But per atom, bromine is 40 times as effective as chlorine
at destroying the ozone layer.
Bromine, the ozone - depleting element found in methyl bromide, is nearly 60 times more effective
at destroying ozone than the chlorine found in CFCs.9 This means that even though its atmospheric lifetime is quite short (a little over a year) 31, the immediate impact of changes in methyl bromide emissions on the ozone layer is very high compared to other chemicals.
Not exact matches
An eerie «polar stratospheric cloud,» which
destroys ozone at a rapid rate, hangs above Kiruna, Sweden, in January 2000.
Similarly, Gordon Chin, a project scientist
at NASA's Goddard Space Flight Center in Greenbelt, Maryland, proposed a mission that would explain why the same chemical processes that
destroy ozone in Earth's atmosphere stabilize carbon dioxide in Venus's.
One of the unexpected consequences of the October 28 flare was a fivefold increase in
ozone -
destroying nitric oxide
at 70 miles above Earth's surface.
They found that water vapour and chlorine and bromine from vaporised sea salts would
destroy ozone high in Earth's atmosphere
at a much faster rate than it is naturally created (Earth and Planetary Science Letters, DOI: 10.1016 / j.epsl.2010.08.036).
This is important, as a molecule of
ozone lost in this region has a far larger impact on climate than a molecule
destroyed at higher altitudes by longer - lived gases.»
CFCs, the main
ozone -
destroying chemicals, are to be banned in the European Union
at the beginning of 1995.
AMERICA's Republicans thumbed their noses
at the vast majority of the world's scientists last week by claiming that there is no proof that CFCs are
destroying the Earth's
ozone layer.
Benítez says that a supernova could have gone off
at a mere 100 light - years away — close enough to have blasted Earth with high - energy cosmic rays and
destroy the
ozone layer.
The dangerous pollutant
ozone, it turns out, is
destroyed by hair and body oils, an oddity revealed when researchers
at Missouri University of Science and Technology compared washed and unwashed hair.
During September 1991, about half of the
ozone at altitudes of between 9 and 13 kilometres was
destroyed (Geophysical Research Letters, vol 19, p 1819).
Concern that aircraft crossing this boundary
destroy ozone dates back more than two decades to the construction of the first Concordes, which cruise
at around 16.5 kilometres (55 000 feet).
Although the vortex broke down around mid-March of that winter,
ozone loss continued in a stable remnant and by early April about 70 % of the
ozone at 20 km was
destroyed in this fragment of the vortex.
The common conclusion from a number of independent approaches (including ours) was that up to date more than 50 % of the
ozone at 19 - 20 km altitude have been chemically
destroyed this winter.
E.g. in 1999/2000 about 30 % of the total column
ozone was
destroyed by anthropogenic chemical loss, which is considerably less than the maximum loss
at 19 - 20 km altitude.
Large scale
ozone losses have occurred above the Arctic this past winter with over 50 % of the
ozone destroyed at altitudes around 18 km.
We've changed the atmosphere in other ways, mainly by adding
ozone and aerosols
at the ground, and
destroying ozone high in the atmosphere with CFCs.
We might not be able to see the CO2 rising into the atmosphere just as we were not able to see the CFCs that were going into the
Ozone layer and
destroying it like little Pac - Men gobbling away
at these molecules that protect us from the suns more caustic rays.
«The rate
at which
ozone is being
destroyed in the upper stratosphere is slowing, and the levels of
ozone -
destroying chlorine in that layer of the atmosphere have peaked and are going down»
If you knew the slightest thing about the problem with
ozone destroying chemicals, of which the chlorinated freons were prime culprits, you would know that they were a problem because they were supremely stable in the lower atmosphere (pure chlorine not so
at all), and were able to transport chlorine to the
ozone layer (unlike natural chlorine compounds), whereupon UV light broke them down, released the chlorine, starting a chain reaction
destroying the
ozone.
«Growing quantities of DCM are leaking into the stratosphere, where it is exceptionally effective in
destroying the
ozone,» said David Rowley, an atmospheric chemist
at the University College London, who was not involved in the research.
The destruction of
ozone by CFC compounds requires cold conditions because
at these temperatures acidic gases (hydrochloric and sulphuric acid) condense to form ice crystals and surface chemistry reactions with CFCs occur liberating the
ozone destroying halogen radicals.
Already
at 16 × CO2 Earth is a different, essentially uninhabitable, planet, with global mean warming of 30 °C the tropopause eliminated, the stratosphere filled with water vapor, and the
ozone layer
destroyed.
erlhapp (18:53:52): Wrong: Energetic Particle Precipitation (EPP) drives production of NOx and HOx which
destroys ozone, mainly
at high latitudes.
At altitudes of about 11 to 12 miles (18 to 20 kilometers), more than 80 percent of the
ozone present in January had been chemically
destroyed by late March.
HCFCs will eventually be replaced by substances called hydrofluorocarbons or HFCs, which do not
destroy ozone at all.
Another pathway even less studied is caused by the energetic particle rain
at polar regions, where HOₓ and NOₓ chemical species are created in the polar regions of the thermosphere and mesosphere and transported down to the stratosphere where they
destroy ozone.