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jethro

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

I believe it does science a great dis-service to not publish papers (for free) so we can all lend a hand in understanding our lives. Many on here are fully able to digest the paper and maybe help direct the 'drive' into areas that matter even more?

If they can hack Exeter for mischief then why aren't we 'hacking' all Uni's for knowledge?

Where is the fairness in that you hackers?

Dare Ya!

Hack the world and give us free access!!!!!!

When do we want it?.........NOW!

Edited by Gray-Wolf
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Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

Don't you see this new study as good news?

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

S'naughty trying to badger folk (or so you tell me J'!).

I'd love to read it but I'm already set up to attack it? Why should that be?

Is man such a loose combination of animal and mind that we'll rationalise challenges to our individual abilities and act accordingly?

Too late J', see ya's 2morrow!:D

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Posted
  • Location: Edinburgh
  • Location: Edinburgh

Sometimes you've got to take information where you can get it. Sadly this isn't available for free at the moment (at least not that I can find) but for anyone willing to pay, the abstract is linked to for payment. The abstract does give a clear indication of the findings.

It appears from this that our understanding and measurements were wrong and no, our understanding isn't that clear.This isn't a black eye for AGW nor is it being presented as such, to read that into this study IMO does a dis-service to an investigation making a genuine attempt to progress our knowledge. At no point does the article or the abstract make any such claims.

Clarity on the magnitude of ice loss is imperative to anticipate what changes, if any, we can expect in sea level rise, this paper tries to address this issue.

Personally, I'd see this as positive news, both the refining of our knowledge and the prospect that we've lost less ice than originally thought. It doesn't alter the prospects for loosing more from the fringes if the world continues to warm but it does show promise that sea level rises will be less than anticipated. Given that this is one of the major factors in the future projections of land lost to the oceans, leading to displaced people and loss of land fit for cultivation in a world with a burgeoning population - how can it be anything other than good news?

More information is available here on why these studies have thus far been incomplete and how important they are, together with an indication of the calibre of the scientists involved in this study.

http://dynaqlim.fgi....ull_program.pdf

Hi Jethro, I agree with you - this study is indeed good news, if verified. I'd certainly be happier in a world where the ice caps were shrinking at a slower rate. I think such a revision would still have us at the high end of current IPCC sea level projections (given that they have been seen as too low by most recent studies), and is not an excuse for us to delay action, but it might give us more time to avoid the worst effects of warming.

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

in so far as this years drought /floods/fires we had this statement from Stanford uni in July

http://www.eurekalert.org/pub_releases/2010-07/su-hwc070810.php

so with the occurence being twice as like by the 2030's would we then be able to ascribe the event to AGW forcings?

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Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

When they do these studies do they take every other climate driver as being a static entity, or do they allow for a wide variance and incorporate that into the models too?

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Posted
  • Location: York, North Yorkshire
  • Location: York, North Yorkshire

Hi Folks,

There is a new piece of research by Roy Spencer' group on the role of that has been accepted for publication in the Journal of Geophysical Research:

The papers title is: "On the diagnosis of radiative feedback in the presence of unknown radiative forcing"

http://www.drroyspen...ll-JGR-2010.pdf

As a synopsis this paper puts meat on the central claim of Dr Spencers most recent book " The Great Global Warming Blunder: How Mother Nature Fooled the World's Top Climate Scientists" and Dr Spencer's belief that climate researchers have mixed up cause and effect when observing cloud and temperature changes. This as a result, the climate system giving the illusion of positive cloud feedback.

Here's a following extract from Dr Spencers blog (http://www.drroyspencer.com/), discussing the publication:

"Positive cloud feedback amplifies global warming in all the climate models now used by the IPCC to forecast global warming. But if cloud feedback is sufficiently negative, then manmade global warming becomes a non-issue. While the paper does not actually use the words “cause†or “effectâ€, this accurately describes the basic issue, and is how I talk about the issue in the book. I wrote the book because I found that non-specialists understood cause-versus-effect better than the climate experts did!

This paper supersedes our previous Journal of Climate paper, entitled “Potential Biases in Feedback Diagnosis from Observational Data: A Simple Model Demonstration“, which I now believe did not adequately demonstrate the existence of a problem in diagnosing feedbacks in the climate system.

The new article shows much more evidence to support the case: from satellite data, a simple climate model, and from the IPCC AR4 climate models themselves.

Back to the Basics

Interestingly, in order to convince the reviewers of what I was claiming, I had to go back to the very basics of forcing versus feedback to illustrate the mistakes researchers have perpetuated when trying to describe how one can supposedly measure feedbacks in observational data.

Researchers traditionally invoke the hypothetical case of an instantaneous doubling of the CO2 concentration of the atmosphere (2XCO2). That doubling then causes warming, and the warming then causes radiative feedback which acts to either reducing the warming (negative feedback) or amplify the warming (positive feedback). With this hypothetical, idealized 2XCO2 case you can compare the time histories of the resulting warming to the resulting changes in the Earth’s radiative budget, and you can indeed extract an accurate estimate of the feedback.

The trouble is that this hypothetical case has nothing to do with the real world, and can totally mislead us when trying to diagnose feedbacks in the real climate system. This is the first thing we demonstrate in the new paper. In the real world, there are always changes in cloud cover (albedo) occurring, which is a forcing. And that “internal radiative forcing†(our term) is what gives the illusion of positive feedback. In fact, feedback in response to internal radiative forcing cannot even be measured. It is drowned out by the forcing itself.

Feedback in the Real World

As we show in the new paper, the only clear signal of feedback we ever find in the global average satellite data is strongly negative, around 6 Watts per sq. meter per degree C. If this was the feedback operating on the long-term warming from increasing CO2, it would result in only 0.6 deg. C of warming from 2XCO2. (Since we have already experienced this level of warming, it raises the issue of whether some portion — maybe even a majority — of past warming is from natural, rather than anthropogenic, causes.)

Unfortunately, there is no way I have found to demonstrate that this strongly negative feedback is actually occurring on the long time scales involved in anthropogenic global warming. At this point, I think that belief in the high climate sensitivity (positive feedbacks) in the current crop of climate models is a matter of faith, not unbiased science. The models are infinitely adjustable, and modelers stop adjusting when they get model behavior that reinforces their pre-conceived notions.

They aren’t necessarily wrong — just not very thorough in terms of exploring alternative hypotheses. Or maybe they have explored those, and just don’t want to show the rest of the world the results.

Our next paper will do a direct apples-to-apples comparison between the satellite-based feedbacks and the IPCC model-diagnosed feedbacks from year-to-year climate variability. Preliminary indications are that the satellite results are outside the envelope of all the IPCC models.

No doupt some will find this interesting .... and others will not !!

Y.S

Edited by Yorkshiresnows
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Posted
  • Location: Edinburgh
  • Location: Edinburgh

Hope it's better than Spencer and Braswell's last effort....

http://www.realclima...e-easy-lessons/

The section on Spencer's rather bizarre "internal radiative forcing" [weather] is worth a re-read as that concept rears it's head again in Spencer's new paper. I'll await the professional responses to this paper, but I wonder if Spencer has the wrong end of the stick (yet) again?

Also worth noting is that the feedbacks are a product of the physics in the models, not specifically coded in - from the above RealClimate post: "the concept of feedbacks is just something used to try to make sense of what a model does, and does not actually enter into the formulation of the model itself." Spencer's unfounded accusations against climate modellers do him no favours in the world of real science, and his failure to understand where the feedbacks come from gives me rather serious concerns about the validity of his latest paper. Some might have already made their minds up about the validity of the paper, but I'd prefer to see some independent corroboration, and see how it stands up to criticism.

Edited by sunny starry skies
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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

:whistling:LOL! At least Roy the boy is trying.......very trying :D

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Posted
  • Location: York, North Yorkshire
  • Location: York, North Yorkshire

:whistling:LOL! At least Roy the boy is trying.......very trying :cray:

Its funny how predictable certain folks are ........ :cray:

Anyway, I'd suggest that what this does show is that the mechanics of feedback and forcing are complicated with many unknowns still to be unravelled. The role of clouds is (and as the IPCC admits) on feedback is still an unknown quantity that could potentially be a big player.

Why don't you and SSS read the book ...... now that he has published data on his central claim, you can at least get over the 'its in a book and therefore has not been peer reviewed and is therefore crap' stance. You might actually like what you see.

Better still, go and post your views on his blog and see if you get a response. I see that he is answering comments on the paper at the moment.

Or you could just rubbish another paper that dares to question the 'consensus view' on climate forcing.

Y.S

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

http://www.sciencedaily.com/releases/2010/08/100831073254.htm

Seems the channel between both Antarctic islands must have been open recently and not under 2 km of ice! Isn't there an Arab map showing this????

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Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.

I'll be keeping an open mind over Spencer's latest paper. Especially as his suggestion of a negative overall cloud-feedback is in line with my own expectation...

Who knows? :cray::cray:

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

I think it's a very wide and poorly studied area Pete. If we look at past warmings (CO2 V's Temp) what impact did 'clouds' have on the final outcome?. It's like over the Arctic, are low stratoform over the ice in winter a positive or negative?

Over the equator, more heat, more ability for the air to hold moisture less clouds (and so more heat?).

Temperate regions? What type of cloud will 'heating bring'?, ask the russians this summer (and other swathes of europe) and what did that lack of cloud mean to the biomass below (and it's ability to absorb CO2 this summer?)

To say 'Tall bright clouds equals loss of heat' is not going to do it (for me) but the experience of past warmings would say that if CO2 goes up then so do temps no matter what clouds do as they settle into the warming pattern. Most likely 'swings and roundabouts' is the best we can hope for?

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Posted
  • Location: York
  • Weather Preferences: Long warm summer evenings. Cold frosty sunny winter days.
  • Location: York

It is not as simple as saying clouds provide a positive or negative feedback. There are many different cloud types at different levels within our atmosphere and I am sure that some will produce positive feedback and some will provide negative feedback. My own believe is that high is positive low is negative. This has been explored both both Svensmark and Spencer.

Clearly some on here do not want to cotemplate the possibility that there maybe a greater player at work than manmade GHG's and that until we actually understand the role of clouds then we will not understand what drives temprature.

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

Don't we take the 'role of clouds' as a read? Isn't it important to find how any 'novel' drivers might alter this 'role' with more heat (energy) in the system? As I have said past 'examples of warming have showed elevated CO2 and temp so whatever the shakedown through the 'warming' warming still occurs in these past examples. If we had past CO2 spikes that didn't end up with warming and then the CO2 returned back to 'background' levels (and not 'high' ones) then we might think that there was a 'feedback' strong enough to negate the extra capacity to hold heat but I haven't come across such examples?

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Posted
  • Location: York, North Yorkshire
  • Location: York, North Yorkshire

Don't we take the 'role of clouds' as a read? Isn't it important to find how any 'novel' drivers might alter this 'role' with more heat (energy) in the system? As I have said past 'examples of warming have showed elevated CO2 and temp so whatever the shakedown through the 'warming' warming still occurs in these past examples. If we had past CO2 spikes that didn't end up with warming and then the CO2 returned back to 'background' levels (and not 'high' ones) then we might think that there was a 'feedback' strong enough to negate the extra capacity to hold heat but I haven't come across such examples?

Water vapour as a greenhouse gas is far more potent than CO2 and even small changes in low height cloud cover would have an impact on the radiative budget of the Earth (blocking sunlight and the ocean absorbance of solar irradiation). Of course changes in high level cloud would have an opposite effect, trapping heat.

No we don't take the role of clouds as read ... that is the whole point and even the IPCC admit there is a lot more to know about how increasing water vapour in a warming climate will impact on this aspect. It is the biggest uncertainty that there is. So far the climate models all assume a +positive feedback response alone. It is this which is being shown to be highly questionable from Roy Spencers group.

You could argue that changes in PDO / AMO and other ocean cyclical factors may also have a role to play in changing the status quo in this regard.

I believe (at least from what I have read) that a change in cloud cover of just 1% would be sufficient to account for the warming seen since the start of the 20th century.

Would seem perfectly sensible to investigate whether natural cyclical factors have any bearing on the warming seen and whether changes in cloud cover are a possible part of the mechanism.

Y.S

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Posted
  • Location: York, North Yorkshire
  • Location: York, North Yorkshire

Hi Folks,

A little more on the case for the recent paper by Roy Spencer.

The below is taken directly from his blog. Its a nice description of the current situation regarding cloud feedback science (though clearly written from one side of the argument). The emphasis's I have added.

I received a question from a reader today regarding why the writer of a recent article ( http://e360.yale.edu...searchers/2313/ the state of the science on cloud feedbacks did not mention our newly published work.The usual suspects were questioned, but there was nothing new there. Cloud feedbacks are just as uncertain today as they were 20 years ago, blah, blah. More of the same.

Now, I would like to think our new paper (http://www.drroyspencer.com/wp-content/uploads/Spencer-Braswell-JGR-2010.pdf) demonstrated not only the main reason why cloud feedbacks have remained so uncertain, but why their estimation from satellite data tends to give the illusion of a sensitive climate system.

None of the so-called experts mentioned what has been ignored as a potential climate change mechanism: Natural cycles in cloud cover. I had wondered for years why no one investigated the possibility, and our work clarified for me that this indeed is a huge question mark that most researchers do not even realize exists.

Unfortunately, I predict it will be at least 2 years before our paper is digested and believed by influential people in the climate community…if even then. (They still think the truth is lurking in computer models somewhere…just turn this knob a little more to the right left…)

This brings up the issue of how entrenched some ideas get in the scientific community, and not only for scientific reasons.

Dr. Roy in a Previous Millennium

In an earlier life, my claim to fame was demonstrating that satellite passive microwave radiometers could be used to measure rainfall over land. My first paper on the subject (actually, my first published paper ever) had the cover illustration on the front of Nature magazine. Ha! If they only knew I would grow up to be a “denierâ€.

At the time (1983) the established scientists working with NASA wanted to build the first weather radar to fly in space. While this was a worthy effort in its own right — finally realized with the Tropical Rainfall Measuring Mission (TRMM) — one of the radar’s original justifications was to measure rainfall over land.

My work was apparently providing evidence it was not needed. So, as a post-doc newcomer to the field, I was rocking that boat.

For me, that experience was when I lost my innocence. My research worldview was shaken. Scientists are not objective after all! Gasp!

Now, even after over 20 years of telling people of all of my subsequent experiences that only reinforced my claim that scientists are not objective, it seemed like no one was particularly worried about this.

Then Climategate broke upon the scene. Scientists behaving badly! Gasp!

What Was I Talking About? Oh, Yeah, Cloud Feedbacks

So, what I am getting around to is that it will take a long time before the climate research community looks at, understands, and believes what we have done.

Sometimes I have half-jokingly mentioned that it will probably take an IPCC-ordained scientist to “discover†the same thing. I experienced that behavior, too. NASA research centers can be pretty competitive with each other. If it wasn’t invented at their center, it wasn’t invented.

So, getting back to the original question: Why did this science writer not mention my work in his summary article on cloud feedbacks? I’m afraid he’s the last one I would expect to know.

Consider:

1) Most scientists, let alone science writers, will not even be aware that our paper has been published.

2) Even if they know it has been published, they won’t bother to read it because they have already heard it conflicts with IPCC orthodoxy.

3) Even if they dare read it, they probably won’t take the time to understand it, and so they will revert to the IPCC party line, anyway.

4) Even if they read it and understand it, they will not recognize its importance. After all, the reviewers made sure our paper was sanitized so that it would not make any outright claims that could potentially shake the faith of the Believers. The reader will instead have to know enough about the field to figure out for themselves what the implications are.

Fortunately, I have been getting some good feedback in recent days (Hah! Feedback!). A nice note from Lord Monckton basically said, “NOW I see what you have been talking about!â€

A blog reader who doesn’t even do climate research read the whole paper and understood it. Now, THAT is cool.

But, while this is heartening, we still need the mainstream climate scientists to pay attention. Unfortunately, scientific discovery never was the purpose of the IPCC, and you disagree with them at your professional peril.

Y.S

Edited by Yorkshiresnows
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Posted
  • Location: Edinburgh
  • Location: Edinburgh

So Spencer still believes that scientists are naughty and he's repeating debunked rubbish in suggesting there was any substance to the climategate allegations. Of course all the subsequent exonerations by multiple independent panels mean nothing...

Other cloud research has not shown the same links Spencer claims, so it seems he's the one out on a limb, and with a track record of producing ropey results. I'd still be intersted to know how, if clouds are such a powerful negative feedback, we get large palaeoclimatic shifts from small initial orbital forcings. CO2 explains that well, quite apart from all the other direct evidence for CO2 operating as expected today...

Lets see what the professionals have to say, if they care a jot about Spencer's claims these days. The last few times out Spencer's claims were torn to shreds, so I hope he's got his sums, and graphs, in order and not cooked up this time.

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Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

According to the IPCC, clouds are incredibly important and our lack of knowledge and understanding is a major hindrance in projecting future temperature rises.

In spite of this undeniable progress, the amplitude and even the sign of cloud feedbacks was noted in the TAR as highly uncertain, and this uncertainty was cited as one of the key factors explaining the spread in model simulations of future climate for a given emission scenario. This cannot be regarded as a surprise: that the sensitivity of the Earth’s climate to changing atmospheric greenhouse gas concentrations must depend strongly on cloud feedbacks can be illustrated on the simplest theoretical grounds, using data that have been available for a long time. Satellite measurements have indeed provided meaningful estimates of Earth’s radiation budget since the early 1970s (Vonder Haar and Suomi, 1971). Clouds, which cover about 60% of the Earth’s surface, are responsible for up to two-thirds of the planetary albedo, which is about 30%. An albedo decrease of only 1%, bringing the Earth’s albedo from 30% to 29%, would cause an increase in the black-body radiative equilibrium temperature of about 1°C, a highly significant value, roughly equivalent to the direct radiative effect of a doubling of the atmospheric CO2 concentration. Simultaneously, clouds make an important contribution to the planetary greenhouse effect. In addition, changes in cloud cover constitute only one of the many parameters that affect cloud radiative interactions: cloud optical thickness, cloud height and cloud microphysical properties can also be modified by atmospheric temperature changes, which adds to the complexity of feedbacks, as evidenced, for example, through satellite observations analysed by Tselioudis and Rossow (1994).

http://www.ipcc.ch/p.../ch1s1-5-2.html

http://www.ipcc.ch/i...tar/wg1/274.htm

As for Spencer producing ropey results.....

Roy W. Spencer is a climatologist and a Principal Research Scientist for the University of Alabama in Huntsville, as well as the U.S. Science Team Leader for the Advanced Microwave Scanning Radiometer (AMSR-E) on NASA’s Aqua satellite. He has served as senior scientist for climate studies at NASA’s Marshall Space Flight Center in Huntsville, Alabama.

He is known for his satellite-based temperature monitoring work, for which he was awarded the American Meteorological Society's Special Award.

http://en.wikipedia.org/wiki/Roy_Spencer_%28scientist%29

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Posted
  • Location: York
  • Weather Preferences: Long warm summer evenings. Cold frosty sunny winter days.
  • Location: York

SSS I assume next you will be telling us that changes in amount of cloud is driven by CO2 as clearly in your own mind CO2 is the be all and end all when it comes to changes in our climate. Simply because you think spencer is an idiot does not mean that what he is proposing is irrelevant. Our understanding of present changes in climate will only improve once we understand better the effect of clouds.

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

Hey jb!

I don't think the importance is being played down. Temps will rise to meet with their CO2 dopleganger but how fast? Do we need search for rapid climate shift events (and see how they can 'be') or do we rely on clouds making everything alright because we know so little of their effects?

Nice article on Antarctica 125 million years ago though..........how fast did that happen? and more importantly 'Why'?

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Posted
  • Location: York, North Yorkshire
  • Location: York, North Yorkshire

According to the IPCC, clouds are incredibly important and our lack of knowledge and understanding is a major hindrance in projecting future temperature rises.

In spite of this undeniable progress, the amplitude and even the sign of cloud feedbacks was noted in the TAR as highly uncertain, and this uncertainty was cited as one of the key factors explaining the spread in model simulations of future climate for a given emission scenario. This cannot be regarded as a surprise: that the sensitivity of the Earth’s climate to changing atmospheric greenhouse gas concentrations must depend strongly on cloud feedbacks can be illustrated on the simplest theoretical grounds, using data that have been available for a long time. Satellite measurements have indeed provided meaningful estimates of Earth’s radiation budget since the early 1970s (Vonder Haar and Suomi, 1971). Clouds, which cover about 60% of the Earth’s surface, are responsible for up to two-thirds of the planetary albedo, which is about 30%. An albedo decrease of only 1%, bringing the Earth’s albedo from 30% to 29%, would cause an increase in the black-body radiative equilibrium temperature of about 1°C, a highly significant value, roughly equivalent to the direct radiative effect of a doubling of the atmospheric CO2 concentration. Simultaneously, clouds make an important contribution to the planetary greenhouse effect. In addition, changes in cloud cover constitute only one of the many parameters that affect cloud radiative interactions: cloud optical thickness, cloud height and cloud microphysical properties can also be modified by atmospheric temperature changes, which adds to the complexity of feedbacks, as evidenced, for example, through satellite observations analysed by Tselioudis and Rossow (1994).

http://www.ipcc.ch/p.../ch1s1-5-2.html

http://www.ipcc.ch/i...tar/wg1/274.htm

As for Spencer producing ropey results.....

Roy W. Spencer is a climatologist and a Principal Research Scientist for the University of Alabama in Huntsville, as well as the U.S. Science Team Leader for the Advanced Microwave Scanning Radiometer (AMSR-E) on NASA’s Aqua satellite. He has served as senior scientist for climate studies at NASA’s Marshall Space Flight Center in Huntsville, Alabama.

He is known for his satellite-based temperature monitoring work, for which he was awarded the American Meteorological Society's Special Award.

http://en.wikipedia....%28scientist%29

Great post,

I was attempting to put something similar down and you beat me to it.

Roy Spencer is an Expert in the field ...... perhaps others should not so easily dismiss his findings.

Y.S

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Posted
  • Location: Near Newton Abbot or east Dartmoor, Devon
  • Location: Near Newton Abbot or east Dartmoor, Devon

According to the IPCC, clouds are incredibly important and our lack of knowledge and understanding is a major hindrance in projecting future temperature rises.

In spite of this undeniable progress, the amplitude and even the sign of cloud feedbacks was noted in the TAR as highly uncertain, and this uncertainty was cited as one of the key factors explaining the spread in model simulations of future climate for a given emission scenario. This cannot be regarded as a surprise: that the sensitivity of the Earth’s climate to changing atmospheric greenhouse gas concentrations must depend strongly on cloud feedbacks can be illustrated on the simplest theoretical grounds, using data that have been available for a long time. Satellite measurements have indeed provided meaningful estimates of Earth’s radiation budget since the early 1970s (Vonder Haar and Suomi, 1971). Clouds, which cover about 60% of the Earth’s surface, are responsible for up to two-thirds of the planetary albedo, which is about 30%. An albedo decrease of only 1%, bringing the Earth’s albedo from 30% to 29%, would cause an increase in the black-body radiative equilibrium temperature of about 1°C, a highly significant value, roughly equivalent to the direct radiative effect of a doubling of the atmospheric CO2 concentration. Simultaneously, clouds make an important contribution to the planetary greenhouse effect. In addition, changes in cloud cover constitute only one of the many parameters that affect cloud radiative interactions: cloud optical thickness, cloud height and cloud microphysical properties can also be modified by atmospheric temperature changes, which adds to the complexity of feedbacks, as evidenced, for example, through satellite observations analysed by Tselioudis and Rossow (1994).

http://www.ipcc.ch/p.../ch1s1-5-2.html

http://www.ipcc.ch/i...tar/wg1/274.htm

All this is, afaik, true. But, how come climate does indeed change? We all accept climate changes? So there are other effect than clouds? So why are some people so unwilling to accept the bit about CO2? Yes, if (IF) clouds change by 1% that would have a big effect, but so is a doubling of CO2. And has Dr Spencer shown a 1% change, or indeed any change? Perhaps someone can point out where he does, because I can't see where he does?

As for Spencer producing ropey results.....

Roy W. Spencer is a climatologist and a Principal Research Scientist for the University of Alabama in Huntsville, as well as the U.S. Science Team Leader for the Advanced Microwave Scanning Radiometer (AMSR-E) on NASA’s Aqua satellite. He has served as senior scientist for climate studies at NASA’s Marshall Space Flight Center in Huntsville, Alabama.

He is known for his satellite-based temperature monitoring work, for which he was awarded the American Meteorological Society's Special Award.

http://en.wikipedia.org/wiki/Roy_Spencer_%28scientist%29

Yes, he's nearly as well qualified and experienced as people like Dr Michael Mann and Dr James Hansen - but I'm sure that doesn't mean you accept every word they say :rolleyes:

Edited by Devonian
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Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

I'm sorry Dev but I find your tone in that post to be really quite argumentative, for arguments sake.

SSS raised a point about the significance of cloud feedback - I posted the official IPCC opinion on their importance and the lack of understanding.

SSS also questioned Spencer's results on the basis that he's produced some ropey results - I posted his qualifications and positions held, so that people can see he's actually really rather well qualified to make this study.

Quite what Mann, Hansen and other people's perception on CO2 and climate change have to do with what I posted is I'm afraid, beyond me.

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Posted
  • Location: Swallownest, Sheffield 83m ASL
  • Location: Swallownest, Sheffield 83m ASL

Just because you don't have loads of letters after your name doesn't mean you don't understand the science. Why do you think boards like this exist? It's to learn and discover the workings of Earth's climate. Just because some have a huge amount of letters belonging to them doesn't make them right..

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