What are the sources of ozone-depleting substances?
The main cause of ozone depletion and the ozone hole is manufactured chemicals, especially manufactured halocarbon refrigerants, solvents, propellants, and foam- blowing agents (chlorofluorocarbons (CFCs), HCFCs, halons), referred to as ozone-depleting substances (ODS).
Where are HCFCs found?
Chlorofluorocarbons (CFCs) are anthropogenic compounds that have been released into the atmosphere since the 1930s in various applications such as in air-conditioning, refrigeration, blowing agents in foams, insulations and packing materials, propellants in aerosol cans, and as solvents.
Which gas is responsible for ozone depletion?
Chlorofluorocarbons (CFCs)
Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and halons destroy the earth’s protective ozone layer, which shields the earth from harmful ultraviolet (UV-B) rays generated from the sun.
What are HCFCs used for?
HCFCs were used in a wide variety of applications, including refrigeration, air conditioning, foam blowing, solvents, aerosols, and fire suppression.
Is methane an ozone-depleting substance?
Ozone-depleting substances are also very potent greenhouse gases, contributing to the phenomenon as other substances widely known to have a greenhouse effect like carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).
Are HFC ozone-depleting?
HFC emissions cause increased warming of the stratosphere, speeding up the chemical reactions that destroy ozone molecules, and they also decrease ozone levels in the tropics by accelerating the upward movement of ozone-poor air. “HFCs are, in fact, weak ozone-depleting substances.”
How do HCFCs destroy ozone?
While HCFCs contain chlorine atoms, they are less damaging to the ozone layer because they also contain hydrogen atoms, which causes them to break down in the atmosphere faster. HCFCs are currently being phased out in favor of HFCs, which do not contain chlorine.
How do ozone-depleting substances destroy ozone molecules?
on the stratospheric ozone layer. Gaseous CFCs can deplete the ozone layer when they slowly rise into the stratosphere, are broken down by strong ultraviolet radiation, release chlorine atoms, and then react with ozone molecules. See Ozone Depleting Substance.)
Which chemical in an ozone depleting substance is directly responsible for ozone depletion?
chlorofluorocarbons (CFCs)
Researchers found evidence that linked the depletion of the ozone layer to the presence of chlorofluorocarbons (CFCs) and other halogen-source gases in the stratosphere. Ozone-depleting substances (ODS) are synthetic chemicals, which were used around the world in a wide range of industrial and consumer applications.
How hydrocarbons deplete the ozone layer?
Ultraviolet Radiation A type of hydrocarbons that are nonreactive, nonflammable organic molecules in which both chlorine and fluorine atoms replace some of the hydrogen atoms. Use of CFCs is one of the primary causes of stratospheric ozone depletion. A form of oxygen in which three atoms of oxygen occur together.