"Tipping points" again
James Annan
-
http://environment.guardian.co.uk/climatechange/story/0,,1865081,00.html
"The scientific opinion is that we have a ceiling of 440 parts per
million [ppm] of atmospheric carbon before there is a tipping point, a
step change in the rate of global warming," said Professor Smith.
-
RC did a good-humoured take-down of some of the "tipping points"
rhetoric some time ago. But it keeps on coming back like a bad
penny...it really makes me wonder if there is something in the human
psyche that requires the existence of an impending catastrophe.
(Whatever happened to good old bird flu?)
My prediction, for what it's worth, is that we will be told we have "10
years to act" indefinitely, certainly well beyond a decade from now,
irrespective of any actions that are taken.
James
William M Connolley
On Wed, 6 Sep 2006, James Annan wrote:
> Does this make sense to anyone here?
> -
> http://environment.guardian.co.uk/climatechange/story/0,,1865081,00.html
>
> "The scientific opinion is that we have a ceiling of 440 parts per
> million [ppm] of atmospheric carbon before there is a tipping point, a
> step change in the rate of global warming," said Professor Smith.
> -
Only in that I heard that he was "some kind of architect" (not sure if its even
the same chap) with a somewhat wacky take on things...
> RC did a good-humoured take-down of some of the "tipping points"
> rhetoric some time ago. But it keeps on coming back like a bad
> penny...it really makes me wonder if there is something in the human
> psyche that requires the existence of an impending catastrophe.
> (Whatever happened to good old bird flu?)
>
> My prediction, for what it's worth, is that we will be told we have "10
> years to act" indefinitely, certainly well beyond a decade from now,
> irrespective of any actions that are taken.
But would you bet on it ;-)?
-W.
William M Connolley | w...@bas.ac.uk | http://www.antarctica.ac.uk/met/wmc/
Climate Modeller, British Antarctic Survey | (01223) 221479
If I haven't seen further, it's because giants were standing on my shoulders
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James Annan
> Only in that I heard that he was "some kind of architect" (not sure if its even
> the same chap) with a somewhat wacky take on things...
I guess the headline:
"Climate change will reach point of no return in 20 years, says expert"
was originally "Climate change will reach point of no return in 20
years, says expert in the completely unrelated field of sustainable
energy". But of course these things always get edited down :-)
>>
>>My prediction, for what it's worth, is that we will be told we have "10
>>years to act" indefinitely, certainly well beyond a decade from now,
>>irrespective of any actions that are taken.
>
>
> But would you bet on it ;-)?
Most assuredly. Of course, there will also be plenty of "we're all
doomed", "better get used to it" and "Rarely is the questioned asked, is
our children learning?"
Oops. I meant "The fundamental debate: is it manmade or natural?"
Of course, not all of the above will appear in the peer-reviewed
literature - I hope :-)
James
crandles
team also seem to be pretty much "on board with real climate" over the
tipping point situation. However, Myles Allen did suggest that the most
likely near tipping point could be economic in that the cost of dealing
with 'it', (whatever 'it' is), is likely to increase more than
exponentially.
Fuller details of this answer can be heard by listening to:
http://www.climateprediction.net/science/pubs/OpenDay2006/q_a_1.wmv
between 23 minutes 10seconds to 25:30.
Other climateprediction.net open day talks are available from
Alastair McDonald
>
> -
> http://environment.guardian.co.uk/climatechange/story/0,,1865081,00.html
Since he does not seem to be claiming he is a climate scientist, perhaps he
was quoting James Hansen. See:
http://www.cbsnews.com/stories/2006/03/17/60minutes/main1415985.shtml
Hansen also wrote:
"The CO2 amount of 440 ppm is a critical threshold. Other things being
"normal", it is the peak CO2 amount in a scenario (1) that would keep
additional global warming from exceeding 1°C (1.8°F). Based on the history
of the Earth, it is estimated that warming greater than 1°C above today's
level would weaken the ice sheets that cover Greenland and Antarctica,
causing eventual rise of sea level by several meters. "
See http://www.giss.nasa.gov/research/briefs/hansen_11/
Imagine you have an old set of scales, like the kind used to symbolise
justice. If you put a pound weight in one pan the scales will tip over
on that side, then add a weight of one gram to the other pan and
nothing will happen.
Add 2nd gram weight to the second pan and nothing will happen.
Add 3rd gram weight to the second pan and nothing will happen.
Add 4th gram weight to the second pan and nothing will happen.
...
Add 100th gram weight to the second pan and nothing will happen.
...
Add 200th gram weight to the second pan and nothing will happen.
...
Add 300th gram weight to the second pan and nothing will happen.
Add 400th gram weight to the second pan and nothing will happen.
...
Add 450th gram weight to the second pan and nothing will happen.
Add 451st gram weight to the second pan and nothing will happen.
Add 452nd gram weight to the second pan and nothing will happen.
Add 453rd gram weight to the second pan and nothing will happen.
Add 454th gram weight to the second pan and the scales will tip over.
The Greenland ice is like those scales. When global temperature rises
above a certain level it will begin to melt, and if the temperature does
not fall then the ice will eventually disappear completely. But if we stop
pumping CO2 into the atmosphere the temperature will not fall. It will
continue to rise because of 'commitment'.
See http://www.ucar.edu/news/record/
----------
Related Article: The Climate Change Commitment
Wigley, T.M.L. (2005), "The Climate Change Commitment," Science, vol. 307,
pp. 1766-69.
Abstract
Even if atmospheric composition were fixed today, global-mean temperature
and sea level rise would continue due to oceanic thermal inertia. These
constant-composition (CC) commitments and their uncertainties are
quantified. Constant-emissions (CE) commitments are also considered. The CC
warming commitment could exceed 1°C. The CE warming commitment is 2° to 6°C
by the year 2400. For sea level rise, the CC commitment is 10 centimeters
per century (extreme range approximately 1 to 30 centimeters per century)
and the CE commitment is 25 centimeters per century (7 to 50 centimeters per
century). Avoiding these changes requires, eventually, a reduction in
emissions to substantially below present levels. For sea level rise, a
substantial long-term commitment may be impossible to avoid.
---------
James, what levels of CO2 do you think we should not exceed, bearing in
mind that at 380 ppm the Greenland ice sheet is already starting to melt,
hurricanes are starting to intensify, and forest fires are raging throughout
the world?
Coby, do you see now why geo-engineering is necessary. Even a
complete ban on all fossil fuel burning would not prevent serious
repercussions
Cheers, Alastair.
James Annan
> James, what levels of CO2 do you think we should not exceed, bearing in
> mind that at 380 ppm the Greenland ice sheet is already starting to melt,
> hurricanes are starting to intensify, and forest fires are raging throughout
> the world?
I think that under any reasonably comprehensive assessment of global
change, the AGW-induced change will, in the long term, be close to
logarithmic in the concentration of CO2 (assuming some rough
stabilisation). I don't have much idea for an "optimal" trajectory of
CO2 into the future given the various competing demands, but I do think
that it would be sensible to work significantly harder towards limiting
emissions than we are currently doing. Personally, I would start with a
revenue-neutral carbon tax, which seems like a complete no-brainer which
would steer the market in the right direction without the need for
excessive red tape and regulation. If I were king for a day, I'd do that
within the UK even without international co-operation, as I am sure that
the long-term benefits (eg energy efficiency/independence, development
of world-leader status in new technology) would be substantial. But
unfortunately the concept of a "new tax" (even one that simply replaces
old taxes) is electoral suicide given a brain-dead electorate and
dishonest media.
I see no sign, or even hint, or even hypothesis, which supports the
claim of "a step change in the rate of global warming" at 440ppm or any
other level, which is the quote with which I started this thread. But
maybe in 1000 years, Greenland will be green and Londoners will have gills.
James
Don Libby
From: "Alastair McDonald" <a...@abmcdonald.freeserve.co.uk>
Newsgroups: gmane.science.general.global-change
Sent: Wednesday, September 06, 2006 5:14 PM
Subject: [Global Change: 578] Re: "Tipping points" again
(snip)
Hansen also wrote:
"The CO2 amount of 440 ppm is a critical threshold. Other things being
"normal", it is the peak CO2 amount in a scenario (1) that would keep
additional global warming from exceeding 1°C (1.8°F). Based on the history
of the Earth, it is estimated that warming greater than 1°C above today's
level would weaken the ice sheets that cover Greenland and Antarctica,
causing eventual rise of sea level by several meters. "
See http://www.giss.nasa.gov/research/briefs/hansen_11/
Related Article: The Climate Change Commitment
Wigley, T.M.L. (2005), "The Climate Change Commitment," Science, vol. 307,
pp. 1766-69.
Abstract
Even if atmospheric composition were fixed today, global-mean temperature
and sea level rise would continue due to oceanic thermal inertia. These
constant-composition (CC) commitments and their uncertainties are
quantified. Constant-emissions (CE) commitments are also considered. The CC
warming commitment could exceed 1°C. The CE warming commitment is 2° to 6°C
by the year 2400. For sea level rise, the CC commitment is 10 centimeters
per century (extreme range approximately 1 to 30 centimeters per century)
and the CE commitment is 25 centimeters per century (7 to 50 centimeters per
century). Avoiding these changes requires, eventually, a reduction in
emissions to substantially below present levels. For sea level rise, a
substantial long-term commitment may be impossible to avoid.
---------
(end quote)
The two most aggressive emission reduction scenarios in SRES/TAR (A1T and
B1) would stabilize CO2 between 500 & 600 ppm by 2100. Both of these
scenarios assume a reduction in emissions to substantially below present
levels by 2100, yet both would yield peak concentrations above Hansen's 440
and current CC 380. Damned if we do and damned if we don't, so why bother?
(Hint: what CC commitment level avoids 60 meter sea level rise by 6000 AD?)
-dl
Alastair McDonald
> I see no sign, or even hint, or even hypothesis, which supports the
> claim of "a step change in the rate of global warming" at 440ppm or any
> other level, which is the quote with which I started this thread. But
> maybe in 1000 years, Greenland will be green and Londoners will have
> gills.
You provided a convincing argument for your beliefs, but I must confess
that I have found by beliefs in error in the past. I believed that the Big
Bang Theory was rubbish and I was completely convinced that the
expansion of the Universe was the result of continuous creation. I also
believed that the Younger Dryas (YD) stadial began when the pro-glacial
Lake Agassiz burst out through the Gulf of St. Lawrence. That seems
untrue now as well.
A HINT
The evidence shows that over the last 120,000 year the climate of the
northern hemisphere has changed abruptly. When the last glacial maximum
ended 20,000 years ago, that was an abrupt climate change to conditions
warmer than today. This was followed by a severe blip, then later the
climate deteriorated in two steps back to glacial conditions of the YD
stadial. When the YD ended, temperatures in Greenland rose by 20F
in as little as three years. This is more than a hint that climate alters
in step changes, not smoothly.
Of course it is argued that the rapid changes all happened went he NH
was covered in ice, but there is still ice in the NH. There is the ice
sheet in Greenland and the sea ice in the Arctic Ocean. Thus whether
it is land or sea ice which is responsible for those abrupt changes, the
potential for yet another rapid change is still there. And of course,
rapid changes are not restricted to cooling. From LGM to Holocene,
there were 3 major rapid changes only one, entry to the YD, of which
was a cooling, although that is the one best known.
.
NO SIGN
In my example of a tipping point there is no sign of the scales tipping,
until the threshold is exceeded, therefore there will be no sign. This
is one of the dangers of abrupt climate change - it will happen without
warning!
A HYPOTHESIS
Your argument that since CO2 will slowly increase then so will temperature
does seem to make sense, however have you considered what happens
when ice melts. The temperature remains steady at the melting point
until all the ice has gone then it starts to rise. The disappearance of the
ice is a tipping point when the temperature start to leap. Unlike my
example of the scales, this is directly applicable to climate. It seems
that the NH ice is a cause of rapid climate change. In fact the hypothesis
that sea ice causes rapid climate change is expounded in this paper:
http://www.deas.harvard.edu/climate/eli/reprints/Gildor-Tziperman-2003.pdf
440ppm ?
Of course that leaves the question "Why is 440 ppm the magic number?"
Well I don't believe it is. The Greenland and Arctic sea ice is already
melting and because of the ice albedo effect, the melting can only
accelerate. We have already passed one tipping point, and we are
sliding faster and faster towards the next!
Cheers, Alastair.
Alastair McDonald
> Damned if we do and damned if we don't, so why bother?
Shouldn't that be "Damned if we do and exterminated if we don't."
> (Hint: what CC commitment level avoids 60 meter sea level rise by 6000
> AD?)
Hint: without the ice the Earth's albedo is greatly reduced causing global
warming
well in excess of that induced by a doubling of CO2. Think of the Eocene
for
similar levels of greenhouse gases and ice.
Cheers, Alastair.
PS There is a recent report published in ScienceExpress at
http://www.sciencemag.org/cgi/rapidpdf/1129007v1.pdf
Satellite Gravity Measurements Confirm Accelerated Melting of Greenland Ice
Sheet
J. L. Chen 1*, C. R. Wilson 2, B. D. Tapley 1
Abstract
Using time-variable gravity measurements from the Gravity Recovery and
Climate Experiment (GRACE) satellite mission, we estimate ice mass changes
over Greenland during the period April 2002 to November 2005. After
correcting for effects of spatial filtering and limited resolution of GRACE
data, estimated total ice melting rate over Greenland is -239 ± 23 cubic
kilometers per year, mostly from East Greenland. This estimate agrees
remarkably well with a recent assessment of -224 ± 41 cubic kilometers per
year, based on satellite radar interferometry data. GRACE estimates in
southeast Greenland suggest accelerated melting since the summer of 2004,
consistent with the latest remote sensing measurements.
======================
If we take the current rate of melting as 250 cubic kilometers (CK) and
the total Greenland ice as 2,500,000 CK, then it will melt completely in
10,000 years. But until three years ago it was melting at 80 CK, so in
three years it has increased by three times. In another nine years time
it
could be melting at 3^3 = 27 times faster. That would mean that the
life of the Greenland ice would be reduced to approx 400 years, and
nine years later to 15 years. So it could all be gone in less than
9 + 9 + 15 = 33 years!
Don Libby
From: "Alastair McDonald" <a...@abmcdonald.freeserve.co.uk>
Newsgroups: gmane.science.general.global-change
Subject: [Global Change: 582] Re: "Tipping points" again
> Damned if we do and damned if we don't, so why bother?
Shouldn't that be "Damned if we do and exterminated if we don't."
Many species will be exterminated, especially if they lack the knowledge or
ability to build climate-controlled enclosures. Doubtful that our species
would be exterminated, however, our way of life probably would be.
> (Hint: what CC commitment level avoids 60 meter sea level rise by 6000
> AD?)
Hint: without the ice the Earth's albedo is greatly reduced causing global
warming
well in excess of that induced by a doubling of CO2. Think of the Eocene
for
similar levels of greenhouse gases and ice.
Right, maintaining ice caps is a good motivator, but what level of
atmospheric CO2 stabilization is sufficient to avoid melting the ice caps?
440? 380? Less?
I don't think any of the SRES/TAR scenarios include methane emissions from
melted permafrost or oceanic caltrhates, do they?
If melting the ice caps cannot be avoided by any imaginable emissions
reduction scenario, then I say launch the aerosol parasol! (But don't over
do it.)
-dl
tom-b...@ntlworld.com
during the 1990s was due mainly to change in the earth's albedo and
that the warming effect of of CO2 has been vastly overestiimated.
William M Connolley
Errrrmmm... obviosuly there are so many of these things that you couldn't
possibly mention every one of them, but how about a quick quote from just one of
them that says, directly, "the warming effect of of CO2 has been vastly
overestiimated"?
Alastair McDonald
>> during the 1990s was due mainly to change in the earth's albedo and
>> that the warming effect of of CO2 has been vastly overestiimated.
>
> Errrrmmm... obviosuly there are so many of these things that you couldn't
> possibly mention every one of them, but how about a quick quote from just
> one of
> them that says, directly, "the warming effect of of CO2 has been vastly
> overestiimated"?
Yes, just one scientific paper arguing that or even a newspaper report
would
probably supply a lead tothe scientific soource.
I have not heard that idea being put forward before, but I think it is worth
pointing out that the melting of the ice is probably/certainly caused by the
higher levels of CO2.
Cheers, Alastair.
James Annan
> Errrrmmm... obviosuly there are so many of these things that you couldn't
> possibly mention every one of them, but how about a quick quote from just one of
> them that says, directly, "the warming effect of of CO2 has been vastly
> overestiimated"?
YHBT :-)
James
gerh...@aston.ac.uk
I think the main reason is the different impacts they would have on the
transportation sector and electricity in particular.
Even in the US, gasoline is taxed at around 50 cents per gallon (300
gallons or so per metric tonne, ie of the order of $150 per metric
tonne of carbon). In Europe gasoline taxes are the equivalent of close
to $1000 per metric tonne of carbon.
A metric tonne of coal might contain something like 7500 kWh (back of
the envelope, assuming 30 MJ/kg). With 33% efficiency that would yield
2500 kWh of electricity.
At $1000 per metric tonne of carbon, that would be an absolute killer
(40 cents per kWh in carbon taxes for coal generated electricity, back
of the envelope).
So, a carbon tax that's very modest in its effects for transportation
fuels would have huge impacts on the relative competitiveness of
natural gas, nuclear and coal.
Worse, coal is a low cost domestic fuel. Many countries do not want to
substitute it with imported natural gas or nuclear power. And
politicians know that that would be the main effect.
Consequently, nearly all taxation schemes in place make a distinction
between different sectors.
And if there is a gasoline tax in place (even in the US as said above,
not low in terms of $ per metric tonne of carbon), adding a separate
carbon tax just adds administrative costs, confusion. It's much more
straightforward to just raise the gasoline tax.
http://www.whitehouse.gov/news/releases/2001/03/20010314.html
--------------------------
'A recently released Department of Energy Report, "Analysis of
Strategies for Reducing Multiple Emissions from Power Plants,"
concluded that including caps on carbon dioxide emissions as part of a
multiple emissions strategy would lead to an even more dramatic shift
from coal to natural gas for electric power generation'
--------------------------
(President Bush on the subject)
Even in countries that do place a great political emphasis on climate
change, politicians know what a single carbon tax level across all
sectors would do, and they generally don't like it. They'll make
exemptions for coal (Germany for example - and the scheme isn't
actually a carbon tax, but the European Emissions Trading Scheme, which
is close) or for farmers (New Zealand), and they'll tax diesel,
gasoline, kerosene, heating oil, nuclear electricity and red diesel all
differently per metric tonne of carbon (the climate change levy in the
UK translates into something stratospheric for nuclear, and something
extremely modest for coal - it's per kWh of electricity rather than per
tonne of carbon ...)
Don Libby
From: "Don Libby" <dli...@tds.net>
Newsgroups: gmane.science.general.global-change
Sent: Thursday, September 07, 2006 8:28 AM
Subject: [Global Change: 583] Re: "Tipping points" again
> Right, maintaining ice caps is a good motivator, but what level of
> atmospheric CO2 stabilization is sufficient to avoid melting the ice caps?
> 440? 380? Less?
A piece of the puzzle from http://www.grida.no/climate/ipcc_tar/wg1/358.htm
suggests that stabilization at 2x pre-industrial atmos CO2 concentration
would lead to stable air temperature increase of 2-4 degrees C over present.
The missing piece: is air temperature increase of 2-4 degrees C sufficient
to melt the polar ice sheets over 4-5 thousand years?
-dl
William M Connolley
On Sat, 9 Sep 2006, Don Libby wrote:
> The missing piece: is air temperature increase of 2-4 degrees C sufficient
> to melt the polar ice sheets over 4-5 thousand years?
Gr yes; Ant no.
-W.
Don Libby
From: "William M Connolley" <w...@bas.ac.uk>
Newsgroups: gmane.science.general.global-change
Sent: Saturday, September 09, 2006 2:37 PM
Subject: [Global Change: 604] Re: "Tipping points" again
>
>
> On Sat, 9 Sep 2006, Don Libby wrote:
>> The missing piece: is air temperature increase of 2-4 degrees C
>> sufficient
>> to melt the polar ice sheets over 4-5 thousand years?
>
> Gr yes; Ant no.
>
> -W.
Gr maybe - we don't really know the extent of ice cover during the Holocene
Thermal Maximum, approx 5-10 k years ago, when temps were an estimated 3
degrees C higher - do we?
Ant no - Vostok cores show temps tipping into that range about 10k ybp,
130k, 240k, 325k, and 410k - and obviously, there remained ice cover at
Vostok throughout.
So, I guess Hansen likes stabilization at 440 because it commits us to a
global warming in the neighborhood of previous warmings that the ice caps
and humans have survived - and avoids tipping into Alistair's ice-free
Eocene, perhaps.
-dl
Coby Beck
news:<Pine.GSO.4.55.0609092037440.15629@bsucena>...
>
>
> On Sat, 9 Sep 2006, Don Libby wrote:
> > The missing piece: is air temperature increase of 2-4 degrees C
sufficient
> > to melt the polar ice sheets over 4-5 thousand years?
>
> Gr yes; Ant no.
(after quickly realizing that was not "Grrr, yes and no"!) I wonder if the
answer is not
GIS: yes,
WAIS: maybe/partly
EAIS: no
Coby
Coby Beck
news:<000501c6d45a$07bcb2b0$e97ede42@youro0kwkw9jwc>...
> >> The missing piece: is air temperature increase of 2-4 degrees C
> >> sufficient
> >> to melt the polar ice sheets over 4-5 thousand years?
> >
> > Gr yes; Ant no.
> >
>
> Gr maybe - we don't really know the extent of ice cover during the
Holocene
> Thermal Maximum, approx 5-10 k years ago, when temps were an estimated 3
> degrees C higher - do we?
I don't think it is generally accepted that the Holocene Maximum was 3oC
higher. NOAA says it was primarily a seasonal only variation (and
regional), being a NH summer phenomenon.
"In summary, the mid-Holocene, roughly 6,000 years ago, was generally warmer
than today, but only in summer and only in the northern hemisphere. More
over, we clearly know the cause of this natural warming, and know without
doubt that this proven "astronomical" climate forcing mechanism cannot be
responsible for the warming over the last 100 years."
http://www.ncdc.noaa.gov/paleo/globalwarming/holocene.html
> Ant no - Vostok cores show temps tipping into that range about 10k ybp,
> 130k, 240k, 325k, and 410k - and obviously, there remained ice cover at
> Vostok throughout.
How long were these temps maintained?
> So, I guess Hansen likes stabilization at 440 because it commits us to a
> global warming in the neighborhood of previous warmings that the ice caps
> and humans have survived - and avoids tipping into Alistair's ice-free
> Eocene, perhaps.
WRT survial, don't forget that the key difference is the rate at which we
are warming, not whatever temperature we may stabilize at.
Coby
Alastair McDonald
The ice in Greenland did not melt during the Holocene otherwise there would
be no ice cores stretching back to the Eemian 120 k years ago. OTOH it
does seem likely that the ice they did melt during the Eemian when global
temperatures were 2-3C higher than today, which explains why the ice cores
from Greenland only go back 120,000 years.
Coby is right. It is a lot more complicated than is generally believed.
This also applies to the forcing. For an ice sheet to form it needs a
cold summer when the snow never retreats, but for an ice sheet to
melt it needs a warm winter, which implies an increase in greenhouse
gases. Those gases are CO2 and H2O, and their increase is caused
by warm oceans during the summer. The current melting of the ice
is a result of the increased CO2 thanks to Man.
Land and sea behave differently.
Land ice and sea ice behaves differently.
Summer and winter have different effects.
Greenhouse gases and solar radiation have different effects.
Of course the last point is not widely recognised since it is generally
believed that the forcing occurs near the tropopause for both solar and
greenhouse gases.
Although a rise of 2C will not melt the Antarctic ice at the high altitude
of the South Pole, it could cause a warm South Pacific ocean to emit
more CO2 which would melt some ice exposing a low albedo surface
which also causes warming and more melting of the ice.
Cheers, Alastair.
CobblyWorlds
> Errrrmmm... obviosuly there are so many of these things that you couldn't
> possibly mention every one of them, but how about a quick quote from just one of
> them that says, directly, "the warming effect of of CO2 has been vastly
> overestiimated"?
I think he's talking about this 'sort of thing'. Douglas Hoyt, Post 13
http://climatesci.atmos.colostate.edu/2006/09/01/peer-reviewed-paper-which-supports-the-lyman-et-al-ocean-cooling-diagnosis/
Which refers to:
http://home.wanadoo.nl/bijkerk/albedo2.GIF
and
http://home.wanadoo.nl/bijkerk/albedo-temp.GIF
(Both at the webpage of Andre Bjerk! - must be a year
since I locked horns with him, if time allowed I'd 'catch up' with him.
;)
And to:
Enric Palle "Can Earth's Albedo and Surface Temperatures Increase
Together?"
http://www.bbso.njit.edu/~epb/reprints/Palle_etal_EOS_2006.pdf
I'd welcome any thoughts on this issue of Albedo/Global Ave Temp.
I've still got quite a bit of reading to do before I venture any public
thoughts.
I'm trying to get the time to look into this, and much else, but keep
being
tied up by increasingly personal attacks by contrarists desperate
because
I keep demolishing their arguments. It seems to me that the rational
ones
have changed their minds or shut up, leaving a hardcore of nutty
fundamentalists.
William M Connolley
On Sat, 9 Sep 2006, Don Libby wrote:
> Gr maybe - we don't really know the extent of ice cover during the Holocene
> Thermal Maximum, approx 5-10 k years ago, when temps were an estimated 3
> degrees C higher - do we?
Try: http://en.wikipedia.org/wiki/Image:Holocene_Temperature_Variations.png
-W.
William M Connolley | w...@bas.ac.uk | http://www.antarctica.ac.uk/met/wmc/
Climate Modeller, British Antarctic Survey | (01223) 221479
If I haven't seen further, it's because giants were standing on my shoulders
--
William M Connolley
On Sun, 10 Sep 2006, CobblyWorlds wrote:
> > Errrrmmm... obviosuly there are so many of these things that you couldn't
> > possibly mention every one of them, but how about a quick quote from just one of
> > them that says, directly, "the warming effect of of CO2 has been vastly
> > overestiimated"?
>
> I think he's talking about this 'sort of thing'. Douglas Hoyt, Post 13
> http://climatesci.atmos.colostate.edu/2006/09/01/peer-reviewed-paper-which-supports-the-lyman-et-al-ocean-cooling-diagnosis/
Interesting, but doesn't actually say anything about CO2.
-W.
> Which refers to:
>
> http://home.wanadoo.nl/bijkerk/albedo2.GIF
> and
> http://home.wanadoo.nl/bijkerk/albedo-temp.GIF
> (Both at the webpage of Andre Bjerk! - must be a year
> since I locked horns with him, if time allowed I'd 'catch up' with him.
> ;)
>
> And to:
>
> Enric Palle "Can Earth's Albedo and Surface Temperatures Increase
> Together?"
> http://www.bbso.njit.edu/~epb/reprints/Palle_etal_EOS_2006.pdf
>
>
> I'd welcome any thoughts on this issue of Albedo/Global Ave Temp.
>
> I've still got quite a bit of reading to do before I venture any public
> thoughts.
> I'm trying to get the time to look into this, and much else, but keep
> being
> tied up by increasingly personal attacks by contrarists desperate
> because
> I keep demolishing their arguments. It seems to me that the rational
> ones
> have changed their minds or shut up, leaving a hardcore of nutty
> fundamentalists.
>
>
> >
William M Connolley | w...@bas.ac.uk | http://www.antarctica.ac.uk/met/wmc/
Don Libby
From: "William M Connolley" <w...@bas.ac.uk>
Newsgroups: gmane.science.general.global-change
Subject: [Global Change: 610] Re: "Tipping points" again
>
>
> On Sat, 9 Sep 2006, Don Libby wrote:
>> Gr maybe - we don't really know the extent of ice cover during the
>> Holocene
>> Thermal Maximum, approx 5-10 k years ago, when temps were an estimated 3
>> degrees C higher - do we?
>
> Try:
> http://en.wikipedia.org/wiki/Image:Holocene_Temperature_Variations.png
>
> -W.
This image shows a maximum anomaly less than 2 deg C, which conflicts with
statements that arctic temps were 3 deg C higher 5-10k ybp. Perhaps I am
confusing average temps above the arctic circle with global average temps?
WHEN THE CANADIAN ARCTIC WAS 5°C WARMER THAN TODAY
J.P. Briner et al., Quaternary Research. Volume 65, Issue 3, May 2006
Numerous proxies, including chironomid-inferred July air temperatures,
diatom-inferred lakewater pH, and sediment organic matter, reveal a
pronounced Holocene thermal maximum as much as 5°C warmer than historic
summer temperatures from 10,000 to 8500 cal yr B.P.
A wider look puts the estimated Holocene Thermal Maximum between 0.8 and 2.4
deg C :
Holocene thermal maximum in the western Arctic (0-180deg W)
D.S. Kaufman, et al Quaternary Science Reviews 23 (2004) 529-560
And from Greenland proper - it would appear that the ice sheet survived the
Eemian Thermal Maximum:
Here we present an undisturbed climate record from a North Greenland ice
core, which extends back to 123,000 years before the present, within the
last interglacial period. The oxygen isotopes in the ice imply that climate
was stable during the last interglacial period, with temperatures 5 degC
warmer than today.
K. K. Andersen, et al NATURE , VOL 431, 9 SEPTEMBER 2004
So, to my rather less expert eyes, it would appear that stabilization at 440
ppmv may be adequate to preserve a substantial portion of the Greenland ice
sheet for several thousand years. Is this a reasonable doubt?
-dl
CobblyWorlds
No it doesn't William,
But I've come across Hoyt, and one of my 'local dolts'( who probably
got it off Hoyt) via Climate Science, The claim is that this explains
the recent warming and therefore means CO2 has nil/less than expected
effect.
To quote from Hoyt:
"It seems to me that Hansen and all the modelers are ignoring
observations that show that solar insolation at the Earth's surface
has increased dramatically in recent years. The papers by Palle et al.,
Pinker et al., Wielicki et al., and Wild et al. show that these
insolation increases are roughly ten times larger than the
corresponding insolation changes attributable to greenhouse gases. It
seems to me that these observations invalidate the models."
I still find people using the general curve of a logarithm (when they
should consider it's local behaviour) and waving 'Beer-Lambert' round
like a talisman to ward off any suggestion of warming by CO2. (One of
said people is "Associate Director of Research, Faculty of Science &
Technology Chair" at a British university!)
James Annan
> If carbon taxes are such a non-brainer, why are they hardly used?
There was an attempt in this direction, the "fuel tax escalator" of the
previous Conservative administration in the UK, eventually abandoned a
few years ago under Labour. It only taxed transport fuel, of course. It
was brought down by a campaign of civil disobedience from a small number
of lorry-drivers and farmers, the latter who weren't even affected by
it, but who have a radical right-wing core which was eager to jump on a
bandwagon that they thought might bring down the Labour govt.
The press in the UK has a strong dependence on advertising from the car
industry, so was hardly likely to talk about the advantages of a
long-term well-signposted shift in taxation strategy.
Nevertheless, it would be remiss to ignore the fact that the tax which
is supposedly "very modest in its effects for transportation" might well
be a significant factor in explaining the remarkable difference in
efficiency of motor vehicles between the USA and most of the rest of the
developed world.
Fuel taxes tend to be regressive, and no-one would claim they are the
whole answer. But there is unlikely to be any magic bullet that solves
all the problems in one go. A lot of nudges in the right direction might
be more realistic.
James
gerh...@aston.ac.uk
maybe I wasn't terribly clear, or you didn't carefully read my posting.
What is hardly used is a general tax on carbon, ie one that is the same
for coal fired electricity and vehicle fuel.
Quoting what you said:
"Personally, I would start with a revenue-neutral carbon tax, which
seems like a complete no-brainer which would steer the market in the
right direction without the need for excessive red tape and regulation.
If I were king for a day, I'd do that within the UK even without
international co-operation, as I am sure that the long-term benefits
(eg energy efficiency/independence, development of world-leader status
in new technology) would be substantial."
Taxing petrol yields energy independence, taxing coal does not
(generally speaking).
It is well known what a revenue-neutral carbon tax that is the same for
all sectors would do at $100 per tonne of carbon (hmm steer the market
in the right direction without the need for excessive red tape and
regulation), it would kill coal and do little about transportation
demand.
The problem is that many politicians don't think that would be the
"right direction".
If you didn't mean a general carbon tax applicable across all sectors,
but instead just meant high taxes on transportation fuels, I am happy
with that, it is a no brainer, maybe with some argument about the ideal
level, but even in the US there are substantial taxes on gasoline and
diesel compared to the tax load on coal (or compared to the value of
the underlying product).
Countries usually make exceptions for coal, because they don't like the
alternatives (nuclear or nat gas imports, or very high priced
renewables).
Robert A. Rohde
temperatures 2-4 C warmer than now. For global warming predictions of
~3 C at 2100, polar temperatures may increase 5-8 C above modern.
It is entirely plausible that we will exceed the conditions of any
reasonable Eemian analog before the end of this century.
-Robert
James Annan
> James,
>
> maybe I wasn't terribly clear, or you didn't carefully read my posting.
Or perhaps we are talking rather at cross purposes.
I don't accept that a "carbon tax" would have to be a uniform rate
across all forms of CO2 emissions, even if this does seem a logical
starting point. Taxes always have exemptions and other details.
Obviously, even matching the existing taxes on petrol would cause a
major upheaval if aplied across the board. It's true that some (probably
most, perhaps even all) of the research seems to basically consider a
flat rate, but I interpret this to be a rough estimate, a sort of
starting bid rather than a definitive proposal. (Or more probably, it is
presented as an additional flat-rate tax on top of the taxes already
applied - I don't think the authors are advocating large tax cuts on
petrol.)
> It is well known what a revenue-neutral carbon tax that is the same for
> all sectors would do at $100 per tonne of carbon
I recall a figure of about $25-30 being suggested as reasonable (but if
that is per tonne of carbon as CO2 then it matches your figure). Even
that would not have to be introduced in one go - a clearly-signposted
ramping up of the tax from a small initial level over years (decades,
even) would give a long time to adapt, and plenty of incentive to do so.
Sequestration would probably be plausible at that level too.
James
gerh...@aston.ac.uk
figure of $25-30 per tonne of carbon dioxide then apply to?
Suppose, for coal, an equivalent subsidy was considered for its energy
independence and social benefits (saving the jobs of miners in areas of
Germany the Social Democrats hold very dear), isn't it much easier to
just have no tax and no subsidy?
And likewise for gasoline, why add another layer of complexity? Why not
just fold it into the general decision as to what the best level of the
gasoline tax should be?
And finally, what is the "no brainer" decision then that you were
talking about that policy makers aren't making even though it's such a
"no brainer"?
I am left a little bit confused as to what you are actually proposing
that is different from what is in fact widely done.
James Annan
> Ok, but if you don't want to impose a constant rate, what does that
> figure of $25-30 per tonne of carbon dioxide then apply to?
I would expect that $25-30 per tonne of CO2 could apply pretty much
across the board (but not instead of the existing taxes on petrol). You
suggested $100 per tonne of carbon which is a rather different
proposition entirely!
> Suppose, for coal, an equivalent subsidy was considered for its energy
> independence and social benefits (saving the jobs of miners in areas of
> Germany the Social Democrats hold very dear), isn't it much easier to
> just have no tax and no subsidy?
If some people/govts decide that energy independence (say, via local
coal) is more important than worrying abot CO2 emissions, that's up to
them. The "no brainer" was that if people want to reduce emissions, a
tax on them would surely push the market towards reductions (implicitly:
as an alternative to such ideas as emissions caps, regulations on
efficiency, govt-controlled investment in alternative energy in the hope
that some magic solution turns up...whatever other schemes there are
floating around).
> I am left a little bit confused as to what you are actually proposing
> that is different from what is in fact widely done.
What's (potentially) different is introducing a "polluter pays" penalty
for CO2. What is already widely done is by definition the status quo, so
hoping that it will result in emissions reduction seems like wishful
thinking.
James
gerh...@aston.ac.uk
> across the board (but not instead of the existing taxes on petrol). You
> suggested $100 per tonne of carbon which is a rather different
> proposition entirely!
As you said earlier, a tonne of carbon will yield 44/12=3.67 tonnes of
carbon dioxide. $100 per tonne of carbon is therefore the same as $100
per 3.67 tonnes of carbon dioxide or $27 per tonne of carbon dioxide.
If you do apply an additional tax of $25-30 per tonne of CO2 across the
board, that'll primarily hurt coal fired electricity generation, and
have a very modest effect on transportation (rough back of the
envelope, it would raise US gasoline prices by 10% and European
gasoline prices by 5%).
> If some people/govts decide that energy independence (say, via local
> coal) is more important than worrying abot CO2 emissions, that's up to
> them.
There is a continuum from subsidies to taxes and the final level can
depend on more than one factor. I don't see a problem with governments
saying that CO2 exactly offsets the benefits of coal (or nearly enough
so, administration costs mean that 0 is the appropriate rate even when
the offsetting yields a value slightly above or below 0).
> The "no brainer" was that if people want to reduce emissions, a
> tax on them would surely push the market towards reductions (implicitly:
> as an alternative to such ideas as emissions caps, regulations on
> efficiency, govt-controlled investment in alternative energy in the hope
> that some magic solution turns up...whatever other schemes there are
> floating around).
Yes a tax will yield (relatively speaking at least) emissions
reductions. That is a "no brainer".
> What's (potentially) different is introducing a "polluter pays" penalty
> for CO2. What is already widely done is by definition the status quo, so
> hoping that it will result in emissions reduction seems like wishful
> thinking.
The "polluter pays" penalty, I would argue, is already there, and
folded into the taxation/subsidy decisions for individual fuels.
Making it explicit by introducing offsetting taxes and subsidies (say
extra taxes on nuclear to make sure it does not benefit from the tax on
CO2), I think, potentially only introduces extra complexity.
If you are suggesting an increase in CO2 across the board by $25-30, I
accept that'll reduce emissions compared to not having the tax (though
it's unlikely to be enough to actually reduce emissions, rather it'll
lower the emissions growth rate), but I can also tell you why
governments are not very keen, and that as said this across the board
increase would primarily affect the competiveness of coal, and with
restrictions on nuclear build, particularly so compared with natural
gas, as $25-30 is not enough at present to make much of a difference
for renewables.
Earlier though, you were suggesting that you wouldn't want the carbon
tax applied across the board. If you wanted increases primarily in
gasoline taxes, I'd be very happy with that, particularly where the US
is concerned (though phased in there's already been a hefty price
increase over recent years in the US).
I'd also be very happy, if you wanted to enhance the competitiveness of
nuclear. For me France is the model country in terms of energy policy,
and they don't even need an explicit carbon dioxide tax to get to per
capita emissions a third those of the US (6 2/3 compared to 20
roughly), and 40% lower (6 2/3 compared to 11) than Germany and
Denmark.
If you want more renewables, direct subsidies for renewables are the
much better option, otherwise CO2 taxes would have to rise to levels
that'll kill coal and lead to either 80% + nuclear (if the regulatory
environment is favourable) or 80% + natural gas and substantial price
increases for consumers.
Michael Tobis
> There is a continuum from subsidies to taxes and the final level can
> depend on more than one factor. I don't see a problem with governments
> saying that CO2 exactly offsets the benefits of coal (or nearly enough
> so, administration costs mean that 0 is the appropriate rate even when
> the offsetting yields a value slightly above or below 0).
The problem is not that 0 is excluded a priori. The problem is that 0
is bad policy once we consider the actual evidence.
From the climate change and ocean chemistry points of view, a ton of
carbon is a ton of carbon; hence the environmental costs are
equivalent. On the short-run geopolitical calculus, you argue, I
think, that coal is preferable because it is plentiful (and hence
available in sufficient quantities from more stable and mature
countries). In the long run, though, coal is the far greater threat
for exactly the same reason, its abundance. If we tax other fossil
fuels relative to coal we encourage building infrastructure that
depends upon coal, making it even harder to move away from it.
But it's coal that provides the bulk of our carbon fuel inventory. A
world in which all the petroleum and methane have been burned over the
next few centuries will be a dramatically changed one, but it may not
be catastrophic. On the other hand, a world in which all the coal has
been consumed on that time scale will likely be disastrous on a scale
that surpasses even a massive exchange of nuclear weapons. We simply
must not dig up all the coal.
In addition, coal provides substantially less energy per ton of CO2.
Perhaps this is redundant: it's why a carbon tax shifts us away from
coal after all. However, in the planetary view, a preference for coal
to petroleum is sheer lunacy, as it yields fewer benefits and more
costs.
You argue for the cost/benefit calculations of individual countries.
This is very like the libertarian fallacy which assumes that the best
policy for the nation is simply the aggregate of the best policy for
individuals. It is very easy to identify important examples where this
is not the case. Similarly, the best policy for the world is not the
aggregate of the best policy of its individual nations. That is
precisely the nut of the problem.
By reasserting parochial interests over the interests of the globe,
you are of necessity misallocating costs and benefits on a global
scale. It's always in my personal benefit to have cheap fuel: my
personal incremental impact on the climate system will always be
trivial. In a similar way, it may always be in the selfish interests
of any country to burn coal. The consequences of failing to reframe
the question in global terms are at the root of the trainwreck we see
coming.
There is time to hit the brakes, but I share Coby's pessimism that we
will have the maturity to manage. The train is on autopilot, and I see
your argument as encouraging the human engineers to remain asleep.
mt
gerh...@aston.ac.uk
I see where you are coming from.
Germany or Denmark are countries that put considerable emphasis on
climate change, yet neither has a carbon tax as such.
What I am trying to answer is the question why that is so.
And I think the answer is that while they value climate highly they
value energy independence (and particularly in the case of Germany
social benefits) just as highly.
As happens, personally I'd favour energy policies like those in France.
Replacing coal with nuclear should cut world CO2 emissions something
like 30 or 40%. High gasoline taxes might cut US transportation demand
in half. I do find it instructive to look at French per capita
emissions compared to other countries.
http://www.eia.doe.gov/pub/international/iealf/tableh1cco2.xls
F 2000 6.73
F 2004 6.71
Germany 2000 10.31
Germany 2004 10.46
USA 2000 20.60
USA 2004 20.18
At $25 per tonne as an implicitly accepted reasonable value for CO2, I
think that other considerations are more important for the tax/subsidy
decision. Gasoline is taxed ten times as heavily as that in Europe.
Deep mined coal in Germany still gets heavy subsidies. Based on a quick
google, about a hundred euros per tonne of carbon, though this is
supposed to be phased out.
A hundred Euros per tonne is nearly twice the cost of imported coal,
and it is over $30 per tonne of carbon dioxide (the link is to a German
Green Party website).
I suppose another way of expressing my main point is:
If CO2 taxes are to have a significant impact that goes beyond the
value put on other considerations, $25 as an implicit value is too low.
That's less than the fear premium put on nuclear power in Germany, or
the energy independence premium coal has in places like Germany,
Denmark, the UK, the US or Malaysia.
-------------------
With CO2 taxes being implicit, rather than explicit, it is rather tough
to estimate what the implied value actually is. After all it depends on
other implied values (like energy independence, avoided traffic
accidents and so forth).
My educated guess is that $25 per tonne of carbon dioxide is somewhere
near what the implied value in Europe is, and in the US it's maybe half
that.
I also think that translates into a willingness to spend something like
0.2% of GDP in Germany, and 0.1% of GDP in the US.
5% of GDP is what I think it roughly would take to get emissions to
zero within 30 years.
http://heikoheiko.blogspot.com/2006/07/comparisons-between-europea-and-us.html
That may not sound like much, and it is not, if people were convinced
that the survival of mankind was at stake.
But it is a lot when compared to other priorities, like say healthcare,
or education, or defense spending. 5% of US GDP is a quarter of the US
federal budget and more than the US spends on defense.
Heiko
Alastair McDonald
> There is time to hit the brakes, but I share Coby's pessimism that we
> will have the maturity to manage. The train is on autopilot, and I see
> your argument as encouraging the human engineers to remain asleep.
If you go for a revenue neutral solution, as is being proposed by the
Liberal Democrats in the UK, you do not achieve anything, because
you are only moving one type of spending to another. All spending
inevitably means using energy and the vast majority of all energy is
produced today by burning fossil fuels.
There was a naive economic idea called the labour theory of value,
but today the labour is all done by machines so the value, not the
price, is set by the energy expended. Scarcity can set the price
much higher than the value, but in general they are the same.
So, in order for us to reduce global CO2 levels we must not just
pay more for fossil fuels, we must use less. This means we will
have to be poorer. I too share Coby's pessimism, but if we do
not cut back on our own consumption then Mother Nature, aka
James Lovelock's Gaia, will do it for us!
Cheers, Alastair.
gerh...@aston.ac.uk
that assumes a 1 to 1 relationship between wealth and CO2 emissions.
I think that renewables are entirely up to the job of providing all the
energy a high tech civilisation needs, at a cost, yes, but not actually
all that high a cost when compared to world GDP.
Alastair McDonald
Heiko,
I am assuming a 1 to 1 relationship between wealth and CO2 emissions,
but since we in Britain are burning twice our share per head of oil, I am
assuming that we will have to cut back to the 50% which is our
share. With everyone in the world using their fair share we would still
be producing the same CO2 as now and the atmopheric level would
continue to rise at 2 ppm per year. Therefore we would have to cut back
on the 50% of current use to 20% in order that CO2 levels do not rise,
but the Greenland ice would still melt. Do you really believe that we
can produce the 80% shortfall in energy from renewables?
Cheers, Alastair.
James Annan
> The "polluter pays" penalty, I would argue, is already there, and
> folded into the taxation/subsidy decisions for individual fuels.
I don't accept that anyone has made any meaningful attempt to base fuel
taxes on a "polluter pays" principle.
> If you are suggesting an increase in CO2 across the board by $25-30, I
> accept that'll reduce emissions compared to not having the tax (though
> it's unlikely to be enough to actually reduce emissions, rather it'll
> lower the emissions growth rate), but I can also tell you why
> governments are not very keen, and that as said this across the board
> increase would primarily affect the competiveness of coal, and with
> restrictions on nuclear build, particularly so compared with natural
> gas, as $25-30 is not enough at present to make much of a difference
> for renewables.
If a particular mix of usage (amongst the fossil fuels) was preferred,
and already achieved by the established mix of taxes, then I'm sure it
would not be beyond the wit of man to devise a reasonably "equitable"
(and adaptively modified) increase across the board which would lead to
the desired outcome of downward pressure on emissions without causing a
mad dash away from coal.
(with "equitable" defined here to mean having small marginal effects
between the major fuels - whether this is really "equitable" for anyone
who claims to care about emissions is another matter.)
James
gerh...@aston.ac.uk
it's been an enlightening discussion for me, clearing up a few things
in my own mind.
>From a marginal cost of emissions avoided approach, it makes sense to
raise taxes across the board to that level, it just so happens that the
actual taxes/subsidies on fuels are determined by many more factors,
with an estimate of the marginal cost of emissions avoided only one
component.
One reason gasoline taxes are so high is that the state needs revenue,
and so something needs to be taxed to pay for necessary state
expenditures. Labour is for example, even though there is no suggestion
that it ought to be discouraged, or that it is always associated with
pollution or external damages.
I originally commented because you mentioned carbon taxes as a no
brainer, and that made me wonder why, if it is a no brainer, on the
face of it, it isn't a widely used instrument.
After our discussion, I now think the answer is that climate damages
are considered in the taxation/subsidy decision, but the implied level
of the carbon tax is only around $25 per metric tonneof CO2 in Europe,
while other considerations bring taxation for petrol up to $250 per
metric tonne of CO2, and taxation for coal to zero or even negative
values in parts of Europe.
I also think that it is quite hard to make the tax explicit. One reason
is the argument used for ecological tax reform: Taxes introduce
economic distortions (disincentives to production/work), and those may
be quite harmless for petrol, and rather major for labour (or domestic
coal). Therefore, taxing petrol rather than labour may result in
economic gains, and the cost to society of the tax is much lower (ie
may actually be negative) than the cost to the fuel purchaser.
On your two points specifically:
On "polluter pays" I am not sure what you mean. I do think that
European governments take climate into account when setting fuel
taxes/subsidies. Are you saying you disagree with that, or do you mean
something else with "polluter pays" in this context?
I am sure it is possible to design taxes that'll avoid a major rush
away from coal as an unintended consequence. But aren't policymakers
doing that already? And isn't the question then not, what the implied
value of carbon dioxide emissions reductions should be, and whether
European/American policy is undervaluing the benefits of emissions cuts?
gerh...@aston.ac.uk
I believe we can produce more than 100% from renewables, and actually
go carbon negative by doing sequestration at the same time, that is
actively taking carbon out of the air again.
In fact I think we could get there very fast indeed (years, not decades
or a century) given the right level of effort and willingness to do
without. I just don't think that world society is giving this the
required level of attention (WWII in the US or Soviet Union type of
attention) to make it happen, because, rhetoric aside, climate change
is actually not widely seen as that urgent or threatening.
Eli Rabett
gerh...@aston.ac.uk wrote:
> Michael,
>
> I see where you are coming from.
>
> Germany or Denmark are countries that put considerable emphasis on
> climate change, yet neither has a carbon tax as such.
>
> What I am trying to answer is the question why that is so.
>
> And I think the answer is that while they value climate highly they
> value energy independence (and particularly in the case of Germany
> social benefits) just as highly.
>
> As happens, personally I'd favour energy policies like those in France.
> Replacing coal with nuclear should cut world CO2 emissions something
> like 30 or 40%. High gasoline taxes might cut US transportation demand
> in half. I do find it instructive to look at French per capita
> emissions compared to other countries.
>
> http://www.eia.doe.gov/pub/international/iealf/tableh1cco2.xls
>
> F 2000 6.73
> F 2004 6.71
>
> Germany 2000 10.31
> Germany 2004 10.46
>
> USA 2000 20.60
> USA 2004 20.18
>
http://rabett.blogspot.com/2006/05/what-devil-are-they-doing-in-virgin.html
and the difference between France and other European countries is
consistent showing that nuclear power is an answer.
Another interesting point in the data is that oil refining emits a lot
of CO2 being very energy intensive (see the Virgin Islands) You see
the same sort of extreme emissions from a number of small countries
which have oil refining/pumping operations.
Eli Rabett
hank
James Annan wrote:
> My prediction, for what it's worth, is that we will be told we have "10
> years to act" indefinitely, certainly well beyond a decade from now,
> irrespective of any actions that are taken.
That's the definition of an increasing curve, eh? It always looks flat
behind you and steeper ahead.
The possibility changes, or rather what's possible is defined by where
we are at the moment.
Nobody's saying we have ten years to reverse thedecline of the
passenger pigeon and concomitant increase in its primary food, the
mosquito -- we live with mosquitos and forget we eradicated their
primary predator. Now it's mosquitos darkening the skies, it used to
be passenger pigeons flying overhead for days in such large groups.
Now we take mosquitos for granted; then our grandparents took passenger
pigeons for granted.
Coby Beck
news:<1158432081.3...@m7g2000cwm.googlegroups.com>...
>
>
> James Annan wrote:
> > My prediction, for what it's worth, is that we will be told we have "10
> > years to act" indefinitely, certainly well beyond a decade from now,
> > irrespective of any actions that are taken.
>
> That's the definition of an increasing curve, eh? It always looks flat
> behind you and steeper ahead.
> The possibility changes, or rather what's possible is defined by where
> we are at the moment.
James Hansen's at it again!
http://msnbc.msn.com/id/14834318/
Coby
gerh...@aston.ac.uk
Hansen may be a climate science expert, but this particular argument
hasn't much to do with climate science as such and is awfully weak. If
we start ten years later, we'll just have to reduce emissions more
steeply to get to the same end result. It won't be too late, rather
it'll require a greater effort to get to the same end goal.
Michael Tobis
It is entirely possible that by waiting ten years we will reach a
condition where some desired state that we might have reached in the
foreseeable future becomes entirely inaccessible. For example, if the
Greenland or West Antractic ice sheets warm up enough fail
mechanically, restoring them will not be feasible without a severe
cooling. Restrained warming will not be enough.
I think the right way to think about it is that there are multiple
tipping points in the system.
Based on what we have read here and elsewhere of late we will lose the
perennial Arctic ice very shortly. It is probably already be too late
to prevent this; even if we were to succumb to a vast epidemic and
disappear from the earth next month, hence not just clamp emissions
levels but actually stop emitting altogether, it seems likely that
perennial Arctic sea ice will vanish within decades due to the forcing
already in place. This will remove a summer temperature maximum of 0 C
at the Arctic surface and may have consequences for the entire
circulation of the atmosphere and the ocean.
Had we heeded early warnings twenty years ago, perhaps we might have
avoided this fate, but it's likely too late now. Reducing emissions
will never reverse this. We must actually remove carbon to allow sea
ice to the familiar configuration.
To state such a thing without proof is inadequate when you are
questioning an expert in a discipline distinct from your own. In the
present case your assertion appears to me entirely and
straightforwardly incorrect.
mt
Coby Beck
news:1158484362.7...@m7g2000cwm.googlegroups.com...
>
>> http://msnbc.msn.com/id/14834318/
>
> Hansen may be a climate science expert, but this particular argument
> hasn't much to do with climate science as such and is awfully weak. If
> we start ten years later, we'll just have to reduce emissions more
> steeply to get to the same end result. It won't be too late, rather
> it'll require a greater effort to get to the same end goal.
Unless you are considering the development of technology that actually
removes CO2 from the air, this is incorrect because of how long CO2
concentrations will remain elevated. Reducing emissions (unless you mean by
over two thirds almost instantly, to levels below that being sequestered
now) does not lower concentrations immediately. Even lowering them to below
the 2Gt/yr naturally sequestered now is no guarantee, will the natural sinks
still take up the same annual amount? Will those sinks fill?
I think Hansen is likely considering the possible natural carbon feedbacks
too. We may find the net response from the natural carbon cycle becomes
positive very soon. I also agree with Michael's response concerning ice
sheets and the general point about the response of a complex system.
It is not simply a question of reaching a given point of time with the same
total carbon emissions, the path not mattering.
As for the general question of whether or not this is out of Hansen's area
of expertise, I still disagree. I personally think he is using more gut
than computational model to arrive at such a conclusion, but it is still a
question of climatology.
Coby
Raymond Arritt
> <gerh...@aston.ac.uk> wrote in message
> news:1158484362.7...@m7g2000cwm.googlegroups.com...
>>
>>> http://msnbc.msn.com/id/14834318/
>>
>> Hansen may be a climate science expert, but this particular argument
>> hasn't much to do with climate science as such and is awfully weak. If
>> we start ten years later, we'll just have to reduce emissions more
>> steeply to get to the same end result. It won't be too late, rather
>> it'll require a greater effort to get to the same end goal.
>
> Unless you are considering the development of technology that actually
> removes CO2 from the air, this is incorrect because of how long CO2
> concentrations will remain elevated.
This touches on one of my favorite ideas: removing CO2 from the air.
We need to find some big flat place that gets a lot of sunlight (maybe
the Qattara Depression?), put a layer of something impermeable like clay
on the bottom, fill it up with boatloads of rubisco and chloroplasts and
stuff, put a transparent cover on it, pump CO2 and water in one end, get
oxygen and glucose out the other end. Bingo, problem solved, and you
get a useful product as a bonus.
Granted maybe it would be a little more complicated than that.
OK, I'll shut up and go back to that review I've been putting off.
gerh...@aston.ac.uk
http://www.bren.ucsb.edu/academics/courses/203/Readings/SlipperySlope%2017Jun04v21.pdf
I had a more up to date one, but the link's gone dead.
Hansen's alternative scenario has peak CO2 of 475 PPM in 2100 and
maximum warming not exceeding 1C.
Certainly on the CO2 front, this is entirely achievable with a start
in 2016 rather than 2006. As far as I can fathom his argument seems to
be that lag times in energy infrastructure will make it impossible to
achieve the required reductions starting in 2016, while they'd be
achievable starting in 2006.
If that is indeed what he is saying, I strongly disagree with it, and
it is also not a question where a climatologist would have any special
expertise.
gerh...@aston.ac.uk
I get the general idea of a tipping point, in short and in the extreme,
once ice sheets start breaking down, we may get to a new equilibrium,
where even pre-industrial carbon dioxide levels won't be enough to get
us back to the previous equilibrium.
Hansen writes that it is commonly assumed that ice sheet disintegration
will take millennia, and he thinks, though that is outside of his area
of expertise (he actually says that in the paper I linked in my reply
to Coby), it's probably only a few centuries.
To get from that to a decade by pointing to lags in energy
infrastructure is where I either misunderstand him, or think his
argument is very weak.
Alastair McDonald
Hansen begins the article you quote with the following paragraph:
"In a recent article (Hansen, 2004) I included a photograph taken by Roger
Braithwaite with a rushing stream pouring into a hole in the Greenland ice
sheet. The photo relates to my contention that disintegration of ice sheets
is a wet, potentially rapid, process, and consequent sea level rise sets a
low limit on the global warming that can be tolerated without risking
dangerous anthropogenic interference with climate."
I suspect that you do not realise the significance of a "wet process" and
why it is potentially rapid. Wet in this case means water, not ice or
steam. But water forms water vapour, a cold steam, and water vapour is the
main greenhouse gas. The problem with water is that the water vapour it
produces increases exponentially with temperature (because of the
Clausius-Clapeyron relationship.) Thus once the surface of an ice sheet
starts to melt and become wet, then there is potenitally a runaway effect as
the surface water warms and the greenhouse effect from the water vapour
increases causing more melting.
This means that once an ice sheet starts to melt there is no way to stop it
melting completely. So the tipping point is not when the ice sheet
disappears, but when it starts melting. That is the point of no return.
Hansen obviously thinks we have ten years in which to prevent the ice sheets
from beginning to melt. I, and Manlowski think otherwise.
Cheers, Alastair.
>
> >
>
Eli Rabett
http://www.columbia.edu/~jeh1/hansen_slippery.pdf#search=%22slippery%20slope%20hanson%22
gerh...@aston.ac.uk
> melting completely. So the tipping point is not when the ice sheet
> disappears, but when it starts melting. That is the point of no return.
I must admit that I do not find that explanation convincing,
particularly the bit about water vapour from melting ice. But you may
have phrased things poorly. Could you give a link to a more detailed
explanation of what you are trying to say?
Alastair McDonald
> particularly the bit about water vapour from melting ice. But you may
> have phrased things poorly. Could you give a link to a more detailed
> explanation of what you are trying to say?
Here's a link that explains the runaway effect of water vapour
http://earthobservatory.nasa.gov/Study/WaterVapor/
It is also a copy here, which may be easier to print or read:
http://www.intute.ac.uk/sciences/worldguide/html/883_articles.html
It concludes with one of my mantras - "There is a certain sense of
complacency that water vapor feedback is understood. And that comes from the
fact that a lot of these global climate models agree with each other,"
Folkins observes. "But just because they agree, doesn't mean they are all
right."
But don't confuse a runaway greenhouse with what is happening on Venus.
When water vapour runs away it generates cloud which prevents the Earth
reaching > 400C :-)
http://en.wikipedia.org/wiki/Greenhouse_effect#Runaway_greenhouse
The above concludes "the Earth is far from this runaway condition, as is
also self-evident from the stability of the climate through geological
time." That statement is false because there was a violent change in climate
at the end of the Younger Dryas only 10,000 years ago, and many more before
that.
For the effects of melting ice especially the Greenland ice sheet see:
Sea Level, Ice, and Greenhouses -- FAQ by Bob Grumbime of NOAA
http://www.radix.net/~bobg/faqs/sea.level.faq.html
Then put 2 and 2 together and get the 4 which I summarised.
Cheers, Alastair.