Ozone depleting substances
From Swikipedia
Introduction
Ozone depleting substances (ODS) are those substances which deplete the ozone layer and are widely used in refrigerators, air-conditioners, fire extinguishers, in dry cleaning, as solvents for cleaning, electronic equipment and as agricultural fumigants.
Ozone depleting substances include:
• Chlorofluorocarbons (CFCs)
• Halon
• Carbon tetrachloride, Methyl chloroform
• Hydrobromofluorocarbons (HBFCs)
• Hydrochlorofluorocarbons (HCFCs)
• Methyl bromide
• Bromochloromethane (BCM)
Brief Description
Past and present effects of ODSs:
Halocarbons, and in particular ODSs, have contributed to positive direct radiative forcing and associated increases in global average surface temperature. The total positive direct radiative forcing due to increases in industrially produced ODS and non-ODS halocarbons from 1750 to 2000 is estimated to be 0.33± 0.03 W m–2, representing about 13% of the total due to increases in all well-mixed greenhouse gases over that period.
Stratospheric ozone depletion observed since 1970 is caused primarily by increases in oncentrations of reactive chlorine and bromine compounds that are produced by degradation of anthropogenic ODSs, including halons, CFCs, HCFCs, methyl chloroform (CH3CCl3), carbon tetrachloride (CCl4) and methyl bromide (CH3Br).
Ozone depletion produces a negative radiative forcing of climate, which is an indirect cooling effect of the ODSs.
Warming due to ODSs and cooling associated with ozone depletion are two distinct climate forcing mechanisms that do not simply offset one another. The spatial and seasonal distributions of the cooling effect of ozone depletion differ from those of the warming effect. A limited number of global climate modelling and statistical studies suggest that ozone depletion is one mechanism that may affect patterns of climate variability which are important for tropospheric circulation and temperatures in both hemispheres. However, observed changes in these patterns of variability cannot be unambiguously attributed to ozone depletion.
Each type of gas has had different greenhouse warming and ozone depletion effects depending mainly on its historic emissions, effectiveness as a greenhouse gas, lifetime and the amount of chlorine and/ or bromine in each molecule. Bromine-containing gases currently contribute much more to cooling than to warming, whereas CFCs and HCFCs contribute more to warming than to cooling. HFCs and PFCs contribute only to warming.
Current policies, measures and instruments:
A variety of policies, measures and instruments have been implemented in reducing the use or emissions of ODSs and their substitutes, such as HFCs and PFCs. These include regulations, economic instruments, voluntary agreements and international cooperation. Furthermore, general energy or climate policies affect the indirect GHG emissions of applications with ODSs, their substitutes, or not-in-kind alternatives.
List of Regulations laid by the Government of India, Ministry of Environment and Forests:
Regulation of production and consumption of ozone depleting substances
Prohibition on export to or import from countries not specified in Schedule VI
Ozone depleting substances are to be exported to or imported from countries specified in Schedule VI under a licence
Regulation of the sale of ozone depleting substances
Regulation on the purchase of ozone depleting substances
Regulation on the use of ozone depleting substance
Prohibition on new investments with ozone depleting substances
Regulation of import, export and sale of products made with or containing ozone depleting substances
Regulation on reclamation and destruction of ozone depleting substances
Regulation on manufacture, import and export of compressors
Procedure for registration, cancellation of registration and appeal against such orders
Monitoring and reporting requirements
Exemption
References:
http://www.envfor.nic.in/legis/ods/odsrcr.html
http://www.environment.gov.au/atmosphere/ozone/ods/index.html
