This really comes under the one
road too far. A simple test using
hardware would absorb the Earth’s GDP for decades and then be likely controversial.
Much more practical is my
objective of terraforming the deserts into woodland and related ecologies. This at least can shift heat on perhaps
thirty percent of the land and would certainly affect climate hugely and most likely
for the best.
In short, practical geoengineering
will be about using agriculture and modest technical assists to reclaim arable
lands world wide.
In the meantime we get to hear
about massive technology fixes.
Testing geoengineering as a solution to climate change
by Staff Writers
Solar radiation management - Artist's concept of a spray ship that could whiten clouds with salt water. Credit:
Solar radiation management is a class of theoretical concepts for
manipulating the climate in order to reduce the risks of global warming caused
by greenhouse gasses. But its potential effectiveness and risks are uncertain,
and it is unclear whether tests could help narrow these uncertainties.
A team composed of Caltech's Doug MacMynowski, Carnegie's Ken Caldeira
and Ho-Jeong Shin, and Harvard's David Keith used modeling to determine the
type of testing that might be effective in the future. Their work has been
published online by Energy and Environmental Science.
Ideas for solar radiation management include increasing the amount of
aerosols in the stratosphere, which could scatter incoming solar heat away
from Earth'ssurface,
or creating low-altitude marine clouds to reflect these same rays. Clearly the
size of the scale and the intricacies of the many atmospheric and climate
processes make testing these ideas difficult.
"While it is clearly premature to consider testing solar radiation
management at a scale large enough to measure the climate response, it is not
premature to understand what we can learn from such tests," said Doug
MacMynowski of the California Institute of Technology, who led the research.
"But we did not address other important questions such as the
necessary testing technology and the social and political implications of such
tests."
Using models the team was able to demonstrate that smaller-scale tests
of solar radiation management
could help inform decisions about larger scale deployments. Short-term tests
would be particularly effective at understanding the effects of geoengineering
on fast-acting climate dynamics.
But testing would require several decades and, even then, would need to
be extrapolated out to the centuries-long time scales relevant to studying
climate change.
Some scientists have
theorized that volcanic eruptions could stand in for tests, as they would cause
same types of atmospheric changes as aerosols. But they wouldn't be as
effective as a sustained test.
"No test can tell us everything we might want to know, but tests
could tell us some things we would like to know," Caldeira said.
"Tests could improve our understanding of likely consequences of
intentional interference in the climate system and could also improve our
knowledge about the climate's response to the interference caused by ourcarbon dioxide emissions."
He added: "We conducted a scientific investigation into what might
be learned by testing these proposals. We are not advocating that such tests should
actually be undertaken,"
NCEP Reanalysis data for this study was provided by NOAA/OAR/ESRL PSD,
Boulder, Colorado
from their website.
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