HCFC-22

Chlorodifluoromethane, or HCFC-22, is a compound used primarily as a refrigerant. It was developed to replace Chlorofluorocarbons (CFCs), when their phaseout began in the late 1970s.

Background
CFCs, which were used for aerosol sprays as well as for refrigerants, were found to be depleting stratospheric ozone, the kind that protects the planet from harmful UV rays. Because they are very stable, "there are no natural processes that remove CFCs from the lower atmosphere [and] over time, winds drive them into the stratosphere." Once in the stratosphere, CFCs are broken down by ultra violet radiation into their components, one of which is atomic chlorine. Chlorine breaks down Ozone at a rapid pace. The destruction is so efficient, in fact, that "one chlorine atom can destroy over 100,000 Ozone molecules," which is a faster rate than Ozone can be created. In addition to ozone destruction, CFCs also absorb and trap heat in the atmosphere. The heat trapped in these chemicals contributes to the problem of global climate change.

HCFCs were seen to be the solution to the ozone depletion problem because they could be used as refrigerants much like CFCs, but their ozone depletion rate was much lower. They are, however, still greenhouse gases that trap heat in the atmosphere and contribute to global warming. While their concentration in the atmosphere is much lower than other greenhouse gases such as carbon dioxide, "the warming effect that they produce ranges from 3000 to 13000 times that of carbon dioxide."

The Subsidiary Body for Scientific and Technological Advice, a group established under the United Nations Framework Convention on Climate Change, is considering whether the destruction of HCFC-23, a greenhouse gas created as a by-product in the manufacture of the refrigerant gas HCFC-22, should be entitled to emission credits and be included in the Clean Development Mechanism. The issue will be under discussion at the December 2008 COP14 meeting in Poznan, Poland.

Related SourceWatch articles

 * Accra Climate Change Talks 2008
 * Clean Development Mechanism
 * Clean Development Mechanism and HCFC-23 destruction
 * COP14
 * COP15
 * Emissions Trading
 * Joint Implementation
 * Kyoto Protocol
 * United Nations Framework Convention on Climate Change