International Environmental Policy: Controlling Ozone Depletion - PowerPoint PPT Presentation

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International Environmental Policy: Controlling Ozone Depletion

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Title: International Environmental Policy: Controlling Ozone Depletion


1
International Environmental PolicyControlling
Ozone Depletion
2
Ozone The Basics
  • Ozone is a naturally occurring gas in the
    atmosphere.
  • An ozone molecule contains three oxygen atoms
    O3.
  • Ozone is found in two layers
  • Bad ozone 10 of ozone is in the lower
    atmosphere (troposphere), where it is a toxic
    component in smog.
  • Good ozone 90 is found in the ozone layer
    in the stratosphere (6 to 10 miles above the
    earth), where it blocks harmful UV-B radiation.

3
Ozone The Basics
4
Benefits of Good Ozone
  • If the ozone layer did not absorb ultraviolet
    (UV)-B radiation from the sun, people would
    suffer more
  • Skin cancer
  • Cataracts
  • Suppressed immune systems

5
Ozone Depletion
  • Stratospheric ozone is depleted by reactions with
    chemicals produced as gases at ground level.
  • Important ozone-depleting gases
  • Chlorofluorocarbons (CFCs) and other
    chlorine-containing gases, formerly used in
    refrigeration, air conditioning, and other uses.
  • Bromine-containing gases (mostly halons),
    originally developed to extinguish fires.

6
Ozone Depletion
  • Stratospheric ozone concentrations have dropped
    by about 3, on average, since the 1980s.
  • Ozone concentrations have fallen more near the
    poles, and not at all near the equator.

7
Ozone Depletion
  • Estimated changes in surface UV radiation from
    1979 to 1992

8
Ozone Depletion
  • The link between man-made chemical emissions and
    depletion of the stratospheric ozone layer was
    discovered starting in the mid-1970s.
  • The most important step in preventing ozone
    depletion
  • Montréal Protocol on Substances that Deplete the
    Ozone Layer (1987)

9
Montréal Protocol
  • The Montréal Protocol and later amendments
    required a phaseout of production and consumption
    of ozone-depleting chemicals.
  • The Montréal Protocol has been ratified by over
    180 nations.
  • In the US, the Montréal Protocol was implemented
    in the provisions of the Clean Air Act of 1990.

10
Montréal Protocol
  • Predicted Effects of the Montréal Protocol

11
Montréal Protocol
  • To facilitate international cooperation in
    reducing production of ozone-depleting
    substances, the Montréal Protocol
  • allowed trading of emission reduction credits
    between countries.
  • established a Multilateral Fund to assist
    developing countries in the transition toward CFC
    substitutes.
  • Indias annual consumption of refrigerators is
    expected to climb from 6 million in 1989 to 80
    million in 2010, so its participation in the
    Montréal Protocol is crucial.
  • India ratified the agreement in 1992.

12
Policy Changes in the U.S.
  • The Clean Air Act of 1990 ended production of
    CFCs on December 31, 1995.
  • Rather than calling for an abrupt ban on
    production, policies were designed to be more
    cost-effective.

13
Policy Changes in the U.S.
  • Cost-effective provisions
  • Congress enacted an excise tax on production of
    ozone-depleting chemicals. The tax was gradually
    raised over time.
  • Allowances were issued to producers of
    ozone-depleting chemicals. Over time the number
    of allowances was reduced.
  • The 1990 Clean Air Act called for a national
    recycling program for CFCs. Existing supplies of
    CFCs could still be legally used.
  • Policies like these provided incentives for the
    development of safer alternatives to
    ozone-depleting chemicals.

14
Costs and Benefits of the CFC Phaseout
  • The EPA estimated (in 1987) that the costs of
    phasing out CFCs would be 27 billion through
    2075.
  • For example, the value of CFCs in
    air-conditioning products was estimated to be
    10.9 billion.
  • The EPA estimated that the benefits of
    eliminating CFCs (value of health effects and
    crop damage averted) would be 6.5 trillion.
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