GC: n

CT: Nobel Prize-winning chemist F. Sherwood Rowland probably never intended to be an environmental whistle-blower. But in the 1970s, when he and his postdoctoral associate Mario Molina at the University of California-Irvine studied a set of compounds called chlorofluorocarbons, or CFCs, they realized that they had uncovered a problem. They found that, if left unchecked, CFCs posed a serious threat to life on earth.

S: ACS – http://www.acs.org/content/dam/acsorg/education/resources/highschool/chemmatters/gc-nobel-prize-winnder-sherwood-rowland.pdf (last access: 16 December 2015)

N: 1. Composed of chloro- (before vowels chlor-, word-forming element used in chemistry, usually indicating the presence of chlorine in a compound, but sometimes “green,” from Latinized combined form of Greek khloros), fluoro- (combined form of fluorine, non-metallic element, 1813, coined by English chemist Sir Humphry Davy (1778-1829) from fluorspar (“calcium fluoride,” modern fluorite), the late eighteenth century name of the mineral where it was first found) and -carbon (on-metallic element, 1789, coined 1787 in French by Lavoisier as charbone, from Latin carbonem (nominative carbo) “a coal, glowing coal; charcoal”).
Frequent use in plural.
2. A family of chemicals composed primarily of carbon, hydrogen, chlorine, and fluorine whose principal applications are as refrigerants and industrial cleansers and whose principal drawback is the tendency to destroy the Earth’s protective ozone layer.
Throughout the second half of the 20th century, nearly all air conditioners used chlorofluorocarbons (CFCs) as their refrigerant, but because these chemicals are damaging to Earth’s ozone layer, CFC production stopped in the United States in 1995. Nearly all air conditioning systems now employ halogenated chlorofluorocarbons (HCFCs) as a refrigerant, but these are also being gradually phased out, with most production and importing stopped by 2020 and all production and importing stopped by 2030.
Hydrofluorocarbons, which don’t deplete the ozone layer, became popular in the 1990s when they replaced the ozone-depleting gases phased out under the original and revised Montreal Protocol chlorofluorocarbons (CFC) and hydrochlorofluorocarbons (HCFC). First signed in 1987 and updated continuously since then, the Montreal Protocol has proven tremendously effective at accomplishing its original goal repairing the ozone layer and is now seen as a model for international cooperation.
Hydrofluorocarbons, or HFCs, became popular following the phase-down of chlorofluorocarbons, another refrigerant, which, in the 1970s, scientists discovered were breaking down the ozone. While HFCs don’t destroy the ozone, they are strong greenhouse gases
The U.S. Department of Energy’s (DOE’s) Fermi National Accelerator Laboratory (Fermilab) has replaced old equipment and reduced energy consumption through a partnership with its electric utility, Commonwealth Edison. Fermilab upgraded the centralized cooling system and separated the system into two segments — a “comfort system” to cool the employee office space and a “process system” for the equipment and accelerators. Backup cooling capacity is provided and cooling can be shifted between the process and comfort systems when necessary. The new 4500-ton cooling system is expected to use 40% less energy and is free of ozone-depleting chlorofluorocarbons (CFCs).
Not only are the new chillers approximately 40% more energy efficient, they are also more environmentally friendly because they do not use CFCs. Fermilab was one of the first DOE sites to comply with the DOE directive from former Energy Secretary Richardson to replace all pre-1984 chillers using Class I CFCs such as R-11.
3. A CFC is an abbreviation for chlorofluorocarbon. CFCs are compounds that contains atoms of chlorine, fluorine, and carbon.
In 1928, Thomas Midgley, Jr. aided by Charles Franklin Kettering invented a “miracle compound” called Freon. Freon represents several different chlorofluorocarbons, or CFCs, which are used in commerce and industry. The CFCs are a group of aliphatic organic compounds containing the elements carbon and fluorine, and, in many cases, other halogens (especially chlorine) and hydrogen. Freons are colorless, odorless, nonflammable, noncorrosive gases or liquids.
Because Freon is non-toxic, it eliminated the danger posed by refrigerator leaks. In just a few years, compressor refrigerators using Freon would become the standard for almost all home kitchens. In 1930, Thomas Midgley held a demonstration of the physical properties of Freon for the American Chemical Society by inhaling a lung-full of the new wonder gas and breathing it out onto a candle flame, which was extinguished, thus showing the gas’s non-toxicity and non-flammable properties. Only decades later did people realize that such chlorofluorocarbons endangered the ozone layer of the entire planet.
The stalks of the rhubarb resemble red stalks of celery and are the only edible portion of the plant. The heart-shaped, wide-veined leaves are concentrated with oxalic acid which can be highly toxic. However, oxalic acid has its beneficial side for the environment. In 1995, scientists discovered that oxalic acid helps neutralize chlorofluorocarbons which threaten the ozone layer.
4. Manufacturing facilities eligible include those developing essential or peripheral equipment in the venues of solar energy, wind energy, and geothermal energy, as well as products aimed at energy storage of renewable resources, advanced transmission technologies, renewable (biofuel) technologies, energy conservation technologies (lighting, smart meters, etc.), electric vehicle technologies, carbon capture and sequestration (CCS) technologies, and any product likely to reduce greenhouse gas (GHG) emissions like carbon dioxide, methane, nitrogen oxides, hydrofluorocarbons, and chlorofluorocarbons, to name the most prominent.
5. While a hydrogen fuel-cell economy would almost certainly improve urban air quality, it has the potential unexpected consequences due to the inevitable leakage of hydrogen from cars, hydrogen production facilities, the transportation of the fuel. Uncertainty remains over the effects on the atmosphere because scientists still have a limited understanding of the hydrogen cycle. At present, it seems likely such emissions could accumulate in the air. Such a build-up would have several consequences, chief of which would be a moistening and cooling of the upper atmosphere and, indirectly, destruction of ozone. In this respect, hydrogen would be similar to the chlorofluorocarbons (once the standard substance used for air conditioning and refrigeration), which were to be contained within their devices, but which in practice leaked into the atmosphere and attacked the stratospheric ozone layer.
6. N. Plummer of the United States Geological Survey (USGS) gave a talk on the use of the NETPATH code to correct aquifer C-14 ages for water-rock-gas interaction. This provided a vivid demonstration of the sensitivity of groundwater ages to variable environmental effects; in an extreme case, a 20 ka age was adjusted to zero. Plummer then described the use of chlorofluorocarbons for dating. This method takes advantage of the time-dependent global production of synthetic CFCs, and attendant increase in atmospheric concentration, over the past 50 years. Atmospheric CFC concentrations as a function of time are reasonably well constrained; by defining a temperature dependent distribution content between air and water, CFC groundwater concentration can thus be used to theoretically define the atmospheric concentration, and pinpoint the time of recharge. He outlined the various sources of possible error in age estimation, including recharge temperature and sources of excess CFC contamination.
7. Uranium enrichment plants are major emitters of chemicals which damage the ozone layer, specifically CFC-114 (Freon) used as coolant.
8. chloridofluoridocarbon: form recommended by the IUPAC (International Union of Pure and Applied Chemistry) for the systematic name.

S: 1. OED – http://www.etymonline.com (last access: 17 December 2015); FCB. 2. ED – http://energy.gov/eere/energybasics/articles/glossary-energy-related-terms#C (last access: 17 December 2015). 3. ABOUT – http://chemistry.about.com/od/chemistryglossary/g/Chlorofluorocarbon-Definition.htm (last access: 17 December 2015). 4. SE – http://solarenergy.net/News/12220903-obama-administration-supports-another-%245-billion-for-clean-energy-manufacturing/ (last access: 17 December 2015). 5. RE – http://www.renewableenergyworld.com/articles/2003/06/study-questions-hydrogen-economy-8956.html (last access: 17 December 2015). 6. USNRC – http://pbadupws.nrc.gov/docs/ML0037/ML003741064.pdf (last access: 17 December 2015). 7. WNA – http://www.world-nuclear.org/info/Current-and-Future-Generation/The-Nuclear-Debate/ (last access: 17 December 2015). 8. TERMIUM PLUS (last access: 20 December 2015).

SYN: chloridofluoridocarbon

S: TERMIUM PLUS (last access: 20 December 2015)

CR: carbon, climate change, greenhouse effect, Kyoto Protocol, nuclear energy, ozone layer, stratosphere, stratospheric ozone.