Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Ken Caldeira]

I sure wish he would avoiding putting prescriptive statements in ostensibly
scientific papers. Scientific papers should contain descriptive, not
prescriptive, statements.

That said, I think he is right about long-term climate sensitivity being
higher than the century-scale sensitivity inferred from climate models and
analysis of historical data.


On Thu, Jul 21, 2011 at 11:07 PM, Emily  wrote:

> Hi,
>
> here is a recent paper from Jim Hansen,including some figures I've read
> before, which stunned me:
>
> "In the early Pliocene global temperature was no more than 1-2°C warmer
> than today, yet sea level was 15-25 meters (50-80 feet) higher."
>
> best wishes,
>
> Emily.
>
>
> *Paleoclimate Implications: Accepted Paper and 'Popular Science'*
>
>
> "Paleoclimate Implications for Human-Made Climate Change" has been
> reviewed, revised in response to the referee's suggestions, and accepted
> for publication in "Climate Change at the Eve of the Second Decade of
> the Century: Inferences from Paleoclimate and Regional Aspects:
> Proceedings of Milutin Milankovitch 130th Anniversary Symposium" (Eds.
> A. Berger, F. Mesinger and D Šijački), Springer.
>
> This final version has also been published in arXiv:1105.0968v3
> [physics.ao-ph]
>  0ebaeb14fdbf5dc65289113c1&id=**fbefcc8464&e=60a7483168
> >
>
> A__'popular science' summary
>  0ebaeb14fdbf5dc65289113c1&id=**d3b93e0894&e=60a7483168
> >
> of the paper, intended for lay audience, is available.
>
> Thanks especially to reviewer Dana Royer for helpful comments,
> foundations and NASA program managers for research support, and a number
> of people for comments on an early draft of the paper, as delineated in
> the acknowledgements.
>
> Jim Hansen
>
> --
> You received this message because you are subscribed to the Google Groups
> "geoengineering" group.
> To post to this group, send email to 
> geoengineering@googlegroups.**com
> .
> To unsubscribe from this group, send email to geoengineering+unsubscribe@*
> *googlegroups.com .
> For more options, visit this group at http://groups.google.com/**
> group/geoengineering?hl=en
> .
>
>

-- 
You received this message because you are subscribed to the Google Groups 
"geoengineering" group.
To post to this group, send email to geoengineering@googlegroups.com.
To unsubscribe from this group, send email to 
geoengineering+unsubscr...@googlegroups.com.
For more options, visit this group at 
http://groups.google.com/group/geoengineering?hl=en.

Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[John Nissen]

Dear Ken,

I've already looked at this interesting paper [1], from Jim Hansen and
Mikiko Sato - but I'd not read before of his conjecture about rate of ice
mass loss doubling per decade, producing many metres of sea level rise this
century.  But the implication is that the situation can be saved simply by
reducing fossil fuel emissions!  Is that the prescription that you are
complaining about?  Wouldn't a well-considered prescription be welcome from
somebody as eminent as Prof Hansen?  Geoengineering for example!  I don't
see a way out of our predicament without it.  Do you, Ken?

Does Hansen accept that 90% sea ice could be gone as soon as at end summer
2016? (BTW, I've another reference to this date we've been arguing about
[2].)

Hansen seems to dismiss methane as always producing less forcing than CO2:

"*This sensitivity has the merit that CO2 is the principal GHG forcing and
perhaps the only one with good prospects for quantification of its long-term
changes.*" (page 15)

However the paper is relevant to the methane issue in several ways.  One
argument, which I've heard from Jeff Ridley, is that there is no sign of a
methane excursion at previous interglacials* such as end-Eemian, when it was
hotter, so we don't need to worry about having an excursion now.  Hansen
shows that it was never hotter than it is now (in Holocene) by more than one
degree.

Elsewhere Hansen points out that the current rate of global warming is much
higher than it has been for millions of years.  Andrew Lockley suggests it's
higher than even it was at the PETM some 55.8 million years ago, when
temperatures rose about 6 C [3].  That rate of change is important, because
of methane's short lifetime.  The increasing speed of change implied by
Hansen's climate sensitivity is thus relevant to methane.

A further way that the paper is relevant to methane is because of climate
sensitivity to radiative forcing.  The paper suggests various alternative
values that could be taken - see [1] table 1.   If we get over 2 W/m-2 from
methane, then that certainly takes us over the danger line of 2 degrees
global warming, using his argument.

Cheers,

John

* During the past 800,000 years, methane never rose much above 700 ppb until
recently, see [1] figure 2

[1] Full paper http://arxiv.org/ftp/arxiv/papers/1105/1105.0968.pdf

Abstract here:
http://arxiv.org/abs/1105.0968v3

[2] http://www.bbc.co.uk/news/science-environment-13002706

[3] http://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum

---

On Thu, Jul 21, 2011 at 11:07 PM, Emily  wrote:

> Hi,
>
> here is a recent paper from Jim Hansen,including some figures I've read
> before, which stunned me:
>
> "In the early Pliocene global temperature was no more than 1-2°C warmer
> than today, yet sea level was 15-25 meters (50-80 feet) higher."
>
> best wishes,
>
> Emily.
>
>
> *Paleoclimate Implications: Accepted Paper and 'Popular Science'*
>
>
> "Paleoclimate Implications for Human-Made Climate Change" has been
> reviewed, revised in response to the referee's suggestions, and accepted
> for publication in "Climate Change at the Eve of the Second Decade of
> the Century: Inferences from Paleoclimate and Regional Aspects:
> Proceedings of Milutin Milankovitch 130th Anniversary Symposium" (Eds.
> A. Berger, F. Mesinger and D Šijački), Springer.
>
> This final version has also been published in arXiv:1105.0968v3
> [physics.ao-ph]
> <
> http://columbia.us1.list-manage.com/track/click?u=0ebaeb14fdbf5dc65289113c1&id=fbefcc8464&e=60a7483168
> >
>
> A__'popular science' summary
> <
> http://columbia.us1.list-manage.com/track/click?u=0ebaeb14fdbf5dc65289113c1&id=d3b93e0894&e=60a7483168
> >
> of the paper, intended for lay audience, is available.
>
> Thanks especially to reviewer Dana Royer for helpful comments,
> foundations and NASA program managers for research support, and a number
> of people for comments on an early draft of the paper, as delineated in
> the acknowledgements.
>
> Jim Hansen
>
> --
> You received this message because you are subscribed to the Google Groups
> "geoengineering" group.
> To post to this group, send email to geoengineering@googlegroups.com.
> To unsubscribe from this group, send email to
> geoengineering+unsubscr...@googlegroups.com.
> For more options, visit this group at
> http://groups.google.com/group/geoengineering?hl=en.
>
>
-- 
You received this message because you are subscribed to the Google Groups
"geoengineering" group.
To post to this group, send email to geoengineering@googlegroups.com.
To unsubscribe from this group, send email to
geoengineering+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/geoengineering?hl=en.

-- 
You received this message because you are subscribed to the Google Groups 
"geoengineering" group.
To post to this group, send email to geoengineering@googlegroups.com.
To unsubscribe from this group, send email to 
geoengineering+unsubscr...@googlegroups.com.
For more options,

Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Ken Caldeira]

Two points:

I am not opposed to scientists making prescriptive statements in their roles as 
citizens. 

However, I am opposed to prescriptive statements (statements about what we 
should do) in peer-reviewed scientific papers. 

I think science is about establishing objective facts about the world. As 
citizens, we take these facts and our values and make judgments about what we 
should do. 

I am 100% in favor of Jim Hansen making prescriptive statements. I would just 
prefer that he not do it in the context of a peer-reviewed scientific paper. 

Science cannot tell us what to do. It can give us information which we can use 
to make decisions. 

If the science gets mixed up with politics in peer-reviewed scientific 
publications, I think it ends up weakening the credibility of the entire 
scientific publication process (since statements whose truth value cannot be 
empirically established are obviously getting past reviewers). 

I should say that the worst in this respect are the economists, who insist that 
they should be regarded as a science while simultaneously trying to tell us 
what we should be doing. 

---

On deployment of some sort of solar reflection system:  all of our model 
results indicate that a high co2 world with deflection of some sunlight would 
be more similar to a low co2 world than is a high co2 world without deflection 
of sunlight. 

So, do I think that direct environmental damage from greenhouse gases could be 
diminished by deploying such a system?  Yes, probably although I am not 100% 
certain of this. 

Do I think near-term deployment will reduce overall risk and improve long-term 
well-being? Of this I am less certain, as it is hard to predict the various 
sociopolitical, as well as environmental, repercussions that might occur. 

Ken Caldeira
kcalde...@carnegie.stanford.edu
+1 650 704 7212
http://dge.stanford.edu/labs/caldeiralab

Sent from a limited-typing keyboard

On Jul 22, 2011, at 16:38, John Nissen  wrote:

> 
> 
> Dear Ken,
> 
> I've already looked at this interesting paper [1], from Jim Hansen and Mikiko 
> Sato - but I'd not read before of his conjecture about rate of ice mass loss 
> doubling per decade, producing many metres of sea level rise this century.  
> But the implication is that the situation can be saved simply by reducing 
> fossil fuel emissions!  Is that the prescription that you are complaining 
> about?  Wouldn't a well-considered prescription be welcome from somebody as 
> eminent as Prof Hansen?  Geoengineering for example!  I don't see a way out 
> of our predicament without it.  Do you, Ken?
> 
> Does Hansen accept that 90% sea ice could be gone as soon as at end summer 
> 2016? (BTW, I've another reference to this date we've been arguing about [2].)
> 
> Hansen seems to dismiss methane as always producing less forcing than CO2:
> 
> "This sensitivity has the merit that CO2 is the principal GHG forcing and 
> perhaps the only one with good prospects for quantification of its long-term 
> changes." (page 15)
> 
> However the paper is relevant to the methane issue in several ways.  One 
> argument, which I've heard from Jeff Ridley, is that there is no sign of a 
> methane excursion at previous interglacials* such as end-Eemian, when it was 
> hotter, so we don't need to worry about having an excursion now.  Hansen 
> shows that it was never hotter than it is now (in Holocene) by more than one 
> degree.  
> 
> Elsewhere Hansen points out that the current rate of global warming is much 
> higher than it has been for millions of years.  Andrew Lockley suggests it's 
> higher than even it was at the PETM some 55.8 million years ago, when 
> temperatures rose about 6 C [3].  That rate of change is important, because 
> of methane's short lifetime.  The increasing speed of change implied by 
> Hansen's climate sensitivity is thus relevant to methane.
> 
> A further way that the paper is relevant to methane is because of climate 
> sensitivity to radiative forcing.  The paper suggests various alternative 
> values that could be taken - see [1] table 1.   If we get over 2 W/m-2 from 
> methane, then that certainly takes us over the danger line of 2 degrees 
> global warming, using his argument.  
> 
> Cheers,
> 
> John
> 
> * During the past 800,000 years, methane never rose much above 700 ppb 
> until recently, see [1] figure 2
> 
> [1] Full paper http://arxiv.org/ftp/arxiv/papers/1105/1105.0968.pdf
> 
> Abstract here:
> http://arxiv.org/abs/1105.0968v3 
> 
> [2] http://www.bbc.co.uk/news/science-environment-13002706 
> 
> [3] http://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum  
> 
> ---
> 
> On Thu, Jul 21, 2011 at 11:07 PM, Emily  wrote:
> Hi,
> 
> here is a recent paper from Jim Hansen,including some figures I've read
> before, which stunned me:
> 
> "In the early Pliocene global temperature was no more than 1-2°C warmer
> than today, yet sea level was 15-25 meters (50-80 feet) higher."
> 
> best wishes,
> 
> Emily.
> 
> 
>

Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[John Nissen]

Hi Ken,

You take a fundamentally different view of the Earth System and
geoengineering.  I see the Earth System as in an extremely precarious state
and geoengineering as absolutely necessary to nudge the system back into a
state that allows continued habitation of the planet by ourselves and our
offspring.  Do you really think that we can survive the century simply by
reducing carbon emissions?  If we wait for some dramatic event, like
disappearance of Arctic sea ice, as an "emergency" sufficient to justify
geoengineering, don't we risk leaving geoengineering too late?

For me, geoengineering is like chemotherapy when a vital organ has cancer,
or like fire-fighting when parts of the burning building contain
explosives.  You start tackling the problem as quickly as you possibly can,
concentrating on the critical parts.

John

---

On Fri, Jul 22, 2011 at 4:02 PM, Ken Caldeira  wrote:

> Two points:
>
> I am not opposed to scientists making prescriptive statements in their
> roles as citizens.
>
> However, I am opposed to prescriptive statements (statements about what we
> should do) in peer-reviewed scientific papers.
>
> I think science is about establishing objective facts about the world. As
> citizens, we take these facts and our values and make judgments about what
> we should do.
>
> I am 100% in favor of Jim Hansen making prescriptive statements. I would
> just prefer that he not do it in the context of a peer-reviewed scientific
> paper.
>
> Science cannot tell us what to do. It can give us information which we can
> use to make decisions.
>
> If the science gets mixed up with politics in peer-reviewed scientific
> publications, I think it ends up weakening the credibility of the entire
> scientific publication process (since statements whose truth value cannot be
> empirically established are obviously getting past reviewers).
>
> I should say that the worst in this respect are the economists, who insist
> that they should be regarded as a science while simultaneously trying to
> tell us what we should be doing.
>
> ---
>
> On deployment of some sort of solar reflection system:  all of our model
> results indicate that a high co2 world with deflection of some sunlight
> would be more similar to a low co2 world than is a high co2 world without
> deflection of sunlight.
>
> So, do I think that direct environmental damage from greenhouse gases could
> be diminished by deploying such a system?  Yes, probably although I am not
> 100% certain of this.
>
> Do I think near-term deployment will reduce overall risk and improve
> long-term well-being? Of this I am less certain, as it is hard to predict
> the various sociopolitical, as well as environmental, repercussions that
> might occur.
>
> Ken Caldeira
> kcalde...@carnegie.stanford.edu
> +1 650 704 7212
> http://dge.stanford.edu/labs/caldeiralab
>
> Sent from a limited-typing keyboard
>
> On Jul 22, 2011, at 16:38, John Nissen  wrote:
>
>
>
> Dear Ken,
>
> I've already looked at this interesting paper [1], from Jim Hansen and
> Mikiko Sato - but I'd not read before of his conjecture about rate of ice
> mass loss doubling per decade, producing many metres of sea level rise this
> century.  But the implication is that the situation can be saved simply by
> reducing fossil fuel emissions!  Is that the prescription that you are
> complaining about?  Wouldn't a well-considered prescription be welcome from
> somebody as eminent as Prof Hansen?  Geoengineering for example!  I don't
> see a way out of our predicament without it.  Do you, Ken?
>
> Does Hansen accept that 90% sea ice could be gone as soon as at end summer
> 2016? (BTW, I've another reference to this date we've been arguing about
> [2].)
>
> Hansen seems to dismiss methane as always producing less forcing than CO2:
>
> "*This sensitivity has the merit that CO2 is the principal GHG forcing and
> perhaps the only one with good prospects for quantification of its long-term
> changes.*" (page 15)
>
> However the paper is relevant to the methane issue in several ways.  One
> argument, which I've heard from Jeff Ridley, is that there is no sign of a
> methane excursion at previous interglacials* such as end-Eemian, when it was
> hotter, so we don't need to worry about having an excursion now.  Hansen
> shows that it was never hotter than it is now (in Holocene) by more than one
> degree.
>
> Elsewhere Hansen points out that the current rate of global warming is much
> higher than it has been for millions of years.  Andrew Lockley suggests it's
> higher than even it was at the PETM some 55.8 million years ago, when
> temperatures rose about 6 C [3].  That rate of change is important, because
> of methane's short lifetime.  The increasing speed of change implied by
> Hansen's climate sensitivity is thus relevant to methane.
>
> A further way that the paper is relevant to methane is because of climate
> sensitivity to radiative forcing.  The paper suggests various alternative
> values that could be taken -

Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Ken Caldeira]

John,

I have no doubt that, from the perspective of many extant species and
less-fortunate humans, we are indeed in dire straits.

If I were convinced that stratospheric aerosols would work as advertised and
that there would be no unforeseen or unanticipated repercussions, and that
some sort of democratic process could be devised to give the overall effort
political legitimacy, then I would be in favor of early deployment of such
schemes.

However, I am confident that were such systems deployed, there would be
surprises. Maybe the surprise would be how well it works and how everyone
the world over greets the project with such a high degree of appreciation.
On the other hand, the surprise could be that things go rather wrong,
exacerbating international friction, leading to economic disruption, wars,
etc.

Before such systems would be deployed, I would hope that the risk-benefit
balance would be very clearly tipped in the direction of benefit. I just do
not think we are there yet.

Best,

Ken


___
Ken Caldeira

Carnegie Institution Dept of Global Ecology
260 Panama Street, Stanford, CA 94305 USA
+1 650 704 7212 kcalde...@carnegie.stanford.edu
http://dge.stanford.edu/labs/caldeiralab  @kencaldeira


On Sat, Jul 23, 2011 at 12:08 AM, John Nissen wrote:

> Hi Ken,
>
> You take a fundamentally different view of the Earth System and
> geoengineering.  I see the Earth System as in an extremely precarious state
> and geoengineering as absolutely necessary to nudge the system back into a
> state that allows continued habitation of the planet by ourselves and our
> offspring.  Do you really think that we can survive the century simply by
> reducing carbon emissions?  If we wait for some dramatic event, like
> disappearance of Arctic sea ice, as an "emergency" sufficient to justify
> geoengineering, don't we risk leaving geoengineering too late?
>
> For me, geoengineering is like chemotherapy when a vital organ has cancer,
> or like fire-fighting when parts of the burning building contain
> explosives.  You start tackling the problem as quickly as you possibly can,
> concentrating on the critical parts.
>
> John
>
> ---
>
>
> On Fri, Jul 22, 2011 at 4:02 PM, Ken Caldeira  wrote:
>
>> Two points:
>>
>> I am not opposed to scientists making prescriptive statements in their
>> roles as citizens.
>>
>> However, I am opposed to prescriptive statements (statements about what we
>> should do) in peer-reviewed scientific papers.
>>
>> I think science is about establishing objective facts about the world. As
>> citizens, we take these facts and our values and make judgments about what
>> we should do.
>>
>> I am 100% in favor of Jim Hansen making prescriptive statements. I would
>> just prefer that he not do it in the context of a peer-reviewed scientific
>> paper.
>>
>> Science cannot tell us what to do. It can give us information which we can
>> use to make decisions.
>>
>> If the science gets mixed up with politics in peer-reviewed scientific
>> publications, I think it ends up weakening the credibility of the entire
>> scientific publication process (since statements whose truth value cannot be
>> empirically established are obviously getting past reviewers).
>>
>> I should say that the worst in this respect are the economists, who insist
>> that they should be regarded as a science while simultaneously trying to
>> tell us what we should be doing.
>>
>> ---
>>
>> On deployment of some sort of solar reflection system:  all of our model
>> results indicate that a high co2 world with deflection of some sunlight
>> would be more similar to a low co2 world than is a high co2 world without
>> deflection of sunlight.
>>
>> So, do I think that direct environmental damage from greenhouse gases
>> could be diminished by deploying such a system?  Yes, probably although I am
>> not 100% certain of this.
>>
>> Do I think near-term deployment will reduce overall risk and improve
>> long-term well-being? Of this I am less certain, as it is hard to predict
>> the various sociopolitical, as well as environmental, repercussions that
>> might occur.
>>
>> Ken Caldeira
>> kcalde...@carnegie.stanford.edu
>> +1 650 704 7212
>> http://dge.stanford.edu/labs/caldeiralab
>>
>> Sent from a limited-typing keyboard
>>
>> On Jul 22, 2011, at 16:38, John Nissen  wrote:
>>
>>
>>
>> Dear Ken,
>>
>> I've already looked at this interesting paper [1], from Jim Hansen and
>> Mikiko Sato - but I'd not read before of his conjecture about rate of ice
>> mass loss doubling per decade, producing many metres of sea level rise this
>> century.  But the implication is that the situation can be saved simply by
>> reducing fossil fuel emissions!  Is that the prescription that you are
>> complaining about?  Wouldn't a well-considered prescription be welcome from
>> somebody as eminent as Prof Hansen?  Geoengineering for example!  I don't
>> see a way out of our predicament without it.  Do you, Ken?
>>
>> Does Hansen acc

Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Ken Caldeira]

Values and norms do and must guide what questions we ask, but they cannot be
allowed to influence our scientific answers.

Scientific papers should contain empirical statements and not value-based
judgments.


On Sat, Jul 23, 2011 at 4:44 PM, Jerome Whitington <
jwhiting...@dartmouth.edu> wrote:

> Hi All -
>
> Forgive me for joining in - I am a newcomer on this list.
>
> Georges Canguilhem, who analyzed the French medical sciences, argued that
> the objectivity of medicine in fact requires its normative component.
> Research is not only motivated by goals like curing disease, but is
> organized toward those aims in all its detail. He shows that the positive
> agenda of a non-normative physiology, which sought to build up an
> understanding of normal functions in their totality, remained an allusive
> dream. But for Canguilhem this normative dimension hardly undermines
> medicine's claim to objectivity - on the contrary. The science of the normal
> body needs pathology in order to exist.
>
> It strikes me that ecological sciences also have an undeniable clinical
> aspect, at least in a great many research contexts. It is not only that we
> are motivated by goals of repairing the earth - or even just making
> policy-relevant conclusions - but that the research is actually organized in
> such a way. The normative dimension is inescapable, but this doesn't mean
> the methodological basis of research isn't robust. Like medicine, climate
> science implies intervention, and our understanding of climate would be
> hardly as developed were it not so.
>
> Incidentally, Canguilhem attributed this polarized condition of normative
> judgment as an essential element of life itself. Living bodies inherently
> are involved in polarized judgments - inside versus outside, up versus down,
> pain versus pleasure. If life is this normative activity, it means that
> disease is not a strictly objective condition (say, loss of funtionality),
> but also a 'subjective' judgment about that condition (that the loss of
> function is bad). This also helps clarify why people use medical sciences to
> manipulate their bodies in unconventional ways (augmentation, performance
> enhancing drugs). And of course these sciences are also organized around
> normative goals.
>
> Regards,
> Jerome Whitington
> Dartmouth College / NUS
>
>
>
>
>
>
>
> On Fri, Jul 22, 2011 at 6:08 PM, John Nissen wrote:
>
>> Hi Ken,
>>
>> You take a fundamentally different view of the Earth System and
>> geoengineering.  I see the Earth System as in an extremely precarious state
>> and geoengineering as absolutely necessary to nudge the system back into a
>> state that allows continued habitation of the planet by ourselves and our
>> offspring.  Do you really think that we can survive the century simply by
>> reducing carbon emissions?  If we wait for some dramatic event, like
>> disappearance of Arctic sea ice, as an "emergency" sufficient to justify
>> geoengineering, don't we risk leaving geoengineering too late?
>>
>> For me, geoengineering is like chemotherapy when a vital organ has cancer,
>> or like fire-fighting when parts of the burning building contain
>> explosives.  You start tackling the problem as quickly as you possibly can,
>> concentrating on the critical parts.
>>
>> John
>>
>> ---
>>
>>
>> On Fri, Jul 22, 2011 at 4:02 PM, Ken Caldeira wrote:
>>
>>> Two points:
>>>
>>> I am not opposed to scientists making prescriptive statements in their
>>> roles as citizens.
>>>
>>> However, I am opposed to prescriptive statements (statements about what
>>> we should do) in peer-reviewed scientific papers.
>>>
>>> I think science is about establishing objective facts about the world. As
>>> citizens, we take these facts and our values and make judgments about what
>>> we should do.
>>>
>>> I am 100% in favor of Jim Hansen making prescriptive statements. I would
>>> just prefer that he not do it in the context of a peer-reviewed scientific
>>> paper.
>>>
>>> Science cannot tell us what to do. It can give us information which we
>>> can use to make decisions.
>>>
>>> If the science gets mixed up with politics in peer-reviewed scientific
>>> publications, I think it ends up weakening the credibility of the entire
>>> scientific publication process (since statements whose truth value cannot be
>>> empirically established are obviously getting past reviewers).
>>>
>>> I should say that the worst in this respect are the economists, who
>>> insist that they should be regarded as a science while simultaneously trying
>>> to tell us what we should be doing.
>>>
>>> ---
>>>
>>> On deployment of some sort of solar reflection system:  all of our model
>>> results indicate that a high co2 world with deflection of some sunlight
>>> would be more similar to a low co2 world than is a high co2 world without
>>> deflection of sunlight.
>>>
>>> So, do I think that direct environmental damage from greenhouse gases
>>> could be diminished by deploying such a system?  Yes, probably a

RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Eugene Gordon]

Deploy has an ominous and fateful ring. What about some careful, well thought 
through, limited experiments in order to decide about the value and risk of 
deployment? I think that is entirely possible with stratospheric aerosols. I 
think this group is entirely capable if defining and proposing limited 
experiments.

 

From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] 
On Behalf Of Ken Caldeira
Sent: Saturday, July 23, 2011 10:37 AM
To: John Nissen
Cc: em...@lewis-brown.net; geo-engineering grp; John Nissen
Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

 

John,

I have no doubt that, from the perspective of many extant species and 
less-fortunate humans, we are indeed in dire straits.

If I were convinced that stratospheric aerosols would work as advertised and 
that there would be no unforeseen or unanticipated repercussions, and that some 
sort of democratic process could be devised to give the overall effort 
political legitimacy, then I would be in favor of early deployment of such 
schemes.

However, I am confident that were such systems deployed, there would be 
surprises. Maybe the surprise would be how well it works and how everyone the 
world over greets the project with such a high degree of appreciation. On the 
other hand, the surprise could be that things go rather wrong, exacerbating 
international friction, leading to economic disruption, wars, etc.

Before such systems would be deployed, I would hope that the risk-benefit 
balance would be very clearly tipped in the direction of benefit. I just do not 
think we are there yet.

Best,

Ken


___
Ken Caldeira

Carnegie Institution Dept of Global Ecology
260 Panama Street, Stanford, CA 94305 USA
+1 650 704 7212 kcalde...@carnegie.stanford.edu 
http://dge.stanford.edu/labs/caldeiralab  @kencaldeira



On Sat, Jul 23, 2011 at 12:08 AM, John Nissen  wrote:

Hi Ken,

You take a fundamentally different view of the Earth System and geoengineering. 
 I see the Earth System as in an extremely precarious state and geoengineering 
as absolutely necessary to nudge the system back into a state that allows 
continued habitation of the planet by ourselves and our offspring.  Do you 
really think that we can survive the century simply by reducing carbon 
emissions?  If we wait for some dramatic event, like disappearance of Arctic 
sea ice, as an "emergency" sufficient to justify geoengineering, don't we risk 
leaving geoengineering too late?  

For me, geoengineering is like chemotherapy when a vital organ has cancer, or 
like fire-fighting when parts of the burning building contain explosives.  You 
start tackling the problem as quickly as you possibly can, concentrating on the 
critical parts.

John

---

 

On Fri, Jul 22, 2011 at 4:02 PM, Ken Caldeira  wrote:

Two points:

 

I am not opposed to scientists making prescriptive statements in their roles as 
citizens. 

 

However, I am opposed to prescriptive statements (statements about what we 
should do) in peer-reviewed scientific papers. 

 

I think science is about establishing objective facts about the world. As 
citizens, we take these facts and our values and make judgments about what we 
should do. 

 

I am 100% in favor of Jim Hansen making prescriptive statements. I would just 
prefer that he not do it in the context of a peer-reviewed scientific paper. 

 

Science cannot tell us what to do. It can give us information which we can use 
to make decisions. 

 

If the science gets mixed up with politics in peer-reviewed scientific 
publications, I think it ends up weakening the credibility of the entire 
scientific publication process (since statements whose truth value cannot be 
empirically established are obviously getting past reviewers). 

 

I should say that the worst in this respect are the economists, who insist that 
they should be regarded as a science while simultaneously trying to tell us 
what we should be doing. 

 

---

 

On deployment of some sort of solar reflection system:  all of our model 
results indicate that a high co2 world with deflection of some sunlight would 
be more similar to a low co2 world than is a high co2 world without deflection 
of sunlight. 

 

So, do I think that direct environmental damage from greenhouse gases could be 
diminished by deploying such a system?  Yes, probably although I am not 100% 
certain of this. 

 

Do I think near-term deployment will reduce overall risk and improve long-term 
well-being? Of this I am less certain, as it is hard to predict the various 
sociopolitical, as well as environmental, repercussions that might occur. 


Ken Caldeira

kcalde...@carnegie.stanford.edu

+1 650 704 7212  

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

 

Sent from a limited-typing keyboard


On Jul 22, 2011, at 16:38, John Nissen  wrote:

 


Dear Ken,

I've already looked at this interesting paper [1], from Jim Hansen and Mikiko

Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[John Nissen]

Ken,

We all like to be optimistic - it is a human characteristic.  But if you
accept what is happening to the Earth System, as being discovered by people
like Hansen, Wadhams and Shakhova (on climate sensitivity, sea ice retreat
and Arctic methane respectively), then the situation is dire for every human
on this planet.  This is not a question of perspective, but an appreciation
of what appears to be very likely happening, as argued by scientists working
in the field, looking at the data - and not clouding their judgement by
wishful thinking.  None of us wants to see this.  It is very difficult to
believe that it's happening to us.  You look out at our beautiful planet,
and enjoy the fruits (mulberries today!), and it's almost impossible to
believe that this could all change - if we do not act very quickly and
effectively, on several fronts.

As for geoengineering perhaps not working as well as expected, this is all
the more reason for starting sooner, and starting on several different
methods in parallel.  Any of the methods being proposed can easily be
stopped, if it's not having the required effect - or an adverse effect is
too great.  The greatest danger is being too late - and then who we have to
blame but ourselves - us, who have seen the facts of the situation.

Most importantly we must inform our political leaders.  If the situation is
acknowledged by any country as the emergency, even without 100% scientific
certainty, then they are obliged to take action for the sake of their own
citizens, according the UNFCCC Article 3 [1].  It's our duty, as people who
understand what is happening to the Earth System, not to shelter under
misplaced optimism, but come into the open and declare the emergency - if
that's the conclusion from what is being discovered.

John

---

On Sat, Jul 23, 2011 at 3:36 PM, Ken Caldeira  wrote:

> John,
>
> I have no doubt that, from the perspective of many extant species and
> less-fortunate humans, we are indeed in dire straits.
>
> If I were convinced that stratospheric aerosols would work as advertised
> and that there would be no unforeseen or unanticipated repercussions, and
> that some sort of democratic process could be devised to give the overall
> effort political legitimacy, then I would be in favor of early deployment of
> such schemes.
>
> However, I am confident that were such systems deployed, there would be
> surprises. Maybe the surprise would be how well it works and how everyone
> the world over greets the project with such a high degree of appreciation.
> On the other hand, the surprise could be that things go rather wrong,
> exacerbating international friction, leading to economic disruption, wars,
> etc.
>
> Before such systems would be deployed, I would hope that the risk-benefit
> balance would be very clearly tipped in the direction of benefit. I just do
> not think we are there yet.
>
> Best,
>
> Ken
>
>
> ___
> Ken Caldeira
>
> Carnegie Institution Dept of Global Ecology
> 260 Panama Street, Stanford, CA 94305 USA
> +1 650 704 7212 kcalde...@carnegie.stanford.edu
> http://dge.stanford.edu/labs/caldeiralab  @kencaldeira
>
>
>
> On Sat, Jul 23, 2011 at 12:08 AM, John Nissen wrote:
>
>> Hi Ken,
>>
>> You take a fundamentally different view of the Earth System and
>> geoengineering.  I see the Earth System as in an extremely precarious state
>> and geoengineering as absolutely necessary to nudge the system back into a
>> state that allows continued habitation of the planet by ourselves and our
>> offspring.  Do you really think that we can survive the century simply by
>> reducing carbon emissions?  If we wait for some dramatic event, like
>> disappearance of Arctic sea ice, as an "emergency" sufficient to justify
>> geoengineering, don't we risk leaving geoengineering too late?
>>
>> For me, geoengineering is like chemotherapy when a vital organ has cancer,
>> or like fire-fighting when parts of the burning building contain
>> explosives.  You start tackling the problem as quickly as you possibly can,
>> concentrating on the critical parts.
>>
>> John
>>
>> ---
>>
>>
>> On Fri, Jul 22, 2011 at 4:02 PM, Ken Caldeira wrote:
>>
>>> Two points:
>>>
>>> I am not opposed to scientists making prescriptive statements in their
>>> roles as citizens.
>>>
>>> However, I am opposed to prescriptive statements (statements about what
>>> we should do) in peer-reviewed scientific papers.
>>>
>>> I think science is about establishing objective facts about the world. As
>>> citizens, we take these facts and our values and make judgments about what
>>> we should do.
>>>
>>> I am 100% in favor of Jim Hansen making prescriptive statements. I would
>>> just prefer that he not do it in the context of a peer-reviewed scientific
>>> paper.
>>>
>>> Science cannot tell us what to do. It can give us information which we
>>> can use to make decisions.
>>>
>>> If the science gets mixed up with politics in peer-reviewed scientific
>>> p

Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[John Nissen]

reference [1]
http://unfccc.int/essential_background/convention/background/items/1355.php

On Sat, Jul 23, 2011 at 11:43 PM, John Nissen wrote:

>
> Ken,
>
> We all like to be optimistic - it is a human characteristic.  But if you
> accept what is happening to the Earth System, as being discovered by people
> like Hansen, Wadhams and Shakhova (on climate sensitivity, sea ice retreat
> and Arctic methane respectively), then the situation is dire for every human
> on this planet.  This is not a question of perspective, but an appreciation
> of what appears to be very likely happening, as argued by scientists working
> in the field, looking at the data - and not clouding their judgement by
> wishful thinking.  None of us wants to see this.  It is very difficult to
> believe that it's happening to us.  You look out at our beautiful planet,
> and enjoy the fruits (mulberries today!), and it's almost impossible to
> believe that this could all change - if we do not act very quickly and
> effectively, on several fronts.
>
> As for geoengineering perhaps not working as well as expected, this is all
> the more reason for starting sooner, and starting on several different
> methods in parallel.  Any of the methods being proposed can easily be
> stopped, if it's not having the required effect - or an adverse effect is
> too great.  The greatest danger is being too late - and then who we have to
> blame but ourselves - us, who have seen the facts of the situation.
>
> Most importantly we must inform our political leaders.  If the situation is
> acknowledged by any country as the emergency, even without 100% scientific
> certainty, then they are obliged to take action for the sake of their own
> citizens, according the UNFCCC Article 3 [1].  It's our duty, as people who
> understand what is happening to the Earth System, not to shelter under
> misplaced optimism, but come into the open and declare the emergency - if
> that's the conclusion from what is being discovered.
>
> John
>
> ---
>
>
> On Sat, Jul 23, 2011 at 3:36 PM, Ken Caldeira  wrote:
>
>> John,
>>
>> I have no doubt that, from the perspective of many extant species and
>> less-fortunate humans, we are indeed in dire straits.
>>
>> If I were convinced that stratospheric aerosols would work as advertised
>> and that there would be no unforeseen or unanticipated repercussions, and
>> that some sort of democratic process could be devised to give the overall
>> effort political legitimacy, then I would be in favor of early deployment of
>> such schemes.
>>
>> However, I am confident that were such systems deployed, there would be
>> surprises. Maybe the surprise would be how well it works and how everyone
>> the world over greets the project with such a high degree of appreciation.
>> On the other hand, the surprise could be that things go rather wrong,
>> exacerbating international friction, leading to economic disruption, wars,
>> etc.
>>
>> Before such systems would be deployed, I would hope that the risk-benefit
>> balance would be very clearly tipped in the direction of benefit. I just do
>> not think we are there yet.
>>
>> Best,
>>
>> Ken
>>
>>
>> ___
>> Ken Caldeira
>>
>> Carnegie Institution Dept of Global Ecology
>> 260 Panama Street, Stanford, CA 94305 USA
>> +1 650 704 7212 kcalde...@carnegie.stanford.edu
>> http://dge.stanford.edu/labs/caldeiralab  @kencaldeira
>>
>>
>>
>> On Sat, Jul 23, 2011 at 12:08 AM, John Nissen 
>> wrote:
>>
>>> Hi Ken,
>>>
>>> You take a fundamentally different view of the Earth System and
>>> geoengineering.  I see the Earth System as in an extremely precarious state
>>> and geoengineering as absolutely necessary to nudge the system back into a
>>> state that allows continued habitation of the planet by ourselves and our
>>> offspring.  Do you really think that we can survive the century simply by
>>> reducing carbon emissions?  If we wait for some dramatic event, like
>>> disappearance of Arctic sea ice, as an "emergency" sufficient to justify
>>> geoengineering, don't we risk leaving geoengineering too late?
>>>
>>> For me, geoengineering is like chemotherapy when a vital organ has
>>> cancer, or like fire-fighting when parts of the burning building contain
>>> explosives.  You start tackling the problem as quickly as you possibly can,
>>> concentrating on the critical parts.
>>>
>>> John
>>>
>>> ---
>>>
>>>
>>> On Fri, Jul 22, 2011 at 4:02 PM, Ken Caldeira wrote:
>>>
 Two points:

 I am not opposed to scientists making prescriptive statements in their
 roles as citizens.

 However, I am opposed to prescriptive statements (statements about what
 we should do) in peer-reviewed scientific papers.

 I think science is about establishing objective facts about the world.
 As citizens, we take these facts and our values and make judgments about
 what we should do.

 I am 100% in favor of Jim Hansen making prescriptive statements.

RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Eugene Gordon]

I support John Nissen’s view with some slight modification of the wording, but 
not the theme. I like his use of the expression, ‘appears to be likely 
happening’ and want to amplify that. I don’t like Ken’s use of ‘I am 
confident’. As scientists we can express conviction but not certainty until it 
has been achieved following the Scientific Method. The current climate 
observations are highly suggestive of a continuing pattern that will have 
increasingly disastrous effects. I emphasize there is no certainty. However, if 
what we are observing is mostly caused by anthropogenic CO2 emissions then it 
is probably too late to rely on reducing such emissions. Yes, we must no doubt 
do it out of respect for the current understanding and for potential future 
benefits, but reducing CO2 emissions will probably not save the day. In 
parallel, and with comparable conviction, we espouse various geoengineering 
means for halting the perceived, impending disaster. It is highly likely we can 
design and put in place limited experiments to test the ability to mitigate or 
delay. Why do we talk about full implementation rather than careful, limited, 
experimental tests with minimal risk? Implementation is a threat to some. 
Careful, limited testing is far more benign.

 

-gene

 

 

From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] 
On Behalf Of John Nissen
Sent: Saturday, July 23, 2011 6:46 PM
To: kcalde...@stanford.edu
Cc: em...@lewis-brown.net; geo-engineering grp; John Nissen
Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

 

reference [1] 
http://unfccc.int/essential_background/convention/background/items/1355.php 

On Sat, Jul 23, 2011 at 11:43 PM, John Nissen  wrote:


Ken,

We all like to be optimistic - it is a human characteristic.  But if you accept 
what is happening to the Earth System, as being discovered by people like 
Hansen, Wadhams and Shakhova (on climate sensitivity, sea ice retreat and 
Arctic methane respectively), then the situation is dire for every human on 
this planet.  This is not a question of perspective, but an appreciation of 
what appears to be very likely happening, as argued by scientists working in 
the field, looking at the data - and not clouding their judgement by wishful 
thinking.  None of us wants to see this.  It is very difficult to believe that 
it's happening to us.  You look out at our beautiful planet, and enjoy the 
fruits (mulberries today!), and it's almost impossible to believe that this 
could all change - if we do not act very quickly and effectively, on several 
fronts.

As for geoengineering perhaps not working as well as expected, this is all the 
more reason for starting sooner, and starting on several different methods in 
parallel.  Any of the methods being proposed can easily be stopped, if it's not 
having the required effect - or an adverse effect is too great.  The greatest 
danger is being too late - and then who we have to blame but ourselves - us, 
who have seen the facts of the situation.

Most importantly we must inform our political leaders.  If the situation is 
acknowledged by any country as the emergency, even without 100% scientific 
certainty, then they are obliged to take action for the sake of their own 
citizens, according the UNFCCC Article 3 [1].  It's our duty, as people who 
understand what is happening to the Earth System, not to shelter under 
misplaced optimism, but come into the open and declare the emergency - if 
that's the conclusion from what is being discovered.  

John

---

 

On Sat, Jul 23, 2011 at 3:36 PM, Ken Caldeira  wrote:

John,

I have no doubt that, from the perspective of many extant species and 
less-fortunate humans, we are indeed in dire straits.

If I were convinced that stratospheric aerosols would work as advertised and 
that there would be no unforeseen or unanticipated repercussions, and that some 
sort of democratic process could be devised to give the overall effort 
political legitimacy, then I would be in favor of early deployment of such 
schemes.

However, I am confident that were such systems deployed, there would be 
surprises. Maybe the surprise would be how well it works and how everyone the 
world over greets the project with such a high degree of appreciation. On the 
other hand, the surprise could be that things go rather wrong, exacerbating 
international friction, leading to economic disruption, wars, etc.

Before such systems would be deployed, I would hope that the risk-benefit 
balance would be very clearly tipped in the direction of benefit. I just do not 
think we are there yet.

Best,

Ken


___
Ken Caldeira

Carnegie Institution Dept of Global Ecology
260 Panama Street, Stanford, CA 94305 USA
+1 650 704 7212 kcalde...@carnegie.stanford.edu 
http://dge.stanford.edu/labs/caldeiralab  @kencaldeira





On Sat, Jul 23, 2011 at 12:08 AM, John Nissen  wrote:

Hi Ken,

Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Fulkerson, William]

Dear Ken:
I love your sentence about economists.  The problem is that they are often 
consulted by the press as experts whether or not they are, and they don't 
always caveat their statements to indicate they are not scientists.
The best,
Bill

On Jul 22, 2011, at 11:03 AM, "Ken Caldeira" 
mailto:kcalde...@gmail.com>> wrote:

Two points:

I am not opposed to scientists making prescriptive statements in their roles as 
citizens.

However, I am opposed to prescriptive statements (statements about what we 
should do) in peer-reviewed scientific papers.

I think science is about establishing objective facts about the world. As 
citizens, we take these facts and our values and make judgments about what we 
should do.

I am 100% in favor of Jim Hansen making prescriptive statements. I would just 
prefer that he not do it in the context of a peer-reviewed scientific paper.

Science cannot tell us what to do. It can give us information which we can use 
to make decisions.

If the science gets mixed up with politics in peer-reviewed scientific 
publications, I think it ends up weakening the credibility of the entire 
scientific publication process (since statements whose truth value cannot be 
empirically established are obviously getting past reviewers).

I should say that the worst in this respect are the economists, who insist that 
they should be regarded as a science while simultaneously trying to tell us 
what we should be doing.

---

On deployment of some sort of solar reflection system:  all of our model 
results indicate that a high co2 world with deflection of some sunlight would 
be more similar to a low co2 world than is a high co2 world without deflection 
of sunlight.

So, do I think that direct environmental damage from greenhouse gases could be 
diminished by deploying such a system?  Yes, probably although I am not 100% 
certain of this.

Do I think near-term deployment will reduce overall risk and improve long-term 
well-being? Of this I am less certain, as it is hard to predict the various 
sociopolitical, as well as environmental, repercussions that might occur.

Ken Caldeira
kcalde...@carnegie.stanford.edu
+1 650 704 7212
http://dge.stanford.edu/labs/caldeiralab

Sent from a limited-typing keyboard

On Jul 22, 2011, at 16:38, John Nissen 
<johnnissen2...@gmail.com>
 wrote:



Dear Ken,

I've already looked at this interesting paper [1], from Jim Hansen and Mikiko 
Sato - but I'd not read before of his conjecture about rate of ice mass loss 
doubling per decade, producing many metres of sea level rise this century.  But 
the implication is that the situation can be saved simply by reducing fossil 
fuel emissions!  Is that the prescription that you are complaining about?  
Wouldn't a well-considered prescription be welcome from somebody as eminent as 
Prof Hansen?  Geoengineering for example!  I don't see a way out of our 
predicament without it.  Do you, Ken?

Does Hansen accept that 90% sea ice could be gone as soon as at end summer 
2016? (BTW, I've another reference to this date we've been arguing about [2].)

Hansen seems to dismiss methane as always producing less forcing than CO2:

"This sensitivity has the merit that CO2 is the principal GHG forcing and 
perhaps the only one with good prospects for quantification of its long-term 
changes." (page 15)

However the paper is relevant to the methane issue in several ways.  One 
argument, which I've heard from Jeff Ridley, is that there is no sign of a 
methane excursion at previous interglacials* such as end-Eemian, when it was 
hotter, so we don't need to worry about having an excursion now.  Hansen shows 
that it was never hotter than it is now (in Holocene) by more than one degree.

Elsewhere Hansen points out that the current rate of global warming is much 
higher than it has been for millions of years.  Andrew Lockley suggests it's 
higher than even it was at the PETM some 55.8 million years ago, when 
temperatures rose about 6 C [3].  That rate of change is important, because of 
methane's short lifetime.  The increasing speed of change implied by Hansen's 
climate sensitivity is thus relevant to methane.

A further way that the paper is relevant to methane is because of climate 
sensitivity to radiative forcing.  The paper suggests various alternative 
values that could be taken - see [1] table 1.   If we get over 2 W/m-2 from 
methane, then that certainly takes us over the danger line of 2 degrees global 
warming, using his argument.

Cheers,

John

* During the past 800,000 years, methane never rose much above 700 ppb until 
recently, see [1] figure 2

[1] Full paper  
 
http://arxiv.org/ftp/arxiv/papers/1105/1105.0968.pdf

Abstract here:

RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Veli Albert Kallio]

Have you been wondering, why the North Pole's sea ice is looking like this 
today? 
http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png

Cryosphere Today has reported a phenomenal North Pole melting:

North Pole's Ice Cap currently melts away at a phenomenal weekly rate of: 14.9%.

Melting figures of the Arctic Ocean for the last 7 days are:

17.07.2011: ice area 5,456,000 km2 - melting   98,000 km2
18.07.2011: ice area 5,383,000 km2 - melting   73,000 km2
19.07.2011: ice area 5,283,000 km2 - melting 100,000 km2
20.07.2011: ice area 5,083,000 km2 - melting 200,000 km2 - 24 hour ice area 
reduction: 3.93%
21.07.2011: ice area 4,931,000 km2 - melting 152,000 km2 - 24 hour ice area 
reduction: 3.08%
22.07.2011: ice area 4,843,000 km2 - melting   88,000 km2
23.07.2011: ice area 4,726,000 km2 - melting 117,000 km2 - 24 hour ice area 
reduction: 2.48%

At the start of the week, 16.07.2011 the ice area was 5,554,000 km2. 
 
A daily sea ice melting rate 77,000 km2 could melt all ice from the North Pole 
by the autumn equinox. The current rate of disappearing sea ice is much higher. 
This suggests that the open seas are increasing solar energy absorption at 
higher rates than the shortening of daylight hours are reducing the sunlight 
supply. A return of cold weather and clouds can break this vicious circle.
 
The fact that the North Pole Sea Ice Cap is able to lose 10.5% of its size in 
just over the last 4 days is a matter of immense concern to me as our train may 
have already lost its breaks...

WattsUpWithThat.com suggests the sun has entered a more intense phase in its 
sun-spot cycle and the sea ice is now melts. They now say the sea ice melting 
intensifies over the next few years until solar activity peaks, after that the 
sunspots disappear and the Arctic Oceans sea ice cover recovers. The concern 
over melting sea ice is alarmism as it is all due to a recent change in solar 
weather, the increasing radiation drives global warming and, therefore, North 
Pole's sea ice is now melting.
However, this contradicts their own sea ice area outlook projection: 
http://www.arcus.org/files/search/sea-ice-outlook/2011/07/images/pan-arctic/july_panarctic_fig1.png

In June WattsUpWithThat.com forecasted the second largest sea ice area in 
September with ice area recovery to 5,100,000 km2. WattsUpWithThat.com 
forecasting logic apparently expects the Arctic Ocean to be freezing 374,000 
km2 by September. 
 
We should change our Googlrgroup's name to: Geoengineering Now!
 
Kind regards,
 
Albert
 



From: wf...@utk.edu
To: kcalde...@gmail.com
CC: johnnissen2...@gmail.com; em...@lewis-brown.net; 
geoengineering@googlegroups.com; j...@cloudworld.co.uk
Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
Date: Sun, 24 Jul 2011 19:05:59 +



Dear Ken:
I love your sentence about economists.  The problem is that they are often 
consulted by the press as experts whether or not they are, and they don't 
always caveat their statements to indicate they are not scientists.
The best,
Bill

On Jul 22, 2011, at 11:03 AM, "Ken Caldeira"  wrote:





Two points:


I am not opposed to scientists making prescriptive statements in their roles as 
citizens. 


However, I am opposed to prescriptive statements (statements about what we 
should do) in peer-reviewed scientific papers. 


I think science is about establishing objective facts about the world. As 
citizens, we take these facts and our values and make judgments about what we 
should do. 


I am 100% in favor of Jim Hansen making prescriptive statements. I would just 
prefer that he not do it in the context of a peer-reviewed scientific paper. 


Science cannot tell us what to do. It can give us information which we can use 
to make decisions. 


If the science gets mixed up with politics in peer-reviewed scientific 
publications, I think it ends up weakening the credibility of the entire 
scientific publication process (since statements whose truth value cannot be 
empirically established are obviously getting past reviewers). 


I should say that the worst in this respect are the economists, who insist that 
they should be regarded as a science while simultaneously trying to tell us 
what we should be doing. 


---


On deployment of some sort of solar reflection system:  all of our model 
results indicate that a high co2 world with deflection of some sunlight would 
be more similar to a low co2 world than is a high co2 world without deflection 
of sunlight. 


So, do I think that direct environmental damage from greenhouse gases could be 
diminished by deploying such a system?  Yes, probably although I am not 100% 
certain of this. 


Do I think near-term deployment will reduce overall risk and improve long-term 
well-being? Of this I am less certain, as it is hard to predict the various 
sociopolitical, as well as environmental, repercussions that might occur. 

Ken Caldeira 
kcalde...@carnegi

RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Eugene Gordon]

The world is full of economic experts. Little good it is doing; the economies 
of most countries are disasters. It is easy to take a swing at economists. My 
choice for bums of the year are the politicians.

 

From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] 
On Behalf Of Fulkerson, William
Sent: Sunday, July 24, 2011 3:06 PM
To: 
Cc: John Nissen; em...@lewis-brown.net; geo-engineering grp; John Nissen
Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

 

Dear Ken:

I love your sentence about economists.  The problem is that they are often 
consulted by the press as experts whether or not they are, and they don't 
always caveat their statements to indicate they are not scientists.

The best,

Bill

On Jul 22, 2011, at 11:03 AM, "Ken Caldeira"  wrote:

Two points:

 

I am not opposed to scientists making prescriptive statements in their roles as 
citizens. 

 

However, I am opposed to prescriptive statements (statements about what we 
should do) in peer-reviewed scientific papers. 

 

I think science is about establishing objective facts about the world. As 
citizens, we take these facts and our values and make judgments about what we 
should do. 

 

I am 100% in favor of Jim Hansen making prescriptive statements. I would just 
prefer that he not do it in the context of a peer-reviewed scientific paper. 

 

Science cannot tell us what to do. It can give us information which we can use 
to make decisions. 

 

If the science gets mixed up with politics in peer-reviewed scientific 
publications, I think it ends up weakening the credibility of the entire 
scientific publication process (since statements whose truth value cannot be 
empirically established are obviously getting past reviewers). 

 

I should say that the worst in this respect are the economists, who insist that 
they should be regarded as a science while simultaneously trying to tell us 
what we should be doing. 

 

---

 

On deployment of some sort of solar reflection system:  all of our model 
results indicate that a high co2 world with deflection of some sunlight would 
be more similar to a low co2 world than is a high co2 world without deflection 
of sunlight. 

 

So, do I think that direct environmental damage from greenhouse gases could be 
diminished by deploying such a system?  Yes, probably although I am not 100% 
certain of this. 

 

Do I think near-term deployment will reduce overall risk and improve long-term 
well-being? Of this I am less certain, as it is hard to predict the various 
sociopolitical, as well as environmental, repercussions that might occur. 


Ken Caldeira 

kcalde...@carnegie.stanford.edu

+1 650 704 7212

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





Sent from a limited-typing keyboard


On Jul 22, 2011, at 16:38, John Nissen  wrote:

 


Dear Ken,

I've already looked at this interesting paper [1], from Jim Hansen and Mikiko 
Sato - but I'd not read before of his conjecture about rate of ice mass loss 
doubling per decade, producing many metres of sea level rise this century.  But 
the implication is that the situation can be saved simply by reducing fossil 
fuel emissions!  Is that the prescription that you are complaining about?  
Wouldn't a well-considered prescription be welcome from somebody as eminent as 
Prof Hansen?  Geoengineering for example!  I don't see a way out of our 
predicament without it.  Do you, Ken?

Does Hansen accept that 90% sea ice could be gone as soon as at end summer 
2016? (BTW, I've another reference to this date we've been arguing about [2].)

Hansen seems to dismiss methane as always producing less forcing than CO2:

"This sensitivity has the merit that CO2 is the principal GHG forcing and 
perhaps the only one with good prospects for quantification of its long-term 
changes." (page 15)

However the paper is relevant to the methane issue in several ways.  One 
argument, which I've heard from Jeff Ridley, is that there is no sign of a 
methane excursion at previous interglacials* such as end-Eemian, when it was 
hotter, so we don't need to worry about having an excursion now.  Hansen shows 
that it was never hotter than it is now (in Holocene) by more than one degree.  

Elsewhere Hansen points out that the current rate of global warming is much 
higher than it has been for millions of years.  Andrew Lockley suggests it's 
higher than even it was at the PETM some 55.8 million years ago, when 
temperatures rose about 6 C [3].  That rate of change is important, because of 
methane's short lifetime.  The increasing speed of change implied by Hansen's 
climate sensitivity is thus relevant to methane.

A further way that the paper is relevant to methane is because of climate 
sensitivity to radiative forcing.  The paper suggests various alternative 
values that could be taken - see [1] table 1.   If we get over 2 W/m-2 from 
methane, then that certainl

RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Eugene Gordon]

Albert:

 

No! Geoengineering Yesterday. In any case it is interesting that sunspots are 
now getting attention. Most climate scientists have ignored sunspots despite 
excellent perfect  correlation back to the year 1500. So much for the science!

 

-gene

 

From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] 
On Behalf Of Veli Albert Kallio
Sent: Sunday, July 24, 2011 4:23 PM
To: wf...@utk.edu; kcalde...@gmail.com
Cc: John Nissen; em...@lewis-brown.net; Geoengineering FIPC; John Nissen; Peter 
Wadhams
Subject: RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

 

Have you been wondering, why the North Pole's sea ice is looking like this 
today? 
 
<http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png> 
http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png

Cryosphere Today has reported a phenomenal North Pole melting:

North Pole's Ice Cap currently melts away at a phenomenal weekly rate of: 14.9%.

Melting figures of the Arctic Ocean for the last 7 days are:

17.07.2011: ice area 5,456,000 km2 - melting   98,000 km2
18.07.2011: ice area 5,383,000 km2 - melting   73,000 km2
19.07.2011: ice area 5,283,000 km2 - melting 100,000 km2
20.07.2011: ice area 5,083,000 km2 - melting 200,000 km2 - 24 hour ice area 
reduction: 3.93%
21.07.2011: ice area 4,931,000 km2 - melting 152,000 km2 - 24 hour ice area 
reduction: 3.08%
22.07.2011: ice area 4,843,000 km2 - melting   88,000 km2
23.07.2011: ice area 4,726,000 km2 - melting 117,000 km2 - 24 hour ice area 
reduction: 2.48%

At the start of the week, 16.07.2011 the ice area was 5,554,000 km2. 
 
A daily sea ice melting rate 77,000 km2 could melt all ice from the North Pole 
by the autumn equinox. The current rate of disappearing sea ice is much higher. 
This suggests that the open seas are increasing solar energy absorption at 
higher rates than the shortening of daylight hours are reducing the sunlight 
supply. A return of cold weather and clouds can break this vicious circle.
 
The fact that the North Pole Sea Ice Cap is able to lose 10.5% of its size in 
just over the last 4 days is a matter of immense concern to me as our train may 
have already lost its breaks...

WattsUpWithThat.com suggests the sun has entered a more intense phase in its 
sun-spot cycle and the sea ice is now melts. They now say the sea ice melting 
intensifies over the next few years until solar activity peaks, after that the 
sunspots disappear and the Arctic Oceans sea ice cover recovers. The concern 
over melting sea ice is alarmism as it is all due to a recent change in solar 
weather, the increasing radiation drives global warming and, therefore, North 
Pole's sea ice is now melting.
However, this contradicts their own sea ice area outlook projection:  
<http://www.arcus.org/files/search/sea-ice-outlook/2011/07/images/pan-arctic/july_panarctic_fig1.png>
 
http://www.arcus.org/files/search/sea-ice-outlook/2011/07/images/pan-arctic/july_panarctic_fig1.png

In June WattsUpWithThat.com forecasted the second largest sea ice area in 
September with ice area recovery to 5,100,000 km2. WattsUpWithThat.com 
forecasting logic apparently expects the Arctic Ocean to be freezing 374,000 
km2 by September. 
 
We should change our Googlrgroup's name to: Geoengineering Now!
 
Kind regards,
 
Albert
 

  _  

From: wf...@utk.edu
To: kcalde...@gmail.com
CC: johnnissen2...@gmail.com; em...@lewis-brown.net; 
geoengineering@googlegroups.com; j...@cloudworld.co.uk
Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
Date: Sun, 24 Jul 2011 19:05:59 +

Dear Ken:

I love your sentence about economists.  The problem is that they are often 
consulted by the press as experts whether or not they are, and they don't 
always caveat their statements to indicate they are not scientists.

The best,

Bill

On Jul 22, 2011, at 11:03 AM, "Ken Caldeira"  wrote:

Two points:

 

I am not opposed to scientists making prescriptive statements in their roles as 
citizens. 

 

However, I am opposed to prescriptive statements (statements about what we 
should do) in peer-reviewed scientific papers. 

 

I think science is about establishing objective facts about the world. As 
citizens, we take these facts and our values and make judgments about what we 
should do. 

 

I am 100% in favor of Jim Hansen making prescriptive statements. I would just 
prefer that he not do it in the context of a peer-reviewed scientific paper. 

 

Science cannot tell us what to do. It can give us information which we can use 
to make decisions. 

 

If the science gets mixed up with politics in peer-reviewed scientific 
publications, I think it ends up weakening the credibility of the entire 
scientific publication process (since statements whose truth value cannot be 
empirically established are obviously getting past reviewers). 

 

I should say that the worst in this respect are the economists

Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Mike MacCracken]

As I understand it from scientific presentations at the IUGG conference in
Melbourne, recent reconciliation of US and European satellite observations
of solar irradiance give a quiet sun value of 1360.8 W/m2 (so average over
the Earth of 340.2 W/m2 before about 30% reflected)--two years ago the
baseline values of the instruments differed by about 5 W/m2, although their
variations were in excellent agreement. Apparently, some stray light was
found to be leaking in, and correcting for this has brought observations of
the baseline into agreement.

The variation over solar cycles is really quite small compared to the
magnitude of the greenhouse forcing. Asserting that the accelerating melting
back of Arctic sea ice is due to the sunspot cycle is, given that the
relative magnitude of the GHG induced changes, is thus really
unsubstantiated wishful thinking.

Mike MacCracken

PS to Gene--Excellent correlation of what--and how accurate are each of the
records. Suggesting something is "perfect" would really mean no room for any
volcanic effects or anything else--just not a scientific statement.


On 7/24/11 4:33 PM, "esubscript...@montgomerycountymd.gov"
 wrote:

> Albert:
>  
> No! Geoengineering Yesterday. In any case it is interesting that sunspots are
> now getting attention. Most climate scientists have ignored sunspots despite
> excellent perfect  correlation back to the year 1500. So much for the science!
>  
> -gene
>  
> 
> From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com]
> On Behalf Of Veli Albert Kallio
> Sent: Sunday, July 24, 2011 4:23 PM
> To: wf...@utk.edu; kcalde...@gmail.com
> Cc: John Nissen; em...@lewis-brown.net; Geoengineering FIPC; John Nissen;
> Peter Wadhams
> Subject: RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
>  
> 
> Have you been wondering, why the North Pole's sea ice is looking like this
> today? 
> http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png
> <http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png
> > 
> 
> Cryosphere Today has reported a phenomenal North Pole melting:
> 
> North Pole's Ice Cap currently melts away at a phenomenal weekly rate of:
> 14.9%.
> 
> Melting figures of the Arctic Ocean for the last 7 days are:
> 
> 17.07.2011: ice area 5,456,000 km2 - melting   98,000 km2
> 18.07.2011: ice area 5,383,000 km2 - melting   73,000 km2
> 19.07.2011: ice area 5,283,000 km2 - melting 100,000 km2
> 20.07.2011: ice area 5,083,000 km2 - melting 200,000 km2 - 24 hour ice area
> reduction: 3.93%
> 21.07.2011: ice area 4,931,000 km2 - melting 152,000 km2 - 24 hour ice area
> reduction: 3.08%
> 22.07.2011: ice area 4,843,000 km2 - melting   88,000 km2
> 23.07.2011: ice area 4,726,000 km2 - melting 117,000 km2 - 24 hour ice area
> reduction: 2.48%
> 
> At the start of the week, 16.07.2011 the ice area was 5,554,000 km2.
>  
> A daily sea ice melting rate 77,000 km2 could melt all ice from the North Pole
> by the autumn equinox. The current rate of disappearing sea ice is much
> higher. This suggests that the open seas are increasing solar energy
> absorption at higher rates than the shortening of daylight hours are reducing
> the sunlight supply. A return of cold weather and clouds can break this
> vicious circle.
>  
> The fact that the North Pole Sea Ice Cap is able to lose 10.5% of its size in
> just over the last 4 days is a matter of immense concern to me as our train
> may have already lost its breaks...
> 
> WattsUpWithThat.com suggests the sun has entered a more intense phase in its
> sun-spot cycle and the sea ice is now melts. They now say the sea ice melting
> intensifies over the next few years until solar activity peaks, after that the
> sunspots disappear and the Arctic Oceans sea ice cover recovers. The concern
> over melting sea ice is alarmism as it is all due to a recent change in solar
> weather, the increasing radiation drives global warming and, therefore, North
> Pole's sea ice is now melting.
> However, this contradicts their own sea ice area outlook projection:
> http://www.arcus.org/files/search/sea-ice-outlook/2011/07/images/pan-arctic/ju
> ly_panarctic_fig1.png
> <http://www.arcus.org/files/search/sea-ice-outlook/2011/07/images/pan-arctic/j
> uly_panarctic_fig1.png>
> 
> In June WattsUpWithThat.com forecasted the second largest sea ice area in
> September with ice area recovery to 5,100,000 km2. WattsUpWithThat.com
> forecasting logic apparently expects the Arctic Ocean to be freezing 374,000
> km2 by September.
>  
> We should change our Googlrgroup's name to: Geoengineering Now!
>  
> Kind regards,
>  
> Albert
>  
> 
> 
> From: wf...@utk.edu
> To: kcalde...@gma

Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[Andrew Lockley]

er sea ice at around 2016 +/- 3 years;
>
> b) a vast quantity of Arctic methane is in a critical condition such that it
> could be released into the Arctic atmosphere over the next decade or two,
> sufficient to cause more global warming than CO2;
>
> c) the sensitivity of the climate to radiative forcing appears to be much
> great than previously thought - which emphasises the importance of retaining
> the sea ice and preventing a methane excursion.
>
> 2.  If you take into account the threat of ocean acidification, then the CDR
> (carbon dioxide removal) is required as well as SRM.
>
> Cheers,
>
> John
>
> ---
>
> On Sun, Jul 24, 2011 at 2:14 PM, Andrew Lockley 
> wrote:
>>
>> Well I think that the scientific evidence is clear. Considering population
>> effects, current social change (urbanization, industrialization) and
>> technology/political lag, I say that we cannot avoid dangerous climate
>> change of 2C or higher without geoengineering -  specifically SRM. ( less
>> than 5% chance)  And that is without considering the chronic apathy of the
>> worlds governments on the issue. Even 2C is probably not safe.
>>
>> Prior work on the issue tends to underestimate feedbacks, societal lag
>> times and current emissions trajectories. We have been conning ourselves for
>> far too long.
>>
>> Shoot me down if you can, but I'll put a hundred dollars on me being
>> right.
>>
>> And if I am right, we better have our ships and planes ready when it all
>> kicks off, because otherwise we'll be the shepherds who should have cried
>> wolf.
>>
>> I get sick of all this pussy-footing. We need to be clear. We can already
>> be highly confident that geoengineering is needed. We therefore need to be
>> building knowledge and capacity right now.
>>
>> Who will step up and challenge me? Etc group? Any other takers?
>>
>> A
>>
>> On 24 Jul 2011 12:50, "Eugene Gordon"  wrote:
>> > I support John Nissen’s view with some slight modification of the
>> > wording, but not the theme. I like his use of the expression, ‘appears to 
>> > be
>> > likely happening’ and want to amplify that. I don’t like Ken’s use of ‘I am
>> > confident’. As scientists we can express conviction but not certainty until
>> > it has been achieved following the Scientific Method. The current climate
>> > observations are highly suggestive of a continuing pattern that will have
>> > increasingly disastrous effects. I emphasize there is no certainty. 
>> > However,
>> > if what we are observing is mostly caused by anthropogenic CO2 emissions
>> > then it is probably too late to rely on reducing such emissions. Yes, we
>> > must no doubt do it out of respect for the current understanding and for
>> > potential future benefits, but reducing CO2 emissions will probably not 
>> > save
>> > the day. In parallel, and with comparable conviction, we espouse various
>> > geoengineering means for halting the perceived, impending disaster. It is
>> > highly likely we can design and put in place limited experiments to test 
>> > the
>> > ability to mitigate or delay. Why do we talk about full implementation
>> > rather than careful, limited, experimental tests with minimal risk?
>> > Implementation is a threat to some. Careful, limited testing is far more
>> > benign.
>> >
>> >
>> >
>> > -gene
>> >
>> >
>> >
>> >
>> >
>> > From: geoengineering@googlegroups.com
>> > [mailto:geoengineering@googlegroups.com] On Behalf Of John Nissen
>> > Sent: Saturday, July 23, 2011 6:46 PM
>> > To: kcalde...@stanford.edu
>> > Cc: em...@lewis-brown.net; geo-engineering grp; John Nissen
>> > Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
>> >
>> >
>> >
>> > reference [1]
>> > http://unfccc.int/essential_background/convention/background/items/1355.php
>> >
>> > On Sat, Jul 23, 2011 at 11:43 PM, John Nissen 
>> > wrote:
>> >
>> >
>> > Ken,
>> >
>> > We all like to be optimistic - it is a human characteristic. But if you
>> > accept what is happening to the Earth System, as being discovered by people
>> > like Hansen, Wadhams and Shakhova (on climate sensitivity, sea ice retreat
>> > and Arctic methane respectively), then the situation is dire for every 
>> > human
>> > on this planet. This is not a question of perspective, but an appreciation
&

Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise

[rongretlarson]

List, Andrew, John , David , Ken 

Andrew - I have re-read the paper you have cited below and decided to try to 
put the numbers there into the context of the paper by Dr. David Wasdell that 
you alerted us to on the 20th - which I also. found fascinating. For others, I 
am referring to a large body of work on climate feedbacks that can be found at 
http://www.apollo-gaia.org/. The specfic one of most pertinence to this 
discussion and comparison to the Davis-Caldeira Science article (that you cite 
below) is at: 

http://www.apollo-gaia.org/Climate%20Sensitivity.pdf 

Using the numbers from the recent (Science-Davis-Caldeira) cite, I find (from 
the right hand sides of their figure 1 C (for ppm CO2) and figure 1d - for 
temperature rise, presumably above the 280 ppm level), those three points fall 
slightly below the straight line that Dr. Wasdell terms the "Charney 
sensitivity". Dr. Hansen would be about 2.5 times higher in predicted 
temperature and Dr. Wasdell about 3 times higher (both including positive 
feedbacks that I believe all would agree are not included in the Davis-Caldeira 
pape)r. 

This is not meant to be a criticism of theDavis Caldeira paper - as they 
clearly stated which model they were employing to come to their conclusions - 
and there are many valuable conclusions there. But I do think it important in 
the current discussion (see the thread title) on Hansen to point out this 
factor of 2.5 - which (by Dr.Wasdell) could be a factor of 3. Everyone seems 
convinced that the current breed of models is leaving out a lot - and 
apparently mostly of the positive freedback character. I don't believe that 
message is being heard at all clearly by the general population (which is what 
Andrew is betting his $100 on). 

For those who have not read the Wasdell analysis, his higher curve is justified 
by experimental (not theoretical) results attributed to three publications of 
other investigators besides Dr. Hansen - namely (in shorthand) Engelbeen 
(Vostok), Pagani (Paleo), and Kiehl (100 Ma history). They together validate 
(amazingly closely) his climate senstivity proposal of 7.8 degrees at 560 ppm 
(doubling). Davis-Caldeira are at about 2.5; Hansen at 6 degrees. 

Also need to point out that Dr. Hansen sees about a 50 ppm drop from 
"geoengineering" only with 100 Gt C of new forests -which can be amplified a 
good bit when combined with Biochar. 

I include John Nissen as a cc - as this "Wasdell" approach strongly supports 
his proposal to move faster generally because of the positive feedback that is 
surely not being considered in the Davis-Caldeira model - but is so apparent 
already in the Arctic. ANd is the reason for this thread. 

I hope someone closer to this than myself can explain how slow the missing 
feedbacks might be - and why. From what I have read there have been some pretty 
dramatic quick "flips" in the past. 

Ron 
- Original Message -
From: "Andrew Lockley"  
To: "John Nissen"  
Cc: "geo-engineering grp"  
Sent: Monday, July 25, 2011 11:49:48 AM 
Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise 

For an alternative perspective on committed warming, note the following: 

Comment in SciAm 
http://www.scientificamerican.com/article.cfm?id=guaranteed-global-warming-with-existing-fossil-fuel-infrastructure
 
Paper in Science http://www.sciencemag.org/content/329/5997/1330.abstract 

"Slowing climate change requires overcoming inertia in political, 
technological, and geophysical systems. Of these, only geophysical 
warming commitment has been quantified. We estimated the commitment to 
future emissions and warming represented by existing carbon 
dioxide–emitting devices. We calculated cumulative future emissions of 
496 (282 to 701 in lower- and upper-bounding scenarios) gigatonnes of 
CO2 from combustion of fossil fuels by existing infrastructure between 
2010 and 2060, forcing mean warming of 1.3°C (1.1° to 1.4°C) above the 
pre-industrial era and atmospheric concentrations of CO2 less than 430 
parts per million. Because these conditions would likely avoid many 
key impacts of climate change, we conclude that sources of the most 
threatening emissions have yet to be built. However, CO2-emitting 
infrastructure will expand unless extraordinary efforts are undertaken 
to develop alternatives." 

The authors note the pending expansion of infrastructure. I can't 
access the paper, so I can't see the assumptions used. However, I 
strongly suspect that it won't include Schaeffer's methane estimates 
(see summary comment on Climate Progress 
http://thinkprogress.org/romm/2011/02/17/207552/nsidc-thawing-permafrost-will-turn-from-carbon-sink-to-source-in-mid-2020s-releasing-100-billion-tons-of-carbon-by-2100/).
 
I also suspect that it won't be using the carbon cycle feedback and 
consequential sensitivity estimates recently exchanged on this