Geoengineers
to release planet-cooling gas into New Mexico atmosphere
Two
Harvard engineers are planning to spray thousands of tonnes of
sun-reflecting chemical particles into the atmosphere to artificially
cool the planet, using a balloon flying 80,000 feet over Fort Sumner,
New Mexico.
17
July, 2012
The
field experiment in solar geoengineering aims to ultimately create a
technology to replicate the observed effects of volcanoes that spew
sulphates into the stratosphere, using sulphate aerosols to bounce
sunlight back to space and decrease the temperature of the Earth.
David
Keith,
one of the investigators, has argued that solar geoengineering could
be an inexpensive method to slow down global warming, but other
scientists warn that it could have unpredictable, disastrous
consequences for the Earth’s weather systems and food supplies.
Environmental groups fear that the push to make geoengineering a
“plan B” for climate change will undermine efforts to reduce
carbon emissions.
Keith,
who manages a multimillion dollar geoengineering research
fund provided by Microsoft founder Bill Gates,
previously commissioned a
study by
a US aerospace company that made the case for the feasibility of
large-scale deployment of solar geoengineering technologies.
His
US experiment, conducted with American James Anderson, will take
place within a year and involve the release of tens or hundreds of
kilograms of particles to measure the impacts on ozone chemistry, and
to test ways to make sulphate aerosols the appropriate size. Since it
is impossible to simulate the complexity of the stratosphere in a
laboratory, Keith says the experiment will provide an opportunity to
improve models of how the ozone layer could be altered by much
larger-scale sulphate spraying.
“The
objective is not to alter the climate, but simply to probe the
processes at a micro scale,” said Keith. “The direct risk is very
small.”
While
the experiment may not harm the climate, environmental groups say
that the global environmental risks of solar geoengineering have been
amply identified through modelling and the study of the impacts of
sulphuric dust emitted by volcanoes.
“Impacts
include the potential for further damage to the ozone layer, and
disruption of rainfall, particularly in tropical and subtropical
regions – potentially threatening the food supplies of billions of
people,” said Pat Mooney, executive director of the Canadian-based
technology watchdog ETC Group. “It will do nothing to decrease
levels of greenhouse gases in the atmosphere or halt ocean
acidification. And solar geoengineering is likely to increase the
risk of climate-related international conflict – given that the
modelling to date shows it poses greater risks to the global south.”
A
scientific study
published last month concluded
that solar radiation management could decrease rainfall by 15% in
areas of North America and northern Eurasia and by more than 20% in
central South America.
Last
autumn, a British field test of a balloon-and-hosepipe device that
would have pumped water into the sky generated controversy.
Thegovernment-funded
project – Stratospheric Particle Injection for Climate Engineering
(Spice) – was cancelled after
a row over patents and a public outcry by global NGOs, some of whom
argued the project was a “Trojan horse” that would open the door
to full-scale deployment of the technology.
Keith
said he opposed Spice from the outset because it would not have
improved knowledge of the risks or effectiveness of solar
geoengineering, unlike his own experiment.
“I
salute the British government for getting out and trying something,”
he said. “But I wish they’d had a better process, because those
opposed to any such experiments will see it as a victory and try to
stop other experiments as well.”
The
Guardian understands that Keith is planning to use the Gates-backed
fund to organise a meeting to study the lessons of Spice.
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