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September 26,
2007, 11.00 a.m.
On the occasion
of the 20th
anniversary of
the Montreal
Protocol for the
protection of
the ozone layer,
scientists
gathered at the
Academy of
Athens today,
September 26,
2007. They noted
that the success
of the Montreal
Protocol is
largely based on
scientific
progress made
over the last
decades. A world
of extreme high
chlorine, low
ozone, and high
UV has presently
been avoided.
Continued
adherence to the
Montreal
Protocol will
assure that this
remains the case
in the future.
It is perhaps
one of the most
illustrious
examples of a
successful
global
collaboration
between
scientific,
industrial and
environmental
organizations
and policy
makers. Control
of ozone
depleting
substances as
imposed by the
Montreal
Protocol is not
the only factor
that influences
the variability
of ozone and of
harmful solar UV
radiation.
Aerosols,
volcanic
eruptions and
climate change
also influence
the expected
recovery of the
ozone layer from
the effects of
halocarbons.
In areas like
Greece where
climate change
may lead to
significant
reduction in
precipitation
and more
frequent heat
waves with more
intense urban
ozone and
aerosol
pollution
events, new
scientific and
policy
challenges will
have to be
faced.
Impact of
Climate Change –
Ozone climate
Interactions
-
The decrease
in
ozone-depleting
substances
is a
dominant
factor in
the expected
return of
ozone levels
to pre-1980
values.
However
changes in
climate will
influence
if, when,
and to what
extent ozone
will return
to pre-1980
values in
different
regions.
-
Future
increases of
greenhouse
gas
concentrations
will
contribute
to the
average
cooling in
the
stratosphere.
Chemical
reaction
rates in the
atmosphere
are
dependent on
temperature,
and thus the
concentration
of ozone is
sensitive to
climate
changes.
Stratospheric
cooling was
observed
during the
past two
decades.
Further
changes to
the
temperature
and
circulation
of the
stratosphere
could affect
climate and
weather in
the
troposphere.
Implications for
Policy
Formulation
-
The
Montreal
Protocol is
working
:
There is
clear
evidence of
a decrease
in the
atmospheric
burden of
ozonedepleting
substances
and some
early signs
of
stratospheric
ozone
recovery.
-
Failure to
comply with
the Montreal
Protocol
would delay,
or could
even
prevent,
recovery of
the ozone
layer.
-
Understanding
the
interconnections
between
ozone
depletion
and climate
change is
crucial for
projections
of future
ozone
abundances.
-
Stratospheric
and
tropospheric
ozone are
critical
components
of the
global
climate
system.
Understanding
this system
requires
continuation
and
strengthening
of
observation
systems for
ozone and
other
relevant
species,
both from
ground and
space. These
observations
will provide
indispensable
information
about the
phase-out of
halocarbons
as required
by the
Montreal
Protocol and
about the
evolution of
the
atmosphere
under
climate
change.
Continuous
efforts in
laboratory
studies and
model
developments
are also
needed.
-
It is
imperative
to develop
similar
cooperative
relationships
between
scientific,
industrial
and
environmental
organizations
and policy
makers to
develop
effective
approaches
to
environmental
threats in
the
"anthroposcene"
era.
Prof. S. Rowland
(Nobel Prize /
Univ. of
California, USA)
Prof. G.
Brasseur (Assoc.
Director NCAR,
USA)
Prof. R. Bojkov
(Previous WMO,
Univ. of
Dresden)
Prof. M.-L.
Chanin (CNRS,
France)
Dr. J. Farman
(Ozone
Secretariat, UK)
Dr. S.
Godin-Beekmann
(Vice President,
IO3C / CNRS,
France)
M. Gonzalez
(Executive
Secretary, UNEP
Ozone
Secretariat)
Prof. I. Isaksen
(President, IO3C
/ Univ. of Oslo,
Norway)
Prof. I. Karol
(Voeikov Main
Geophysical
Observ., Russia)
Prof. M. Kurylo
(NASA, USA)
Dr. M. McFarland
(DuPont
Fluoroproducts,
USA)
Prof. J. Pyle
(Univ. of
Cambridge, UK)
Prof. R.
Stolarski (NASA
Goddard Space
Flight Center,
USA)
Prof. C. Zerefos
(President of
NOA, Secretary
IO3C)
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