slide1 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Understanding and Governing the Risks of Solar Radiation Management (SRM) - A few basic ideas to start our discussions PowerPoint Presentation
Download Presentation
Understanding and Governing the Risks of Solar Radiation Management (SRM) - A few basic ideas to start our discussions

Loading in 2 Seconds...

play fullscreen
1 / 36

Understanding and Governing the Risks of Solar Radiation Management (SRM) - A few basic ideas to start our discussions - PowerPoint PPT Presentation


  • 79 Views
  • Uploaded on

Understanding and Governing the Risks of Solar Radiation Management (SRM) - A few basic ideas to start our discussions. 2011 January 31 M. Granger Morgan Department of Engineering and Public Policy Carnegie Mellon University Pittsburgh, PA 15213 tel: 412-268-2672

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Understanding and Governing the Risks of Solar Radiation Management (SRM) - A few basic ideas to start our discussions' - tamah


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1
Understanding and Governing the Risks of Solar Radiation Management (SRM)-A few basic ideas to start our discussions

2011 January 31

M. Granger Morgan

Department of

Engineering and Public Policy

Carnegie Mellon University

Pittsburgh, PA 15213

tel: 412-268-2672

e-mail: granger.morgan@andrew.cmu.edu

three ways to change the climate

To cool the earth either:

Increase albedo

just a little bit

(this is fast).

Remove CO2

and other GHGs

(this is slow).

OR

Three ways tochange the climate:

To warm the earth

add CO2 and other

GHGs.

there has been a lot of confusion about nomenclature
There has been a lot of confusion about nomenclature

Too many things are being termed “geoengineering.” The result is that people make general statements that actually only apply to one subset of possible strategies.

The Royal Society has introduced two terms that help:

SRMor “solar radiation management”

CDR or “carbon dioxide removal”

three ways to change the climate4
Three ways tochange the climate:

To cool the earth either:

Increase albedo

just a little bit

(this is fast).

Remove CO2

and other GHGs

(this is slow).

OR

To warm the earth

add CO2 and other

GHGs.

SRM

CDR

4

four examples of how the earth s albedo might be increased

The first of these is probably the most feasible so I will concentrate on just that option.

Four examples of how the earth's albedo might be increased:
  • 1. Add small reflecting particles in the stratosphere.
  • 2. Add more clouds in the lower part of the atmosphere.
  • 3. Place various kinds of reflecting objects or diffraction gratings in space either near the earth or at a stable location (the L1 point) between the earth and the sun.
  • 4. Change large portions of the planet's land cover from things that are dark and absorbing, such as trees, to things that are light and reflecting, such as open snow-cover or grasses.
stratospheric aerosols
Stratospheric aerosols

Adding more of the right kind of fine particles to the stratosphere can increase the amount of sunlight that is reflected back into space.

There is clear evidence from many large past volcanic eruptions that this mechanism can cool the planet (Mount Pinatubo produced global scale cooling of about 0.5°C).

Figure source: NASA and IPCC.

Source: Novim report, 2009, p. 14

this is not hard to do and probably not all that expensive
This is not hard to do,and probably not all that expensive

David Keith has suggested that it should be possible to create microscopic reflecting composite particles that would be self-orienting and self-levitating, and thus might not have to be replaced very frequently.

A single nation could do these within its national boundaries

Figure sources: EADS; NASA; www.carlstumpf.com

while there is
While there is…

…a great deal of uncertainty about SRM, last year in Nature David Keith, Ted Parson and I argued that three things are pretty certain:

in order to get a better estimate of cost
In order to get a better estimate of cost…

My colleagues Jay Apt and David Keith recently commissioned a study by Aurora Flight Systems.

The folks at Aurora concluded that delivery by special aircraft is probably the most cost-effective strategy.

slide10

Modest infrastructure

They conclude that total cost might be just a few $billion/year

comparing costs
Comparing costs

How does the cost of achieving ~80% reduction in the emissions of CO2 and other GHGs compare to the cost of SRM (which, of course, would have no impact on CO2 level but could “eliminate” warming)?

the cost of ghg abatement

0.25 to 3.3x1012 $/year

0.4% to 5.5% of world GDP/year

60x1012 $/year

The cost of GHG abatement

Today, the world is emitting about 50x109 tonnes per year CO2-eq

(of which about 30x109 is CO2)

The IPCC 4th assessment says:

"Modelling studies show that global carbon prices rising to US$20-80/tCO2-eq by 2030 are consistent with stabilisation at around 550ppm CO2-eq by 2100. For the same stabilisation level, induced technological change may lower these price ranges to US$5-65/tCO2-eq in 2030."

(50x109 tCO2-eq)(5 to 65$/tCO2-eq) = 250 to 3300x109 $/year

The size of the global economy is of the order of $60x1012

the cost of srm
The cost of SRM

~ 6 x109 $/year

~ 0. 01% of world GDP/year

60x1012 $/year

BOTTOM LINE: It is probably safe to assume that the direct monetary cost of SRM would be >100 times less than the cost of a full program of GHG abatement.

At this cost, one or several nations that started experiencing serious climate impacts, might be tempted to unilaterally engage in SRM.

if we change albedo a little

If we change albedo a little…

…to cool the planet, what else might happen?

Possibilities include:

  • Impacts will not be uniform. Some places will change more than others.
  • Precipitation patterns will shift (of course, that is also happening under climate change).
  • Continued and growing impacts on the oceans as they take up more and more CO2.
  • Particles in the stratosphere can provide reactive surfaces that might contribute to the destruction of the ozone layer.

15

my phd student kate ricke
My PhD student Kate Ricke:

Is exploring how uniformly SRM could offset the effect of rising radiative forcing. Using climateprediction.net she has looked at a number of different SRM scenarios that made uniform

modifications to stratospheric optical depth to approximately stabilize mean global near-surface air temperature under SRES A1B.

She finds that the effectiveness of any given amount of modification to optical depth in returning regional climates to their baseline state varied from region to region and varied over time.

kate finds that optimal srm varies regionally
Kate finds that “Optimal” SRM varies regionally

“Optimum” by region in 2020s

“Optimum” by region in 2070s

More Geoengineering

Less Geoengineering

Approximate Global-Mean SAT (°C)

Source: Ricke, Morgan and Allen, Nature Geoscience, 2010

imperfect compensation and regional disparities
Imperfect compensation and regional disparities

Source: Ricke, Morgan and Allen, Nature Geoscience, 2010

in a new round of studies
In a new round of studies…

Kate is doing “perturbed physics” runs to see if any of the range of values of key model parameters that are consistent with past climate can result in dramatically different outcomes.

So far, it looks like the general finding that responses will likely be different in different parts of the world, and that they may diverge over time, remains true.

acification of the oceans
Acification of the oceans

I hardly need to note for this audience that much of the CO2 we put into the atmosphere ultimately ends up in the oceans.

Today the oceans are 30% more acidic

than before the industrial revolution.

Source: Doney et al., Annual Reviews of Marine Science, 2009

during this workshop
During this workshop…

…I look forward to learning whether there is agreement that this means the demise of most coral reefs and the ecosystems they support.

375ppm +1°C

450-500ppm +2°C

>500ppm >3°C

Source: O. Hoegh-Guldberg et al., "Coral reefs under rapid climate change and ocean acidification," Science, 318, pp. 1737-1742, December 14, 2007.

21

shell dissolution e g pteropod or sea butterfly
Shell dissolution(e.g. pteropod or "sea butterfly")

A key food source for juvenile pink salmon and other small fish.

22

Source: Orr et al., Nature, 2005; Wikipedia; www.ims.uaf.edu

serious studies of acidification have hardly begun
Serious studies of acidification have hardly begun

23

Source: Doney et al., Annual Reviews of Marine Science, 2009

and as ken will no doubt point out
And as Ken will no doubt point out…

…the longer one does SRM by injecting fine particles in the stratosphere, the greater the risk of rapid change if one suddenly stops.

Such changes could devastate many terrestrial ecosystems.

Source: Matthews and Caldeira, PNAS, 2007.

given all the uncertainties

Two reasons to say no:

If in a few decades we have major climate surprise (e.g., lose half the ice in Greenland so sea level goes up >3m), we may have a billion people at risk and need to take collective protective action.

Given all the uncertainties…

…shouldn't we just create a global taboo against geoengineering as we have for CBW?

We may need a bit of geoengineering in combination with abatement to “get the world over the hump” while we reduce GHG levels.

Figure source: www.globalwarmingart.com

the cfr workshop
The CFR workshop…

Because the diplomatic community was almost completely unaware of SRM, in 2008 we organized a workshop at the Council on Foreign Relations in Washington, DC.

The workshop led to a paper that appeared in the 2009 March/April issue of Foreign Affairs.

Participants in the 2008 workshop were all from North America.

To extend the conversation to a more international group, we ran a second workshop in April 2009 in Lisbon, Portugal.

Source: Council on Foreign Relations

the lisbon workshop
The Lisbon Workshop…

…was hosted by the Ministry of Science, Technology and Higher Education of

the Government of Portugal. The two-day workshop was held at the facilities of the Gulbenkian Foundation.

Co-sponsors included: IRGC, CMU-CDMC, U Calgary. Participants came from N. America, EU, China, Russia, and India.

27

4

Sources:

Gulbenkian & Qian Yi

the lisbon workshop has been followed by
The Lisbon Workshop has been followed by…

March 2010: The discussion of

risk governance at the Asilomar conference on geoengineering

Sep. 2009: The governance section of the Royal Society’s report on Geoengineering

Ongoing: Adoption of the “allowed zone” concept by the NCEP in its advice to the US Gvt.

Jan 2010

Jan 2011

March 2010: Testimony to a joint session of the US House Science Committee and the Science Committee of the UK Parliament

Ongoing: IRGC’s co-sponsorship of the Royal Society’s follow-on project on global risk governance

June 2009: Contributions by several IRGC-linked experts at the US NRC workshop on geoengineering

August 2010: First multi-university summer study program for graduate students on geoengineering held at Heidelberg. Second will be summer 2011 in Calgary

March 2010: Evening briefing to CFR

global norms versus global regulations
Global norms versus global regulations

There are some already calling for formal global regulation of any SRM-related research.

At this early stage, that would be a recipe to make sure that no research gets done.

I think the proper way forward in the early stages is for the international research community to agree on some norms about what constitutes modest research that will have no significant impact and thus should be allowed, subject only to national rules. Any such work should be open and transparent, and all results should be made public.

defining an allowed zone

Defining an allowed zone

Source: Morgan and Ricke, IRGC, 2010

for more
For more…

…on the policy and risk governance issues in SRM go to “publications” at:

www.IRGC.org

www.irgc.org/IMG/pdf/SRM_Opinion_Piece_web.pdf

thanks
Thanks

Portions of this work have been supported by the Climate Decision Making Center funded by the US National Science Foundation (SES-0345798), by an NSF Graduate Fellowship to Kate Ricke, and by the International Risk Governance Council (IRGC). The views are those of the speaker.