fossil fuels. One of the main by-products of fossil fuel combustion is carbon dioxide (CO2). The ever-increasing use of fossil fuels in industry, transportation, and construction has added large amounts of CO2 to Earth’s atmosphere. Atmospheric CO2 concentrations fluctuated between 275 and 290 parts per million by volume (ppmv) of dry air between 1000 CE and the late 18th century but had increased to 316 ppmv by 1959 and rose to 412 ppmv in 2018. CO2 behaves as a greenhouse gas—that is, it absorbs infrared radiation (net heat energy) emitted from Earth’s surface and reradiates it back to the surface. Thus, the substantial CO2 increase in the atmosphere is a major contributing factor to human-induced global warming.
How does the use of hydrocarbons affect global warming and climate change?
Are there different types of hydrocarbons?
- Nineteenth-century chemists classified hydrocarbons as either aliphatic or aromatic on the basis of their sources and properties.
- Aliphatic (from Greek aleiphar, “fat”) hydrocarbons derive from the chemical breakdown of fats or oils. They are divided into alkanes, alkenes, and alkynes.
- Alkanes have only single bonds, alkenes contain a carbon-carbon double bond, and alkynes contain a carbon-carbon triple bond.
- Aromatic hydrocarbons make up a group of related substances obtained by chemical breakdown of certain pleasant-smelling plant extracts. They are classified as either arenes, which contain a benzene ring as a structural unit, or as nonbenzenoid aromatic hydrocarbons, which possess special stability but lack a benzene ring.
