http://forums.canadiancontent.net/newreply.php?do=newreply&p=1246870
… And?
Both of the aforementioned studies provide no direct link to anthropogenic sources... That’s it.
They didn't claim to, they just examined the contribution of some greenhouse gases to the top of atmosphere radiative imbalance. I already provided links earlier that show that human activities are leading to increases of many greenhosue gases.
In the event that you seek to extrapolate a proposed relationship based on the analysis of isotopic analysis 0f 12-C &13-C, see:
*Carbon cycle modeling and the residence time of natural and anthropogenic atmospheric CO2: on the construction of the "Greenhouse Effect Global Warming" dogma.
Tom V. Segalstad
What part of that actually refutes the origin of carbon dioxide? It makes claims that the IPCC in 1990 had low-balled the lifetime of carbon dioxide based on mass balances of the C12/C13 ratio, but nowhere did it deny the source of atmospheric carbon dioxide...
“In fact, the lower stratosphere is cooling substantially (by about -0.5K per decade)5, so the warming trend seen at the surface is expected to diminish with altitude and change into a cooling trend at some point in the troposphere. Even so, it has been suggested that the cooling trend seen in the satellite data is excessive4,7,8. The diffculty in reconciling the information from these different sources has sparked a debate in the climate community about possible instrumental problems and the existence of global warming4,7,”
*Effects of orbital decayon satellite-derived lower-tropospheric temperature trends
Frank J. Wentz & Matthias Schabel
The updated and corrected versions of the Microwave Sounding Unit still shows a cooling trend in the stratosphere. See figure 7 on the MSU webpage here:
RSS / MSU and AMSU Data / Description
3. Claudine Chen, John Harries, Helen Brindley, and Mark Ringer.
“In each case, the concentrations of CO2, CH4, O3, N2O, CFC-11, CFC-12, CFC-113, and HCFC-22 used within HadGEM1 at the relevant times”
This study offers no relationship of any warming trend with any anthropogenic sources of CO2, CH4, O3 or N2O. CFC’s are far too insignificant in the AGW debate to offset he major components – also, water vapor is not incorporated in the model – considering that water vapor is the biggest driver in the system, the inclusion of this study in the context of this discussion is pointless.
Water vapor is not the biggest driver, it's the largest component, which is a huge difference. And it's not excluded. If you would read instead of cherry pick, in fact just above the sentence you cherry picked is this:
Spectra were simulated using the line-by-line radiative transfer model (LBLRTM) [Clough, et al., 2005], version 10.3, at a spectral resolution of 0.1 cm-1. LBLRTM was run with user-defined profiles constructed using monthly mean HadGEM1 output fields of specific humidity, temperature, and sea surface temperature from the global circulation model for April, May, and June of 1970 to simulate IRIS spectra. The process was then repeated for profiles from 2006 to simulate TES spectra. In each case, the concentrations of CO2, CH4, O3, N2O, CFC-11, CFC-12, CFC-113, and HCFC-22 used within HadGEM1 at the relevant times were also used to provide input to the radiative transfer model calculations. In both cases the profiles above the altitudes provided by the model were padded with standard tropical atmosphere values [Anderson, et al., 1986].
The part I emphasized should have tipped you off first. Second, no global circulation model can work without water. There would be no clouds. No moist-adiabat. No precipitation. And finally, if you would have even bothered to look for the Anderson reference, I found the entire paper at this URL:
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA175173&Location=U2&doc=GetTRDoc.pdf
you would have noticed that Anderson et al. also include water vapour...
This study is an extension of the Griggs and Harries, 2007; Harries, et al and is subject to the same failings as references 1&2.
See links in post #34, 73 or 79.
“To reduce the variability seen in the spectrum, cloud-free spectra are used. A two step process was used to identify clouds in the spectra [Harries, et al., 2001]. The first step is to filter out thick clouds by comparing the brightness temperature at 1127.7 cm-1 (most transparent part of spectral range) with the skin temperature from the NCEP reanalysis. Differences greater than 6 K between the NCEP skin temperature and observed brightness temperature were flagged as cloudy [Haskins, et al., 1997]. The second step removes spectra with residual contamination from ice clouds. This is done by exploiting the difference in absorption coefficient in ice and water between the 8 um and 11 um bands. [Ackerman, et al., 1990]”
These actions affect the reliability of the results. The natural processes are subjectively omitted which skew the results to eliminate any opportunity to analyze the dynamic interaction(s).
They aren't looking to analyze the same dynamic interactions that you're thinking of, surely. As you inquired about earlier, how do you know what the contribution is when greenhouse gas bands have wave numbers that overlap in the observed spectra? What their process above does is filter out the noise. If you're looking for a x-ray signal, do you want to look at the entire spectra your broad-based instrument measures, or do you want to look in a specific window so that the noise is reduced?
4. K
aicun Wang and Shunlin Liang. 2009. Global atmospheric downward longwave radiation over land surface under all-sky conditions from 1973 to 2008, Journal of Geophysical Research, 114, D19101, doi:10.1029/2009JD011800.
So what? Where is the connection to anthropogenic sources?.. This discussion is exclusively about anthropogenic GW.
Right. And for that part, please refer to the references in post #34, 73 or 79.
There’s that pesky water vapor again… Do none of our studies recognize the impact of water vapour?
No, of course not. Putting more carbon dioxide in the air causes more outgoing long wave radiation to be tarpped in our atmosphere. The result is the temperature goes up. In response to temperature rises, water vapour goes up. Which increases temperatures further.
The water vapour positive feedback is a large part of the warming we experience from our carbon dioxide. It doubles what we would experience without the feedback. I cited this material already...
According to Marty et al, 2002;
“The atmospheric flux of longwave radiation is emitted predominantly by clouds, water vapor, carbon dioxide and ozone. The flux varies mostly with the cloud amount and cloud optical depth, mean cloud emitting temperature, as well as integrated water vapor content (Marty et al., 2002).”
*(Testing longwave radiation parameterizations under clear and overcast skies at Storglaci¨aren, Sweden J. Sedlar1 and R. Hock, April 27, 2009)
Further: “However, such models are not applicable when vertical profile data of temperature and moisture are lacking”
*(J. Sedlar and R. Hock: Testing longwave radiation parameterizations at Storglaci¨aren).
Yeah...I'm not denying water vapour as a contributor. I'm denying it as a driver. It's physically impossible for water vapour to be the driver, because water vapour content is a function of temperature and pressure. If you try to add more than the atmosphere can carry, you get rain. The atmosphere responds very quickly to water vapour.
5. Rolf Philipona, Bruno Dürr, Christoph Marty, Atsumu Ohmura, and Martin Wild. 2004. Radiative forcing - measured at Earth’s surface - corroborate the increasing greenhouse effect. Geophysical Research Letters, Vol. 31, L03202. doi:10.1029/2003GL018765.
From the document: ”Water vapor had the greatest influence and it was chiefly the diurnal and annual variations of the temperature lessened by this circumstance”
Conclusion of AGW is based on uncorroborated data from IPCC that have no founding in the relative CO2 emissions from both anthropogenic and non-anthropogenic sources. Further, water vapor is identified as the largest contributor, yet the doc offers simply honorable mention and does not quantify it’s dynamic contribution.
You're quoting the study quoting John Tyndall, from 1861...
It's clear you aren't even reading these papers...the very end of the introduction states:
Here we present the changes and trends of radiative fluxes at the surface and their relation to greenhouse gas increases and temperature and humidity changes measured from 1995 to 2002 at eight stations of the Alpine Surface Radiation Budget (ASRB) network.
That is a dynamic contribution. I already explained to you how it's dynamic, it's a feedback...
Further in the paper, where the actual results are:
On average the final corrected LDRcf,tc,uc measurements show an increase of +1.8 (0.8) W/m^2 with a 95% significance level at almost all stations. This remaining increase of longwave downward radiation demonstrates radiative forcing that is due to enhanced greenhouse gas concentrations and feedbacks, and is in reasonably good agreement with the expected +1.58 W/m^2 increase predicted by MODTRAN radiative transfer model calculations.
So, even given the spatial constraints of the study area, this study still produces results consistent with line-by-line transfer calculations.
This study assumes that O3, N2O, CH4, CO and CO2 are generated from anthropogenic sources…. This is not he case, unless of course you can prove such.
From the doc: “With measurements at high spectral resolution, this increase can be quantitatively attributed to each of several anthropogenic gases.”
Where is the proof? How is it quantified? There isn’t even any form of mention that natural sources might contribute into the system.
These are all gases which have been documented to be released increasingly by human activity. Nobody seriously disagrees with that. You can read the entire AR4 Chapter 9 in WG1 to see that.
are primarily anthropogenic in nature, but are not considered relevant (significant) enough to force climate.
Right. Their contributions are very small.
7. Murphy, D. M., S. Solomon, R. W. Portmann, K. H. Rosenlof, P. M. Forster, and T. Wong (2009), An observationally based energy balance for the Earth since 1950, Journal of Geophysical Research, 114, D17107, doi:10.1029/2009JD012105.
Doc focuses on aerosols and sulfates: These are small players in the AGW issue… Too small in the grand scheme.
Not at all. Aerosols and sulfates could potentially counter all the observed warming to date, but with huge consequences.
“About 20% of the integrated positive forcing by greenhouse gases and solar radiation since 1950 has been radiated to space.”
Show me the confidence levels from the period between 1950 and 1970 when there were no satellites to make such observations. If the pre-1970 data is reliant in surface measures how do they propose to provide a sense of equilibrium between the pre and post satellite periods?... Lemme guess, over-generous statistical models?
No, their first line in the abstract is "We examine the Earth’s energy balance since 1950, identifying results that can be obtained without using global climate models."
Why don't you do something radical, and actually read...they use surface temperature, ocean heat content, and satellite observations of radiative fluxes. The 20% figure is an estimate from their Figure 6.
“between 1970 and 2000 due to direct and indirect forcing by aerosols as well as semidirect forcing from greenhouse gases and any unknown mechanism can be estimated as −1.1 ± 0.4 W m−2 (1σ). This is consistent with the Intergovernmental Panel on Climate Change's best estimates…”
Best estimates?.. From the IPCC – what a joke, Show me facts, not assumptions, extrapolations and best guesses.
It's not an assumption, or guess, it follows from the work they did. Science produces estimates. There is no 100% certainty...you're living in a dream world if you think that a single scientific paper produces anything like a fact. It produces results...
8. Tim P. Barnett, David W. Pierce, and Reiner Schnur. 2001. Detection of anthropogenic climate change in the world's oceans. Science, Vol. 292, 270-274. doi: 10.1126/science.1058304.
Founded on estimated anthropogenic sources… You clearly stated earlier in the thread that the sources are, factually anthropogenic… How is it that this study employs unconfirmed estimates?
Where are these estimates? Where is there any reference to the relativism between anthropogenic and non-anthropogenic sources?
The anthropogenic component of rising greenhouse gas levels have been documented by many researchers. You know, you can actually follow the references in papers I cite too. Read the paper...
“Large-scale increases in the heat content of the world's oceans have been observed to occur over the last 45 years.”
Self-fulfilling prophecy… Narrow sample size offers no relative comparison to any period that experienced changes in the oceans on a pre-anthropogenic basis.
So, if there are multiple data sets combined with satellites in the air you accuse them of statistical tricks. If they can go back further, then you say it's not enough.
That's not very objective. In fact you're just grasping at straws now.
9. The International ad hoc Detection and Attribution Group. 2005.
From the doc[FONT="]: “Disclaimer - ‘…makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed… ‘[/FONT]
Off to a really great start there, eh? If the researchers lack any form of confidence in their offering, I can’t see this as being a compelling argument.
Have you read a government science document that didn't include such a disclaimer? I doubt it.
Some pretty big assumptions in the modeling. I guess that we now understand why the authors required such a broad disclaimer, don’t we.
Which assumptions do you think are riskiest?
Possible effects of snow cover?.. Goes directly towards long wave outgoing radiation spectra.
They were talking about boreholes...
Results confirm previous conclusions that about 50% of the decadal pre-anthropogenic Northern Hemisphere temperature variance can be attributed to a direct response to solar and volcanic variability (Crowley et al. 2004).”
Have identified 2 non-anthropogenic sources, which is infinitesimally more than the other references you’ve hung your hat on, yet the list of non-anthropogenic sources is woefully incomplete and serves to over-simplify a highly complex issue.
My opening statement:
"My defining statement is this: we've experienced about 0.8°C warming over the last century. The first part of the century was a mixture of anthropogenic and natural variability, while the latter half has been dominated by the anthropogenic signal...."
The part you quoted from the document is consistent with what I said...
“The IPCC TAR concluded that “... most of the warming observed over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations” (IPCC 2001). This assessment was made with a very broad range of evidence, including evidence from a number of optimal detection studies using several different coupled climate models.”
The IPCC is recanting many of the previously held positions…. His assumption is erroneous and speculative….. Evidently more reason that the authors have a need for a disclaimer.
You're a tool. I knew eventually you'd do this.
From post #33 :
“Water vapour is the most important greenhouse gas, and carbon dioxide (CO2) is the second-most important one. Methane, nitrous oxide, ozone and several other gases present in the atmosphere in small amounts also contribute to the greenhouse effect.”
AR4 WGI Chapter 1: Historical Overview of Climate Change Science - FAQ 1.3 What is the Greenhouse Effect?
So when it's convenient to you, apparently they don't need a disclaimer. I see how it is...
Unbelievable.
The reference to the Brazilian rainforest can be found in Chapter 13 of the IPCC Working Group II report, the same section of AR4 in which claims are made that the Himalayan glaciers are rapidly melting because of global warming. Last week, the data leading to this claim were disproved as well, a scandal being labeled “glacier-gate” or “Himalaya-gate”
The Amazon, that's a funny story. You might like this:
In sum:
– Samanta et al data show a drought region green up that is on average indistinguishable from Saleska et al (but they call it NO green up).
– Samanta et al data almost exactly reproduce Saleska et al’s most salient bottom-line result (but they say what we did was not reproducible).
– the Samanta et al paper, based on a three-month drought response, says not one word about long-term climate change scenarios reviewed in IPCC (but they advertise their analysis as “reject[ing] claims” put forward by the IPCC).
RealClimate: Saleska Responds (green is green)
20 pgs into the doc and we see it is fully reliant on generous assumptions and relies extensively on old (now revised) IPCC docs.
And less than 100 posts into this thread you show that you'll use a source when it's convenient and trash it when it isn't.
Pathetic. I'm through wasting my time with you. Other readers can have a go if they wish, though I'd advise them to save their time.
[FONT="]
10. Gerald A. Meehl, Warren M. Washington, Caspar M. Ammann, Julie M. Arblaster, T. M. L. Wigley, and Claudia Tebaldi. 2004.
I’ll get to this one later.
Whatever, more of the same disingenuous crap I'm sure.
