Global Warming In November

Well gosh, this sucks limes.

Greg said "The huge uptick we saw during the last part of the current year is the result of global warming, which has been pushing temperatures up, and the current El Nino, which probably started to affect these measurements in late September."

I am assuming when you say global warming you mean human caused. How much of the warming was el nino and how much was global warming?

In other words - how much of the warming was natural and how much human?

Secondly - why would the human portion surge like that?

The additional CO2 is pretty linear.

It seems to me (and this is pure speculation) - that the surge in warming is caused by nature and not the human caused portion.

Finally, how much of the increase in warming was caused by adjustments made to GISS over the last year or so?

I vaguely recall that some additional adjustments were made which warmed the present and cooled the past - but cannot recall the magnitude of the adjustments.

Does anybody here recall?

Rick, El Nino affects how heat is distributed between the atmosphere and the oceans but it doesn't change the total heat in the system. It's a part of natural variability which is why temperatures don't follow a nice linear path like the rise in CO2. Since the heat capacity of ocean water is around 1000 times that of the atmosphere it doesn't take much of a change in the distribution of heat between the oceans and atmosphere to have a large effect on atmospheric temperatures.

So the temperature spike in 2015 is due to the natural variability of El Nino but the fact that 2015 will be the warmest such El Nino year on record is due to anthropogenic global warming.

Worse than that: "Anthropogenic global warming is real and has been happening for a number of years now."

RickA: "It seems to me (and this is pure speculation) – that the surge in warming is caused by nature and not the human caused portion."

No one cares what it "seems" to you.

Dave Werth:

El Nino affects how heat is distributed between the atmosphere and the oceans but it doesn’t change the total heat in the system. It’s a part of natural variability which is why temperatures don’t follow a nice linear path like the rise in CO2.

Nicely put, Dave. And when the observed timing and strength of ENSO is an input to coupled climate models rather than a state variable, projected GMST matches observed GMST between 1998 and 2013 (the so-called "pause") much more closely. See the 2013 paper in Nature by Kosaka and Xie. It's paywalled, but Texas State Climatologist John Nielsen-Gammon posted an accessible (in more ways that one) discussion at the time.

AGW-deniers crowed that the pause (which was not a pause at all, merely a temporary slowing of the rate of increase) was a fatal falsification of climate model projections. For climate scientists though, it was an opportunity to refine the models by resolving short-term "noise" to forcings.

I think that there are two things being conflated by deniers when they talk about 'natural variability'. There are natural phenomena that cause droughts, floods, El Nino, hurricanes etc. , but those are not sources of energy variability. They can be influenced by energy inputs, but they don't cause them.
Then there are natural factors that do cause energy input changes to they system (earth), like Milankovitch cycles, volcanoes, changes in the sun's intensity and so on. But just speculating whether current warming is caused by natural variability, is a red herring, unless you can demonstrate or point to the natural forcing that is responsible.
We know that man made increases of Co2 is continuing. We know that Co2 is a greenhouse gas that causes warming. We know that results in an increasing imbalance between energy inputs and out puts to the system (earth again). We also know that that energy gets moved around and exchanged within the system (earth also). Most is taken up by the oceans, but it doesn't stay there forever. They system overall will continues to heat up as long as equilibrium has not been achieved. We also know that there is no known other external natural forcing that can account for the added energy imbalance into the system...you know...earth.

RickA:

Good questions. About 20 percent of the increase over the last two months is from EL Nino, but the strength of the El Nino is certainly enhanced by warm ocean waters, which are warmer because of human effects by about 100%. So, one way to look at this is to go to the graph at the top of the post and notice how the current spike compares to earlier spikes. The difference between the spikes, over time, is the incrementally increased difference in human effects.

A slightly different way to think of it is this. The pure natural El Nino contribution makes up part of the up-down-ness of the graph, the overall trend represents the human contribution.

Also, the increase in CO2 is linear, but the effect on surface temperatures is not, because the surfacer temperature is the wagging tail of the dog.

http://scienceblogs.com/gregladen/2013/06/19/the-earth-is-the-dog-atmos…

skeptictmac57: Well put.

Why is it that I don't expect RickA to thank Dave Werth or scepticmac57 for their informative replies?

Why am I not surprised that RickA doesn't mention ENSO's cooling component, La Niña, and that the global warming in La Niña years shows a strong warming trend? (The graph linked to below more or less illustrates this:
http://rabett.blogspot.dk/2014/12/plenty-of-trend-at-bottom.html )

Why am I not surprised that RickA, who claims to be an engineer, doesn't mention the lag time between CO2 emissions and warming. (Or is there something I've misunderstood?)

Why am I not surprised that RickA veers into conspiracy territory by mentioning, while showing no understanding of, surface temperature adjustments? Has he ever casually mentioned the many adjustments that have been made to the UAH satellite data, which tend to bring the satellite data more in line with surface data?

Could it be that RickA isn't interested in learning, but in denying?

In the next-to-last paragraph, you say that November 2015 is the warmest and second-warmest month by anomaly on the record. I assume this is a typo, what is the correct second-warmest month?

What are the temps anomalous of?
From a 1961-1990 average?
Why are the anomalies consistently negative from 1880-1940?

See Noevo, why is it that you make so many claims about climate change but don't know the most basic stuff?

Read the post.

To Greg #17, or anyone out there:

Why are the anomalies consistently negative from 1880-1940?

Read. The. Post.

To Greg #17 & #19:

I don’t see it.

To anyone else out there:
Why are the anomalies consistently negative from 1880-1940?

A better question, "see what an ignoramus i am", is what difference it makes? Try to make an answer that deals with science rather than your dishonesty.

SN,

Here's an idea; if you can't unravel a mystery, ask better questions.

If you don't want to do that because you have an underhanded agenda, knock it off.

How much of the warming was el nino

The warmest 12 month period in the 1997/98 El Nino was about 0.22℃ above the trend at that time.

I don’t see it.

This is not news for someone who doesn't see anything.

OK, I'll explain. Normally I would have explained this basic concept right away. I like it when people ask questions, allowing us to have an honest and forward moving conversation. But See Noevo has repeatedly demonstrated a lack of interest in a forward moving, honest conversation. Also, annoyingly, See Noevo is quick to criticize climate science yet demonstrates a lack of basic understanding of the simplest of concepts. I wanted to make sure this was clearly understood, thus my reticence to address the question right away.

An anomaly is a difference. In this context, a temperature anomaly is a number that reflects the difference between an arbitrarily set baseline. So, for example, if we expect a value of 1, but a measurement comes out as 1.1, then the anomaly is 0.1. If we expect a value of 1, but a measurement comes out as 0.9, then the anomaly is -0.1.

Anomalies are used mainly for three reasons. One is that different measurement contexts have different scales of variation, or measurements reside in vastly different parts of a scale. So, for example, if I say "my child has a fever" I could easily say "My child has a body temperature of 100.1" and you would know he has a fever. But if I'm a zoo keeper and I say "The aardvark has a temperature of 92.4" you might not know what I mean, you might not know if the aardvark is sick. So I would put it in relative terms and report the anomaly. "The aardvark's measured temperature is 0.8 degrees above the average for normal non-sick aardvarks." Then you know the aardvark has a fever.

Another reason anomalies are used is to allow the use of more temperature measurements. The temperature data are taken from a wide range of sources. It is possible for a thermometer to be off by a fixed amount. The differences in temperature are valid measurements, but the absolute value is not correct. More commonly, not all thermometers are properly placed. So, a properly placed thermometer would give one value, the incorrectly placed thermometer would give a different value. But for measurements taken over decades with that thermometer, the anomaly values (the differences from day to day, not the absolute values) properly track temperature change, even if the values themselves are all off by a degree. It is more accurate, honest, and numerically correct, therefore, to use anomalies rather than absolute values.

Anomalies reflect climatological relativism and relevance. If we are looking at change over time, anomalies are actually what we are looking at.

Finally, there is a statistical phenomenon that gives anomalies another advantage. When measurements are being checked against each other, it is statistically more reliable to compare anomalies than absolute measures.

So, in climatology we use a baseline, and the values that are then uses are measured against that baseline. It has become common in climatology to pick a baseline that is at least a couple of decades long (for long term trends, 30 or 50 years are common). Any time period will do, but for things like TV weather reporting, a recent time period makes more sense. This way the weather reporter can say "it is colder than we normally experience" by reference to a current/recent baseline.

There are two annoying facts in the reporting of global surface temperatures that many of us would like to fix.

1) Different data bases or institutions use different baselines. From a purely scientific, statistical point of view this is of no consequence. Various analyses can use the different baselines exactly because anomaly data are being used, or if the scale matters, it is a simple matter to adjust arithmetically. But when it comes to talking about this stuff to the general public, unnecessary confusion among those who don't know how this all works can arise.

2) Since we are talking about the prospect of global surface temps warming because of, essentially, industrialization, it would be better to settle on a "pre-industrial" value, but that is generally not done.

I report the NASA GISS data exactly as it is developed by NASA GISS. I have considered adding or switching to a pre-industrial baseline scale. And, if we were involved in an honest, forward moving conversation, I would not hesitate to do that .But we are not. We are involved in a conversation where one "side," the scientists, are trying to have an honest forward moving conversation, and the other "side," the deiners of science, those with a nefarious political agenda, or who just are not that smart, or whatever, would use a baseline decision such as this (picking a pre-industrial value) as an accusation of manipulating the date, or some other such thing.

NASA GISS uses, as stated in the post, of 1951-1980. All the values used to make the chart above are compared to the average across those years. Global warming was well underway prior to that period of time. Therefore many of the values, especially those in the first part of the series of values, will be negative.

From the article:

The baseline in the case of NASA GISS is 1951-1980, which does not represent pre-industrial levels.

I'm sorry Greg, we crossed there. Rather spectacularly :-)

#27
Thanks for a very helpful description.

#2
"In other words – how much of the warming was natural and how much human?"

"Why is 2015 so hot? A recent analysis by Climate Central makes clear that virtually all of the warming — some 95 percent — is due to human activity. The rest is due to the small, short-term boost to global temperatures from our current El Niño, along with some other natural factors."
http://thinkprogress.org/climate/2015/12/15/3732080/nasa-2015-hottest-y…

"Based on the analysis described in the Methodology section below, we estimate the 2015 global temperature anomaly to be 1.05ºC (1.89ºF) above the 1850–1900 average that the IPCC takes to be “pre-industrial.” The year 2015 is therefore likely to be remembered as the first year that two symbolic thresholds were set: the 1ºC (1.8ºF) temperature anomaly threshold and the 400 parts per million (ppm) CO2 threshold.

Of that 1.05ºC temperature departure from pre-industrial, roughly 1.0ºC is due to the anthropogenic forcing, about 0.05ºC (0.09ºF) to 0.1ºC (0.18ºF) is due to El Niño and about 0.02ºC (0.04ºF) is due to higher solar activity. The remainder is well within the range of variations due to random weather, especially winter weather in Siberia and Canada. Volcanoes contribute very little at this time."
http://www.climatecentral.org/2015-global-temp-record

This is the unambiguous answer to RickA's question. It would, however, be inconvenient for him to accept that answer.

"OK, I’ll explain. Normally I would have explained this basic concept right away. I like it when people ask questions, allowing us to have an honest and forward moving conversation. But See Noevo has repeatedly demonstrated a lack of interest in a forward moving, honest conversation. Also, annoyingly, See Noevo is quick to criticize climate science yet demonstrates a lack of basic understanding of the simplest of concepts."

Your patience is amazing.

cosmicomics #31:

Thank you for your response.

I note that the climate central method compared the observation data to simulated global mean temperature rise from 1850-1900:

"In addition the observational data was compared with simulated global mean temperature rise from 1850–1900 in the CMIP5 models (Figure 2)."

I would be very interested in what an analysis would conclude if they compared observations with "simulated global mean temperature rise from 1900 - 1950, instead.

The reason I would be interested in this period is that it includes a larger temperature rise than 1850-1900, which I believe to be largely unexplained by an increase in CO2 due to humans.

Most scientists and analysis indicate that most of the warming (i.e. more than 50%) after 1950 is due to human causes - which (to me anyway) implies that less than 50% of the warming before 1950 was caused by humans. In other words - the warming from 1900 - 1950 was mostly non-human caused (> 50% natural).

Or put another way - if 95% of the warming is due to human emitted CO2 - what explains the warming from 1900 - 1950?

I cannot help but speculate that a fair amount of this warming was natural (more than 50% anyway) - and not caused by human CO2 emissions.

And if that is the case - than would the percentage of warming due to humans drop from 95% to a lower number if the comparison was shifted from 1850-1900 to 1900 - 1950?

Now you may think this is not a relevant question.

What do you think?

sorry - I had meant to delete the "Now you may think this is not a relevant question" before I hit post.

RickA

Or put another way – if 95% of the warming is due to human emitted CO2 – what explains the warming from 1900 – 1950?

The general view is that it was a combination of sparse volcanism (low sulphate aerosol loading = reduced aerosol negative forcing) and some increase in solar output.

Neither applies to warming since ~1940.

There was plenty of fossil fuel use before some magical date deniers assume to be the start of it. Coal was being burned for well over a century prior to 1900.

A huge proportion of the African rain forest was removed before 1930 or so. Other forests were cut. Other land use effects that contribute to global warming by releasing CO2 or damaging sinks were well underway before 1930.

And yes, there was reduced negative forcing in particular around the late 20s through the 30s.

That time period, by the way, is like a miniature Global Warming 1.0. Climate changes at that time are not well enough studied, but around 1860-1880 or so we saw an uptick in the rate of CO2 being added to the atmosphere, and this moderate but meaningful rate continued until about 1960. During the middle of that time, as noted, aerosols reduced, so you get an uptick in warming. That uptick in warming happened around the same time as a period of very severe tropical storms, all sorts of odd weather, and a healthy dose of desertification. There were also a lot of forest fires, and some of that was way worse because of bad lumbering practices (and lumbering-sparking locomotives running around among the slash).

The implied idea that warming and warming related effects before the magical date (which moves around between 1960 and 1980) was a period of global warming looking stuff with no actual AGW is, simply, wrong.

https://scripps.ucsd.edu/programs/keelingcurve/wp-content/plugins/sio-b…

RickA:

"Or put another way – if 95% of the warming is due to human emitted CO2 – what explains the warming from 1900 – 1950?"

In a very real sense the answer is irrelevant. If the physics tells us what's causing the warming in recent years, it doesn't really matter if we've figured out which of the various possible external forcings caused warming or cooling in the past. If our knowledge of previous solar cycles didn't exist at all, for instance, that wouldn't change our understanding of solar output over the last few decades.

Let us imagine we're very uncertain of what caused people to die before guns were invented. Your position is equivalent to saying "yeah, there's a body there with a gunshot wound to the head, but we don't know how Sir Joe Blow III died in 1215, therefore we can't say with certainty that the gunshot wound caused this modern death".

"Let us imagine we’re very uncertain of what caused people to die before guns were invented. Your position is equivalent to saying “yeah, there’s a body there with a gunshot wound to the head, but we don’t know how Sir Joe Blow III died in 1215, therefore we can’t say with certainty that the gunshot wound caused this modern death”."

Yeah, I was thinking of a similar analogy too, but didn't develop it. Thanks for doing that!

Greg Laden

The implied idea that warming and warming related effects before the magical date (which moves around between 1960 and 1980) was a period of global warming looking stuff with no actual AGW is, simply, wrong.

Yes, and I was oversimplifying above. To be fair, I did point out to RickA that there was an anthro effect before mid-C20th but I can't find the comment here - it may have been at ATTP's.

BBD #36 - So that would natural, not human caused (lack of volcanoes and sun). As I indicated - humans caused some warming 1900 - 1950 - but less than 1/2 (50%).

dhogaza #39 - I disagree. If the comparison shows 95% human caused now - but the comparison only shows 70% human caused (I made that up) when comparing two warm periods (comparing to 1900 - 1950 instead of the pretty flat 1850 to 1900) that makes a pretty big difference to me.

Greg - I don't deny there was an anthro effect prior to 1950 - it is just that it is less than 50% of the warming is due to anthro prior to 1950.

What I have trouble reconciling in my mind is going from anthro being less than 50% of the cause of warming pre-1950 and then jumping to more than 100% after 1950 - no gradual ramp up - just a giant step right at 1950. It makes no sense to me.

If the comparison I suggested (two warm periods) showed instead of 95% human, 70% human (or whatever it shows) I could understand it better.

Even with the el nino number being 5% of the warming - at least we are acknowledging that el nino is natural and not human caused - and are not saying humans caused 110% of the warming (which is the part I have trouble with). I just wonder if it is really smaller - like 70% or something - if the comparison is between a warm period (now) and another warm period (1900 - 1950).

RickA-"Even with the el nino number being 5% of the warming – at least we are acknowledging that el nino is natural and not human caused "
What makes you think that warming from an El Nino event cannot have a human caused component? Does El Nino generate energy on it's own?

RickA said "Even with the el nino number being 5% of the warming – at least we are acknowledging that el nino is natural and not human caused – and are not saying humans caused 110% of the warming (which is the part I have trouble with)."

Again, El Nino does not cause any warming, it merely shifts some of the warming from the oceans to the atmosphere. When you look at all the known natural causes of climate change there should actually be a slight cooling trend. That's why it's possible to say humans have caused 110% of recent warming. The only other option is that there is some large unknown natural cause of climate change. That's possible but with the attention climate science has received over the last 30 years it seems extremely unlikely.

RickA “Even with the el nino number being 5% of the warming – at least we are acknowledging that el nino is natural and not human caused – and are not saying humans caused 110% of the warming (which is the part I have trouble with).”

No scientist has ever stated humans have caused more than 100% of the anomalous warming of Earth; claiming a scientist has said so is asinine and dishonest.

The evidence shows, and therefore most scientists agree, that humans have caused about 110% of the observed warming of Earth. We know with very high confidence how much energy human activities have added to Earth: about 10% of that energy is still not observed.

RickA

If you average the natural forcing change (solar and volcanism) over the C20th there is no trend.

So some other physical mechanism is required to explain the centennial warming trend.

The climate system isn't powered by unicorn flatulence.

BBD:

"The climate system isn’t powered by unicorn flatulence."

At least that would be an external forcing! :)

Maybe it would be helpful if somebody could post or point to a shaded graph of warming over the expected cooling trend that carefully explains all the elements. People often do better with visuals. Combine that with built-in prejudice against climate scientists, and you have an extra high communications hurdle that the usual shorthand may not surmount.

To Greg #27:

Thanks for your response.
It was almost twice as long as your article!
But I still have some issues.

When I originally asked “What are the temps anomalous of?”, I was thinking they *might* be the *difference* in average temperature *changes*. For example, say the average temp from 1951-1980 was 58.0 F, but the average annual change in that time period was +0.1 F. Then say the average temp from 1880 to 1881 changed by -0.2 F. The “anomaly” under this scenario would be -0.3 F.

But I THINK you’re saying that the anomaly in your blog article is just the difference in absolute temps
(“a temperature anomaly is a number that reflects the difference between an arbitrarily set baseline.”).
That is, the difference from the average temp of 1951-1980.

*I’m not sure that’s what you mean, though,* because then you seem to be implying the anomaly is not of absolute temps but rather of temp changes (“It is possible for a thermometer to be off by a fixed amount. The differences in temperature are valid measurements, but the absolute value is not correct… But for measurements taken over decades with that thermometer, the anomaly values (the differences from day to day, not the absolute values) properly track temperature change, even if the values themselves are all off by a degree.”).

I think my version of “anomaly” might possibly be more valuable. It mitigates the effect of possible inaccuracies or biases in *absolute* temperature measurements taken over a hundred years ago. Because, as I think you say, as long as the *absolutes* are off consistently, the *differences/changes* in the absolutes could still be meaningful.

And because I was thinking the anomalies represented *differences* from the 1951-1980 average temperature *changes*, I kept asking why the 1880-1940 anomalies were consistently negative.

https://en.wikipedia.org/wiki/Attribution_of_recent_climate_change

Desertphile- "The jury is still “out” on if ENSO has been modified by humans. ININO5 sums to +1.12c from year 1856 to 2014— close enough to the human-caused signal to suggest no change when the signal is removed."
I see. I will take that into consideration.
I was thinking along the lines of this:
http://www.climatecentral.org/news/climate-change-could-make-super-el-n…

It seems very plausible that dumping more energy into the deep oceans could intensify an El Nino event when the conditions are optimal. But I will concede that it still falls in to the 'yet to be confirmed' category.

Indeed. But inspired by Greg's comment at #27, I was thinking more of an unsophisticated illustration of the underlying idea...
Meh...

http://www.bloomberg.com/graphics/2015-whats-warming-the-world/

The anomaly values are not absolute temperatures. The relative values (that results in negative or positive) reflects the fact that the number used in the graph is on a scale where the specified baseline is zero. Putting this yet another way, the specified baseline is the average of those years anomaly values. Very simple. If you add together all the anomaly values for the baseline period, the result will be zero, plus or minus rounding errors.

Greg Laden: " Very simple. If you add together all the anomaly values for the baseline period, the result will be zero, plus or minus rounding errors."

Explaining high school math to someone who has insisted all of the world's geophysicists are wrong. Maybe you could have a go at the Flat Earth believers that, inexplicably, appear to be increasing in numbers on various Internet forums (such as YouTube).

Perhaps Greg Laden could also write a blog entry about the "point of diminishing returns" when it comes to explaining reality, over and over and over and over again, to the same person or people who reject reality. What is the upper limit for attempts before giving up? I mean "the social contract" mentioned by Kant and others--- how much do sane people owe in time and effort to try and educate someone who has no interest at all in being educated, yet insists (many times) that everyone educate him (and some times her)?

Thirty years ago, in FidoNet's HOLYSMOKE echo (message forum) people encountered Young Earth Creationists for the first time, and these people tried very hard, at great length, expending vast amounts of time and effort, to educate the Creationists. The Creationists had no interest at all in the answers to their "questions," almost all of which were falsehoods stated under the pretense of asking questions. Day after day, for a decade, dozens of people explained reality to the same individual Creationists, and it was all, without exception, of no value at all to the Creationists: they didn't want to learn.

The exact same process is occurring with deniers of the evidence for human-caused climate change. Greg Laden here is wasting his time (which of course as a non-Scientology customer he is free do so) explaining basic math to someone who has been conditioned to reject explanations about how the world works.

Why bother, when it is already known and understand that the person asking questions has no desire to learn? When does the "social contract" expire?

To Greg #58:

“The anomaly values are not absolute temperatures… Very simple. If you add together all the anomaly values for the baseline period, the result will be zero, plus or minus rounding errors.”

I was already aware the anomaly values were not absolute temperatures.

But, very simply, the anomaly values represent differences BETWEEN absolute temperatures - in this case, A (the average absolute temperature for a given year) minus B (the average absolute temperature for 1951-1980).

And as I said, such anomalies are only as reliable as the absolute temperature measurements themselves, which, as you noted, may not be reliable.

I think my version of “anomaly” would possibly be more reliable, and valuable.

No you weren't, because you are not smart enough to play that dumb.

As explained, it is not true that anomalies are only as good as the absolute temperatures. Again, you have misunderstood.

What I have trouble reconciling in my mind is going from anthro being less than 50% of the cause of warming pre-1950 and then jumping to more than 100% after 1950 – no gradual ramp up – just a giant step right at 1950. It makes no sense to me.

The root cause is cognitive bias. It's a rich and complex field of conditions - see if you can pick which one(s) fit(s) your symptomology.

SN

It's not a step change, it is a progression.

http://www.climatechange2013.org/images/figures/WGI_AR5_Fig8-18.jpg

#43
"What I have trouble reconciling in my mind is going from anthro being less than 50% of the cause of warming pre-1950 and then jumping to more than 100% after 1950 – no gradual ramp up – just a giant step right at 1950. It makes no sense to me."

It doesn't make sense to anyone. (See #65.) Unless you can find a reasonable explanation for your giant step, you're left with wizardry or divine intervention. Is that what you're claiming?

RickA: "“What I have trouble reconciling in my mind is going from anthro being less than 50% of the cause of warming pre-1950 and then jumping to more than 100% after 1950 – no gradual ramp up – just a giant step right at 1950. It makes no sense to me.”"

Where does anyone say that?

BBD:

Checkmate, alarmists!

Source: http://www.realclimate.org/index.php/archives/2013/10/the-evolution-of-…

Hardy har-har. And all too horribly true. Look at the error bars on 'The Natural Cycle' :-)

Greg #68:

IPCC 5 Chapter 10 - Executive summary (pg. 869):

"More than half of the observed increase in global mean surface temperature (GMST) from 1951 to 2010 is very likely due to the observed anthropogenic increase in greenhouse gas (GHG) concentrations."

Now I read this statement as saying that it is not very likely that more than 1/2 of the warming before 1950 is anthropogenic.

If evidence of this existed - they would have pushed the date back - i.e. 1930 to 2010 or 1900 to 2010 - etc.

So that takes care of the pre-1950 portion of my argument. There is not enough evidence to support saying more than 1/2 of pre-1950 warming is caused by humans - which supports my opinion that less than 1/2 of the warming pre-1950 is caused by humans.

As to the post-1950 warming - many people on this blog have argued in the past that but for human aerosols, which have a cooling effect, it would be even warmer - and attribute 110% of the warming post 1950 to humans.

To Greg #62:

“As explained, it is not true that anomalies are only as good as the absolute temperatures. Again, you have misunderstood.”

But if the absolute temps are lower than the baseline’s AND are significantly under-stated for some reason, then the anomalies will be both negative and significantly *over*-stated.

To illustrate, I’ve made up a simple and *fictitious* example:

Accurate temps baseline 1951-1954: Average 58.0 F. [Sequence: 58.1, 57.8, 57.9, 58.3; Average increase +0.1.]

INaccurate temps for 1900-1903: 54.0, 54.5, 53.8, 54.1.
INaccurate anomalies: -4.0, -3.5, -4.2, -3.9.
Vs.
Accurate temps for 1900-1903: 58.0, 58.5, 57.8, 58.1.
Accurate anomalies: 0.0, +0.5, -0.2, +0.1.
……
Then, using MY version of “anomalies” (difference in temp *changes*),
you get +0.4, -0.8, +0.2,
regardless whether you use the inaccurate comparative temps or the accurate comparative temps.

Desertphile #71:

Gavin says the best guess is 110%:

http://www.realclimate.org/index.php/archives/2014/08/ipcc-attribution-…

He is a climate scientist.

Are you sure about your statement?

RickA

So that takes care of the pre-1950 portion of my argument. There is not enough evidence to support saying more than 1/2 of pre-1950 warming is caused by humans – which supports my opinion that less than 1/2 of the warming pre-1950 is caused by humans.

This is the very definition of a strawman argument. Nobody claims otherwise.

For improved clarity on this issue, all you have to do is look at the evolution of major forcings over the C20th - something also handily documented in AR5. Reading to learn, rather than to quote-mine, would have a dramatic effect on your topic knowledge.

Here is the relevant figure to get you started.

And Rick, remember that if you average volcanic aerosol forcing and solar forcing across the whole century the trend is flat. Natural variability tends to cancel out over multidecadal timescales.

So to explain the centennial warming trend as a whole you need to look at the longer-term, ongoing changes in net forcing. When you do, you see that there is a net increase, becoming substantial post-1970, and that it is predominantly driven by anthropogenic emissions of GHGs.

2016 set to be hottest year on record globally
http://www.theguardian.com/environment/2015/dec/17/2016-set-to-be-hotte…

RickA, what Gavin Schmidt is saying in that RC post is that if it wasn't for cooling factors, mostly aerosols, the warming would be 110% of what it actually has been.

The figure from AR5-WG1 that BBD linked shows it at a glance.

To Greg #74:

Two points:
1)
“First, the baseline is used to get a starting point from the anomalies, not the absolute temperatures.”

I’d say the baseline is used to get a starting point FOR (not “from”) the anomalies,
and the baseline DOES use the absolute temperatures. Without absolute temperatures, how would you calculate anomalies from the baseline?

2)
“Second, there is no reason to assume that temperatures are biased in one direction or another. Third the use of anomalies obviates any bias in the temperature measure errors. Forth, studies have been done to look at biases and they have not come up with anything interesting.”

If the absolute temperature measurements, even from long ago, are NOT biased in one direction or another, and are NOT in error, then why not use the absolute temperature measurements?

But as I said, they ARE using the absolute temps anyway; their calculated anomalies are simply the difference between measured absolute temps.

BBD:

I think you are talking about intrinsic natural variability.

I am talking about all non-human forcings.

If the sun gets more active for a century, than it will get warmer - and it will not cancel out (necessarily).

The warming from 1900 - 1950 gets blamed by a lot of people on the sun being in an active period.

That is not intrinsic natural variability - that is nature.

Intrinsic natural variability (at least my understanding) is when heat slops around from the ocean to the atmosphere or visa versa. Moving the heat around - but not new heat.

Nature is intrinsic plus all the other non-human forcings - whether they are orbital and act over 1000's of years or the sun and act over centuries or a volcano and act over 2 years.

Just to make sure we are on the same page - do you agree that intrinsic natural variability is not the same thing as all natural focings?

If not - why not?

Mal Adapted #81:

I understand that.

But Gavin is saying that the best guess is that humans caused 100% of the net warming (after the cooling is subtracted from the warming) - from 1950 to today.

That is that all the warming we have measured from 1950 to today is caused by our human emissions.

Zero caused by el nino.

Or am I misunderstanding you and Gavin?

RickA

Just to make sure we are on the same page – do you agree that intrinsic natural variability is not the same thing as all natural focings?

If not – why not?

This is all natural variability. The distinction you are making is between internal variability and total natural variability. It sounds like you are actually talking about unforced internal variability.

If the sun gets more active for a century, than it will get warmer – and it will not cancel out (necessarily).

Sure, but that isn't what happened, as I have explained.

See Noevo

If you want to play around with baselines and get a sense of what is going on, you can experiment with the data visualisation tools provided at WoodForTrees.

Here is a quick example where GISTEMP, HADCRUT4 and RSS are rebaselined to the UAH 1981 - 2010 period for ease of comparison.

I think you guys are mixing stuff up.

The IPCC statement I quoted above is that more than 1/2 the warming is from anthropogenic increase in GHG concentrations.

Gavins statement is:

"The bottom line is that multiple studies indicate with very strong confidence that human activity is the dominant component in the warming of the last 50 to 60 years, and that our best estimates are that pretty much all of the rise is anthropogenic."

And Gavin goes on to show the center of the bell curve on 110%.

Now you guys are netting Anthro increases of GHGs with all the non-anthro stuff (sun, volcano, etc.).

BBD - that chart shows Anthro and non-Anthro.

I have no problem with the IPCC version because more than half can be 51%, which still allows for netting with the sun or whatever other non-human forcings there are.

It is when people start to sloppily say 110% of the observed warming is Anthro that I have trouble - because it doesn't read as netting out the non-Anthro.

RickA:

There is not enough evidence to support saying more than 1/2 of pre-1950 warming is caused by humans – which supports my opinion that less than 1/2 of the warming pre-1950 is caused by humans.

No. Lack of evidence for something is not evidence for the opposite.

And you call yourself a lawyer. Sheesh.

Now you guys are netting Anthro increases of GHGs with all the non-anthro stuff (sun, volcano, etc.).

The non-Anthro forcings (sun, volcano) are zero or negative since 1950.

So what is your point?

From:
http://www.realclimate.org/index.php/archives/2014/08/ipcc-attribution-…

forrest curo says:
27 Aug 2014 at 9:56 AM

Um, I’m getting a little confused about an attribution greater-than 100%. Does this mean that the trend without human influences would have been ‘cooling’, ie that the human effects are offsetting influences that would have (before we destablizing the system) gone the opposite direction?

[Response: exactly. – gavin ]

#84, #85
As you yourself put it in #84:
"Intrinsic natural variability (at least my understanding) is when heat slops around from the ocean to the atmosphere or visa versa. Moving the heat around – but not new heat."

So yes, "Zero caused by el nino." El Niño, as you suggested, redistributes heat from the ocean to the surface. In La Niña years the redistribution goes the other way, but La Niña years still show a warming trend.
http://rabett.blogspot.dk/2014/12/plenty-of-trend-at-bottom.html
https://www.skepticalscience.com/graphics.php?g=67

The modern warming trend is caused by human activity. It's primarily the result of cumulative CO2 emissions, so you won't find jumps much bigger than the jump from 2014 to 2015. Other causes have been looked into, and they've been found wanting.

RickA

BBD – that chart shows Anthro and non-Anthro.

Yes, so it shows how anthropogenic forcing has increased relative to natural forcing.

I have no problem with the IPCC version because more than half can be 51%, which still allows for netting with the sun or whatever other non-human forcings there are.

The pretty picture from AR5 shows the relative contributions from all major forcings. Only anthropogenic forcings have increased sufficiently to account for observed modern warming.

It is when people start to sloppily say 110% of the observed warming is Anthro that I have trouble – because it doesn’t read as netting out the non-Anthro.

Look at the figure from AR5. Burning fossil fuels produces a cooling haze of aerosols as well as a warming infusion of CO2. Gavin and others are correct to suggest that we might be warmer still right now if not for those aerosols.

#89
Re. the 110% figure, Mal Adapted's explanation #81 could hardly be clearer. Desertphile #71 has made the same point.

So why do you then write, "It is when people start to sloppily say 110% of the observed warming is Anthro that I have trouble." This is a blog with a comment thread, not a peer-reviewed paper. There are people commenting here who are scientifically well-founded, and there may be some, like me, who aren't. In any case, some inaccuracies and instances of sloppiness can be expected, but instead of focusing on the essential, you make an effort not to understand by insisting on inaccuracies, even after the proper explanation has been presented. You show no interest in learning.

Part of the problem here is calibrating to a moving target.

If you look at surface temperature estimates from proxies from the last several centuries, the temperature wiggles up and down. That wiggling started to include an unnatural upward trend some time in the recent past. Before around 1900 it is probably very hard to see that, but it is very likely there. During the first half of the 20th century, you can see it. During the last half of the 20th century it is the dominant signal. Etc.

Moving from an up and down squiggle in a certain area to a squiggle sitting on an upward trend is a 100% human effect.

“More than half of the observed increase in global mean surface temperature (GMST) from 1951 to 2010 is very likely due to the observed anthropogenic increase in greenhouse gas (GHG) concentrations.”

Let's give RickA the benefit of the doubt for the moment, and assume that he's correct. Now let's see where that leads us:

Ninety-nine percent (99%) is truly "more than half", so we have no contradiction...

Then, to continue RickA's logic in #72, "... it is not very likely that more than 99% of the warming before 1950 is anthropogenic."

Hence, if RickA is correct, he is pointing out that only 1% of the warming before 1950 is likely to be other than human-caused...

Ergo, per RickA, it is overwhelmingly probable that nearly all the warming before 1950 is caused by human activity.

Good job, RickA. You seem to be making progress. Finally.

RickA:

That is that all the warming we have measured from 1950 to today is caused by our human emissions.

Zero caused by el nino.

Or am I misunderstanding you and Gavin?

What you apparently haven't understood is that el nino (actually, all quasi-periodic oceanic oscillations) only moves heat around in the global system. The accumulation of heat, whether in the atmosphere, the land or the ocean, is due to external radiative forcing. Since solar output has been effectively constant during the period of interest, that means more heat is being retained in the global system. That's due to the increasing amount of Tyndall gasses in the atmosphere, and the only source of those is anthropogenic. By the same token, anthropogenic aerosols have reduced radiative forcing to varying extents by increasing albedo, causing more incoming solar radiation to be reflected.

BTW, I've also noticed that RickA seems to be making a genuine effort to overcome his initially apparent cognitive bias. He should be encouraged as long as he continues to show the effort.

Just had a record breaking December heatwave here in my home town.

Four days in a row over forty degrees Celsius.

Port Augusta, a town not too far to my north was the hottest town on the planet just last week with temperatures hitting 47.2 Celsius

http://www.pressreader.com/australia/sunday-mail/20151220/2814792753717…

Or 117 degrees Fahrenheit whilst on that day my home city reached 43.2 or 109.76 F.

Oh and there's this to look forward to over the next few days :

http://www.abc.net.au/news/2015-12-23/sa-in-for-worst-christmas-day-fir…

After I start work early tomorrow because I'm working outside in 39 degree Celsius (102 F) heat.

After struggling to keep my garden of native plants alive after a poor nights sleep by spending hours soaking the ground in water as rainfall is well below average.

Damn right I take Denialist bullshit personally.

Oh & don't tell me that Adelaide and Australia generally is always hot in summer. That we always fear bushfires and swelter, scorch and wilt in extreme heat.

Gee, I know.

I have, after all, lived here for most of my life. So yeah. I know we get hot and I also can durn well recognise a trend and unusual conditions for my location when I feel them on my skin and experience them more often and worse than I ever have before thankyou.

When we have our longest heatwave on record one year and the hottest the next and now the earliest now all in very quick succession; how stupid do you have to be to think that's just purely coincidence especially given all of, well, the science?

https://www.climatecouncil.org.au/angry-summer