Global InformationGreenhouse gas information
Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. What distinguishes them from other gases is that they absorb the wavelengths of radiation that a planet emits, resulting in the greenhouse effect.[1] The Earth is warmed by sunlight, causing its surface to radiate heat, which is then mostly absorbed by greenhouse gases. Without greenhouse gases in the atmosphere, the average temperature of Earth's surface would be about −18 °C (0 °F),[2] rather than the present average of 15 °C (59 °F).[3][4]
The five most abundant greenhouse gases in Earth's atmosphere, listed in decreasing order of average global mole fraction, are:[5][6] water vapor, carbon dioxide, methane, nitrous oxide, ozone. Other greenhouse gases of concern include chlorofluorocarbons (CFCs and HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons, SF
6, and NF
3. Water vapor causes about half of the greenhouse effect, but humans are not directly adding to its amount,[7] so it is not a driver of climate change.[8]
Carbon dioxide is causing about three-quarters of global warming and can take thousands of years to be fully absorbed by the carbon cycle.[9][10] Methane causes most of the remaining warming and lasts in the atmosphere for an average of 12 years.[11] Human activities since the beginning of the Industrial Revolution (around 1750) have increased carbon dioxide by over 50%,[12] up to a level not seen in over 3 million years.[13] The atmospheric methane concentrations have increased by over 150% during the same time period.[14]
Without human influence, the natural flows of carbon between the atmosphere, terrestrial ecosystems, the ocean, and sediments would be fairly balanced.[15][16] The vast majority of carbon dioxide emissions by humans come from the burning of fossil fuels. Further contributions come from agriculture and industry.[17]: 687 [18][19] Methane emissions originate from agriculture, fossil fuel production, waste, and other sources.[20] If current emission rates continue then global warming will surpass 2.0 °C (3.6 °F) sometime between 2040 and 2070. This is a level which the Intergovernmental Panel on Climate Change (IPCC) says is "dangerous".[21]
- ^ Matthews, J.B.R.; Möller, V.; van Diemenn, R.; Fuglesvedt, J.R.; et al. (9 August 2021). "Annex VII: Glossary". In Masson-Delmotte, Valérie; Zhai, Panmao; Pirani, Anna; Connors, Sarah L.; Péan, Clotilde; et al. (eds.). Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (PDF). IPCC / Cambridge University Press. pp. 2215–2256. doi:10.1017/9781009157896.022. ISBN 9781009157896.
- ^ Cite error: The named reference
NASACO2was invoked but never defined (see the help page). - ^ Cite error: The named reference
Trenberth2003was invoked but never defined (see the help page). - ^ Le Treut, H., R. Somerville, U. Cubasch, Y. Ding, C. Mauritzen, A. Mokssit, T. Peterson and M. Prather, 2007: "Chapter 1: Historical Overview of Climate Change". In: "Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change". [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
- ^ "Atmospheric Concentration of Greenhouse Gases" (PDF). U.S. Environmental Protection Agency. 1 August 2016. Archived (PDF) from the original on 19 October 2021. Retrieved 6 September 2021.
- ^ "Inside the Earth's invisible blanket". sequestration.org. Archived from the original on 28 July 2020. Retrieved 5 March 2021.
- ^ Gavin Schmidt (1 October 2010). "Taking the Measure of the Greenhouse Effect". NASA Goddard Institute for Space Studies – Science Briefs.
- ^ "NASA Science Mission Directorate article on the water cycle". Nasascience.nasa.gov. Archived from the original on 17 January 2009. Retrieved 16 October 2010.
- ^ "Global Greenhouse Gas Emissions Data". United States Environmental Protection Agency. 12 January 2016.
- ^ "Climate Change Indicators: Greenhouse Gases". United States Environmental Protection Agency. 16 December 2015.
Carbon dioxide's lifetime cannot be represented with a single value because the gas is not destroyed over time, but instead moves among different parts of the ocean–atmosphere–land system. Some of the excess carbon dioxide is absorbed quickly (for example, by the ocean surface), but some will remain in the atmosphere for thousands of years, due in part to the very slow process by which carbon is transferred to ocean sediments.
- ^ "Understanding methane emissions". International Energy Agency.
- ^ "Carbon dioxide now more than 50% higher than pre-industrial levels". National Oceanic and Atmospheric Administration. 3 June 2022. Retrieved 30 August 2022.
- ^ Lindsey, Rebecca. "Climate Change: Atmospheric Carbon Dioxide". climate.gov. Archived from the original on 24 June 2013. Retrieved 2 March 2020.
- ^ "Understanding methane emissions". International Energy Agency.
The concentration of methane in the atmosphere is currently over two-and-a-half times greater than its pre-industrial levels
- ^ Prentice, I.C. (2001). "The carbon cycle and atmospheric carbon dioxide". In Houghton, J.T. (ed.). Climate change 2001: the scientific basis: contribution of Working Group I to the Third Assessment Report of the Intergouvernmental Panel on Climate Change. hdl:10067/381670151162165141.
- ^ "An Introduction to the Global Carbon Cycle" (PDF). University of New Hampshire. 2009. Archived (PDF) from the original on 8 October 2016. Retrieved 6 February 2016.
- ^ Canadell, J.G., P.M.S. Monteiro, M.H. Costa, L. Cotrim da Cunha, P.M. Cox, A.V. Eliseev, S. Henson, M. Ishii, S. Jaccard, C. Koven, A. Lohila, P.K. Patra, S. Piao, J. Rogelj, S. Syampungani, S. Zaehle, and K. Zickfeld, 2021: Chapter 5: Global Carbon and other Biogeochemical Cycles and Feedbacks. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 673–816, doi:10.1017/9781009157896.007.
- ^ "Global Greenhouse Gas Emissions Data". U.S. Environmental Protection Agency. 12 January 2016. Archived from the original on 5 December 2019. Retrieved 30 December 2019.
The burning of coal, natural gas, and oil for electricity and heat is the largest single source of global greenhouse gas emissions.
- ^ "AR4 SYR Synthesis Report Summary for Policymakers – 2 Causes of change". ipcc.ch. Archived from the original on 28 February 2018. Retrieved 9 October 2015.
- ^ "Global Methane Tracker 2023". International Energy Agency. 21 February 2023.
- ^ "Analysis: When might the world exceed 1.5C and 2C of global warming?". Carbon Brief. 4 December 2020. Archived from the original on 6 June 2021. Retrieved 17 June 2021.