Scientific Consensus On Climate Change

A new paper examines what is behind the ~2% of climate change related peer reviewed research that run contrary to widely accepted scientific consensus on climate change to see why those papers are wrong.

There is a scientific consensus that increasing greenhouse gas concentration in the atmosphere causes surface warming, and that CO2 is a major greenhouse gas. This consensus is based on physics. We don't need to observe the effects of human greenhouse gas pollution to know this. There is consensus that human burning of fossil fuel causes an increase in CO2 in the atmosphere. We don't need to observe this to know it, because we know how combustion works. But it is relatively simple to measure, and it has been measured, and it is true. There is consensus that the planet's surface has warmed. This is expected from the physics and the fact that we are increasing atmospheric CO2, but it is also relatively easy to measure, it is measured, and it is true. There are varying levels of understanding the effects of this process, and varying degrees to which the effects of surface warming are thought to cause specific effects. One could probably characterize the scientific consensus as a widespread understanding that surface warming has had and will have a range of effects, with many of those effects being changes in weather patterns or regional climatology (how warm/cool/dry/wet a region generally is across he seasons) arising from a combination of "natural variability" (what would happen without greenhouse gas pollution) and anthropogenic global warming.

It is interesting, then, to see the results of various studies of scientific consensus related to climate change. Two kinds of studies have been done. One asks scientists what they think, the other reviews the scientific literature to see what the peer reviewed papers that address climate change say. In both cases we see a number between 90 (or, really, 95) and 100 percent agreement on the stuff in the paragraph above. It is not surprising that the vast majority of scientists, and the vast majority of research papers, have very similar things to say about climate change. This is not new science, and while climate is very complex, the basics of anthropogenic global warming are well understood. The results of empirical research closely match expectations derived from the physics. It all hangs together pretty well.

What is surprising is to see that 3-6% or so disagreement. Who are those scientists, why do they disagree, what do those papers say?

I would assume that since consensus research takes time, and often looks at several years worth of papers, that some of that non-consensus reflects older thinking and older research. Also, there are climate contrarians, including some scientists, who oppose the consensus for reasons not based on the science. That sort of denial presumably comes from the simple fact that some corporations or wealthy individuals will see reduced profits as we make the inevitable shift away from fossil fuels. So some of that non-consensus may be bought and paid for self interested maneuvering.

Rasmus Benestad, Dana Nuccitelli, Stephan Lewandowsky, Katherine Hayhoe, Hans Olav Hygen, Rob van Dorland, and John Cook, in "Learning from mistakes in climate research" (Theoretical and Applied Climatology) looks at the non-consensus peer reviewed literature.

The paper is here, and author Dana Nuccitelli has a writeup on the paper here. From the abstract:

Among papers stating a position on anthropogenic global warming (AGW), 97 % endorse AGW. What is happening with the 2 % of papers that reject AGW? We examine a selection of papers rejecting AGW. An analytical tool has been developed to replicate and test the results and methods used in these studies; our replication reveals a number of methodological flaws, and a pattern of common mistakes emerges that is not visible when looking at single isolated cases. Thus, real-life scientific disputes in some cases can be resolved, and we can learn from mistakes. A common denominator seems to be missing contextual information or ignoring information that does not fit the conclusions, be it other relevant work or related geophysical data. In many cases, shortcomings are due to insufficient model evaluation, leading to results that are not universally valid but rather are an artifact of a particular experimental setup. Other typical weaknesses include false dichotomies, inappropriate statistical methods, or basing conclusions on misconceived or incomplete physics. We also argue that science is never settled and that both mainstream and contrarian papers must be subject to sustained scrutiny. The merit of replication is highlighted and we discuss how the quality of the scientific literature may benefit from

The researchers found that cherry picking was the most common explanation for the non-consensus papers contrary results. In other words, it is not the case that a small number of paper simply found the physics, or some other aspect of, global warming to be different than other researchers found, or that they were looking at a part of the system that acts differently. Rather, these papers were wrong, and for a specific reason.

We found that many contrarian research papers omitted important contextual information or ignored key data that did not fit the research conclusions. For example, in the discussion of a 2011 paper by Humlum et al. in our supplementary material, we note,

The core of the analysis carried out by [Humlum et al.] involved wavelet-based curve-fitting, with a vague idea that the moon and solar cycles somehow can affect the Earth’s climate. The most severe problem with the paper, however, was that it had discarded a large fraction of data for the Holocene which did not fit their claims.

The authors attempted a replication of that particular research, and found that the model they used only worked for part of the underlying data. The data that were ignored by Humlum et al contradicted their findings.

Another problem identified by Benestad et al is the lack of a consistent sensible alternative explanation for their alleged findings. "...there is no cohesive, consistent alternative theory to human-caused global warming. Some blame global warming on the sun, others on orbital cycles of other planets, others on ocean cycles, and so on. There is a 97% expert consensus on a cohesive theory that’s overwhelmingly supported by the scientific evidence, but the 2–3% of papers that reject that consensus are all over the map, even contradicting each other."

Go read Dana Nuccitelli's post in The Guardian for more discussion of this interesting new paper. Also, the lead author has a post on this paper at RealClimate.

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He is not Galileo in most ways...G had evidence of his position. And the RCC did not say his evidence was wrong, but that he was not to publish it until they could figure out how to handle the information(ie incorporate it into dogma). And he was not punished for the science but because his bosses gave orders and he refused them.
So some dimwit with no evidence and NOT being arrested does not make him a Galileo!

One word : EVIDENCE!

Favours the climatologists who've actually y'know done the experiments and looked at the observations.

Like Galileo did.

Oh & Galilei also wasn't a right wing shill and ideologue funded by fossil fools.*

Go figure ..

* For once NOT a typo. No insult intended to palaeontologists.

OH & cherry picking a few issues witha the odd US station and saying thatsomehow overrides known physics and a mass of global observations? Yeah that's not real science or convincing evidence.

See also :…

See also the web pages of NASA and NOAA and the NSIDC and thousands, tens, hundreds of thousands of peer reviewed science papers published by teams of experts that have devoted years,decades, of their lives to understanding the actual realities here.

To then turn around and call them liars and worse and abuse them and call yourselves Galileo's is just disgustingly wrong and would have Bruno spinning on his flaming stake.

Where are you living? Are you moving from the mid-Atlantic to Newfoundland, to get a jump on climate change, because where you live is getting too warm? One of the fallacies of catastrophic anthropogenic global warming is that PEOPLE who believe it are not intelligently moving towards the poles. Furthermore if you ask people living in San Diego, they LIKE the weather of the last decade, they LIKE it. They don't like living with downgraded water usage, but they're willing to take it, because they really ENJOY Jan daytime highs averaging 67 degrees, and summer daytime highs averaging (thus far this summer) 77 degrees. They LOVE this sh*t. Or take Silicon Valley, Jan hi 62 degrees, summer 80. They love it. They're not running to Vancouver, much less Anchorage. And everybody knows THEY ARE SMART.

Unless you can get the smart people to move waay north, unless you can get the President to stop flying himself to California, burning 25,000 pounds of jet fuel, for a 3-day trip, unless you can prevent the Paris UNFCCC delegates from burning tens of millions of pounds of jet fuel, to make a real stand against other people burning fossil fuels, because only some people get to do it, profligately, the cause is lost. When Christiana Figueres takes a sailboat across the Atlantic, and up the Seine, when Al Gore sells his mansion, and takes up a 1500-square foot abode, and only drives a Prius, then and only then, will people start to believe that they are serious about cutting C02 emissions to combat climate change. And Obama stopping flying 747 and sending his family on jet-fueled vacation trips.

By Mark Schooley MD (not verified) on 25 Aug 2015 #permalink

All good, but perhaps we are now giving too much oxygen to the 2% - in most of my work on LCA the cut-off threshold (where the bit missing is smaller than the errors in the rest of the data) is 3-5%. 97% consensus from scientists trained always to be critical and questioning of everything is astonishing and rounding for cut-off error this IS 100% agreement. So now lets get on with the job of keeping carbon in the ground - getting all investment divested from fossil, getting BIG commitments from COP21 in December from our politicians (Sorry everyone embarrassed by Australia's pathetic contribution - please put huge import tariffs on our coal to penalise our cheating). AND innovating so that renewables quickly make fossil fuels obsolete.

By Nigel Howard (not verified) on 25 Aug 2015 #permalink

Nigel, that is always an important question to ask. The 2% has considerably more power than they should because they make up about 40-50% of those who testify before the US Congress, because half of the members of the US Congress are in the pockets of the Koch and the rest of the petrol industry, or are blithering idiots. So maybe we can't avoid the O2

This is a question I wrestle with every day and I don't know the answer.

Mark Schooley MD:

Unless you can get the smart people to move waay north, unless you can get the President to stop flying himself to California, burning 25,000 pounds of jet fuel, for a 3-day trip, unless you can prevent the Paris UNFCCC delegates from burning tens of millions of pounds of jet fuel, to make a real stand against other people burning fossil fuels, because only some people get to do it, profligately, the cause is lost.

You're probably right that the cause is lost, but it's not because politicians and celebrities aren't all modeling every possible step to reduce their personal carbon footprints. It's because people like you get all your information about anthropogenic global warming from mass media and denier blogs, rather than directly from working climate scientists.

I presume from your comment that you haven't heard of the Tragedy of the Commons. It's what happens when producing an economic good has costs that aren't included in the price consumers pay for the product. Because nobody owns the air, fossil fuel producers don't have to account for the climate change costs caused by the CO2 emissions their product releases when it's burned. That means they don't have to pass those costs on to consumers in the prices they charges for a gallon of gasoline or a ton of coal.

Just because we don't pay the full cost of energy from fossil fuels every time we fill our gas tanks or pay our utility bills doesn't mean it doesn't have to be paid, though. AGW is already having impacts, and the people who are most affected aren't necessarily the ones most responsible for causing the problem. Hardly seems fair, does it?

Have you figured it out yet? The people most responsible for causing the problem are the ones who use the most energy from burning fossil fuels. That would be those politicians and celebrities, but also everybody else who drives a car, takes a plane trip, or heats their house with fossil energy. As long as we can make somebody else pay for the warming we're causing, the AGW-deniers among us can fool themselves that they're not responsible for it; and the smart people, who aren't fooling themselves, can shrug and carry on business as usual, because why should they make personal sacrifices when people like you ride for free?

The solution is ridiculously simple: our elected representatives must enact a carbon tax, so that the cost of climate change shows up in the prices we pay for energy from fossil fuels. Tragically, as your truculent and poorly-informed comment makes all too clear, that's almost certainly a lost cause. By the time even you can no longer ignore the impacts, we'll be stuck with a world that's at least a degree warmer than it is now, and very likely 2 or even 6 degrees warmer. Then you'll see people moving, away from the savage storms, hellishly-burning forests, dried-out croplands and drowning coastal cities. I'm glad I never had children!

By Mal Adapted (not verified) on 25 Aug 2015 #permalink

"One of the fallacies of catastrophic anthropogenic global warming is that PEOPLE who believe it are not intelligently moving towards the poles."

This is a non sequitur. Humans are usually tethered by property, jobs, schools, and geographically limited social relationships. Many of us adapt to high temperatures with air-conditioning.

Plants and animals are already migrating toward the poles and to higher altitudes.…

By cosmicomics (not verified) on 25 Aug 2015 #permalink

Mark Schooley, MD, you are not making a lot of sense. Are you innumerate? The human race is putting up about 2.5 million pounds of carbon dioxide into the air every second. Your hackneyed right wing examples of “profligate” use of energy are trivial, and they address usage that would probably go on whether or not AGW supporters put on sack cloth and ashes to appease you. Remember, the president’s planes fly routinely as part of national security readiness, whether or not he is on them.

Do you doubt that human induced global warming is real? Are you defending the anti-science position? What is your point? We’ve known about the insulating effect of the atmosphere since the early 1800’s. We’ve know about the ability of carbon dioxide to block infrared since the mid 1800’s. We also know about the corrupting effect of fossil fuel money on our political process. If you want to point fingers at somebody, why not point them at the “polluticians” and businessmen who continually savage climate science in the interest of fossil fuel money.
Have a nice day.

Sorry to burst you kids' bubbles, but I realized in the late 1980s that real estate development in SoCal, the clearing of native chaparral to put up ticky-tackyvilles did not price ecological damage, i.e., what it would cost to re-create the natural landscape that was destroyed, was astronomical.

Garrett Hardin's "Tragedy of the Commons", who didn't read that 40 years ago? Of course you were just babies them, or not yet born.

What I would suggest to some of you, people who are adventurous enough to take on the extreme challenge of raising children, is, don't follow your parents' footsteps of both parents' working to have a "better life", and then sending their kids (you) to mass-indoctrination centers called schools. Life is about interpersonal relationships. One adult leading classes of 20 "other people's kids" is a monstrosity.

Your parents chose it because they experienced it, and it was "convenient" to making more money. Eewe.

Move to a place where one parent has to "bring hoe the bacon," and the other can stay at home, and give intensive one-on-one or one-on-two upbringing. Just because your own parents f'd you doesn't mean you have to do it to your children.

Try something different. If you keep your children at home, you will realize a new dimension of life.

We visited Grand Teton and Yellowstone NP a few years ago in late September. There were a fair number of children. They were all "homeschooled".

Eewe! When did your parents take you to Grand Teton/Yellowsone in fall?

But it isn't just the U.S. Canada, UK, France, Finland, communist China, Cuba, Russia, try to take your kids on vacation at any time of the year when school is in session. Good luck!

By Mark Schooley MD (not verified) on 26 Aug 2015 #permalink

If you found that there was 100% consensus, that in itself should prompt questions about the results being manipulated. ~95% agreement is probably the best we could hope for under the circumstances. If the consensus were 80% that would mean there is some evidence to the contrary that's worth being discussed...

"They were all “homeschooled"

That in itself is meaningless. It could be good; locally the homeschooling movement is dreadful, driven by fundamentalist christians (so no real science - which seems to be your point of view). The biggest problem we have in our math/stat classes for many of them who come to our university is that they lack the background needed to generalize: they perform well on work that is just like the texts' problems, but they perform less well than the general student body on problems where some slight modification is needed.

Strikes me that those of us who understand what is happening are acting but as you say less in terms of adaptation--i.e. moving but relative to mitigation-- not trying to save ourselves but helping everyone toward understanding and acting on the transition toward safer energy.

By Steven Leibo Ph.D. (not verified) on 29 Aug 2015 #permalink

"The most severe problem with the paper, however, was that it had discarded a large fraction of data for the Holocene which did not fit their claims."

In other words, the authors of that paper manipulated data to give them a desired conclusion contrary to the scientific consensus.

Color me unsurprised. If they had any data that honestly contradicted the consensus, we would all have heard about it from the scientific establishment, and those authors would all be rolling in money.

By Christopher Winter (not verified) on 29 Aug 2015 #permalink

From a blog: "Figueres is perhaps the perfect person for the job of transforming "the economic development model" because she's really never seen it work. "If you look at Ms. Figueres' Wikipedia page," notes Cato economist Dan Mitchell: Making the world look at their right hand while they choke developed economies with their left."

What does this even mean? How could this UN official — how could anyone in the developed world — not have seen capitalism work?

And the comment from Dan Mitchell has nothing to do with that first sentence in the blog paragraph I quoted.


The plain fact is that capitalism as practiced is not working as intended. By rejecting sustainablity in favor of unlimited material growth, it dooms itself; and by refusing to account for negative externalities like pollution, it passes the costs of dealing with that pollution on to government — giving us the corporate form of that socialism so many business bigwigs love to blame for all ills.

By Christopher Winter (not verified) on 29 Aug 2015 #permalink

Mark is in anesthesiology. Take his wigged out words w a grain of peripheral nerve blocks.

By LouMaytrees (not verified) on 29 Aug 2015 #permalink

In Dec. World Leaders are to meet in Paris to discuss Global Warming, at issue is the amount of greenhouse gases we our emitting, and their plan of action, to Stop this Heating Up and Burning Up our Planet !

Globally we our emitting 40 - 50 Billion Toxic Tons of Carbon Dioxide a Year.

The United States emitted 6.8 Billion Toxic Tons of Carbon Dioxide in 2014

In the 1850s - 1870s parts per million of Carbon in our atmosphere was between 260 - 280.

In the 1980s, there was 350 ppm of Carbon.

2015 - 404 ppm in Our Atmosphere.
We have passed the 1C. baseline Temp Increase !

India, Pakistan, Japan, and the Middle East, Record Breaking, Killing Heat Waves !

The Pacific Ocean is 3 - 8 degrees warmer than Normal, and flowing in to the Arctic Ocean !

Massive Whales,Salmon, Starfish, Sea Lions, Sea Stars, Sea Urchins, and Bird Die - Offs !

The Jet Stream is acting like a balloon that is loosing air.

The Arctic Ice and Snow may be gone at the end of this Summer or Next. A Huge Natural Cooler for the Northern Hemisphere, that no man or woman has ever lived without !

The meeting in Paris, should be about Closing the Fossil Fuel Faucet.

"Professor Chris Field is bullshitting the planet. On whether 1.5C is still feasible" Kevin Hester

"The message is already clear, that if the world does want to strive to limit warming to 1.5C or less, we don't have very much of the carbon budget left." Professeor Chris Field

"There is no carbon budget any more and 5C is baked in according to both Shell petroleum and the International Energy Authority. " Kevin Hester

"Chris Field is the founding director of the Carnegie Institution's department of global ecology and professor for interdisciplinary environmental studies at Stanford University. He is the co-chair of the Intergovernmental Panel on Climate Change's (IPCC) working group two (WGII) and US nominee for the chair of the IPCC."
With people like this driving the IPCC you can see why we are all done for." Kevin Hester.

There is No Carbon Budget

California emitted 459 Toxic Tons of Carbon Dioxide in 2014.

Gov Browns call to reduce this to 1990 levels so we can continue to emit over 400 million Toxic Tons a year, will not help us stop or slow down Global Warming and Sea Levels Rising.

"Updates to the 2020 Limit.
Calculation of the original 1990 limit approved in 2007 was revised using the scientifically updated IPCC 2007 fourth assessment report (AR4) global warming potentials, to 431 MMTCO2e. Thus the 2020 GHG emissions limit established in response to AB 32 is now slightly higher than the 427 MMTCO2e in the initial Scoping Plan." Ca. Gov. Data

What will the Temp. be at 415 ppm ?

"Ice sheets contain enormous quantities of frozen water. If the Greenland Ice Sheet melted, scientists estimate that sea level would rise about 6 meters (20 feet). If the Antarctic Ice Sheet melted, sea level would rise by about 60 meters (200 feet)." National Snow and Ice Data Center.

When will Sea Level Rise to 220 - 300 Feet ? 2020 ? 2025 ? ?

What will the ppm of Carbon be when this happens ?

As of Now, they are talking about capping GHGs at 450 ppm.

What will the Temp. be at 450 ppm ?

We must transition to 100% Renewable Energy

Implement a California Residential and Commercial Feed in Tariff.

California Residential Feed in Tariff would allow homeowners to sell their Renewable Energy to the utility, protecting our communities from, Global Warming, Poison Water, Grid Failures, Natural Disasters, Toxic Natural Gas and Oil Fracking.

A California Commercial FiT in Los Angeles, Palo Alto, an Sacramento Ca. are operating NOW, paying the Business Person 17 cents cents per kilowatt hour.

Sign and Share this petition for a California Residential Feed in Tariff.

By Daniel Ferra (not verified) on 30 Aug 2015 #permalink