More evidence CO2 not culprit
noo b
confusion, disagreement and, for some, disillusionment. When the
political process shows such a lack of unanimity, it is pertinent to
ask whether the science behind the politics is as settled as some
participants maintain.
Earlier this month (The Australian, December 9) I commented on
recently published results showing huge swings in atmospheric carbon
dioxide, both up and down, at a time of global cooling 33.6 million
years ago.
Paul Pearson and co-authors in a letter (The Weekend Australian,
December 11) took exception to my use of their data and claimed I
misrepresented their research, a claim I reject since I quoted their
data (the veracity of which they do not contest) but offered an
alternative hypothesis, namely that the present global warming theory
(which was not the subject of their study) is inconsistent with the
CO2-temperature variations of a past age.
Some senior scientists, who are adherents of orthodox global warming
theory, do not like authors publishing data that can be used to argue
against orthodoxy, a point made by unrelated authors with startling
clarity in the Climategate leaked emails from the University of East
Anglia.
In the scientific method, however, re-examination of data and
formulation of alternative hypotheses is the essence of scientific
debate. In any case, the debate on the link between atmospheric CO2
and global temperature will continue since it is not dependent on a
single result.
Another example is a study by Richard Zeebe and colleagues, published
in Nature Geoscience, of a release of CO2 and an increase in
temperature 55 million years ago. At this time there was an increase
in global temperature of between 5C and 9C, from a temperature regime
slightly warmer than today's (that I will call moderate Earth) to
greenhouse temperatures. It can be argued this example may have a
message for humanity because the rate of release of CO2 into the
atmosphere at the time of this warming was of a similar order to the
rate of anthropogenic release today. However, the analogy turns out to
be incomplete when the data is compared with present estimates of
climate sensitivity to atmospheric CO2, and Zeebe and his colleagues
conclude that the large temperature increase cannot be explained by
our existing understanding of CO2 temperature linkage. Indeed, they
write, "our results imply a fundamental gap in our understanding of
the amplitude of global warming associated with large and abrupt
climate perturbations. This gap needs to be filled to confidently
predict future climate change."
I argue there are at least two possible hypotheses to explain the data
in this study: either the link between atmospheric CO2 content and
global temperature increase is significantly greater (that is, more
dangerous) than the existing models show or some mechanism other than
atmospheric CO2 is a significant or the main factor influencing global
temperature.
The first hypothesis is consistent with climate change orthodoxy.
Recent writings on climate sensitivity by James Hansen are consistent
with it, as was the Intergovernmental Panel on Climate Change in its
pre-Copenhagen update, The Copenhagen Diagnosis.
Indeed, the 26 authors of the IPCC update went a step further, and
encouraged the 46,000 Copenhagen participants with the warning: "A
rapid carbon release, not unlike what humans are causing today, has
also occurred at least once in climate history, as sediment data from
55 million years ago show. This `Palaeocene-Eocene thermal maximum'
brought a major global warming of 5C, a detrimental ocean
acidification and a mass extinction event. It serves as a stark
warning to us today."
We have to treat such a warning cautiously because, as Pearson and his
colleagues pointed out in their letter two weeks ago, "We caution
against any attempt to derive a simple narrative linking CO2 and
climate on these large time scales. This is because many other factors
come into play, including other greenhouse gases, moving continents,
shifting ocean currents, dramatic changes in ocean chemistry,
vegetation, ice cover, sea level and variations in the Earth's orbit
around the sun."
Sound science also requires us to consider the second of the above two
hypotheses. Otherwise, if we attempt to reconcile Zeebe's observation
by inferring climate sensitivity to CO2 is greater than that used for
current models, how do we explain Pearson's observation of huge swings
in atmospheric CO2, both up and down, which appear poorly correlated
with temperatures cooling from greenhouse Earth to moderate Earth?
The two geological results discussed both show some discrepancies
between observation and model predictions. Such discrepancies do not
in any sense reduce the merit of the respective authors' work; rather
they illustrate a healthy and continuing process of scientific
discovery.
In addition, unrelated satellite data analyses published in the past
two years by physicist David Douglass and distinguished atmospheric
scientist John Christy in two journals, International Journal of
Climatology and Earth and Environment, provide observational evidence
that climate sensitivity associated with CO2 is less than that used in
present climate modelling, by a factor of about three.
Thus we have two geological examples and two satellite data studies
pointing towards a lesser role of CO2 in global warming. This argument
does not discount the reality of global warming during the past
century or the potential consequences should it continue at the same
rate, but it does suggest we need a broader framework in considering
our response. The Copenhagen summit exposed intense political
differences in proposals to manage global warming. Scientists are also
not unanimous in claiming to understand the complex processes driving
climate change and, more important, scientific studies do not
unambiguously point to a single solution. Copenhagen will indeed prove
to be a historic meeting if it ushers in more open-minded debate.
http://www.theaustralian.com.au/news/opinion/more-evidence-co2-not-culprit/story-e6frg6zo-1225814230258
Surfer
>
>http://www.theaustralian.com.au/news/opinion/more-evidence-co2-not-culprit/story-e6frg6zo-1225814230258
>
>
> I argue there are at least two possible hypotheses to explain the data
> in this study: either the link between atmospheric CO2 content and
> global temperature increase is significantly greater (that is, more
> dangerous) than the existing models show or some mechanism other than
>atmospheric CO2 is a significant or the main factor influencing global
> temperature.
>
<Snip>
>
> Sound science also requires us to consider the second of the above two
> hypotheses.
>
Yes of course.
But so far no mechanism other than increasing atmospheric CO2 has been
identified as a possible cause for CURRENT warming.
Cf
http://en.wikipedia.org/wiki/Milankovitch_cycles
".....Since orbital variations are predictable[10], if one has a model
that relates orbital variations to climate, it is possible to run such
a model forward to "predict" future climate.
<snip>
An often-cited 1980 study by Imbrie and Imbrie determined that,
"Ignoring anthropogenic and other possible sources of variation acting
at frequencies higher than one cycle per 19,000 years, this model
predicts that the long-term cooling trend which began some 6,000 years
ago will continue for the next 23,000 years."[11]....."
So if mankind had not put extra CO2 into the air, the climate could be
expected to be cooling right now.
Surfer
<Start extract>
Thinkahead of Sydney Posted at 5:22 PM December 29, 2009
Whilst i have the utmost respect for Michael, i am baffled to think
why he would link a 55M year old random event with todays warming of
the planet. The so called Paleocene - Eocene Thermal Maximum, which
occurred 55 million years ago, had a number of factors contribute to
it:
* Firstly, we have not found any evidence as yet to why this event occurred.
This evidence could have been lost to erosion, and may be significant.
However, we all KNOW that increasing CO2 levels (man made or not)
will increase the Earths temperature.
* The drake passage was shut, meaning that Antarctica was not thermally
isolated
* The Pacific - Atlantic oceans circulated into each other, as Central American
continent was still below sea level (yes, the seas were much higher)
* The world had no significant ice sheets
* The temperature increased by about 6 degrees Celsius over the space of
20,000 years.
We have proof that between the start and end of the 20th Century (yes,
only 100 years) average global temps increased by 0.74 +/-0.18 Degrees
Celsius. Sure it may be a natural event, but even on a natural scale,
55 million years ago, temps only increased by: 6 / 20000 = 0.0003 per
year on avg. Wake up fools!
<End extract>
Surfer
>
>http://www.theaustralian.com.au/news/opinion/more-evidence-co2-not-culprit/story-e6frg6zo-1225814230258
>
http://www.theaustralian.com.au/news/opinion/more-evidence-co2-not-culprit/comments-e6frg6zo-1225814230258
<Start extract>
Andrew of Brisbane Posted at 1:02 PM December 29, 2009
The article is very interesting but the headline is very misleading.
It is the headline that most people will read and of the people who
does read the entire article many would not be able to interprete it.
Even this article raises the possibility that Co2 emmissions could
cause a much bigger problem than models show. It also raises a few
other possibilities and the headline only concentrates on the others
as it is more likely to be read. This is the reason why the climate
sceptics will probably get more support over the coming years. Very
dangerous.
<End extract>
Morton Davis
"Surfer" <n...@spam.net> wrote in message
news:3juvj5h7r936ntrqr...@4ax.com...
> On Fri, 1 Jan 2010 14:01:48 +1100, "noo b" <b...@xxx.com> wrote:
>>
>>http://www.theaustralian.com.au/news/opinion/more-evidence-co2-not-culprit/story-e6frg6zo-1225814230258
>>
>
>>
>> I argue there are at least two possible hypotheses to explain the data
>> in this study: either the link between atmospheric CO2 content and
>> global temperature increase is significantly greater (that is, more
>> dangerous) than the existing models show or some mechanism other than
>>atmospheric CO2 is a significant or the main factor influencing global
>> temperature.
>>
> <Snip>
>>
>> Sound science also requires us to consider the second of the above two
>> hypotheses.
>>
>
> Yes of course.
>
> But so far no mechanism other than increasing atmospheric CO2 has been
> identified as a possible cause for CURRENT warming.
>
There is no warming. There has been no increase in CO2.
Bill Snyder
And we believe you, because we would never dream of putting actual
evidence ahead of the unsupported word of some random wingnut on
Usenet.
--
Bill Snyder [This space unintentionally left blank]