No wounded pride here. I just don't think the anthropogenic part of global warming really started until the last half of the 20th Century. Warming before then was primarily from other causes. Climate scientists would tell you the same thing. Those studies you're looking at must just be statistical in nature to have such diverse answers. That is they're projecting warming based on current trends rather than using the physical properties as a basis of their projection.
Here is a graph that plots several model simulations along with a number of proxy reconstructions and the instrument record. I don't see anything terribly out of whack regarding the model simulations regarding the LIA or the MWP. I got it from this blog post.
Here is a discussion of the difficulty of reconciling models and paleoclimate data. It's not as easy as you might think.
There are a myriad of different studies out there and I'm not going to take the time to look them up. Some may start at the height of the LIA (around 1600) but that's not true of all of them. I think most of the ones you're referring to probably started in the middle 1800's which was at the tail of the LIA. Regardless of that if there is a physical basis to the study rather than just statistical modeling they should converge on reality.
That's quite a leap from "We haven't figured it all out" to "the IPCC isn't sure if GW even exists". You don't have to figure everything out to say you know something about a subject.
Al Gore is just a boogeyman for you, he has nothing to do with the real issues.
The Wikipedia entry on the greenhouse effect also says:
The major non-gas contributor to the Earth's greenhouse effect, clouds, also absorb and emit infrared radiation and thus have an effect on radiative properties of the atmosphere
Recent research on the subject indicates clouds net effect on global warming is likely slightly positive and very unlikely to be strongly negative. (Dessler 2010)
Sorry to not answer sooner but I went to a Jethro Tull concert Thursday and got busy a work Friday.
Interesting paper. Thanks for that. But even Usokin himself says not to read too much into it in regards to climate science. To quote from a comment on RealClimate:
Ilya Usoskin responded to yr considerations as follows:
“Dr. Ladbury is right. No statistically significant conclusion can be drawn concerning the shape of the distribution of the Grand Minima shape. But the matter is that the division on Maunder-like and Spoerer-like minima has been done much earlier basing on only a few minima. Our present result is consistent with such a division, although a long-tail continuous distribution cannot be excluded. I also agree that hardly any direct implication for climate studies is apparent, and we were primarily interested in observational constraints for solar dynamo models.”
The last glaciation started ending about 20,000 years ago. It ended because of changes in insolation but that is probably due more to Milankovitch Cycles than changes in solar state. 9500 BCE was the end of the transition from glaciation to an interglacial. While it is a factor it's not likely that changes in solar state by itself drives the cycles of the ice age.
Hmm... It doesn't appear that Dr. Usokin considered Milankovitch Cycle changes into his work. I wonder if it would change much if he did.
I've never seen any evidence that climate scientists have tried to erase the MWP. Looking at Dr. Usokin's Figure 17 it appears that solar activity wasn't particularly high during that period. That would appear to support that contention that the MWP was more of a regional rather than global phenomenon.
Is it linear when temperatures rise about the same amount for each doubling of CO2? I didn't think that was a linear relationship but you're obviously better trained in statistics than I am so maybe I'm wrong.
GCM's are primarily physical models. Some things that are not well understood are parameterized but the fundamentals are based on known physical relationships. It don't think it's fair to say the climate sensitivity is basically unknown. Oscillations like the PDO may well be a neutral factor over long enough periods as the positive and negative phases cancel each other out. Happy is not a word I would use regarding proxy reconstructions. I would just say they are the best information we have at the moment and are more useful than assuming we know nothing.
Individual scientists and small groups can certainly fall victim to bending science but as the group becomes larger that becomes much more difficult to pull off. Given the global nature of climate research I find it difficult to believe that such a conspiracy could hold together for such a long period of time over so many different research groups. Scientists are too competetive for that. You focus on the MBH vs. M&M controversy but ignore all of the similar reconstructions (at least 10) since then from different researchers using different proxy data that basically support Mann's original graph. Even applying the suggested improvements in statistical analysis didn't change Mann's graph much. It's time to move on.
Until the middle of the 20th Century solar variation was likely the primary driver of temperature changes from the Maunder Minimum. CO2 levels had only risen from about 280 ppmv to 315 ppmv by then. Since then it has risen to 390 ppmv.
I don't think I've ever heard climate scientists use the terms usual or unusual regarding the solar state. They just contended that since the mid 20th Century that solar activity hadn't changed enough to account for the observed warming. And it's true that the last 4 or 5 cycles until the present one have been about equivalent to each
Actually, no. It would show less cooling, but not warming.
Care to prove that? 2010 was hotter than 1997 or 1999 and the equal of 1998. Other than 1998 every year in the 2000's other than 2000 itself was warmer than any year in the 1990's.
Cooling in the face of increasing CO2?
If you expect a monotonic increase in temperatures with increasing CO2 your expectations are unrealistic.
The initial insistence that the MWP never existed,...
That was an accusation about Michael Mann's "hockey stick graph" which has absolutely nothing to do with GCM's. It was a graph of proxy observations. Find me one quote about GCM's not modeling those things properly.
Observed data is what really happens. Models try to emulate reality In general the GCM's do a decent job of modeling reality and as I said nothing that has happened contradicts them. You may choose to believe otherwise but I doubt you really understand what models are really modeling.
Well, my point was that if you had chosen 12 or 14 years for your graph instead of 13 years the data would have shown warming. That's why I called it cherry picking.
Nothing that has happened contradicts the GCM's. They're not even trying to predict what happens on less than 30 year time scales. Anyone who thinks otherwise doesn't understand what they're designed to do. They don't predict weather.
What cooling in the 00's? It was the warmest decade on record. I see professor Easterbrook's RSS MSU graph shows a cooling trend from 2002 to about 2009.5 but he doesn't specify what channel's data he is using, where it came from. If he used Channel TLS data a cooling trend is expected in the stratosphere. Without more details I can't make a judgement about whether he has a point with the graph but I'm skeptical and feel it could be another case of cherry picking. I guess we'll find out by 2020 if there's anything to what he's saying but if it's another "warmest decade on record that kind of destroys his argument. Some scientists have said that 2012 or maybe 2013 is likely to set a new record for highest temperature year so maybe we don't have to wait that long.
I don't get where you think the models don't match the MWP or the Little Ice Age. I've never seen any indication that they don't.
Before the 1960's that were marked as the center of the largest, longest, hottest Grand Solar Maximum in eleven thousand years...
This graph says otherwise. It looks like we're at the highest solar maximum in eleven hundred years though.
And that's even before I note that we don't have even approximately reliable records of global temperatures prior to perhaps the 1980s (certainly none before the 1960s) and satellites designed to measure it,...
I'd like to see you justify that statement more fully. One of the first thing scientists did when they decided they wanted to calculate a global temperature was examine the existing instrument temperature record that goes back to early 1700's in some cases. They found that since the mid 1800's or so the temperature record was accurate enough and widespread enough to be useful, maybe not perfect but useable. I'm sure there are papers that address that in detail but I'm not taking the time to look them up. Of course the number they calculate for global temperature is not the same number you would get if you integrate the instantaneous temperature of every square millimeter over the whole surface of the Earth but as long as they are consistent in the way they calculate it you get an indication of how the temperature is changing over time.
Of course satellites don't measure temperatures directly like a thermometer does. Instead the temperature is calculated using known correlations between temperature and the radiative properties of various layers of the atmosphere (I guess you could say that bulb thermometers use known correlations of the expansion properties of certain liquids to temperature so maybe it's the same thing:-). I don't see how satellites are more reliable than a well made thermometer. They still have to be calibrated. On top of that satellites have been measuring the Sun for a similar length of time and haven't found enough variation to account for observed temperature changes.
I'm not precisely certain how you can refer to points a) and b) above as "straw men".
I got the implication that you felt everyone on my side of the issue agreed with those statements which is simply not true. That's why I called them straw men. Maybe I read too much into it. If so I'm sorry.
The statement you replied to was my post that said "Solar activity had nothing to do with "The Year Without a Summer". It was the eruption of Tambora that caused that.". Perhaps I should have qualified that better by saying "Changes in solar activity had practically nothing to do with TYWaS". Other years with similar levels of solar activity had much more normal summers so I don't see how you can say the Sun was a significant factor for that unusual summer.
Climate does not respond immediately to solar variation. There is a lag time of 6 months to a few years. If there were other factors of the solar state that were significant I think we would have at least figured out there was something wrong by now. But the known factors appear to sync pretty well with the observed reality so at best your other factors are 2nd order effects.
You read too much into what I said if you think I said CO2 is the only possible explanation. It's not a binary question. There are many factors that go into what the climate is, CO2 merely being one of the more important of them (but not most important, that's the Sun). Some of those multidecadal oscillations may have much to do with the natural resonance of the topology they operate in and the physical characteristics of the medium as they do with solar cycles. Some of those mysterious other factors that you talk about.
Hum.... You have a rather simplistic view of climate modeling. GCM's include the trapping due to all known greenhouse gases, the dynamics of water vapor in the atmo
What does faith have to do with the value of the permittivity constant? It is what it is. Maybe if it were something else we wouldn't be here but that has nothing to do with faith. Same thing with the direction of time and entropy. They are what they are. Science allows us to quantify them. Mathematically speaking it may be perfectly reasonable for them to go the other way but that is not a characteristic of the universe we live in at the present time. To believe that the universe is the way it is because some creator made it that way for us is something that does require faith. We may not know all of the answers to your questions but perhaps we will in the future.
2+2=4 because it is defined that way in our mathematical system. If it ever appears that is incorrect my first reaction would be to look at the assumptions I used that could be wrong.
I think my comment "except maybe that humans are capable of actually understanding reality on some level" covers your "faith in the scientific method". I have faith in the scientific method because it works so far. If it stops working I may have to reconsider.
I would call myself an agnostic who leans toward atheism. I don't think you'd find any comments by me that are particularly scathing to the religious people who post here other than to point out that it doesn't require religion to believe the answers science gives us. Some of the scientific answers are stronger than others but I just attribute that to our lack of understanding. Science doesn't have all of the answers of course but as a model of reality I think it does a reasonable job.
The Little Ice Age is not considered the starting point of Anthropogenic Global Warming. Please give me an example of where you think it is. Although there is a bit of effect before then the anthropogenic part of global warming didn't really start to kick in until the 1960's. I'm perfectly happy if you consider 1960 as the starting point.
I consider the Darfur Conflict to be a case of climate refugees. Long term drought has caused nomadic herders to encroach on the land of non-nomadic farmers.
Many coastal residents in Bangladesh have been forced to abandon their land because of the encroaching ocean making their farms untenable. More climate refugees.
Inuit villages have been forced to move because of the encroaching ocean, partially because of rising sea level but mainly because the sea ice doesn't protect the shoreline from wave erosion like it used to.
I'm sure I could come up with plenty of other situations if I cared to take the time to research it.
When I said the production and calibration techniques were well refined by that time I was referring to 1880. I'm sorry I didn't make that clearer. It was pretty late when I replied. The instrument temperature datasets that climatologists use generally don't go much earlier than 1850. By that time thermometers were plenty accurate for their purposes. I challenge you to prove otherwise.
The incoming radiant energy from the Sun is mostly in the visible (and ultraviolet) wavelengths. Greenhouse gases are transparent to those. When that incoming visible radiant energy gets absorbed by the surface (land or ocean) it gets re-radiated in the infra-red wavelengths that greenhouse gases are more opaque to. So greenhouse gases are like a filter that allows the higher frequencies through and blocks the lower frequencies. The surface converts the frequencies down.
Clouds reflect sunlight, shading the land and sea, consequently decreasing temperature
If it were only that simple. Clouds can not only reflect sunlight back off the Earth but they can reflect or absorb the Outgoing Longwave Radiation that arises from the surface of the planet. At night that is the dominant effect of clouds. Also near the terminator between the light and dark sides of the planet they can reflect sunlight toward the surface. The net effects of clouds on global warming is currently thought to be slightly positive.
13 years in this case was just cherry picked to use the extremely hot year of 1998 as a starting point. But more to your point, there are various knows cycles of natural variability like El Nino, the Pacific Decadal Oscillation and others that don't wash out in a 13 year cycle but do to a greater extent in a 30 year cycle. 30 years is a bit arbitrary but it's reasonable.
The precise wording of the report (which wasn't a UN report but just from and organization affiliated with them) was that there would be up to 50 million refuges. So that was the maximum they considered possible. I don't know that they specified a minimum.
By the 1880's thermometers were quite accurate. The mercury thermometer was invented in 1714 I believe. The production and calibration techniques were well refined by that time. When you combine many measurements from many instruments the errors tend to average out.
If as you say the precise mechanism is unknown then it's a pretty big assumption just to say that the Sun caused the Earth to cool in the 17th century and warm in the 20th century. I don't think you can have it both ways.
No, the GW adherents have already stated that the sun has absolutely no effect on global temperature.
Not this "GW adherent" (and most others I suspect). The Sun is the primary source of heat energy on the Earth. When the Sun's output starts varying enough to explain the total temperature change I'll say "It's the Sun!". But not until then.
So, what "single specific change"s are you saying failed to occur? What "hockey-stick warming prediction" failed to happen? I suspect you fail to understand the temporal nature of the predicted changes. Most of them occur over a period of decades or longer, not in the next 10 years. Global warming means more energy in the atmosphere, energy that gives a boost to the weather that is already going to happen. An increase in the severity of weather is an expected effect.
The terms Global Warming and Climate Change were both used in the 1950's. More recently Frank Luntz told George W. Bush he should use Climate Change rather than Global Warming because it sounded less dangerous. Saying people changed from Global Warming to Climate Change because they couldn't justify Global Warming is a shibboleth.
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No wounded pride here. I just don't think the anthropogenic part of global warming really started until the last half of the 20th Century. Warming before then was primarily from other causes. Climate scientists would tell you the same thing. Those studies you're looking at must just be statistical in nature to have such diverse answers. That is they're projecting warming based on current trends rather than using the physical properties as a basis of their projection.
Here is a graph that plots several model simulations along with a number of proxy reconstructions and the instrument record. I don't see anything terribly out of whack regarding the model simulations regarding the LIA or the MWP. I got it from this blog post.
Here is a discussion of the difficulty of reconciling models and paleoclimate data. It's not as easy as you might think.
There are a myriad of different studies out there and I'm not going to take the time to look them up. Some may start at the height of the LIA (around 1600) but that's not true of all of them. I think most of the ones you're referring to probably started in the middle 1800's which was at the tail of the LIA. Regardless of that if there is a physical basis to the study rather than just statistical modeling they should converge on reality.
That's quite a leap from "We haven't figured it all out" to "the IPCC isn't sure if GW even exists". You don't have to figure everything out to say you know something about a subject.
Al Gore is just a boogeyman for you, he has nothing to do with the real issues.
The Wikipedia entry on the greenhouse effect also says:
The major non-gas contributor to the Earth's greenhouse effect, clouds, also absorb and emit infrared radiation and thus have an effect on radiative properties of the atmosphere
Recent research on the subject indicates clouds net effect on global warming is likely slightly positive and very unlikely to be strongly negative. (Dessler 2010)
I laughed but if you look at his number he's one of the old geezers of /.
Sorry to not answer sooner but I went to a Jethro Tull concert Thursday and got busy a work Friday.
Interesting paper. Thanks for that. But even Usokin himself says not to read too much into it in regards to climate science. To quote from a comment on RealClimate:
Ilya Usoskin responded to yr considerations as follows:
“Dr. Ladbury is right. No statistically significant conclusion can be drawn concerning the shape of the distribution of the Grand Minima shape. But the matter is that the division on Maunder-like and Spoerer-like minima has been done much earlier basing on only a few minima. Our present result is consistent with such a division, although a long-tail continuous distribution cannot be excluded. I also agree that hardly any direct implication for climate studies is apparent, and we were primarily interested in observational constraints for solar dynamo models.”
http://www.realclimate.org/?comments_popup=502 coment 168
The last glaciation started ending about 20,000 years ago. It ended because of changes in insolation but that is probably due more to Milankovitch Cycles than changes in solar state. 9500 BCE was the end of the transition from glaciation to an interglacial. While it is a factor it's not likely that changes in solar state by itself drives the cycles of the ice age.
Hmm... It doesn't appear that Dr. Usokin considered Milankovitch Cycle changes into his work. I wonder if it would change much if he did.
I've never seen any evidence that climate scientists have tried to erase the MWP. Looking at Dr. Usokin's Figure 17 it appears that solar activity wasn't particularly high during that period. That would appear to support that contention that the MWP was more of a regional rather than global phenomenon.
Is it linear when temperatures rise about the same amount for each doubling of CO2? I didn't think that was a linear relationship but you're obviously better trained in statistics than I am so maybe I'm wrong.
GCM's are primarily physical models. Some things that are not well understood are parameterized but the fundamentals are based on known physical relationships. It don't think it's fair to say the climate sensitivity is basically unknown. Oscillations like the PDO may well be a neutral factor over long enough periods as the positive and negative phases cancel each other out. Happy is not a word I would use regarding proxy reconstructions. I would just say they are the best information we have at the moment and are more useful than assuming we know nothing.
Individual scientists and small groups can certainly fall victim to bending science but as the group becomes larger that becomes much more difficult to pull off. Given the global nature of climate research I find it difficult to believe that such a conspiracy could hold together for such a long period of time over so many different research groups. Scientists are too competetive for that. You focus on the MBH vs. M&M controversy but ignore all of the similar reconstructions (at least 10) since then from different researchers using different proxy data that basically support Mann's original graph. Even applying the suggested improvements in statistical analysis didn't change Mann's graph much. It's time to move on.
Until the middle of the 20th Century solar variation was likely the primary driver of temperature changes from the Maunder Minimum. CO2 levels had only risen from about 280 ppmv to 315 ppmv by then. Since then it has risen to 390 ppmv.
I don't think I've ever heard climate scientists use the terms usual or unusual regarding the solar state. They just contended that since the mid 20th Century that solar activity hadn't changed enough to account for the observed warming. And it's true that the last 4 or 5 cycles until the present one have been about equivalent to each
Say it to their face.
Actually, no. It would show less cooling, but not warming.
Care to prove that? 2010 was hotter than 1997 or 1999 and the equal of 1998. Other than 1998 every year in the 2000's other than 2000 itself was warmer than any year in the 1990's.
Cooling in the face of increasing CO2?
If you expect a monotonic increase in temperatures with increasing CO2 your expectations are unrealistic.
The initial insistence that the MWP never existed, ...
That was an accusation about Michael Mann's "hockey stick graph" which has absolutely nothing to do with GCM's. It was a graph of proxy observations. Find me one quote about GCM's not modeling those things properly.
Observed data is what really happens. Models try to emulate reality In general the GCM's do a decent job of modeling reality and as I said nothing that has happened contradicts them. You may choose to believe otherwise but I doubt you really understand what models are really modeling.
Well, my point was that if you had chosen 12 or 14 years for your graph instead of 13 years the data would have shown warming. That's why I called it cherry picking.
Nothing that has happened contradicts the GCM's. They're not even trying to predict what happens on less than 30 year time scales. Anyone who thinks otherwise doesn't understand what they're designed to do. They don't predict weather.
What cooling in the 00's? It was the warmest decade on record. I see professor Easterbrook's RSS MSU graph shows a cooling trend from 2002 to about 2009.5 but he doesn't specify what channel's data he is using, where it came from. If he used Channel TLS data a cooling trend is expected in the stratosphere. Without more details I can't make a judgement about whether he has a point with the graph but I'm skeptical and feel it could be another case of cherry picking. I guess we'll find out by 2020 if there's anything to what he's saying but if it's another "warmest decade on record that kind of destroys his argument. Some scientists have said that 2012 or maybe 2013 is likely to set a new record for highest temperature year so maybe we don't have to wait that long.
I don't get where you think the models don't match the MWP or the Little Ice Age. I've never seen any indication that they don't.
Maybe we should put some of those who don't believe bin Laden was killed in the same room with Seal Team 6 for some personal convincing.
From what I can tell, there is also absolutely no evidence that he was killed in Pakistan this year, either. All we have is the word of politicians.
I'd love to see you say that straight to the face of one of the SEALs involved in the operation.
Before the 1960's that were marked as the center of the largest, longest, hottest Grand Solar Maximum in eleven thousand years ...
This graph says otherwise. It looks like we're at the highest solar maximum in eleven hundred years though.
And that's even before I note that we don't have even approximately reliable records of global temperatures prior to perhaps the 1980s (certainly none before the 1960s) and satellites designed to measure it, ...
I'd like to see you justify that statement more fully. One of the first thing scientists did when they decided they wanted to calculate a global temperature was examine the existing instrument temperature record that goes back to early 1700's in some cases. They found that since the mid 1800's or so the temperature record was accurate enough and widespread enough to be useful, maybe not perfect but useable. I'm sure there are papers that address that in detail but I'm not taking the time to look them up. Of course the number they calculate for global temperature is not the same number you would get if you integrate the instantaneous temperature of every square millimeter over the whole surface of the Earth but as long as they are consistent in the way they calculate it you get an indication of how the temperature is changing over time.
Of course satellites don't measure temperatures directly like a thermometer does. Instead the temperature is calculated using known correlations between temperature and the radiative properties of various layers of the atmosphere (I guess you could say that bulb thermometers use known correlations of the expansion properties of certain liquids to temperature so maybe it's the same thing :-). I don't see how satellites are more reliable than a well made thermometer. They still have to be calibrated. On top of that satellites have been measuring the Sun for a similar length of time and haven't found enough variation to account for observed temperature changes.
I'm not precisely certain how you can refer to points a) and b) above as "straw men".
I got the implication that you felt everyone on my side of the issue agreed with those statements which is simply not true. That's why I called them straw men. Maybe I read too much into it. If so I'm sorry.
The statement you replied to was my post that said "Solar activity had nothing to do with "The Year Without a Summer". It was the eruption of Tambora that caused that.". Perhaps I should have qualified that better by saying "Changes in solar activity had practically nothing to do with TYWaS". Other years with similar levels of solar activity had much more normal summers so I don't see how you can say the Sun was a significant factor for that unusual summer.
Climate does not respond immediately to solar variation. There is a lag time of 6 months to a few years. If there were other factors of the solar state that were significant I think we would have at least figured out there was something wrong by now. But the known factors appear to sync pretty well with the observed reality so at best your other factors are 2nd order effects.
You read too much into what I said if you think I said CO2 is the only possible explanation. It's not a binary question. There are many factors that go into what the climate is, CO2 merely being one of the more important of them (but not most important, that's the Sun). Some of those multidecadal oscillations may have much to do with the natural resonance of the topology they operate in and the physical characteristics of the medium as they do with solar cycles. Some of those mysterious other factors that you talk about.
Hum.... You have a rather simplistic view of climate modeling. GCM's include the trapping due to all known greenhouse gases, the dynamics of water vapor in the atmo
What does faith have to do with the value of the permittivity constant? It is what it is. Maybe if it were something else we wouldn't be here but that has nothing to do with faith. Same thing with the direction of time and entropy. They are what they are. Science allows us to quantify them. Mathematically speaking it may be perfectly reasonable for them to go the other way but that is not a characteristic of the universe we live in at the present time. To believe that the universe is the way it is because some creator made it that way for us is something that does require faith. We may not know all of the answers to your questions but perhaps we will in the future.
2+2=4 because it is defined that way in our mathematical system. If it ever appears that is incorrect my first reaction would be to look at the assumptions I used that could be wrong.
I think my comment "except maybe that humans are capable of actually understanding reality on some level" covers your "faith in the scientific method". I have faith in the scientific method because it works so far. If it stops working I may have to reconsider.
I would call myself an agnostic who leans toward atheism. I don't think you'd find any comments by me that are particularly scathing to the religious people who post here other than to point out that it doesn't require religion to believe the answers science gives us. Some of the scientific answers are stronger than others but I just attribute that to our lack of understanding. Science doesn't have all of the answers of course but as a model of reality I think it does a reasonable job.
The Little Ice Age is not considered the starting point of Anthropogenic Global Warming. Please give me an example of where you think it is. Although there is a bit of effect before then the anthropogenic part of global warming didn't really start to kick in until the 1960's. I'm perfectly happy if you consider 1960 as the starting point.
I consider the Darfur Conflict to be a case of climate refugees. Long term drought has caused nomadic herders to encroach on the land of non-nomadic farmers.
Many coastal residents in Bangladesh have been forced to abandon their land because of the encroaching ocean making their farms untenable. More climate refugees.
Inuit villages have been forced to move because of the encroaching ocean, partially because of rising sea level but mainly because the sea ice doesn't protect the shoreline from wave erosion like it used to.
I'm sure I could come up with plenty of other situations if I cared to take the time to research it.
When I said the production and calibration techniques were well refined by that time I was referring to 1880. I'm sorry I didn't make that clearer. It was pretty late when I replied. The instrument temperature datasets that climatologists use generally don't go much earlier than 1850. By that time thermometers were plenty accurate for their purposes. I challenge you to prove otherwise.
The incoming radiant energy from the Sun is mostly in the visible (and ultraviolet) wavelengths. Greenhouse gases are transparent to those. When that incoming visible radiant energy gets absorbed by the surface (land or ocean) it gets re-radiated in the infra-red wavelengths that greenhouse gases are more opaque to. So greenhouse gases are like a filter that allows the higher frequencies through and blocks the lower frequencies. The surface converts the frequencies down.
Clouds reflect sunlight, shading the land and sea, consequently decreasing temperature
If it were only that simple. Clouds can not only reflect sunlight back off the Earth but they can reflect or absorb the Outgoing Longwave Radiation that arises from the surface of the planet. At night that is the dominant effect of clouds. Also near the terminator between the light and dark sides of the planet they can reflect sunlight toward the surface. The net effects of clouds on global warming is currently thought to be slightly positive.
We'll just have to wait and see, won't we.
13 years in this case was just cherry picked to use the extremely hot year of 1998 as a starting point. But more to your point, there are various knows cycles of natural variability like El Nino, the Pacific Decadal Oscillation and others that don't wash out in a 13 year cycle but do to a greater extent in a 30 year cycle. 30 years is a bit arbitrary but it's reasonable.
The precise wording of the report (which wasn't a UN report but just from and organization affiliated with them) was that there would be up to 50 million refuges. So that was the maximum they considered possible. I don't know that they specified a minimum.
By the 1880's thermometers were quite accurate. The mercury thermometer was invented in 1714 I believe. The production and calibration techniques were well refined by that time. When you combine many measurements from many instruments the errors tend to average out.
If as you say the precise mechanism is unknown then it's a pretty big assumption just to say that the Sun caused the Earth to cool in the 17th century and warm in the 20th century. I don't think you can have it both ways.
Jeremy Irwin posted this further down the thread.
That link requires AGU membership. For non-members: Feulner and Rahmstorf's paper (pdf)
My thanks to him.
No, the GW adherents have already stated that the sun has absolutely no effect on global temperature.
Not this "GW adherent" (and most others I suspect). The Sun is the primary source of heat energy on the Earth. When the Sun's output starts varying enough to explain the total temperature change I'll say "It's the Sun!". But not until then.
So, what "single specific change"s are you saying failed to occur? What "hockey-stick warming prediction" failed to happen? I suspect you fail to understand the temporal nature of the predicted changes. Most of them occur over a period of decades or longer, not in the next 10 years. Global warming means more energy in the atmosphere, energy that gives a boost to the weather that is already going to happen. An increase in the severity of weather is an expected effect.
The terms Global Warming and Climate Change were both used in the 1950's. More recently Frank Luntz told George W. Bush he should use Climate Change rather than Global Warming because it sounded less dangerous. Saying people changed from Global Warming to Climate Change because they couldn't justify Global Warming is a shibboleth.