Jenifer Marohesy does have a valid point regarding the recent cooling. It's not the first  anomoly observed to the AGW theory.  Hudson Institute environmental economist Dennis Avery said: "The Earth's warming from 1915 to 1940 was just about as strong as the "scary" 1975 to 1998 warming in both scope and duration - and occurred too early to be blamed on human-emitted CO2. The cooling from 1940 to 1975 defied the Greenhouse Theory, occurring during the first big surge of man-made greenhouse emissions. Most recently, the climate has stubbornly refused to warm since 1998, even though human CO2 emissions have continued to rise strongly."

Regarding the recent cooling the Earth has been getting cooler since 1998. The drop has now been going for a decade, with another big drop last year. The peer-reviewed journal, Nature, reported on May 1 that according to a new (and hopefully improved) climate model, global surface temperatures may not increase over the next decade.

So how can you on the one hand build a theory of AGW on the observed warming of 1975 - 1998 and yet ignore the recent cooling (when CO2 emissions are rising) and ignore the pre war warming (when CO2 emissions were still low), as well as the post war cooling (when CO2 emissions were rising)?

OK then where is my description wrong. I haven't heard anyone deny these observed trends.

Also the IPCC did predict a steady rise in temperature this decade so the observed trend is at odds with the AGW orthodoxy. There is an adjustment going to climate models (some have described as ass-covering) and now were are told there will be another 15 years of cooling before AGW returns.

It would not have been difficult for Jennifer Marohasy to get her facts straight. Instead she chose to build an absurd little strawmen to mislead people.

Climate change and the hockey stick graphs:

http://www.ozpolitic.com/forum/YaBB.pl?num=1170222422/72#72

An example of why you should be wary of people who describe a picture to you but won't show you the actual picture:



An explanation for this particular change:

http://www.ifm-geomar.de/index.php?id=4192&L=1

During the last decades, temperature maxima were regularly broken. A new study to be published May 1st in the international science magazine “Nature” suggests that a reprieve may be expected over the next decade, as natural climate variations may temporarily offset the long-term warming trend. This result was obtained by researchers from the Leibniz Institute of Marine Sciences (IFM-GEOMAR) in Kiel and the Max Planck Institute (MPI) for Meteorology in Hamburg.

To date climate change projections, as published in the last IPCC report, only considered changes in future atmospheric composition. This strategy is appropriate for long-term changes in climate such as predictions for the end of the century. However, in order to predict short-term developments over the next decade, models need additional information on natural climate variations, in particular associated with ocean currents. Lack of sufficient data has hampered such predictions in the past. Scientists at IFM-GEOMAR and from the MPI for Meteorology have developed a method to derive ocean currents from measurements of sea surface temperature (SST). The latter are available in good quality and global coverage at least for the past 50 years. With this additional information, natural decadal climate variations, which are superimposed on the long-term anthropogenic warming trend, can be predicted. The improved predictions suggest that global warming will weaken slightly during the following 10 years.

“Just to make things clear: we are not stating that anthropogenic climate change won’t be as bad as previously thought”, explains Prof. Mojib Latif from IFM-GEOMAR. “What we are saying is that on top of the warming trend there is a long-periodic oscillation that will probably lead to a to a lower temperature increase than we would expect from the current trend during the next years”, adds Latif. “That is like driving from the coast to a mountainous area and crossing some hills and valleys before you reach the top”, explains Dr. Johann Jungclaus from the MPI for Meteorology. “In some years trends of both phenomena, the anthropogenic climate change and the natural decadal variation will add leading to a much stronger temperature rise.”

Emmy-Noether1 fellow and lead author Dr. Noel Keenlyside from IFM-GEOMAR continues: “In addition to the greenhouse gas concentrations we are using observed SST’s of the past decades in our climate model simulations, a method which has already successfully been applied for seasonal predictions and El Niño forecasting. The SST’s influence the winds and the heat exchange between ocean and atmosphere, and both factors impact ocean currents. The results are very encouraging and show that at least for some regions around the world, it is possible to predict natural climate oscillations on decadal time scale. Europe and North America are two such regions because they are influenced by the North Atlantic and Tropical Pacific, respectively.”

Decadal climate precitions are not weather forecasts, as Prof. Latif expands upon: “Such forecasts will not enable us to tell you whether or not we will have a white Christmas in 2012 in northern Germany, but we will be able to provide a tendency as to whether or not some decades will be warmer or cooler than average. Of course, always with the assumption that no other unforeseen effects such as volcanic eruptions occur, which can have a substantial effect on our climate as well”, summarizes Prof. Latif.

More information:

Science Paper:

Keenlyside, N. S., M. Latif, J. Jungclaus, L. Kornblueh, and E. Roeckner, 2008: Advancing Decadal-Scale Climate Prediction in the North Atlantic Sector. Nature, 453, 84-88.

1Emmy Noether Programme

The Emmy Noether Programme supports young researchers in achieving independence at an early stage of their scientific careers. Young postdocs gain the qualifications required for a university teaching career during a DFG-funded period, usually lasting five years, in which they lead their own Independent Junior Research Group.

Contact

Prof. Dr. Mojib Latif, Tel. +49-431 - 600 4050, mlatif@ifm-geomar.de

Dr. Andreas Villwock (Öffentlichkeitsarbeit), Tel. +49-431 - 600 2802, avillwock@ifm-geomar.de

pjb05 wrote on May 22^nd, 2008 at 10:13am:


Come on. You start at an El Nino Year and you finish on the next La Nina year in the cycle. 11 years of data ? How easily can the wool be pulled over your eyes? It's totally criminal to mislead people that way.

As freedvier pointed out, you have to look at the genuine set of data (NASA GISS data) to see the real picture.

There are more graphs here that go further back:

http://www.ozpolitic.com/forum/YaBB.pl?num=1170222422/72#72

No doubt the temperature variation has occurred in the past, but it is the rate of change that has the scientists worried. Probably also that the natural causes of slow change don't appear to be responsible.

I don't think it can be said with any certainty the the present rate and extent of warming is unusual. What you don't mention regarding your 'infalible' graphs is that only the very recent section is based on actual direct measurements of temperature. The rest is based on the assumption that one can interpret past temperatures from examining ancient tree rings or ice core samples from ice locked in glaciers. The original graph used by the IPCC was the now discredited Mann's Hockey Stick. 

This showed a nice fit to the AGW theory with temperatures stable for centuries and only shooting up with our age of industrialisation.
It was noticed a couple of significant and fairly well accepted climatological history facts to be conspicuously missing.  The first was the well-documented "Medieval Warm Period" where temperatures, at least in Europe, temperatures were significantly higher.  The second was the "Little Ice Age", a period in which the temperatures dropped so low the Thames River in London froze over.

As I mentioned before the fall into the Little Ice Age about matches the recent warming.

My last reply was somewhat hurried and overly confrontational. (I probably need to calm down.)  One of the reasons we know that the increase in atmospheric CO2 is having an effect of increasing global temperatures is that the upper stratospheric layers have cooled correspondingly. If the observed increase in temperature over the period of industrialisation was due to variations in solar irradiance or cosmic rays inducing increased cloud cover, then you would expect an increase in stratospheric temperature.

The fact that these temperatures have decreased indicates that the CO2 is trapping heat in the lower areas of the atmosphere. The maximum warming occurs about 10km(at least here in the Tropics), and recent research by Yale University published this month shows that the atmospheric temperatures in the Tropics rose about 0.65 degrees Celsius per decade since 1970, which is  probably the fastest warming rate anywhere in Earth's atmosphere. This was monitored at the 10km level. 

This Wikipedia page has some useful links on climate modelling. It's a good place to start if you don't have any prior knowledge apart from the disinformation sites.

http://en.wikipedia.org/wiki/Climate_model


Here's a post that I made over at the old space.com forums where I post as Alpha Tauri. The post  explains the basic fluxes and the application of the CO2 forcing equation. The CO2 forcing equation is based on some pretty fundamental physics. It's a derivation of the Stephan-Boltzmann equation. There is nothing controversial about it.

http://uplink.space.com/showthreaded.php?Cat=&Board=environment&Number=741559&pa...

I'd recommend that you do some basic research into the carbon fluxes and how these are derived. That's the real key to understanding the issue.

Here's another interesting paper.

http://www.cato.org/pubs/pas/pa576.pdf

About the author:

Patrick J. Michaels is senior fellow in environmental studies at the Cato Institute and professor of natural resources
at Virginia Polytechnic Institute and State University. He is a past president of the American Association of State
Climatologists and an author of the 2003 climate science “Paper of the Year” selected by the Association of American
Geographers. His research has been published in major scientific journals, including Climate Research, Climatic
Change, Geophysical Research Letters, Journal of Climate, Nature, and Science. He received his Ph.D. in
ecological climatology from the University of Wisconsin at Madison in 1979. His most recent book is Meltdown:
The Predictable Distortion of Global Warming by Scientists, Politicians, and the Media.

He points to poor science and distortions of a sensation seeking media combining to exagerate the threat.

Here's the conclusion:

It is apparent that many recent stories on
melting of high-latitude ice, hurricanes, and
extinctions are riddled with self-inconsistencies,
are inconsistent with other findings, and
are reported—as much by scientists themselves
as by reporters—in extreme or misleading
fashions that do not accurately portray
the actual research.
This begs for an explanation. Perhaps it is
simply the way science always has been, but
that the dramatic policy implications of
global warming compel some people (including
this author) to examine the refereed literature
with more scrutiny than would normally
be applied. The alternative is that
recently the peer review process has begun to
allow the publication of papers that should
have been dramatically modified before
being accepted.
If the latter is true, then another explanation
is required. One hypothesis would be thatpublic choice” dynamics is now entering into
science. But this would seem to require unethical
behavior on the part of a wide scientific
community. Under this model, the review
process becomes less stringent if a paper promotes
the economic well-being of the reviewer,
and more stringent if it does not.
“Well-being” here means professional
advancement and reward. It is a fact that in
the United States the taxpayer outlay for socalled
global change science is now in excess
of $4 billion annually. Universities reward
their faculty on the amount and quality of
research that they produce, which, in climate
science, requires considerable taxpayer funding.
If the funding stream is threatened by
findings downplaying the significance of climate
change, the public choice model would
predict rather vociferous review. If it is
enhanced, this model would predict a glowing,
positive review.
Whether public choice dynamics is indeed
responsible for the current rather sloppy state
of global warming science is a testable hypothesis,
but beyond the scope of this paper.
It can be tested by noting that adding new
information to a forecast has an equal probability
of changing the forecast in either a positive
or a negative direction. It would be interesting
to undertake a comprehensive analysis
of the recent scientific literature on climate
change to see whether results are significantly
biasing our view of the future into one that is
almost always “worse than we thought” and
rarely “not as bad as we thought.”
Whether or not this bias exists, the recent
tidal wave of global warming papers on polar
ice, hurricanes, and extinctions has included
an incredible number of omissions and
inconsistencies. It is to be hoped that this
paper will help to set the record straight on
these aspects of climate change.