This is off the UK Parliament website: Take special note of part 2.20:
The second category of climate geoengineering methods aims
to offset greenhouse warming by reducing the incidence and absorption
of incoming solar (short-wave) radiation.
Proposals in this category include space-based shades or mirrors
to block a portion of incoming solar radiation; and ways of increasing
the Earth's albedo (that is, its surface reflectivity of the sun's
radiation) by increasing cloud cover, whitening clouds or placing
reflective particles or balloons into the stratosphere.
Cloud Albedo It has been proposed that the Earth could be cooled
by whitening clouds over parts of the ocean.
Aerosol injection Large volcano eruptions result in the mass
injection of sulphate particles—formed from the emitted sulphur
dioxide—into the stratosphere. As these aerosols reflect solar radiation
back to space, or themselves absorb heat, mass eruptions result in a
cooling of the lower atmosphere. The eruption of Mount Tambora in
present day Indonesia, for example, was thought to have produced the
"year without a summer" in 1816. In the 1970s, Professor Budyko proposed
that "artificial volcanoes" be geoengineered. That is, that sulphate
aerosols be injected into the stratosphere to mimic the cooling effect
caused by these "super-eruptions".
Space mirrors Positioning a superfine reflective mesh of
aluminium threads in space between the Earth and the Sun was proposed in
1997 by Dr Lowell Wood and Professor Edward Teller to reduce the amount
of sunlight that reaches the Earth. It has been estimated that a 1%
reduction in solar radiation would require approximately 1.5 million
square kilometres of mirrors made of a reflective mesh.
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|Depiction of the level of environmental impacts and the type international political issues associated with each
progressive stage of Solar Radiation Management research. Click to
Arrangements for the regulation of geoengineering—activities specifically and deliberately
designed to effect a change in the global climate with the aim of
minimizing or reversing anthropogenic climate change—must not be left
until highly disruptive climate change is underway, according
to the UK Parliament’s the Science and Technology Committee in a report
published 18 March.
Serious consideration for regulation should start now and the Committee urges the UK and other governments to “prime the UN pump” in
order to ensure the best chance of eventual multilateral agreement to a
UN-operated regulatory framework. MP Phil Willis, Chairman of the House
of Commons Science and Technology Committee, made the case
for such early action in testimony in a hearing
before the US House of Representatives Science and Technology
|“We should know what other tools we have at our disposal, and if certain proposals,
such as geoengineering, represent an option. But we cannot know until we
have done the research on the full range of impacts of geoengineering.
I’d like to make it clear that we are not advocating for deployment of
geoengineering technologies; I hope that we never get to that point.”
|—US House Committee Chairman Bart Gordon|
Many techniques and technologies fall under the umbrella of geoengineering,
but the area is broadly split into two categories: those that remove
carbon dioxide from the atmosphere
such as sequestering and locking carbon dioxide in geological formations
(Carbon Dioxide Removal, or CDR); and those that
reflect solar radiation (Solar Radiation Management, or SRM). Techniques
in this category include the injection of sulphate aerosols
into the stratosphere to mimic the cooling effect caused by large
The UK Committee outlines three reasons why regulation is needed:
Future geoengineering techniques may allow a single country unilaterally to affect the climate of the Earth.
Small-scale geoengineering testing is already underway.
Geoengineering as a “Plan B” may be required if “Plan A”—the reduction of greenhouse gases—fails.
We are not calling for an international treaty but for the groundwork for regulatory arrangements to begin. Geoengineering techniques should be graded with consideration to factors such as
trans-boundary effect, the dispersal of potentially hazardous materials
environment and the direct effect on ecosystems. The regulatory regimes
for geoengineering should then be tailored accordingly. The controls
should be based on a set of principles that command widespread
agreement—for example, the disclosure of geoengineering research and
open publication of results and the development of governance
arrangements before the deployment of geoengineering techniques.
—“The Regulation of Geoengineering”
Starting work now provides the opportunity to explore fully the technological, environmental, political and regulatory issues. The
Committee recommends the grading of geoengineering techniques and that
regulatory regimes should then be tailored accordingly, with controls
based on a set of widely-agreed principles.
This inquiry was part of a collaboration with the US House of Representatives Science and Technology Committee. In its report the
House of Commons Science and Technology Committee commends to its
successor committee international collaboration as an innovative way to
meet future global challenges.
Geoengineering could affect the entire planet and it would be foolish to ignore its potential to minimize or reverse human caused climate change. There is no sound reason not to begin the
groundwork for regulatory arrangements immediately. I particularly
welcome the solar Radiation Management Governance Initiative that the
Royal Society announced today.
—Chairman of the Committee, Phil Willis MP
Royal Society on SRM Governance. The UK’s Royal Society will undertake
a major new initiative to ensure strict governance of any plans for
solar radiation management (SRM) geoengineering (counteracting global
warming by reflecting a small percentage of the sun’s light and heat
back into space) in partnership with the TWAS, the academy of sciences
for the developing world, and the Environmental Defense Fund (EDF). The
first output of the Initiative will be a set of recommendations for the
governance of geoengineering research, to be released late in 2010.
Proposed geoengineering techniques that reflect the sun’s light and heat back into space may offer valuable opportunities to reduce global
warming, and could do so quite rapidly, but it is likely that their
impacts would also affect rainfall, regional weather patterns and ocean
currents. These impacts would not be restricted by national boundaries,
so actions in one country could have highly significant effects in
another, for example by changing rainfall and so affecting agriculture
and water supply.
The disappointing outcome of Copenhagen has shown that achieving global agreement to reduce emissions of greenhouse gases
is not easy. Some countries or organisations may consider geoengineering
methods by which they could deliberately alter our climate. Large scale
field trials of some solar radiation management techniques could cause
damaging side-effects. It is essential that we consider beforehand what
legislative mechanisms and guidelines are needed, to ensure that any
research that is undertaken will be done in a highly responsible and
controlled manner with full international agreement where necessary.
—Professor John Shepherd FRS (who chaired the Royal Society’s Geoengineering the climate: Science, governance and
uncertainty report published in September 2009, earlier