CO2 from Human Action

Human (anthropogenic) activity, including the use of fossil fuel, releases greenhouse gases like CO2 to the atmosphere.

Over 100 years ago, Svante Arrhenius, a Swedish scientist and Nobel Prize winner, postulated that the emissions of anthropogenic CO2 from fossil fuel combustion could eventually have a profound effect on the heat budget of the atmosphere. In 1904, Arrhenius stated that "the slight percentage of carbonic acid [combination of carbon and oxygen or CO2 and water vapor] in the atmosphere may, by the advances of industry, be changed to a noticeable degree in the course of a few centuries." 1

Beginning in the 1850s, the use of fossil fuels became more common as the Industrial Revolution gained momentum in Europe and North America. Since that time, humans have used the energy in fossil fuels to build a dynamic global economy and an improved quality of life. Over this same period, human activity has added over 300 billion tons of anthropogenic carbon to the global carbon cycle. Since the 1850s, CO2 levels in the atmosphere have increased nearly 30%, and the concentrations of other greenhouse gases like methane (more than doubled) and nitrous oxide (up by about 15%) have also increased.2

Humans are currently adding over 9 billion tons of anthropogenic carbon ToolTip to the atmosphere each year, with nearly 2 billion tons coming from the United States.3 Most of the anthropogenic carbon emissions would result from the combustion of fossil fuels in transportation, electrical generation, and heating and cooling for buildings.2

Reducing the emissions of anthropogenic CO2 and other anthropogenic emissions of carbon-based greenhouse gases is a concrete step that humans can take to address the rising levels of CO2 and other greenhouse gases in the atmosphere.4

  1. (accessed October 2018).
  2. (accessed November 2004).
  3. Carbon Dioxide Information Analysis Center,
    (accessed November 2010).
  4. Pacala, S., and Sokolow, R., 2004, Stabilization wedges - solving the climate problem for the next 50 years with current technologies: Science, v. 305, p. 968-972.