[geo] Ex-NASA scientists says we must remove CO2 from atmosphere | Daily Mail Online

[Andrew Lockley]

Poster's note : seeing this in the Daily Mail is astonishing. It's like a
print version of Fox News, for embittered boomers.

http://www.dailymail.co.uk/sciencetech/article-4704130/To-safeguard-Earth-remove-CO2-atmosphere.html

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Cutting emissions isn't enough: We must remove CO2 from the atmosphere as
soon as possible to avoid extreme climate change, warn scientists

By Harry Pettit For Mailonline17:28, 18 Jul 2017, updated 19:23, 18 Jul 2017
+4

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   - *Scientists say we must reduce the amount of CO2 in the atmosphere by
   12.5%*
   - *Geoengineering measures could accomplish much of the needed CO2
   removal*
   - *These could include replenishing forests or chemically altering the
   oceans*
   - *The researchers hope their study will push governments toward greener
   policies*

To avoid the devastating effects of climate change
,
we must begin actively removing carbon dioxide from the atmosphere as soon
as possible, scientists claim.

Reducing greenhouse-gas emissions is not enough to limit global warming to
a level that wouldn't risk young people's future, research found.

Instead, nations must now look to geoengineering policies like
replenishing forests or chemically altering the oceans to absorb more
carbon dioxide.

Without geoengineering policies, today's young people will one day have to
spend up to £440 trillion ($575 tn) on technologies to extract carbon
dioxide from the air, the study found.

Scroll down for video
[image: In order to protect our children from the devastating effects of
climate change, we must actively remove greenhouse gases from the
atmosphere, scientists claim. Reducing greenhouse-gas emissions is not
enough to limit global warming, they said (stock image)]
+4
In order to protect our children from the devastating effects of climate
change, we must actively remove greenhouse gases from the atmosphere,
scientists claim. Reducing greenhouse-gas emissions is not enough to limit
global warming, they said (stock image)GEOENGINEERING

Geoengineering measures such as reforestation could accomplish much of the
needed CO2 removal from the atmosphere, the researchers said.

Geoengineering policies and technologies aim to tackle climate change
directly by removing CO2 from the air or stopping sunlight reaching the
Earth.

Rather than simply limiting emissions, geoengineering aims to directly
reduce greenhouse gas levels in the atmosphere.

Proposed measures include reforestation of some deserts through large
irrigation schemes, or dumping iron into the oceans to improve the growth
of photosynthetic organisms that can absorb carbon dioxide.

The Columbia researchers claim continued high fossil fuel emissions would
demand cripplingly expensive technological solutions to extract CO2 and
prevent dangerous warming.

But the team says that if we use cheaper geoengineering techniques now -
such as reforestation - humanity will be saved a costly atmospheric repair
bill.

An international team of scientists led by Professor Jim Hansen, Nasa's
former climate science chief, said their conclusion that the world had
already missed targets to curb global warming to within acceptable levels
was 'sufficiently grim' to force them to urge 'rapid emission reductions'.

But the group warned this would not be enough, and that work was needed to
reduce the amount of carbon dioxide in the atmosphere by about 12.5 per
cent.

Asked to assess the world's current progress in fighting climate change,
Professor Hansen, now at Columbia University, New York, told the
Independent
the
's*** is hitting the fan'.

'Continued high fossil fuel emissions unarguably sentences young people to
either a 

[geo] Help: What do we know and what don't we know about solar geoengineering?

[Ken Caldeira]

Folks,

This Sunday evening, I am supposed to help kick off a discussion about what
we know and what we don't know about solar geoengineering.

https://www.grc.org/programs.aspx?id=17348

It would be helpful if some people on this group could attempt to answer
these questions:

*1. What are the most important things we know about solar geoengineering?*

*2. What are the most important things we don't know about solar
geoengineering?*

I would appreciate it if you could put your answers in the form of bullet
points and not write essays. It would also help if you could cite a key
relevant paper or two.

Thanks,
Ken


*Ken Caldeira*
*Carnegie Institution for Science*
Dept of Global Ecology
260 Panama St
Stanford CA 94305 USA
+1 650 704 7212
http://CarnegieEnergyInnovation.org
http://dge.stanford.edu/labs/caldeiralab


Assistant, with access to incoming emails: Jess Barker
jbar...@carnegiescience.edu

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[geo] Hansen et al weigh in on negative emissions

[Greg Rau]

https://www.earth-syst-dynam.net/8/577/2017/esd-8-577-2017.pdf
(unable to paste in abstract accurately)

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Re: [geo] Help: What do we know and what don't we know about solar geoengineering?

[Klaus Lackner]

What are the most important things we know about solar geo-engineering?


  *   It can be done, it is comparatively cheap, but probably not as cheap as 
people think
  *   It will cool the planet, but it will not simply cancel out greenhouse gas 
additions
  *   There is more than one way of doing it, some are more reversible than 
others
  *   It is no substitute for balancing the carbon budget
  *   It acts fast, but needs constant maintenance

What are the most important things we don’t know about solar geo-engineering

  *   Who decides
  *   Who pays for the unintended side effects
  *   What are the unintended side effects for different methods under 
consideration
  *   Benefit – risk analysis over time


From:  on behalf of Ken Caldeira 

Reply-To: "kcalde...@gmail.com" 
Date: Wednesday, July 19, 2017 at 07:48
To: Geoengineering 
Subject: [geo] Help: What do we know and what don't we know about solar 
geoengineering?

Folks,

This Sunday evening, I am supposed to help kick off a discussion about what we 
know and what we don't know about solar geoengineering.

https://www.grc.org/programs.aspx?id=17348

It would be helpful if some people on this group could attempt to answer these 
questions:

1. What are the most important things we know about solar geoengineering?

2. What are the most important things we don't know about solar geoengineering?

I would appreciate it if you could put your answers in the form of bullet 
points and not write essays. It would also help if you could cite a key 
relevant paper or two.

Thanks,
Ken


Ken Caldeira
Carnegie Institution for Science
Dept of Global Ecology
260 Panama St
Stanford CA 94305 USA
+1 650 704 7212
http://CarnegieEnergyInnovation.org
http://dge.stanford.edu/labs/caldeiralab

Assistant, with access to incoming emails: Jess Barker 
jbar...@carnegiescience.edu

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geoengineering@googlegroups.com.
Visit this group at 
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https://groups.google.com/d/optout.

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Re: [geo] Help: What do we know and what don't we know about solar geoengineering?

[Olivier Boucher]

Hello Ken,

my two pence, not repeating Klaus' input.

/1. What are the most important things we know about solar 
geoengineering?/
some techniques can cool the planet, rapidly and in a reversible way 
(although the impacts may not all be reversible)
there are side effects, eg on precipitation patterns, but these may well 
be in the noise for moderate amount
/2. What are the most important things we don't know about solar 
geoengineering?/

what is the upper bound of solar geoengineering?
how quickly can the technology be developed and at what cost?
what regional effects and what climate impacts on human and natural 
systems?

what impacts on the stratosphere for SAI?
can solar engineering be used for engineering the regional climate or 
extreme climate events?


See you on Sunday
Olivier

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Re: [geo] Help: What do we know and what don't we know about solar geoengineering?

[Andrew Revkin]

Only thing I'd add to Klaus's nice summary is this:

We don't know of a model for decision-making on a global intervention on
any other issue yet that can apply neatly to this kind of action.

- CFC/ozone diplomacy was about mitigating something, not adding something.

- Nuclear test ban same.

So the question isn't just "who decides." It's also who decides how to
decide.

- Andy



[image: --]

Andrew Revkin
[image: https://]about.me/revkin



On Wed, Jul 19, 2017 at 10:47 AM, Ken Caldeira <
kcalde...@carnegiescience.edu> wrote:

> Folks,
>
> This Sunday evening, I am supposed to help kick off a discussion about
> what we know and what we don't know about solar geoengineering.
>
> https://www.grc.org/programs.aspx?id=17348
>
> It would be helpful if some people on this group could attempt to answer
> these questions:
>
> *1. What are the most important things we know about solar geoengineering?*
>
> *2. What are the most important things we don't know about solar
> geoengineering?*
>
> I would appreciate it if you could put your answers in the form of bullet
> points and not write essays. It would also help if you could cite a key
> relevant paper or two.
>
> Thanks,
> Ken
>
>
> *Ken Caldeira*
> *Carnegie Institution for Science*
> Dept of Global Ecology
> 260 Panama St
> Stanford CA 94305 USA
> +1 650 704 7212 <(650)%20704-7212>
> http://CarnegieEnergyInnovation.org
> http://dge.stanford.edu/labs/caldeiralab
> 
>
> Assistant, with access to incoming emails: Jess Barker
> jbar...@carnegiescience.edu
>
>
> --
> You received this message because you are subscribed to the Google Groups
> "geoengineering" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to geoengineering+unsubscr...@googlegroups.com.
> To post to this group, send email to geoengineering@googlegroups.com.
> Visit this group at https://groups.google.com/group/geoengineering.
> For more options, visit https://groups.google.com/d/optout.
>



-- 
*ANDREW C. REVKIN*
*ProPublica Senior Reporter
 (*climate etc.)
*Mobile: 914-441-5556 **@revkin , Facebook
, Music *

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Re: [geo] Help: What do we know and what don't we know about solar geoengineering?

[Eric Durbrow]

Possible bullet points
• It is virtually impossible to use SRM as an effective weapon.
• However, some countries may see it as a weapon esp if deployed
unilaterally.


On 19 July 2017 at 9:41:57 , Klaus Lackner (klaus.lack...@asu.edu) wrote:

What are the most important things we know about solar geo-engineering?



   - It can be done, it is comparatively cheap, but probably not as cheap
   as people think
   - It will cool the planet, but it will not simply cancel out greenhouse
   gas additions
   - There is more than one way of doing it, some are more reversible than
   others
   - It is no substitute for balancing the carbon budget
   - It acts fast, but needs constant maintenance



What are the most important things we don’t know about solar geo-engineering

   - Who decides
   - Who pays for the unintended side effects
   - What are the unintended side effects for different methods under
   consideration
   - Benefit – risk analysis over time





*From: * on behalf of Ken Caldeira <
kcalde...@carnegiescience.edu>
*Reply-To: *"kcalde...@gmail.com" 
*Date: *Wednesday, July 19, 2017 at 07:48
*To: *Geoengineering 
*Subject: *[geo] Help: What do we know and what don't we know about solar
geoengineering?



Folks,



This Sunday evening, I am supposed to help kick off a discussion about what
we know and what we don't know about solar geoengineering.



https://www.grc.org/programs.aspx?id=17348




It would be helpful if some people on this group could attempt to answer
these questions:



*1. What are the most important things we know about solar geoengineering?*



*2. What are the most important things we don't know about solar
geoengineering?*



I would appreciate it if you could put your answers in the form of bullet
points and not write essays. It would also help if you could cite a key
relevant paper or two.



Thanks,

Ken




*Ken Caldeira*

*Carnegie Institution for Science*

Dept of Global Ecology

260 Panama St

Stanford CA 94305 USA

+1 650 704 7212

http://CarnegieEnergyInnovation.org


http://dge.stanford.edu/labs/caldeiralab




Assistant, with access to incoming emails: Jess Barker
jbar...@carnegiescience.edu

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.
For more options, visit https://groups.google.com/d/optout

.

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[geo] Climeworks Wins First Helena Prize

[Andrew Lockley]

https://globenewswire.com/news-release/2017/07/19/1054149/0/en/Climeworks-Wins-First-Helena-Prize.html

[image: helena logo.jpg]
Climeworks Wins First Helena PrizeWinner Is First Company to Develop and
Install a Commercial Plant to Capture Carbon Dioxide from the Air
*July 19, 2017 08:50 ET* | *Source:* BCG; Helena

LOS ANGELES, July 19, 2017 (GLOBE NEWSWIRE) -- Helena
, a global NGO and think tank, and The Boston
Consulting Group (BCG) , one of the world’s leading
management consultancies, announced today that Zurich-based firm Climeworks
 has been named the first recipient of The
Helena Prize, a worldwide award designed to spur and support young
entrepreneurs fighting climate change. Climeworks is the first company to
develop and install a commercial plant to capture carbon dioxide from the
air.

Climeworks will receive management and digital consulting support from BCG,
access to Sierra Energy’s Area 52—a state-of-the-art business incubator
workspace at the University of California Davis—and mentorship from leading
climate scientists and clean-tech entrepreneurs. Climeworks’ founders will
receive membership in Helena’s Brain Trust.

Founded by 33-year-old engineers Christoph Gebald and Jan Wurzbacher,
Climeworks is a direct-air carbon capture company. Its plants remove CO2 from
the atmosphere to supply to customers in a wide range of markets, including
commercial agriculture, food and beverage industries, the energy sector,
and the automotive industry. Customers use this pure CO2 in carbonated
drinks or for producing carbon-neutral hydrocarbon fuels and materials.

“We’re thrilled to be the inaugural recipient of the Helena Prize,” said
Gebald and Wurzbacher in a statement. “We have a long road ahead of us, and
our future depends on help from smart partners like Helena and BCG, which
can provide the business advice and know-how we need to grow rapidly. We
look forward to a long-term relationship with them to work toward negative
emissions.”

Earlier this month, Climeworks opened its first plant in Hinwil,
Switzerland, which will supply 900 tons of CO2 annually to a nearby
greenhouse. Unlike other carbon removal technologies, direct-air capture
does not depend on arable land, has a small physical footprint, and is
fully scalable.

Samuel Feinburg, Helena’s executive director and COO, said, “Investing in
and supporting the development of this carbon capture technology is
critical to saving the planet from disaster. Climeworks is the world leader
in this space and we are incredibly proud to be supporting them.”

Jeff Hill, a BCG senior partner and the head of the firm’s Los Angeles
office, said, “Climeworks demonstrates the aim of The Helena Prize, with
its groundbreaking technology and social impact mission. We look forward to
lending our expertise to ensure that the venture grows and gains momentum.”

BCG has committed to assist Helena’s initiatives through pro bono advice
and support from its management consulting practices and BCG Digital
Ventures , the firm’s corporate venture and
incubation arm.

Launched last October as part of a strategic partnership between Helena and
BCG, The Helena Prize is open to anyone 35 or under whose for-profit
venture helps to reduce radiative forcing, a metric of environmental harm.

The Helena Prize was judged by a board of leading climate scientists and
clean-tech entrepreneurs, who will now provide mentorship and guidance to
Climeworks. They include:

   - Aaron Berger, Co-Chairman, Nexus Working Group on Climate Change
   - Alexander Pfeiffer, Doctorate Student, University of Oxford
   - Austin Rosenbaum, National Scholar, Institute of Electrical and
   Electronics Engineers Power & Energy Society
   - Ben Caldecott, Director, Sustainable Finance Programme, Smith School
   of Enterprise and the Environment, University of Oxford
   - Cameron Hepburn, Professor of Environmental Economics, University of
   Oxford
   - Chip Comins, Founder, Chairman, and CEO, American Renewable Energy
   Institute
   - Dan Miller, Co-Founder and Managing Director, Roda Group
   - Gordon L. Clark, Director, Smith School of Enterprise and the
   Environment, University of Oxford
   - John R. Seydel, III, Director of the Office of Sustainability, City of
   Atlanta
   - Klaus S. Lackner, Director, Center for Negative Carbon Emissions
   - Maria D. Carvalho, Policy Team Member, Grantham Research Institute on
   Climate Change and the Environment, London School of Economics and
   Political Science
   - Noah Deich, Executive Director, Center for Carbon Removal
   - Richard Martin, Senior Editor for Energy, *MIT Technology Review*

For more information on Helena and The Helena Prize, please visit
www.helena.co/the-helena-prize.

For all other queries, please contact Priscila Martinez at +1 (424)
230-3309 or prisc...@helena.co.

*ABOUT HELENA*

Helena is a think tank of global leaders who are daring 

RE: [geo] Help: What do we know and what don't we know about solar geoengineering?

[Douglas MacMartin]

Hi Ken,

 

We tried to write some down in our Earth’s Future piece last year, at least for 
stratospheric aerosols

MacMartin, D. G., B. Kravitz, J.C.S. Long, and P.J. Rasch, “Geoengineering with 
stratospheric aerosols: what do we not know after a decade of research?” 
Earth’s Future, 4, 543-548, 2016. doi: 10.1002/2016EF000418 
 

 

I agree with some of what has been said, that some of the biggest/hardest 
questions are on the societal side rather than climate science side, but I 
don’t think very many people would agree to deployment based on what we 
currently know on the climate science (I sure wouldn’t).

 

I’d say what we know is simply that it is plausible that a limited deployment 
of solar geoengineering in addition to (as opposed to an alternative to) could 
reduce climate damages for most, and research has yet to identify any 
“showstoppers”.  We know that using solar geoengineering to move global mean 
temperature all the way back to preindustrial will overcompensate some 
variables and is almost certainly not a reasonable balance of risk, but 
something like 3C --> 1.5C *might* be less risk (with appropriate caveating of 
aggregation, i.e., risk for whom) than allowing the climate to warm to 3C.  We 
know we can achieve at least a few W/m2 of negative RF.

 

There’s a lot of things we don’t know for stratospheric aerosols (and even more 
for MCB or cirrus thinning), including stratospheric processes (microphysics, 
chemistry, dynamics) and how the climate responds differently to that RF in 
contrast to GHG forcing.  It would be valuable as a community to start trying 
to better quantify which uncertainties are most important to resolve, how 
significant they might be on our ability as a society to make informed 
decisions, and what modeling/observation/perturbative field tests might help 
resolve them (including how resolvable some uncertainty might be.  Just to pick 
one random one, is the range of possible unknown impact of sedimenting aerosols 
on cirrus significant enough that it would affect our conclusions about impacts 
of a deployment?  If so, what would we need to do to understand that, how long 
would that take, how much would that cost…  Personally I’d like to talk to 
everyone at the GRC next week to get their expert opinions on these types of 
questions (as well as everyone who isn’t at the GRC).

 

One thing I would like to push back on is the extent of “unknown unknowns”… of 
course one can’t (by definition) bound that, but given the natural analogs, is 
the possibility of these really significant in comparison with the known knowns 
and known unknowns of never considering geoengineering?  

 

See you in a few days,

 

doug

 

From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] 
On Behalf Of Eric Durbrow
Sent: Thursday, July 20, 2017 2:20 AM
To: geoengineering 
Subject: Re: [geo] Help: What do we know and what don't we know about solar 
geoengineering?

 

Possible bullet points 

• It is virtually impossible to use SRM as an effective weapon.

• However, some countries may see it as a weapon esp if deployed unilaterally. 

 

 

On 19 July 2017 at 9:41:57 , Klaus Lackner (klaus.lack...@asu.edu 
 ) wrote:

What are the most important things we know about solar geo-engineering?

 

*   It can be done, it is comparatively cheap, but probably not as cheap as 
people think
*   It will cool the planet, but it will not simply cancel out greenhouse 
gas additions
*   There is more than one way of doing it, some are more reversible than 
others
*   It is no substitute for balancing the carbon budget
*   It acts fast, but needs constant maintenance

 

What are the most important things we don’t know about solar geo-engineering

*   Who decides
*   Who pays for the unintended side effects
*   What are the unintended side effects for different methods under 
consideration
*   Benefit – risk analysis over time

 

 

From: mailto:kcalde...@gmail.com> > on behalf of Ken 
Caldeira mailto:kcalde...@carnegiescience.edu> >
Reply-To: "kcalde...@gmail.com  " 
mailto:kcalde...@gmail.com> >
Date: Wednesday, July 19, 2017 at 07:48
To: Geoengineering mailto:Geoengineering@googlegroups.com> >
Subject: [geo] Help: What do we know and what don't we know about solar 
geoengineering?

 

Folks, 

 

This Sunday evening, I am supposed to help kick off a discussion about what we 
know and what we don't know about solar geoengineering. 

 

https://www.grc.org/programs.aspx?id=17348 

 

 

It would be helpful if some people on this gro

RE: [geo] Help: What do we know and what don't we know about solar geoengineering?

[Andrew Lockley]

My ill structured ramblings on unknowns below


* Aerosol coalescence in steady state, and resulting sedimentation
* sedimentation effect on clouds, especially cirrus
*steady state ozone loss
*sedimentation environmental impacts of novel, engineered and/or insoluble
particles
* MCB plume behaviour (sink or rise, quite likely sink)
* ocean CO2 dissolution from cooling (should be well constrained, but only
one study)
* more analysis of game theory / Socio-political factors regarding
deployment (power blocs, clandestine deployment, rogue state, greenfinger -
vs global consensus)
*interactions between geoengineering in "cocktail" deployment (only one
study)
*costs of monitoring and governance
*redo design & cost studies based on realistic future designs (unmanned,
electric, H2 fuelled)
*brainstorming on unknown unknowns, eg insect migration effects, plankton
circadian rhythms, etc.
*geoengineering observable or not by civilisations on other planets (and
consequences/wisdom thereof)




On 19 Jul 2017 21:58, "Douglas MacMartin"  wrote:

> Hi Ken,
>
>
>
> We tried to write some down in our Earth’s Future piece last year, at
> least for stratospheric aerosols
>
> MacMartin, D. G., B. Kravitz, J.C.S. Long, and P.J. Rasch, “Geoengineering
> with stratospheric aerosols: what do we not know after a decade of
> research?” *Earth’s Future*, *4*, 543-548, 2016. doi: 10.1002/2016EF000418
> 
>
>
>
> I agree with some of what has been said, that some of the biggest/hardest
> questions are on the societal side rather than climate science side, but I
> don’t think very many people would agree to deployment based on what we
> currently know on the climate science (I sure wouldn’t).
>
>
>
> I’d say what we know is simply that it is plausible that a limited
> deployment of solar geoengineering in addition to (as opposed to an
> alternative to) could reduce climate damages for most, and research has yet
> to identify any “showstoppers”.  We know that using solar geoengineering to
> move global mean temperature all the way back to preindustrial will
> overcompensate some variables and is almost certainly not a reasonable
> balance of risk, but something like 3C à 1.5C **might** be less risk
> (with appropriate caveating of aggregation, i.e., risk for whom) than
> allowing the climate to warm to 3C.  We know we can achieve at least a few
> W/m2 of negative RF.
>
>
>
> There’s a lot of things we don’t know for stratospheric aerosols (and even
> more for MCB or cirrus thinning), including stratospheric processes
> (microphysics, chemistry, dynamics) and how the climate responds
> differently to that RF in contrast to GHG forcing.  It would be valuable as
> a community to start trying to better quantify which uncertainties are most
> important to resolve, how significant they might be on our ability as a
> society to make informed decisions, and what modeling/observation/perturbative
> field tests might help resolve them (including how resolvable some
> uncertainty might be.  Just to pick one random one, is the range of
> possible unknown impact of sedimenting aerosols on cirrus significant
> enough that it would affect our conclusions about impacts of a deployment?
> If so, what would we need to do to understand that, how long would that
> take, how much would that cost…  Personally I’d like to talk to everyone at
> the GRC next week to get their expert opinions on these types of questions
> (as well as everyone who isn’t at the GRC).
>
>
>
> One thing I would like to push back on is the extent of “unknown
> unknowns”… of course one can’t (by definition) bound that, but given the
> natural analogs, is the possibility of these really significant in
> comparison with the known knowns and known unknowns of never considering
> geoengineering?
>
>
>
> See you in a few days,
>
>
>
> doug
>
>
>
> *From:* geoengineering@googlegroups.com [mailto:geoengineering@
> googlegroups.com] *On Behalf Of *Eric Durbrow
> *Sent:* Thursday, July 20, 2017 2:20 AM
> *To:* geoengineering 
> *Subject:* Re: [geo] Help: What do we know and what don't we know about
> solar geoengineering?
>
>
>
> Possible bullet points
>
> • It is virtually impossible to use SRM as an effective weapon.
>
> • However, some countries may see it as a weapon esp if deployed
> unilaterally.
>
>
>
>
>
> On 19 July 2017 at 9:41:57 , Klaus Lackner (klaus.lack...@asu.edu) wrote:
>
> What are the most important things we know about solar geo-engineering?
>
>
>
>- It can be done, it is comparatively cheap, but probably not as cheap
>as people think
>- It will cool the planet, but it will not simply cancel out
>greenhouse gas additions
>- There is more than one way of doing it, some are more reversible
>than others
>- It is no substitute for balancing the carbon budget
>- It acts fast, but needs constant maintenance
>
>
>
> What are the most important things we don’t know about solar
> geo-enginee

RE: [geo] Help: What do we know and what don't we know about solar geoengineering?

[Erik Thorstensen]

Just to add to Lackner’s last section

We don’t know

· what the future international decision-making structures will look 
like

best
erik
From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] 
On Behalf Of Klaus Lackner
Sent: Wednesday, July 19, 2017 6:42 PM
To: kcalde...@gmail.com; Geoengineering 
Subject: Re: [geo] Help: What do we know and what don't we know about solar 
geoengineering?

What are the most important things we know about solar geo-engineering?


  *   It can be done, it is comparatively cheap, but probably not as cheap as 
people think
  *   It will cool the planet, but it will not simply cancel out greenhouse gas 
additions
  *   There is more than one way of doing it, some are more reversible than 
others
  *   It is no substitute for balancing the carbon budget
  *   It acts fast, but needs constant maintenance

What are the most important things we don’t know about solar geo-engineering

  *   Who decides
  *   Who pays for the unintended side effects
  *   What are the unintended side effects for different methods under 
consideration
  *   Benefit – risk analysis over time


From: mailto:kcalde...@gmail.com>> on behalf of Ken 
Caldeira mailto:kcalde...@carnegiescience.edu>>
Reply-To: "kcalde...@gmail.com" 
mailto:kcalde...@gmail.com>>
Date: Wednesday, July 19, 2017 at 07:48
To: Geoengineering 
mailto:Geoengineering@googlegroups.com>>
Subject: [geo] Help: What do we know and what don't we know about solar 
geoengineering?

Folks,

This Sunday evening, I am supposed to help kick off a discussion about what we 
know and what we don't know about solar geoengineering.

https://www.grc.org/programs.aspx?id=17348

It would be helpful if some people on this group could attempt to answer these 
questions:

1. What are the most important things we know about solar geoengineering?

2. What are the most important things we don't know about solar geoengineering?

I would appreciate it if you could put your answers in the form of bullet 
points and not write essays. It would also help if you could cite a key 
relevant paper or two.

Thanks,
Ken


Ken Caldeira
Carnegie Institution for Science
Dept of Global Ecology
260 Panama St
Stanford CA 94305 USA
+1 650 704 7212
http://CarnegieEnergyInnovation.org
http://dge.stanford.edu/labs/caldeiralab

Assistant, with access to incoming emails: Jess Barker 
jbar...@carnegiescience.edu
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