Image: Halogenated gas concentrations 1978-2015
Description: The two graphs show global changes in the concentration (measured in parts per trillion, or ppt) of several important halogenated gases in earth's atmosphere. The data were collected from sites around the world between years 1978 and 2015. The left graph shows gases which cause substantial ozone depletion, as well as atmospheric heating. The right graph shows gases for which the main influence is global warming. All gases are human-made and manufactured in industrial amounts starting as early as the mid-twentieth century. Severe depletion of earth's protective ozone layer inspired efforts to reduce the production of some gases starting the late 1980's. Overall, the manufacture of most other gases is still rapidly increasing, as indicated by the logarithmic scale used to graph the concentrations. Data Sources/References: 1. AGAGE (Advanced Global Atmospheric Gases Experiment). 2016. ALE/GAGE/AGAGE data base. Accessed June 2016. https://agage.mit.edu/. 2. Rigby, M. 2016 update to data originally published in: Arnold, T., C.M. Harth, J. Mühle, A.J. Manning, P.K. Salameh, J. Kim, D.J. Ivy, L.P. Steele, V.V. Petrenko, J.P. Severinghaus, D. Baggenstos, and R.F. Weiss. 2013. Nitrogen trifluoride global emissions estimated from updated atmospheric measurements. P. Natl. Acad. Sci. USA 110(6):2029–2034. Data updated July 2016. 3. NOAA (National Oceanic and Atmospheric Administration). 2016. Halocarbons and Other Atmospheric Trace Species group (HATS). Accessed June 2016. https://www.esrl.noaa.gov/gmd/hats/.
Title: Halogenated gas concentrations 1978-2015
Credit: https://www.epa.gov/climate-indicators/climate-change-indicators-atmospheric-concentrations-greenhouse-gases
Author: United States Environmental Protection Agency - Unauthored
Usage Terms: Public domain
License: Public domain
Attribution Required?: No
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