Climate ‘fix’ could deplete ozone
By Helen Briggs Science reporter, BBC News
Research has cast new doubt on the wisdom of using
Sun-blocking sulphate particles to cool the planet.
Sulphate injections are one of several
“geo-engineering” solutions to climate change being
discussed by scientists.
But data published in Science journal suggests the
strategy would lead to drastic thinning of the ozone
This would delay the recovery of the Antarctic ozone
hole by decades, and cause significant ozone loss over
the Arctic, say US researchers.
The idea of pumping sulphur into the upper atmosphere
ito counteract global warming comes from nature.
Major volcanic eruptions emit vast quantities of
sulphur particles that can cool the planet
This was observed following the 1991 eruption of Mount
But one potential drawback is that sulphates provide a
surface on which chlorine gases in polar clouds can
become activated, causing chemical reactions that lead
to the destruction of ozone molecules.
Dr Simone Tilmes of the National Center for
Atmospheric Research (NCar) in Boulder, Colorado, and
colleagues used a combination of measurements and
computer simulations to estimate future ozone loss if
sulphate injections were carried out.
Quantities capable of mitigating climate change would
destroy as much as three-quarters of the ozone layer
over the Arctic, if carried out in the next few
decades, they said.
This would also delay the expected recovery of the
ozone layer over the Antarctic by about 30 to 70
years, they concluded.
Ozone depletion was enhanced in the Antarctic in the
Mt Pinatubo aftermath.
Dr Tilmes said more research was needed before society
attempted global geo-engineering solutions in the
However, she said the study should not rule out the
She told BBC News: “Politicians have to decide what is
most important – if you have climate change you might
have catastrophic conditions – they might decide to do
“If you have to make decisions you need to know what
is good about it and what is bad about it. With this
scheme the bad side is definitely the ozone depletion,
but you can cool the climate.”
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