The Hockey Stick Graph Reality

Nope! More science from the professionals. Too bad you're so brainwashed and confused that you won't accept reality.

 

No answers: And again why does the trend from 1900 to 1950 look steeper than the current trend on the graph ?? And why is the time scale missing ??

BTW ~ 0.2 deg F per decade is ~ 0.1 deg C per decade which is ~ 1 deg C per century which agrees roughly with the climate sensitivity to CO2 of ~ 1 deg C.

 

(Credit: NOAA)

It seems you really don't know what the term "climate sensitivity" actually means. Not surprising. You don't really know much about this at all.

Although it is often shortened to just 'climate sensitivity', the actual scientific term is "equilibrium climate sensitivity" which refers to the total amount of warming that will occur at the Earth's surface once it reaches a new balanced energy state, resulting from the increased greenhouse effect from a doubling of atmospheric carbon dioxide, and a number of feedback effects. For example, when ice melts it makes the Earth's surface less reflective, causing it to absorb more sunlight and warm further. A warmer atmosphere will also hold more water vapor, and water vapor is another greenhouse gas.

From the experts....

Explaned: Climate sensitivity
If we double the Earth’s greenhouse gases, how much will the temperature change? That’s what this number tells you.
MIT
David L. Chandler, MIT News Office
March 19, 2010
Climate sensitivity is the term used by the Intergovernmental Panel on Climate Change (IPCC) to express the relationship between the human-caused emissions that add to the Earth’s greenhouse effect — carbon dioxide and a variety of other greenhouse gases — and the temperature changes that will result from these emissions.

Specifically, the term is defined as how much the average global surface temperature will increase if there is a doubling of greenhouse gases (expressed as carbon dioxide equivalents) in the air, once the planet has had a chance to settle into a new equilibrium after the increase occurs. In other words, it’s a direct measure of how the Earth’s climate will respond to that doubling.

That value, according to the most recent IPCC report, is 3 degrees Celsius, with a range of uncertainty from 2 to 4.5 degrees.

This sensitivity depends primarily on all the different feedback effects, both positive and negative, that either amplify or diminish the greenhouse effect. There are three primary feedback effects — clouds, sea ice and water vapor; these, combined with other feedback effects, produce the greatest uncertainties in predicting the planet’s future climate.

With no feedback effects at all, the change would be just 1 degree Celsius, climate scientists agree. Virtually all of the controversies over climate science hinge on just how strong the various feedbacks may be — and on whether scientists may have failed to account for some of them.

Clouds are a good example. Clouds can have either a positive or negative feedback effect, depending on their altitude and the size of their water droplets. Overall, most scientists expect this net effect to be positive, but there are large uncertainties.

“There is still lots of uncertainty in what the climate sensitivity is,” says Andrei Sokolov, a research scientist in MIT’s Center for Global Change Science, who has been doing research on climate sensitivity for many years. “Feedback is what’s driving things,” he says.

It is important to note that climate sensitivity is figured on the basis of an overall doubling, compared to pre-industrial levels, of carbon dioxide and other greenhouse gases. But the temperature change given by this definition of climate sensitivity is only part of the story. The actual increase might be greater in the long run because greenhouse gas levels in the atmosphere could much more than double without strong policies to control emissions. But in the short run, the actual immediate warming could be less than suggested by the climate sensitivity, since due to the thermal inertia of the ocean, it may take some time after a doubling of the concentration is reached before the climate reaches a new stable equilibrium temperature.

 

I know exactly what climate sensitivity to CO2 is. And I know what the A1B CO2 scenario is. And the results of the data and A1B shows a climate sensitivity to CO2 of ~ 1 deg C.

 

Nah. Observed climate senstivity is well over 3.0C. Lukewarmers are totally contradicted by observed reality.

Calcs? Sure.

global temp has jumped about 1.2C over the past 40 years. That is, 0.3C/decade. Your 0.1 claim is way, way the heck off.

40% CO2 increase, half a doubling on a log scale.

That makes the observed transient climate sensitivity 2.4C.

However, the transient isn't done yet. Even if CO2 emission stopped now, temperature would still rise until equilibrium.

Equilibrium Climate Sensitivity? More like 3.5C.

 

Even the bogus chart above shows ~ 1.2 deg F over 70 years. And that includes the dishonest Karl manipulations.

 

But the real CO2 increase and warming started 40 years ago, and the rise is 1.2 since then. You're using the wrong year to get a fudged rate result that's much too low. But no matter. Rate doesn't set ECS. Total rise does. Hence, your point is irrelevant in any case.

Observed Transient Climate Sensitivity is about 2.4C, no matter what tricks you pull with the dates.

Equilibrium Climate Sensitivity has to be significantly bigger than TCS. How that's worked out it complex, but the point is, it's bigger.

Yet you're here claiming it's 1.0. That's just totally wrong.

 

You didn't even pick up the typo in my post. From the graph above the temperature rise in the last 70 years is 1.2 deg F over the last 70 years. No tricks - right off the graph above. The real world climate sensitivity is ~ 1 deg C. And according to an analysis by D. M. V. Evans the climate sensitivity is most likely less than 0.5 deg C.

Reference - "Evidence Based Climate Science" 2nd Edition, Chapter 20, pages 361 - 392, 2016

 

I wasn't working off that graph, so the F-C thing doesn't matter.

I did overstate a bit. Total temp rise is 1.2C, but only 1.0C over the last 40 years. However, time doesn't matter, only change, so the 1.2C is the figure to use.

So, TCM is already 2.4C.

ECM has to be bigger.

Hence, it's obviously wrong to say ECM is 1.0C or 0.5C.

If you disagree, tell us how a 1.2C rise with half a doubling -- meaning that a full doubling implies a TCM of 2.4C -- can possibly result in an ECM of less than 2.4C.

 

He doesn't realize that the ORIGINAL Marcott chart, doesn't have any big uptick on it.

 

Livefree writes:

"Mark Stein is a far rightwing denier cult liar and propaganda pusher with zero credibility. He is being sued by Dr. Mann for defamation."

It is Dr. Mann who lacks credibility as he got no support on the lawsuit,has been resisting discovery, appears to be losing as he is the one slowing it down,while Mr. Stein WANTS his day in court.

First of all,DR.Mann is all alone on this:


"A few [months] ago, you’ll recall, the ACLU, The Washington Post, NBC News, The Los Angeles Times and various other notorious right-wing deniers all filed amici briefs opposed to Michael Mann and his assault on free speech. They did this not because they have any great love for me, but because their antipathy to wackjob foreign blowhards is outweighed by their appreciation of the First Amendment – and an understanding of the damage a Mann victory would inflict on it. After noting the upsurge of opposition to Mann, Reuters enquired of Catherine Reilly (one of his vast legal team) whether there would be any amici filing pro-Mann briefs:

I asked Reilly if the professor would have any supporting briefs next month when he responds to the defendants in the D.C. appeals court.

“At this point, we don’t know,” she said.

Ms Reilly was a pleasant sort when I met her in court over a year ago, but she struck me as a formidable opponent. So I naturally assumed that the above was what what the political types call “lowering expectations”. As I wrote:

“I would be surprised if Mann didn’t have any supporting briefs. I was in court when Ms Reilly’s genial co-counsel made his argument for Mann, which was a straightforward appeal to authority: Why, all these eminent acronymic bodies, from the EPA and NSF and NOAA even unto HMG in London, have proved that all criticisms of Mann are false and without merit. So I would certainly expect them to file briefs – and, given that Mann sees this as part of a broader “war on science” by well-funded “deniers”, I would also expect briefs from the various professional bodies: the National Academy of Sciences, the American Physical Society, etc. As pleasant as it is to find my side of the court suddenly so crowded, I’m confident Mann will be able to even up the numbers.”

Well, yesterday was the deadline, and not a single amicus brief was filed on behalf of Mann. Not one. So Michael Mann is taking a stand for science. But evidently science is disinclined to take a stand for Michael Mann."

LINK for the rest of the post

=====================

Plus this,

Mark Steyn’s Case Against Climategate Scientist Is Taking So Long A Key Witness Died

"Lawyers representing conservative political commentator Mark Steyn have asked the D.C. Superior Court to expedite his case against climate scientist Michael Mann, mentioning a key witness died waiting for the trial to go to court.

“Something needed to be done to jumpstart this case, a case that threatens the most fundamental First Amendment freedoms,” Dan Kornstein, Steyn’s lawyer, said in a statement.

Steyn has been locked in a legal battle against Mann since 2012, and it’s been four years since the case was brought and “the appeals from defendants’ special motions to dismiss have not been decided, nor has discovery proceeded,” Kornstein said.

“The passage of time since the appeal was argued in this case a year and a half ago while a stay of proceedings was in effect at the trial level has stalled a case whose very existence chills freedom of speech,” he said."

The rest of this in the LINK

Dr, Mann does nothing to get this FIVE YEAR OLD case moving forward. It is Mark Steyn who is trying get it moving. But then most people who follow this,knows Dr. Mann doesn't have a case and wants to avoid discovery.

 

Michael Mann's tree ring circus lives on in the minds of the true believers.

 

Then on January,2017 is a surprise change:

Defend Free Speech!

Excerpt:

"In the glacial progress of the defamation suit against me by Big Climate huckster Michael E Mann, there has been a most interesting development: a fellow scientist, Dr Judith Curry, has now filed an amicus brief against Mann. As the inventor of the global-warming "hockey stick" promoted worldwide by the UN and governments from Canada to New Zealand, Mann is undoubtedly one of the most famous climate "scientists" on the planet. But, if you want to know what a real scientist thinks of him, then don't miss Dr Curry's blistering indictment:

Dr. Mann has transgressed scientific norms and offended First Amendment principles by bringing a defamation claim against Appellants for their pointed criticism of his scientific methodology. Dr. Mann's suit is unsupportable both because of his behavior toward his critics, particularly amicus curiae Dr. Curry, which demonstrates that the debate over climate science is often contentious and because Dr. Mann engages in the debate often to silence rather than to illuminate. The Court ought not be party to stifling debate.

One of the many ways Mann "transgresses scientific norms" is in his sleazy and contemptible campaign against Judith Curry: for example, he links approvingly to anonymous bloggers who accuse her of having "literally gotten into bed with slime like Steyn". As Dr Curry's counsel explains at the start of the brief, this gives her a very real interest in the case:

As it relates to this case, Dr. Curry has been critical of Appellee Michael Mann's methodological approach to climate science and the conclusions he has reached. Dr. Curry has experienced personal and professional attacks from Dr. Mann for her criticisms of his work. Dr. Mann has a pattern of attacking those who disagree with him and this case is another in a long line of tactics to silence debate over the science of global warming. Dr. Curry is a stalwart supporter of free speech and believes it plays a crucial role in the advancement of scientific debate. She has an acute interest in the outcome of this case because should Dr. Mann prevail, he would be emboldened to continue his pattern of attacks against Dr. Curry and others like her, and others would be emboldened to do so. She also has an interest in robust debate on climate science in keeping with the scientific principles she espouses.

For those who want to know the difference between Mann's sue-you-into-silence approach and genuine "robust debate" in keeping with "scientific principles", Dr Curry's brief lays them out:"

LINK for the rest

The ugliness of Dr. Mann is slowly being exposed,who got ZERO amicus curiae support,while Steyn got many.

 

In the real world....

A climate change libel suit heads to trial
The Washington Post
By Chelsea Harvey
December 23, 2016
(excerpts)
A defamation lawsuit filed by a high-profile climate scientist will be allowed to proceed, an appeals court ruled on Thursday.

The case is being brought by Michael Mann of Pennsylvania State University, who is perhaps best known for helping develop the famous “hockey stick” graph used to illustrate global warming. Mann is suing two bloggers who accused him of scientific and academic misconduct in 2012. On Thursday, the D.C. Court of Appeals unanimously ruled that Mann has the right to proceed with the lawsuit.

“Dr. Mann has supplied sufficient evidence for a reasonable jury to find, by a preponderance of the evidence, that statements in the articles written by Mr. Simberg and Mr. Steyn were false, defamatory, and published by appellants to third parties, and, by clear and convincing evidence, that appellants did so with actual malice,” wrote Senior Judge Vanessa Ruiz in the court’s opinion.

“Tarnishing the personal integrity and reputation of a scientist important to one side may be a tactic to gain advantage in a no-holds-barred debate over global warming,” wrote Senior Judge Vanessa Ruiz in the court’s opinion. “That the challenged statements were made as part of such debate provides important context and requires careful parsing in light of constitutional standards. But if the statements assert or imply false facts that defame the individual, they do not find shelter under the First Amendment simply because they are embedded in a larger policy debate.”

This distinction has been pointed out by other climate scientists following the case as well. In a series of tweets on Thursday, NASA climatologist Gavin Schmidt called the ruling “nuanced” and “well argued.”

“Judges make clear that there is a large constitutional gap btw criticism of scientific conclusions or methodology… & allegations of misconduct and fraud,” he tweeted.

The court opinion points out that multiple committees conducted investigations and found no evidence of misconduct, adding that “appellants do not counter any of these reports with other investigations into the CRU emails that reach a contrary conclusion about Dr. Mann’s integrity.”

“On the current record, where the notion that the emails support that Dr. Mann has engaged in misconduct has been so definitively discredited, a reasonable jury could, if it so chooses, doubt the veracity of appellants’ claimed honest belief in that very notion,” the opinion stated.

 

Yep, faux Nobel Laureate Mann sues anyone that disagrees with him. You don't need to sue if the science can stand on it's own. The idiotic judge doesn't understand free speech or anti-slapp. Seeing how justice is supposed to be swift, there is still no trial date.

 

Is that the same dishonest hockey stick that the IPCC has disavowed ??

 

There was a time that I would have jumped in here guns blazing and helped to smite the ignorant. But I've come to realize that it doesn't matter anyway. It's far too late to stop climate change, and our society has decided that it's not going to try anyway.

Our civilization is on a countdown to incredible disruption, no matter what. On the bright side, it's hard to imagine anyone bothering to kick off a nuclear war, once most of humanity is starving and desperate. So maybe our species keeps going an extra few centuries. Good things.

 

Nope! That imaginary fantasy exists entirely in your denier cult mythology.

In the real world, the real Hockey Stick Graph has been scientifically confirmed many times and remains scientifically unchallenged.

Here are the facts, from Dr. Michael Mann himself....

As some readers may know, the conclusion that modern warming is unique in a long-term context came to prominence with the temperature reconstruction that my co-authors and I published in the late 1990s. The resulting "Hockey Stick" curve, which demonstrates that the modern warming spike is without precedent for at least the past 1,000 years, took on iconic significance when it was prominently displayed in the "Summary for Policy Makers" of the 2001 Third IPCC Assessment report. Thus, the "Hockey Stick" curve, as I describe in my recent book, "The Hockey Stick and the Climate Wars," became a focal point of the attacks by industry-funded climate-change deniers.

So, it might not come as a surprise that one of the most egregious misrepresentations of the IPCC's latest report involves the Hockey Stick and conclusions about the uniqueness of modern warming. [4 Things to Know About the IPCC's Climate Change Report]

An urban legend seems to be circulating around the echo chamber of climate-change denial, including contrarian blogs and fringe right-wing news sites. The claim is that the IPCC has "dropped" or "trashed" the Hockey Stick conclusion regarding the unprecedented nature of recent warmth.

A good rule of thumb is that the more insistent climate-change deniers are about any particular talking point, the greater the likelihood is that the opposite of what they are claiming actually holds. The IPCC has, in fact, actually strengthened its conclusions regarding the exceptional nature of modern warmth in the new report. A highlighted box in the "Summary for Policy Makers" states the following (emphasis mine):

"In the northern Hemisphere, the period 1983-2012 was likely the warmest 30-year period of the last 1400 years (medium confidence)."

The original 1999 Hockey Stick study (and the 2001 Third IPCC Assessment report) concluded that recent Northern Hemisphere average warmth was "likely" unprecedented for only the past 1,000 years. The 2007 IPCC Fourth Assessment extended that conclusion back further, over the past 1,300 years (and it raised the confidence to "very likely" for the past 400 years). The new, Fifth IPCC Assessment has now extended the conclusion back over the past 1,400 years. By any honest reading, the IPCC has thus now substantially strengthened and extended the original 1999 Hockey Stick conclusions.

Only in the "up is down, black is white" bizarro world of climate-change denial could one pretend that the IPCC has failed to confirm the original Hockey Stick conclusions, let alone contradict them. [How Words Affect Climate Change Perception]

The stronger conclusions in the new IPCC report result from the fact that there is now a veritable hockey league of reconstructions that not only confirm, but extend, the original Hockey Stick conclusions. This recent RealClimate piece summarizes some of the relevant recent work in this area, including a study published by the international PAGES 2k team in the journal Nature Geoscience just months ago. This team of 78 regional experts from more than 60 institutions representing 24 countries, working with the most extensive paleoclimate data set yet, produced the most comprehensive Northern Hemisphere temperature reconstruction to date. One would be hard-pressed, however, to distinguish their new series from the decade-and-a-half-old Hockey Stick reconstruction of Mann, Bradley and Hughes.


Green dots show the 30-year average of the new PAGES 2k reconstruction. The red curve shows the global mean temperature, according HadCRUT4 data from 1850 onward. In blue is the original hockey stick of Mann, Bradley and Hughes (1999), with its uncertainty range (light blue). Graph by Klaus Bitterman. Credit: Klaus Bitterman, Stefan Rahmstorf

Conclusions about unprecedented recent warmth apply to the average temperature over the Northern Hemisphere. Individual regions typically depart substantially from the average. Thus, while most regions were cooler than present during the medieval era, some were as warm, or potentially even warmer, than the late-20th-century average. These regional anomalies result from changes in atmospheric wind patterns associated with phenomena such as El Niño and the so-called North Atlantic Oscillation. [U.S. Will Warm Dramatically By 2084, NASA Model Shows (Video)]

Colleagues and I, quoting from the abstract of our own article in the journal Science a few years ago (emphasis mine), stated:

"Global temperatures are known to have varied over the past 1,500 years, but the spatial patterns have remained poorly defined. We used a global climate proxy network to reconstruct surface-temperature patterns over this interval. The medieval period [A.D. 950-1250] is found to display warmth that matches or exceeds that of the past decade in some regions, but which falls well below recent levels globally."

These conclusions from our own recent work are accurately represented by the associated discussion in the "Summary for Policy Makers" of the new IPCC report (emphasis mine):

"Continental-scale surface-temperature reconstructions show, with high confidence, multidecadal periods during the Medieval Climate Anomaly (year 950-1250) that were, in some regions, as warm as in the late 20th century. These regional warm periods did not occur as coherently across regions as the warming in the late 20th century(high confidence)."

However, never underestimate the inventiveness of climate-change deniers. Where there's a will, there is, indeed, a way: A meme now circulating throughout the denialosphere is that the IPCC's conclusions about regional warmth contradict our findings, despite the fact that those conclusions are substantially based on our findings.

One could be excused for wondering if climate-change deniers have lost all sense of irony.

The most egregious example of this latest contortion of logic found its way into the purportedly "mainstream" Daily Mail, courtesy of columnist David Rose, who admittedly has a bit of a reputation for misrepresenting climate scientists and climate science. Rose wrote in his column on Sep. 14, "As recently as October 2012, in an earlier draft of this report, the IPCC was adamant that the world is warmer than at any time for at least 1,300 years. Their new inclusion of the 'Medieval Warm Period' — long before the Industrial Revolution and its associated fossil-fuel burning — is a concession that its earlier statement is highly questionable."

The most charitable interpretation is that Rose simply didn't actually read or even skim the final draft of the report, despite writing about it at length. For, if he had, he would be aware that the final draft of the report comes to the strongest conclusion yet about the unprecedented nature of recent warmth, extending the original Hockey Stick conclusion farther back than ever before — to the last 1,400 years.

Moreover, he would be aware that the existence of regional medieval warmth rivaling that of the late 20th century does not contradict that conclusion — indeed, it is the regional heterogeneity of that warmth, as established in ours and other studies, that leads the IPCC report to conclude that current levels of hemispheric average warmth are unprecedented for at least 1,400 years.

The lesson here, perhaps, is that no misrepresentation or smear is too egregious for professional climate-change deniers. No doubt, we will continue to see misdirection, cherry-picking, half truths and outright falsehoods from them in the months ahead as the various IPCC working groups report their conclusions.

Don't be fooled by the smoke and mirrors and the Rube Goldberg contraptions. The true take-home message of the latest IPCC report is crystal clear: Climate change is real and caused by humans, and it continues unabated. We will see far more dangerous and potentially irreversible impacts in the decades ahead if we do not choose to reduce global carbon emissions. There has never been a greater urgency to act than there is now.

The latest IPCC report is simply an exclamation mark on that already-clear conclusion.

 

The tree ring data in the last ~ 100 years show cooling. Quoting Michael Mann on scientific integrity is laughable.

 

The IPCC has set the lower limit of climate sensitivity to 1.5 based on real world data. Even they have finally acknowledged that the models are wrong. There has been plenty of time for this positive feedback to occur - and it hasn't - unless the assumption is made that it will occur (as the models do) the feedback based on data is negative as is the case in almost all natural processes.

 

And so what? Are you crazy enough to suggest that we should all just trust your supposed "tree ring data" that supposedly "shows cooling", and disregard not only the abrupt warming that we can see happening on the planet right now with our own eyes, but also EVERY OTHER TEMPERATURE RECORD IN THE WORLD? All of the ground station instrumental records going back tp 1880 and the satellite records and long term historical records - that ALL indicate an abrupt and rapid warming beginning in the twentieth century? ROTFLMFAO.

The Flat Earth Society feels the same way as your cult.

In the real world of sane people though, Dr. Mann is one the the world's leading climate scientists, well-respected and much honored by his peers, and the author of a great many published scientific papers.

Michael E. Mann (born 1965) is an American climatologist and geophysicist,[1] currently director of the Earth System Science Center at Pennsylvania State University, who has contributed to the scientific understanding of historic climate change based on the temperature record of the past thousand years. He has pioneered techniques to find patterns in past climate change, and to isolate climate signals from "noisy data".[3]

As lead author of a paper produced in 1998 with co-authors Raymond S. Bradley and Malcolm K. Hughes, Mann used advanced statistical techniques to find regional variations in a hemispherical climate reconstruction covering the past 600 years. In 1999 the same team used these techniques to produce a reconstruction over the past 1,000 years (MBH99) which was dubbed the "hockey stick graph" because of its shape. He was one of eight lead authors of the "Observed Climate Variability and Change" chapter of the Intergovernmental Panel on Climate Change (IPCC) Third Scientific Assessment Report published in 2001. A graph based on the MBH99 paper was highlighted in several parts of the report, and was given wide publicity. The IPCC acknowledged that his work, along with that of the many other lead authors and review editors, contributed to the award of the 2007 Nobel Peace Prize, which was won jointly by the IPCC and Al Gore.

Mann was organizing committee chair for the National Academy of Sciences Frontiers of Science in 2003 and has received a number of honors and awards including selection by Scientific American as one of the fifty leading visionaries in science and technology in 2002. In 2012 he was inducted as a Fellow of the American Geophysical Union and was awarded the Hans Oeschger Medal of the European Geosciences Union. In 2013 he was elected a Fellow of the American Meteorological Society, and awarded the status of distinguished professor in Penn State's College of Earth and Mineral Sciences.

Mann is author of more than 200 peer-reviewed and edited publications. He has also published three books: Dire Predictions: Understanding Global Warming (200, The Hockey Stick and the Climate Wars: Dispatches from the Front Lines (2012), and The Madhouse Effect: How Climate Change Denial Is Threatening Our Planet, Destroying Our Politics, and Driving Us Crazy (2016). In 2012, the European Geosciences Union described his publication record as "outstanding for a scientist of his relatively young age". Mann is also a co-founder and contributor to the climatology blog RealClimate.

 

No, your claim is factually incorrect. Real CO2 increase and warming BOTH started more than 100 years ago. But then something funny happened: in the period 1940-1970 CO2 continued to increase, while temperature actually fell. The data for that period disprove the claimed CO2 sensitivity.

No, you are using the up-phase of the 60-year cycle to get a fudged result that's much too high.

Nonsense. You can't measure sensitivity with temperature data without accounting for the relationship between rate of CO2 increase and rate of temperature increase, because you can't reach equilibrium.

No, such claims are false and absurd. If you cherry-pick a period when CO2 and temperature both increased rapidly, you can get a figure of 2.4C, but look at a different period -- 1940-1970 -- and you will find an Observed Transient Climate Sensitivity that is actually NEGATIVE.

 

The "so what" is that tree ring data cannot be used to reliably show temperature history.

Mann is a dishonest individual who faked temperature data for personal gain and got away with it.

 

Good one ^^

 

Nope! Your denier cult Bullshit is what is factually incorrect, bozo.

While CO2 levels did start to slightly increase when the Industrial Revolution in the late 19th century led to increased burning of coal and natural gas and then oil, the initial increase in CO2 was fairly modest. It was only in the latter half of the 20th century that there was a significant "real" increase in both CO2 levels and global temperatures.....and they are in close correspondence because there is a scientifically verified causal connection. Rising CO2 levels are driving global warming, as is confirmed by virtually the entire world scientific community.


Time series of annual values of global mean temperature anomalies (red and blue bars) in degrees Celsius, and carbon dioxide concentrations at Mauna Loa, both from NOAA. Data are relative to a baseline of the 20th-century values. Also given as dashed values are the preindustrial estimated values, with the scale in orange at right for carbon dioxide, where the value is 280 ppmv (parts per million by volume). The latest values exceed 400 ppmv. For temperature, the 2015 value is more than 1 degree Celsius above preindustrial levels. Image credit: Kevin Trenberth/John Fasullo

As for your braindead denier cult myths about the period from 1940 to 1970, they are also complete bullshit. In the real world, as can be clearly seen on this graph, global temperatures spiked sharply upward around 1910 but then the rate of increase went down to a more moderate rate that continued at about the same rate until about 1980. The records apparently show that there was a short upward blip in temperatures in the first half of the 1940s, but that may either be because temperature record keeping was a bit spotty during WWII, or because the war and the consequent burning cities and so on caused a spike in temperatures. Minus the spike, the underlying increasing temperature trend is roughly the same until about 1980, when the modern rapid temperature increases really got rolling. Of the roughly 1.2 degrees C. temperature increase from 1910 to present, about 80% of it has happened in the last 40 years.


Source: NASA GISS