Reflectivity or Absorption of the Sun’s EnergyĪctivities such as agriculture, road construction, and deforestation can change the reflectivity of the earth's surface, leading to local warming or cooling. EPA, Climate Change Indicators in the United States: Atmospheric Concentrations of Greenhouse Gases, 2021. Increases in concentrations of these gases since 1750 are due to human activities in the industrial era. This graph shows the increase in atmospheric concentrations of three of the key greenhouse gases over the last 2,000 years. To learn more about actions that can reduce these emissions, see What You Can Do. To translate abstract greenhouse gas emissions measurements into concrete terms, try using EPA's Greenhouse Gas Equivalencies Calculator. 12įor more information on greenhouse gas emissions, see the Greenhouse Gas Emissions website. Nitrous oxide concentrations have increased from a pre-industrial level of 270 ppb 11 to 332 ppb in 2019. Nitrous oxide: Nitrous oxide concentrations have risen approximately 20 percent since the start of the Industrial Revolution, with a relatively rapid increase toward the end of the 20th century. Methane: Human activities increased methane concentrations during most of the 20th century to more than 2.5 times the pre-industrial level, from approximately 722 parts per billion (ppb) in the 18th century 9 to 1,867 ppb in 2019. 6 Atmospheric carbon dioxide concentrations have increased by more than 40 percent since pre-industrial times, from approximately 280 parts per million (ppm) in the 18th century 7 to 414 ppm in 2020. Burning fossil fuels changes the climate more than any other human activity.Ĭarbon dioxide: Human activities currently release over 30 billion tons of carbon dioxide into the atmosphere every year. 5 These greenhouse gas emissions have increased the greenhouse effect and caused the earth’s surface temperature to rise. Carbon dioxide, methane, and nitrous oxide concentrations are now more abundant in the earth’s atmosphere than any time in the last 800,000 years. Source: Smithsonian National Museum of Natural History, 2018 Greenhouse GasesĬoncentrations of the key greenhouse gases have all increased since the Industrial Revolution due to human activities.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |