Fluoride Action Network

U.S. study finds surprise within greenhouse gases

Source: iTWire | November 19th, 2009 | By William Atkins
Industry type: Greenhouse/Ozone Gases

Researchers from NASA and Purdue University found that carbon dioxide and methane are not as important as fluorine (F) compounds such as chlorofluorocarbons, hydrofluorocarbons, perfluorocarbons, and nitrogen fluoride when it comes to producing greenhouse gases (GHGs).

The authors of the study are Partha P. Bara, Joseph S. Francisco, and Timothy J. Lee (NASA Ames Research Center, Space Science and Astrobiology Division, Moffett Field, California, and Department of Chemistry and Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, Indiana).

Their article “Identifying the Molecular Origin of Global Warming,” appears in the American Chemical Society’s Journal of Physical Chemistry A, which was released on November 12, 2009. [J. Phys. Chem. A, 2009, 113 (45), pp 12694–12699, DOI: 10.1021/jp905097g]

The researchers looked into which chemical and physical properties of certain molecules are most likely to produce greenhouse gases (GHGs) and, thus, are important for the study of global warming and climate change.

They researched numerous chemicals that are often included as greenhouse gases by the Intergovernmental Panel on Climate Change (IPCC), which is an international body that is monitoring global warming.

The researchers used experimental observations and computer modeling for their study.

They discovered that chemical compounds such as chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and nitrogen fluorides, along with the element sulfur (S), had properties that were much more likely to warm the global climate than other compounds that are often associated with global warming, such as carbon dioxide and methane.

Each of these compounds contains fluorine (F) atoms, which were found to be very efficient at blocking radiation.

For instance, perfluorocarbons (PFCs), sometimes referred to as fluorocarbons, are organofluorine compounds that contain only carbon and fluorine bonded together in strong carbon–fluorine bonds.

According to these scientists, the reason why these compounds have greater potential to warm the Earth is because of their efficiency to confine radiation within the atmosphere.

That is, these compounds have the ability to trap infrared (IR) radiation from the Sun within Earth’s atmosphere, which warms up our global climate.

And, most of the fluorine compounds are manufactured industrially by humans.

According to the 11/18/2009 Purdue University article Dozen Lesser-Known Chemicals Have Strong Impact on Climate Change, which appears on the ScienceDaily.com website, “CFC use has waned with the discovery that the chemicals contribute to the destruction of Earth’s ozone layer, which absorbs most of the dangerous ultraviolet radiation from the sun.”

“But HFCs and PFCs are widely used in air conditioning and the manufacturing of electronics, appliances and carpets. Other uses range from application as a blood substitute in transfusions to tracking leaks in natural gas lines.”

The study states, “Although current concentrations of some of these trace gases have been found to be substantially small compared to carbon dioxide, their concentration is on the rise…. With the current rate of increase, they will be important contributors in the future, according to some models.”

The conclusion of the Purdue University article states, “The concern is that, even if emitted into the atmosphere in lower quantities, the [fluorine] chemicals might have a powerful cumulative effect over time. Some of these chemicals don’t break down for thousands of years.”