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Originally posted by rnaa
Continuing to spout off (pun intended) about water being a major GHG is completely unworthy of any serious argument.
Water Vapor Feedback Loop Will Cause Accelerated Global Warming, Professor Warns
ScienceDaily (Feb. 20, 2009) — Here’s yet another reason to hate humidity: it expands global warming, says a Texas A&M University professor.
Andrew Dessler, a professor in the Department of Atmospheric Sciences who specializes in research on climate, says that warming due to increases in greenhouse gases will lead to higher humidity in the atmosphere. And because water vapor itself is a greenhouse gas, this will cause additional warming. This process is known as water vapor feedback and is responsible for a significant portion of the warming predicted to occur over the next century.
“Its a vicious cycle – warmer temperatures mean higher humidity, which in turn leads to even more warming,” Dessler explains.
Originally posted by rnaa
Please go study up on some basic physical chemistry. Your local community college should be able to accommodate you.
Originally posted by john124
As I said - you haven't got very far, and you never will with that kind of attitude. I've seen you post so many comments on ATS about this issue, much more than the average user such as myself, and almost every post is an attack on climate science or denials! When do you get the time to actually study the science of global warming?!
Originally posted by john124
Do you prefer to fantasise over people's personal emails, rather than be a scientist? as you pretend to know-it-all!
Koutsoyiannis, D., A. Efstratiadis, N. Mamassis, and A. Christofides, On the credibility of climate predictions, Hydrological Sciences Journal, 53 (4), 671–684, 2008.
[doc_id=864]
[English]
Geographically distributed predictions of future climate, obtained through climate models, are widely used in hydrology and many other disciplines, typically without assessing their reliability. Here we compare the output of various models to temperature and precipitation observations from eight stations with long (over 100 years) records from around the globe. The results show that models perform poorly, even at a climatic (30-year) scale. Thus local model projections cannot be credible, whereas a common argument that models can perform better at larger spatial scales is unsupported.
The widely accepted (albeit unproven) theory that manmade global warming will accelerate itself by creating more heat-trapping clouds is challenged this month in new research from The University of Alabama in Huntsville.
Instead of creating more clouds, individual tropical warming cycles that served as proxies for global warming saw a decrease in the coverage of heat-trapping cirrus clouds, says Dr. Roy Spencer, a principal research scientist in UAHuntsville's Earth System Science Center.
That was not what he expected to find.
"All leading climate models forecast that as the atmosphere warms there should be an increase in high altitude cirrus clouds, which would amplify any warming caused by manmade greenhouse gases," he said. "That amplification is a positive feedback. What we found in month-to-month fluctuations of the tropical climate system was a strongly negative feedback. As the tropical atmosphere warms, cirrus clouds decrease. That allows more infrared heat to escape from the atmosphere to outer space."
The results of this research were published today in the American Geophysical Union's "Geophysical Research Letters" on-line edition. The paper was co-authored by UAHuntsville's Dr. John R. Christy and Dr. W. Danny Braswell, and Dr. Justin Hnilo of Lawrence Livermore National Laboratory, Livermore, CA.
Orographic cloud in a GCM: the missing cirrus
Journal Climate Dynamics
Publisher Springer Berlin / Heidelberg
ISSN 0930-7575 (Print) 1432-0894 (Online)
Issue Volume 24, Numbers 7-8 / June, 2005
DOI 10.1007/s00382-005-0020-9
Pages 771-780
Subject Collection Earth and Environmental Science
SpringerLink Date Monday, May 02, 2005
PDF (702.7 KB)HTMLFree Preview
Orographic cloud in a GCM: the missing cirrus
S. M. Dean1 , B. N. Lawrence2, R. G. Grainger1 and D. N. Heuff3
(1) Atmospheric Oceanic and Planetary Physics, Clarendon Laboratory, University of Oxford, Oxford, Oxfordshire, UK
(2) British Atmospheric Data Centre, Rutherford Appleton Laboratory, Chilton, Oxfordshire, UK
(3) Department of Physics and Astronomy, University of Canterbury, Christchurch, New Zealand
Received: 13 September 2004 Accepted: 25 February 2005 Published online: 27 April 2005
Abstract Observations from the International Satellite Cloud Climatalogy Project (ISCCP) are used to demonstrate that the 19-level HadAM3 version of the United Kingdom Met Office Unified Model does not simulate sufficient high cloud over land. By using low-altitude winds, from the European Centre for Medium Range Weather Forecasting (ECMWF) Re-Analysis from 1979 to 1994 (ERA-15) to predict the areas of maximum likelihood of orographic wave generation, it is shown that much of the deficiency is likely to be due to the lack of a representation of the orographic cirrus generated by sub-grid scale orography. It is probable that this is a problem in most GCMs.
People like you have no idea how to make a coherent, intelligent argument. Water Vapor Feedback Loop Will Cause Accelerated Global Warming, Professor Warns ScienceDaily (Feb. 20, 2009) — Here’s yet another reason to hate humidity: it expands global warming, says a Texas A&M University professor. Andrew Dessler, a professor in the Department of Atmospheric Sciences who specializes in research on climate, says that warming due to increases in greenhouse gases will lead to higher humidity in the atmosphere. And because water vapor itself is a greenhouse gas, this will cause additional warming. This process is known as water vapor feedback and is responsible for a significant portion of the warming predicted to occur over the next century. “Its a vicious cycle – warmer temperatures mean higher humidity, which in turn leads to even more warming,” Dessler explains.
A simple calculation can determine what the average temperature of the Earth should be for the outgoing radiation just to balance the energy of the absorbed sunlight. This calculation indicates that the average temperature of the Earth’s surface should be about −20 °C.
This is awfully cold. Fortunately, it is also wrong. The Earth’s surface is much warmer than this, a pleasant 15 °C on average. The error in the calculation comes from assuming that the infrared radiation emitted from the Earth passes directly to space. It does not, because it must pass through the atmosphere. ... This absorption is not caused by the main components of the atmosphere, ...Rather, the absorption comes from several minor atmospheric constituents, principally water vapor and carbon dioxide (CO2). ...
The power of these “greenhouse gases” to warm the Earth’s surface is awesome. Although these gases are present in the atmosphere at only minute concentrations, they warm the surface by nearly 35 °C. Their power becomes even clearer if we compare the climate of the Earth to that of the neighboring planets, Mars and Venus. Mars has a thin atmosphere that is almost completely transparent to infrared radiation, giving it an average surface temperature below −50 °C. Venus has a dense, CO2-rich atmosphere that produces an intense greenhouse effect, raising its average surface temperature above 450 °C – hot enough to melt lead.
But if greenhouse gases in the atmosphere warm the Earth to its present habitable state, increasing the concentration of these gases could make the Earth warmer still. This possibility was proposed by the Swedish chemist Svante Arrhenius in 1906, and again with more supporting evidence by the British engineer Guy Callendar in 1938. These proposals were not initially taken seriously, because with the crude tools then available to observe infrared radiation, it looked like the levels of CO2 and water vapor already in the atmosphere were absorbing enough radiation to create the maximum possible greenhouse effect. By the 1950s, however, more precise measurements of infrared spectra showed this belief to be wrong, so increasing CO2 could increase infrared absorption in the atmosphere and raise the surface temperature.
CO2 is not the only greenhouse gas, nor is it the only one emitted by human activities. Other greenhouse gases that are increasing due to human activities include: methane (CH4), which is emitted from rice cultivation, livestock, biomass burning, and landfills; nitrous oxide (N2O), which is emitted from various agricultural and industrial processes; and the halocarbons, a group of synthetic chemicals of which the most important are the chlorofluorocarbons (CFCs), which are used as refrigerants, solvents, and in various other industrial applications. Human activities do not control all greenhouse gases, however. The most powerful greenhouse gas in the atmosphere is water vapor. Human activities have little direct control over its atmospheric abundance, which is controlled instead by the worldwide balance between evaporation from the oceans and precipitation.
By the 1950s and early 1960s, it was also becoming clear that human activities were releasing CO2 fast enough to significantly increase its atmospheric abundance. Figure 1.1 shows how the abundance of CO2 in the atmosphere has varied over the past 1000 years – remaining nearly constant for most of the millennium, then beginning a rapid increase around 1800. This rapid increase closely tracked the sharp rise in fossil-fuel use that began with the industrial revolution.
Despite clear evidence of increasing atmospheric CO2, during the 1960s and 1970s scientific views about likely future climate trends were divided. Some scientists expected the Earth to warm from rising concentrations of CO2 and other greenhouse gases. Others expected the Earth to cool, ... By the early 1980s, however, global temperatures had resumed warming and many new pieces of evidence indicated that greenhouse gases were the predominant human influence and that warming was the predominant direction of concern.
The fact is that we can't account for the lack of warming at the moment and it is a
travesty that we can't. The CERES data published in the August BAMS 09 supplement on 2008
shows there should be even more warming: but the data are surely wrong. Our observing
system is inadequate.
i think the context has been established, just take a look at the file this thread is about
the above quote stands for itself and is essentially a so called skeptic position, isn't it?
Trenberth is talking about our inability to be able to measure the net radiation balance at the top of the atmosphere to the requisite precision to be able to say on short time scales what the energy budget is doing. The observations are inadequate for that - not sure who is saying otherwise
Trenberth doesn't have a model. Instead he is really interested in what exactly is going on in the observations. Where is the energy going, how much is coming in and going out, what are the impacts of La Nina on those fluxes. His frustration is that the current observing platform is not sufficiently accurate to do this properly, and so we end up with imperfect explanations - especially on the short term. For him, 'natural variability' is only the beginning of the answer, not the whole thing. And that's fine
But Trenberth, who acknowledged the e-mail is genuine, says bloggers are missing the point he’s making in the e-mail by not reading the article cited in it. That article – An Imperative for Climate Change Planning (.pdf) — actually says that global warming is continuing, despite random temperature variations that would seem to suggest otherwise.
“It says we don’t have an observing system adequate to track it, but there are all other kinds of signs aside from global mean temperatures — including melting of Arctic sea ice and rising sea levels and a lot of other indicators — that global warming is continuing,” he says.
"Planned adaptation to climate change requires information about what is happening and why. While a long-term trend is for global warming, short-term periods of cooling can occur and have physical causes associated with natural variability. However, such natural variability means that energy is rearranged or changed within the climate system, and should be traceable. An assessment is given of our ability to track changes in reservoirs and flows of energy within the climate system. Arguments are given that developing the ability to do this is important, as it affects interpretations of global and especially regional climate change, and prospects for the future."
Although the sea level budget is reasonably closed for the post-2003 period, the global energy budget is not closed. Increasing land ice melt at expense of ocean expansion to account for sea level rise has consequences for the energy budget. Accordingly another much needed component is the TOA radiation, but CERES [49] data exist only through 2005 and are not yet long or reliable enough to bring to bear on this question. This highlights the need to bring the CERES TOA radiation up to date along with reprocessed cloud data while ensuring that changes in the ocean, sea ice and sea level are maintained with adequate quality control and sampling to provide estimates reliable enough to address the questions posed in the introduction.
The context is now clear. Trenberth is talking about the travesty of the observation system and our inability to see where the heat is going from year to year. It is well known and public that there are problems in recent years with the global climate observation system (earthobservatory.nasa.gov...). Problems are more of a rule in any complex field of science rather than an exception.