[iNow]

The point is that much of the "benefit" on plants from CO2 is negated by the resulting warming. The point is that simply asserting that plants will "thrive" is a bit one-dimensional and misses some important caveats. The point is that some plants may do well, but that many of our food crops probably won't. And, let's not forget about the effect of prolonged drought on crops. They seem to like water, and that may impact growth, too.

It was just another piece of the puzzle. Like you get tired of people accepting that the science of warming is valid, I get tired of people saying that increased CO2 will be a huge benefit because plants like it and stuff.

[JohnB]

iNow, on 19 January 2012 - 04:13 PM, said:

The point is that much of the "benefit" on plants from CO2 is negated by the resulting warming. The point is that simply asserting that plants will "thrive" is a bit one-dimensional and misses some important caveats. The point is that some plants may do well, but that many of our food crops probably won't. And, let's not forget about the effect of prolonged drought on crops. They seem to like water, and that may impact growth, too.

The point is that paper doesn't show that at all. What it purports to show is that the increased growth it assumes from CO2 fertilisation (and you have to go through 3 referenced papers to find where they got that figure) is offset by the decrease in growth caused by warming according to their model. It's arguing about a .6% theoretical decrease in rice output compared to an actual 100% increase.

Seriously. You're on $30k salary and get a pay rise to $58.2k and you are hard done by? Much of the pay rise has been "negated"? Seriously? This paper shows that our food crops have in fact and in reality been doing very well indeed due to the recent warming (and technological improvements). On what factual basis is the idea that our food crops will suffer founded? The fact is that yields are going up and up. This must level off at some point obviously, but there is no factual reason to expect them to decline drastically.

As for the drought bit. Our GCMs aren't so hot on a regional scale so we cannot predict drought in our food growing areas any more than we can predict flood. The weather will do as it has always done, sometimes the rain will come and sometimes it won't. Anyway, aren't we supposed to get more rain in a warmer climate?

You might want to read this. I warn that it is a 12 meg pdf and is 802 pages long. Grab a cup of coffee and have a skim through it, it lists documented weather events from 1 AD to 1900 AD. Aside from giving a historical perspective as to just how common droughts and floods really were there are some fascinating tidbits.

Quote

68 A.D. In England, there was a volcanic eruption followed by an inundation of the sea [tsunami]. The Isle of Wight separated from Hampshire.

Wouldn't that have been cool to see?

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119 A.D. A famine struck Britain “after a pillar of fire was seen for several nights in the air”.

I wonder what the hell that was?

[Essay]

JohnB, on 19 January 2012 - 04:07 PM, said:

To be very clear on this. A model that cannot explain 71% of the observed variance in rice yield is supposedly (accurately) telling us about a theoretical climate induced variance of .24% in rice yield.

OMG! That is a huge disparity!!

JohnB, on 19 January 2012 - 04:07 PM, said:

Putting it another way and using the figures from Table 2 in the paper. The increase in yield in kilos per hectare for rice in the period 1981-2002 was 1,109 kilos. The model, which can only explain 29% of that increase (or 321.61 kg) says that the yield should have been an extra 10.5 kilos more. The yield should have been 1,119.5 kilos per hectare according to the model. So it can't explain 787.39 kilos per hectare increase but it can accurately show the 10.5 kilo decrease due to climate change. At what point am I allowed to express my incredulity at this?

At what point will the "green" revolution be accounted for, in those figures?

~ ?

[JohnB]

Quote

OMG! That is a huge disparity!!

And?

Quote

At what point will the "green" revolution be accounted for, in those figures?

Never, the paper is 4 years old. For myself, I would put the increase in crop yields as a mixture of improved technology (Green revolution), increased warmth (longer growing season) and a bit of extra CO2 fertilisation. The last being the smallest.

Essay, I should add that I do know a bit about chaotic systems. I use the word as shorthand for the full description of climate which is "A complex, chaotic, non linear system". WRT trend lines I find it odd that this science is obsessed with drawing straight lines and finding linear trends in a non linear system. Is that better?

[Essay]

JohnB, on 19 January 2012 - 11:30 PM, said:

And?

...And ...At what point will the "green" revolution be accounted for, in those figures?

JohnB, on 19 January 2012 - 11:30 PM, said:

Never,

...but that dwarfs any changes from climate. How can it not be accounted for?

JohnB, on 19 January 2012 - 11:30 PM, said:

For myself, I would put the increase in crop yields as a mixture of improved technology (Green revolution), increased warmth (longer growing season) and a bit of extra CO2 fertilisation. The last being the smallest.

...good that you have that figured out. I can cite this?

JohnB, on 19 January 2012 - 11:30 PM, said:

Essay, I should add that I do know a bit about chaotic systems. I use the word as shorthand for the full description of climate which is "A complex, chaotic, non linear system". WRT trend lines I find it odd that this science is obsessed with drawing straight lines and finding linear trends in a non linear system. Is that better?

But your phrase "A complex, chaotic, non linear system" doesn't describe climate! It is no wonder that you have the perspective that you do. If I thought climate behaved in that way, I would agree with most of your points about uncertainties ...and about it being out of our control ...and about climate being no different now, than is usual for the past.

As a chaotic system, climate behaves in a simple, robust, non-linear manner; it does not behave in a complex or chaotic, manner [that would describe weather]. If you would learn more than a bit about chaos theory, then you would appreciate why using linear segments to analyze chaotic attractors (and many other aspects of data) does make sense. This is still science; it still works the same.

~

This post has been edited by Essay: 20 January 2012 - 12:09 AM

[JohnB]

Quote

...And ...At what point will the "green" revolution be accounted for, in those figures?

Quote

...but that dwarfs any changes from climate. How can it not be accounted for?

Sorry, not my problem. The paper is from your side of the fence. If they are doing cr*p science and ignoring major factors you must ignore this and believe. If you think accounting for major factors and uncertainties is important, then you will join the ranks of the evil deniers.

Quote

But your phrase "A complex, chaotic, non linear system" doesn't describe climate! It is no wonder that you have the perspective that you do. If I thought climate behaved in that way, I would agree with most of your points about uncertainties ...and about it being out of our control ...and about climate being no different now, than is usual for the past.

For climate it is probably better to drop the "chaotic", but it is a complex system with non linear responses. As to climate being no different now than in the past, (I'm assuming this is about climate in general) then it doesn't come from my beliefs, it comes from the historical record. If you think that climate is behaving or changing in some way differently from how it did in the past, then please show some proof. Otherwise, the "Null Hypothesis" that there is nothing unusual happening must apply.

At this point we can compare reconstructions. Validating your argument are a series of reconstructions that are members of the species "Hockeystick". Now if that was all there was, then I would be on your side. It would be very obvious that the current change in climate was large, serious and very different to what had gone before. But that isn't all there is. There are also a large number of reconstructions and proxies that are not of the species "Hockeystick", these reconstructions show that the current changes in our climate (WRT temperature) are nothing unusual at all. There are also written records and observations from which we can infer which way the temps were going and how fast.

According to the observed facts, the recent warming period that is "mainly" attributed to human activities by the IPCC is indistinguishable from previous periods of totally natural warming.

Quote

As a chaotic system, climate behaves in a simple, robust, non-linear manner; it does not behave in a complex or chaotic, manner [that would describe weather]. If you would learn more than a bit about chaos theory, then you would appreciate why using linear segments to analyze chaotic attractors (and many other aspects of data) does make sense. This is still science; it still works the same.

The last word that I would expect anyone to use to describe climate is "simple". I don't have a problem with using linear "segments" either as I think they can show a much more nuanced picture. for example, for GAT I would show 1850-1880 as warming, 1880-1910 as cooling, 1910-1940 as warming, 1940-1970 as cooling, 1970-2000 as warming and 2000-2012 as pretty level. That's using segments. I would not draw a line from 1850-2012 and pronounce a warming trend of "X degrees/decade" as this obscures the truth of the data. Technically the statement is true, but lacks very necessary detail.

Similarly we could say that according to the figures, the American stockmarket grew from 50 points in 1904 to 60 points in 1932, a growth rate of about 3 points/decade. Kinda misses the big crash of 1929 doesn't it?

Climate is a complex system that responds to a variety of forcings and feedbacks. I believe on of the great fallacies to be the idea that climate responds in a linear fashion to forcings. And that is the assumption. All forcings and feedbacks can be reduced to a W/m-2 value and temperature will change in a linear fashion according to the change in these values. The very definition of a "non linear" system is that it won't behave in such a fashion. The second fallacy is "Climate sensitivity", usually expressed as a temperature change for a doubling of CO2. Note that again a linear response is expected from a non linear system. Climate Sensitivity is also treated as and assumed to be, a constant. I have yet to see this assumption demonstrated as correct in the literature.

I know that they are really smart people who have letters after their names and I don't, but they've also been looking for that elusive value for 30 odd years and really aren't any closer now than they were then. The logical answer is that it doesn't exist. My personal view is that it both does and does not exist. It does not exist as a constant, but does exist as a value dependent upon GAT and atmospheric composition at the time. Upper and lower limits to the value would be set by these and other factors.

[Essay]

...c'mon JB, seriously? Did you even read up on chaos theory? ...a simple wiki browse?
Did you even google: chaotic attractor? ...and hopefully click on images?
===
...or perhaps you did, and this is why we're steering away from that.
===

HEY!

JohnB, on 21 January 2012 - 04:30 PM, said:

I don't have a problem with using linear "segments" either as I think they can show a much more nuanced picture.

I'm glad to see we've addressed the OP!
Progress!

JohnB, on 21 January 2012 - 04:30 PM, said:

Climate is a complex system that responds to a variety of forcings and feedbacks.

...if it were that complex, we wouldn't be able to predict how, 30 years from now, it will be warmer in summer than in winter.

But in truth the language we use is the source of the problem here. We use terms like "simple" and "complex," assuming everyone comes away with the same understanding. But obviously the same sentence can logically lead to opposite conclusions, depending on how the terminology is defined. Learning how science uses these terms will help you discern the various interpretations, as well as evaluate the logic and continuity that such sentences convey.

JohnB, on 21 January 2012 - 04:30 PM, said:

I believe one of the great fallacies to be the idea that climate responds in a linear fashion to forcings. And that is the assumption. All forcings and feedbacks can be reduced to a W/m-2 value and temperature will change in a linear fashion according to the change in these values. The very definition of a "non linear" system is that it won't behave in such a fashion.

...here is an example of how this would become more clear and understandable, if you'd learn the terminology and more precise ways that science applies these terms to various disciplines, paradigms, or theories.

JohnB, on 21 January 2012 - 04:30 PM, said:

The second fallacy is "Climate sensitivity", usually expressed as a temperature change for a doubling of CO2. Note that again a linear response is expected from a non linear system. Climate Sensitivity is also treated as and assumed to be, a constant. I have yet to see this assumption demonstrated as correct in the literature.

...well this sort of takes us back to the OP.

Over short, 30-year segments, linear behaviour can be approximated; and very useful information and predictions can be gathered.

JohnB, on 21 January 2012 - 04:30 PM, said:

I know that they are really smart people who have letters after their names and I don't, but they've also been looking for that elusive value for 30 odd years and really aren't any closer now than they were then. The logical answer is that it doesn't exist.

WHAT?!? By what logic...?

JohnB, on 21 January 2012 - 04:30 PM, said:

My personal view is that it both does and does not exist. It does not exist as a constant, but does exist as a value dependent upon GAT and atmospheric composition at the time. Upper and lower limits to the value would be set by these and other factors.

...for a personal view, it is a good working hypothesis. But I'm very thankful that climate science has progressed far beyond that level.


~

[JohnB]

Quote

But in truth the language we use is the source of the problem here. We use terms like "simple" and "complex," assuming everyone comes away with the same understanding. But obviously the same sentence can logically lead to opposite conclusions, depending on how the terminology is defined. Learning how science uses these terms will help you discern the various interpretations, as well as evaluate the logic and continuity that such sentences convey.

Quote

...here is an example of how this would become more clear and understandable, if you'd learn the terminology and more precise ways that science applies these terms to various disciplines, paradigms, or theories.

Sorry, you don't get to write your own dictionary. Words have very specific meanings, for climate science to say that these meanings differ in "their" branch is crap. The meanings have to stay the same as in other disciplines, otherwise you will cause confusion. A non linear system is defined as "a system whose performance cannot be described by equations of the first degree" in every other science. Making up your own definitions in variance to the accepted use is what a pseudoscience does.

Quote

...for a personal view, it is a good working hypothesis. But I'm very thankful that climate science has progressed far beyond that level.

Then you can provide a value and proof that it is in fact a constant? (There's a Nobel in the offing if you can.) I thought not. Climate science has not "progressed far beyond that level" at all. CS has an assumption that Climate Sensitivity has a specific value and that the value is constant over time. They have yet to provide that value or prove that it is constant over time. On the basis of provability my hypothesis is as valid and as well proven as theirs.

I add that the existence of a single value for Climate Sensitivity perforce means that for a change in forcing the climate will respond in a linear fashion, now then and always. I would like to see some sort of explanation as to exactly how a non linear system can be ruled by a linear response regime, because under the generally accepted meanings of the words, this would make the climate a linear system. (Is that why CS needs to rewrite the dictionary?)

This new definition might do: Non Linear system; A non linear system is one in which the output is not linearly related to the input unless you want it to be.

[Essay]

JohnB, on 22 January 2012 - 02:36 PM, said:

Sorry, you don't get to write your own dictionary. Words have very specific meanings, for climate science to say that these meanings differ in "their" branch is crap. The meanings have to stay the same as in other disciplines, otherwise you will cause confusion. A non linear system is defined as "a system whose performance cannot be described by equations of the first degree" in every other science. Making up your own definitions in variance to the accepted use is what a pseudoscience does.



Then you can provide a value and proof that it is in fact a constant? (There's a Nobel in the offing if you can.) I thought not. Climate science has not "progressed far beyond that level" at all. CS has an assumption that Climate Sensitivity has a specific value and that the value is constant over time. They have yet to provide that value or prove that it is constant over time. On the basis of provability my hypothesis is as valid and as well proven as theirs.

I add that the existence of a single value for Climate Sensitivity perforce means that for a change in forcing the climate will respond in a linear fashion, now then and always. I would like to see some sort of explanation as to exactly how a non linear system can be ruled by a linear response regime, because under the generally accepted meanings of the words, this would make the climate a linear system.

...I'm just going with what the science says. If you can show that the science is as illogical as you suggest, then you deserve the Nobel, istm.
===


JohnB, I expect it may be the forcers, rather than the overall climate, to which my statements above apply, in a more-or-less technically correct manner; but I don't want to get off-topic talking about how science uses jargon, and defines words to mean specific things depending upon the discipline, or co-opts common words to mean new things... such as (respectively) REDOX, and CELL (biology or math systems), or REDUCE (common or chemical).

And with new disciplines it is even worse!

Quote

...regarding "complex adaptive systems"
http://en.wikipedia....adaptive_system
"Various definitions have been offered by different researchers:"

The very fact that glossaries are common should be a clue too:

Quote

http://www.sysbio.de...OBUSTNESS.shtml
ROBUSTNESS
see also: adaptation, integral control, modularity, reliability

Meaning
The insensitivity of system properties to parameter variation and other uncertainties in components and the environment [15].

Biology:
Mostly used with regard to changes in environment, but also as robustness against structural failure (reliability).
Systems Theory:
Mostly used with regard to insensitivity against parameter uncertainties.

Explanation
Biologists and Systems Theorists infer the same basic meaning to the term robustness: A robust system is insensitive to certain changes, allowing it to exhibit a constant behavior in spite of these changes. Differences in meaning look small but are still significant.

Biologists usually mean that the system is robust against variations in its environment, e.g. in concentration levels of nourishing substrates (see examples).
Systems theorists mostly think of uncertainties in system parameters, either because they could not be measured with sufficient accuracy (for use in a model) or because they really do fluctuate over time.

These are different kinds of robustness, so there is a potential for misunderstandings even though the basic meaning is identical.

...my emphases
===


As you indicated, "nuance" is to be appreciated. This argument for a black-n-white rejection of climate science due to the whole linear/non-linear "chaotic" or "complex" or "simple" conflict in descriptions (from your perspective) seems to miss some of the nuance that has developed in the climate sciences... as well as other fields like biology and systems science.

I'm not arguing to "redefine" things, but to use definitions as appropriate--hoping to provide deeper insight. Nor am I arguing to rewrite the dictionary, or to exclude words such as "chaotic" which have an appropriate place and usage. With only a little research, we can determine these nuances... and gain deeper insights.
===

But I was glad you mentioned how linear analysis can be useful in science. That usefulness also applies to the science in Chaos Theory, and in Non-Linear and Adaptive Systems.
Embrace the Chaos! (or at least the Theory)

~

[JohnB]

Essay, I think you misunderstand my POV. There is no black and white rejection of climate science. There is a demand for "proof of concept" for want of a better term.

Especially in a new discipline there are new underlying assumptions. What I'm trying to do is point out where the underlying assumptions could be incorrect. Taking climate sensitivity as an example, there are those trying to "narrow the range" of this figure. They assume that such a figure exists. The logical upshot of arriving at a single definitive figure, or a constant if you will would be that climate becomes forcing X sensitivity = change, by definition a linear system.

Since the climate is dynamic and non linear then climate sensitivity can only possibly exist as an abstract concept defining a range dependent on initial conditions and internal dynamics. (From personal communications I know that some in the climate community share this view.)

So this is not a rejection of climate science, nor a rejection of the general concept of climate sensitivity, but it is a rejection of the concept that climate sensitivity exists as a single unchanging value. See the difference?

Similarly climate science can put any meaning it wants to the term "robust" so long as it's roughly in line with the general meaning, however it cannot co-opt terms from other sciences and redefine them. "Statistically robust" has a meaning in statistics and if climate science wants to use the term then they have to conform to the statistical meaning and not substitute their own.

To take an example from another science, Ecology was virtually started by Malthus and therefore had many Malthusian ideas as underlying concepts, concepts so innate that they weren't even thought of as "assumptions". Top of the list here was the idea of a "balance of nature" and everything was viewed from that perspective. Note how long it took that science to get rid of such a stupid and illogical assumption and how strongly the idea was defended in the face of ever mounting and overwhelming evidence. There are still ecologists today who believe in the "balance of nature", something totally imaginary.

Note also how this gave rise to the Green movement and its logical process. Nature is in balance, therefore it doesn't change. Something is changing, therefore it is out of balance. Since nature is in balance the change cannot be from nature. Therefore man is changing it.

[Essay]

JohnB, on 12 February 2012 - 03:51 AM, said:

Essay, I think you misunderstand my POV. There is no black and white rejection of climate science. There is a demand for "proof of concept" for want of a better term.

Proof of Concept!?! ...about climate?!? Are you rejecting climate science because of the gray areas then?

JohnB, on 12 February 2012 - 03:51 AM, said:

Especially in a new discipline there are new underlying assumptions. What I'm trying to do is point out where the underlying assumptions could be incorrect. Taking climate sensitivity as an example, there are those trying to "narrow the range" of this figure. They assume that such a figure exists. The logical upshot of arriving at a single definitive figure, or a constant if you will would be that climate becomes forcing X sensitivity = change, by definition a linear system.

...So about the climate sensitivity parameter....

They arrive at their consensus by calculating both theoretically (CO2 physics & radiative balance) and from differing sets of empirical observations (Ice Age shifts & MWP/LIA shift). But that doesn't prove anything, though it adds robustness to their conclusion.

But does it really matter if they are wrong? It would matter if they had the sign of the sensitivity wrong, but whatever the magnitude is--one or two or three degrees C per Watt of forcing--we are in for a rough ride as we continue to add more forcing; and adding forcing which is permanent (relative to our civilization) and continuous 24/7/365 decade upon decade, from pole to pole--unlike most forcers.
===

JohnB, on 12 February 2012 - 03:51 AM, said:

Since the climate is dynamic and non linear then climate sensitivity can only possibly exist as an abstract concept defining a range dependent on initial conditions and internal dynamics. (From personal communications I know that some in the climate community share this view.)

So this is not a rejection of climate science, nor a rejection of the general concept of climate sensitivity, but it is a rejection of the concept that climate sensitivity exists as a single unchanging value. See the difference?

It seems obvious to me that "climate sensitivity can only possibly exist as an abstract concept defining a range dependent on initial conditions and internal dynamics." But I suspect you think that must mean it is too complex to be a useful concept.


Both "the balance of nature" and "climate sensitivity" exist as an abstract concept defining a range dependent on initial conditions and internal dynamics--as you say. And as such, each concept is useful in understanding what happens to the relevant system (nature or climate) when a perturbation is introduced.
Oh, hey! That is another one to survey--Perturbation Theory!
===

JohnB, on 12 February 2012 - 03:51 AM, said:

Similarly climate science can put any meaning it wants to the term "robust" so long as it's roughly in line with the general meaning, however it cannot co-opt terms from other sciences and redefine them. "Statistically robust" has a meaning in statistics and if climate science wants to use the term then they have to conform to the statistical meaning and not substitute their own.

Why would you even write this? Again, climate science isn't re-defining any words. But neither do you get to declare your pet discipline's definition as exclusive. Did you read the links about how different disciplines define "robust" differently? So when climate science is looking at data, they use robust statistical analyses (hopefully), and when climate science examines the "systems theory" of climate, they calculate the robustness of system components, feedbacks, and overall output. In both cases they are using robustness as appropriately defined by the relevant disciplines.

Either you don't fully see how climate science works by combining multiple disciplines, or you are working hard to discredit an entire community with basic yellow journalism tactics. I'm sure it is the former, but if you want to avoid looking like the latter, you should read those links on how these words are used and defined (especially "robust") in the field of systems theories, and especially in chaos theory. Don't be limited to just the discipline of statistics for your understanding or definitions... or maybe I should say: Don't limit climate science to only the understanding or definitions from your favorite discipline of statistics.
===

JohnB, on 12 February 2012 - 03:51 AM, said:

To take an example from another science, Ecology was virtually started by Malthus and therefore had many Malthusian ideas as underlying concepts, concepts so innate that they weren't even thought of as "assumptions". Top of the list here was the idea of a "balance of nature" and everything was viewed from that perspective. Note how long it took that science to get rid of such a stupid and illogical assumption and how strongly the idea was defended in the face of ever mounting and overwhelming evidence. There are still ecologists today who believe in the "balance of nature", something totally imaginary.

Note also how this gave rise to the Green movement and its logical process. Nature is in balance, therefore it doesn't change. Something is changing, therefore it is out of balance. Since nature is in balance the change cannot be from nature. Therefore man is changing it.

I disagree with the way you characterize the development of the science and the history of Green social movements, but I know what you mean about folks who view nature as some ideal state upon which humans can only intrude or disrupt (unless they live like cavemen). Right?

Treehuggers have many justifications for relatively insane, special-interest, causes to save this or that. But don't paint climate science with that brush. The pictue is more like the reverse logic from what you presented:
1. We observe and measure how man is changing nature (atmospheric chemistry and composition, land use/ecosystem resource shifts, and ocean chemistry, food chains, and biodiversity).
2. This cumulative change is outside of the "range" "defining" that "balance of nature" (on a geologic time scale).
3. Therefore... Shift will happen in response--and a new balance of nature, and a new climate sensitivity, will be established--eventually.

Shift happens, but we don't need to magnify it exponentially. In fact, since a lot of change already happens normally in the system, we should take steps to avoid magnifying climate shift and ecosystem resource degradation.
===

And another thing about 30 year trends: Why is it... that is was easy to say--when decades ago as people warned of rising temps and melting ice--to say wait another decade or so for true trends to be measured; but now--after only a few years of slower acceleration in temps--now it is easy to claim and perpetuate claims of a conclusive trend? Why don't the denialists need to wait as long as the alarmists were told to wait, before proclaiming the trends as established?
===


But to conclude:
"What I'm trying to do is point out where the underlying assumptions could be incorrect." -JohnB
"...Could be...."

Could be that solar activity has been unusually low during this period where the temps are still warmer than normal but when the anomoly has "leveled out" (or maxed out) so temps haven't become even more "warmer than normal."

...and/or...
Could be there is a mechanism which somewhat limits how much air temperature can increase in a given year; and if more heat continues to be added to the system, then something else changes--such as increased melting of ice, or increased heating of surface waters and the planetary crust.

Hey, didn't the Arctic experience larger than predicted melting... during those years when you point to temperature increases (per year) as having maxed out or leveled off?
Coincidence? "...Could be...."
===

Either way, I'm very skeptical of your suggestion that the science is inadequate or that there is some undiscovered mechanism that will prevent extra heat from continuing to change the system dynamics. Do you think the climate system is too big to fail? ...the bigger they are, y'know, the harder they fall....

~

[JohnB]

Quote

Could be that solar activity has been unusually low during this period where the temps are still warmer than normal but when the anomoly has "leveled out" (or maxed out) so temps haven't become even more "warmer than normal."

Thank you for illustrating my point. "Warmer than normal" what? How about some form of definition of "normal" before declaring anything to be "warmer than normal". See my point? What is normal?

Reverse the .8 degrees of warming that we have had and we are back in the LIA. What a wonderful time, ice fairs on the Thames, all the partying you could wish for, except for the tens of thousands that would freeze to death every winter. Was that "normal"? I happen to think it was, just as I think .8 degrees of temp rise after leaving a period defined as a "Little Ice Age" is also perfectly "normal".

It's late and I've had a long day, so I'll be happy with the answer to that one question. What exactly is the "normal" temperature for the planet?