Where does the "97% agree with GW" number come from?

[yarblek]

@Exapno_Mapcase

…as far as I can tell nobody has even bothered to respond to Bodenstein, possibly because as a pediatrician who backs up none of his claims he is not a credible information source…

The original people who published the article that Bodenstein criticizes responded to him http://www.pnas.org/content/107/52/E189.full:

Though not present here (1), scientific discourse is aided by substantive comments on studies such as ours. We have engaged with such comments in a variety of venues (5, 6) and believe our engagement has further strengthened our thinking and our argument. In the meantime, actors outside of the scientific community are making decisions based on their understanding of the current collective perspective of the scientific community—complex as it may be. Our paper offered a view on the distribution of that perspective, a distribution that does not tell us an immutable truth but nonetheless, illuminates an emergent consensus.

[Aji_de_Gallina]

@zombywoof

Perhaps from this article published in the Proceedings of the National Academy of Sciences, the abstract of which states:

“Here, we use an extensive dataset of 1,372 climate researchers and their publication and citation data to show that (i) 97–98% of the climate researchers most actively publishing in the field support the tenets of ACC outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers.”

@Askance

It comes from the Proceedings of the National Academy of Sciences.

You lose your bet. In effect you pulled your own statement out of your rear, didn’t you? Not much of a contribution to fighting ignorance, was it?

It’s an abstract so I haven’t seen the actual data, but the 97% doesn’t come from the whole 1372 scientists but from those “climate researchers most actively publishing in the field” and we don’t know, from the abstract, what the qualifications are for "climate researchers"or “most actively publishing”, or, more importantly, how many these guys were.

Further research has taken me to a couple of University of Illinois researchers doing an online survey.
I’m quoting the link.

10,257 were invited
3,146 responded
90% agreed that the temperature had risen from pre-1800 levels (not the usual 1850)
82% agreed that humans contribute significantly to the change of mean temperature.
76 of 79 specialists* (96.2%) agree with the risen part
75 of 77 specialists* (97.4%) agree with the human contribution part.

It seems, then that the 97% figure comes from an incredibly small smaple of fewer than 80 people, even if they are the best people.

*Specialist, for this survey, are “those who listed climate science as their area of expertise and who also have published more than 50% of their recent peer-reviewed papers on the subject of climate change”.

[jovan]

@Aji_de_Gallina

It’s an abstract so I haven’t seen the actual data, but the 97% doesn’t come from the whole 1372 scientists but from those “climate researchers most actively publishing in the field” and we don’t know, from the abstract, what the qualifications are for "climate researchers"or “most actively publishing”, or, more importantly, how many these guys were.

It’s an open-access paper, you can read the whole thing for yourself.

Their data is thus:

Total convinced: 903 (~66%)
Total unconvinced: 472

They define a climate expert as someone who has published more than 20 papers.

Number of climate experts: 908
Convinced experts: 817 (~ 90%)
Unconvinced experts: 93

They defined prominent researchers as those whose four most-cited papers had the most citations, giving the following results.

2% of top 50 are unconvinced
3% of top 100 are unconvinced
2.5% of top 200 are unconvinced

Hence, the 97% figure is for the 100 most often cited researchers.

[Aji_de_Gallina]

@jovan

It’s an open-access paper, you can read the whole thing for yourself.

Their data is thus:

Total convinced: 903 (~66%)
Total unconvinced: 472

They define a climate expert as someone who has published more than 20 papers.

Number of climate experts: 908
Convinced experts: 817 (~ 90%)
Unconvinced experts: 93

They defined prominent researchers as those whose four most-cited papers had the most citations, giving the following results.

2% of top 50 are unconvinced
3% of top 100 are unconvinced
2.5% of top 200 are unconvinced

Hence, the 97% figure is for the 100 most often cited researchers.

Thanks for the link and a fantastic :smack::smack::smack::smack::smack: for me.

So, the 97%, in this publication at least, comes from a sample of a sample. It makes sense to highlight the experts, but the claims goes from “97% of climate scientists agree” to “97% of top-cited and published scientists believe” and it’s a diffeent claim and also similar to the study I cited.

[GIGObuster]

Of course if one would check better sources it would had been clear were that super majority of experts are coming from.

The 97% consensus on global warming

That humans are causing global warming is the position of the Academies of Science from 19 countries plus many scientific organizations that study climate science. More specifically, around 95% of active climate researchers actively publishing climate papers endorse the consensus position.

Scientists need to back up their opinions with research and data that survive the peer-review process. A survey of all peer-reviewed abstracts on the subject ‘global climate change’ published between 1993 and 2003 shows that not a single paper rejected the consensus position that global warming is man caused (Oreskes 2004). 75% of the papers agreed with the consensus position while 25% made no comment either way (focused on methods or paleoclimate analysis).

Subsequent research has confirmed this result. A survey of 3146 earth scientists asked the question “Do you think human activity is a significant contributing factor in changing mean global temperatures?” (Doran 2009). More than 90% of participants had Ph.D.s, and 7% had master’s degrees. Overall, 82% of the scientists answered yes. However, what are most interesting are responses compared to the level of expertise in climate science. Of scientists who were non-climatologists and didn’t publish research, 77% answered yes. In contrast, 97.5% of climatologists who actively publish research on climate change responded yes. As the level of active research and specialization in climate science increases, so does agreement that humans are significantly changing global temperatures.

[GIGObuster]

@Aji_de_Gallina

Thanks for the link and a fantastic :smack::smack::smack::smack::smack: for me.

So, the 97%, in this publication at least, comes from a sample of a sample. It makes sense to highlight the experts, but the claims goes from “97% of climate scientists agree” to “97% of top-cited and published scientists believe” and it’s a diffeent claim and also similar to the study I cited.

Remember, it is “Publish or die” for researchers, for blogessors it is “Blog and skip the journals”

[Aji_de_Gallina]

@GIGObuster

Of course if one would check better sources it would had been clear were that super majority of experts are coming from.

The 97% consensus on global warming

@GIGObuster

Remember, it is “Publish or die” for researchers, for blogessors it is “Blog and skip the journals”

Since I quoted Doran yesterday, it comes as no surprise
It usually helps to actually read the study and not the abstract by a biased part.

The real total is 90% to the very simple question "When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?", which also stacks the deck because pre-1800 is the end of LIA (and not the most common 1850 date); and 82% for “*Do you think human activity is a significant contributing factor in changing mean global temperatures?”, *without a clear, technical definition for *significant *(10%, 25%, 35%, 50%, 70%)

The 97% is from less than 80 people in both questions. There’s no doubt that those experts are real experts and top-level at that, however saying 97% of all climate scientists agree is wrong or at least needs to be qualified to death to accept a value of “all” for 80 out of 3000 (or 1300).

[foolsguinea]

Zagzigger, you get pitted here: All you have is the hope that maybe you're not causing the end of the world. - The BBQ Pit - Straight Dope Message Board

[GIGObuster]

@Aji_de_Gallina

Since I quoted Doran yesterday, it comes as no surprise
It usually helps to actually read the study and not the abstract by a biased part.

The real total is 90% to the very simple question "When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?", which also stacks the deck because pre-1800 is the end of LIA (and not the most common 1850 date); and 82% for “*Do you think human activity is a significant contributing factor in changing mean global temperatures?”, *without a clear, technical definition for *significant *(10%, 25%, 35%, 50%, 70%)

The 97% is from less than 80 people in both questions. There’s no doubt that those experts are real experts and top-level at that, however saying 97% of all climate scientists agree is wrong or at least needs to be qualified to death to accept a value of “all” for 80 out of 3000 (or 1300).

It is still a super majority among the experts. And that was the point, the 90% is still a powerful point, but it is even better when the researchers also point at what is what the experts on the matter are telling us.

The attempts to minimize what the experts in the field also report is silly as there is also a consensus on the evidence.

Efforts to minimize what most of the experts are saying are really not being taken seriously.

The 97% consensus on global warming

Science achieves a consensus when scientists stop arguing. When a question is first asked – like ‘what would happen if we put a load more CO2 in the atmosphere?’ – there may be many hypotheses about cause and effect. Over a period of time, each idea is tested and retested – the processes of the scientific method – because all scientists know that reputation and kudos go to those who find the right answer (and everyone else becomes an irrelevant footnote in the history of science). Nearly all hypotheses will fall by the wayside during this testing period, because only one is going to answer the question properly, without leaving all kinds of odd dangling bits that don’t quite add up. Bad theories are usually rather untidy.

…

So a consensus in science is different from a political one. There is no vote. Scientists just give up arguing because the sheer weight of consistent evidence is too compelling, the tide too strong to swim against any longer. Scientists change their minds on the basis of the evidence, and a consensus emerges over time. Not only do scientists stop arguing, they also start relying on each other’s work. All science depends on that which precedes it, and when one scientist builds on the work of another, he acknowledges the work of others through citations. The work that forms the foundation of climate change science is cited with great frequency by many other scientists, demonstrating that the theory is widely accepted - and relied upon.

In the scientific field of climate studies – which is informed by many different disciplines – the consensus is demonstrated by the number of scientists who have stopped arguing about what is causing climate change – and that’s nearly all of them. A survey of all peer-reviewed abstracts on the subject ‘global climate change’ published between 1993 and 2003 shows thatnot a single paper rejected the consensus position that global warming is man caused. 75% of the papers agreed with the consensus position while 25% made no comment either way, focusing on methods or paleoclimate analysis (Oreskes 2004).

[Aji_de_Gallina]

@GIGObuster

It is still a super majority among the experts. And that was the point, the 90% is still a powerful point, but it is even better when the researchers also point at what is what the experts on the matter are telling us.

The attempts to minimize what the experts in the field also report is silly as there is also a consensus on the evidence.

Efforts to minimize what most of the experts are saying are really not being taken seriously.

The 97% consensus on global warming

So, it isn’t 97% but 90%, and that 90% isn’t about whether IPCC4 is correct, it is if temperatures are higher now than at the end of LIA. It’s an incredibly safe bet that 90% of science-based skeptics would also say yes to such a stacked question. 97% is only of 79 people.

“Effort to minimize” are only in your head if one publishes the results of Dorian2009. “Accuracy in telling a story” is the phrase you’re looking for.

[GIGObuster]

@Aji_de_Gallina

So, it isn’t 97% but 90%, and that 90% isn’t about whether IPCC4 is correct, it is if temperatures are higher now than at the end of LIA. It’s an incredibly safe bet that 90% of science-based skeptics would also say yes to such a stacked question. 97% is only of 79 people.

“Effort to minimize” are only in your head if one publishes the results of Dorian2009. “Accuracy in telling a story” is the phrase you’re looking for.

And that shows that there is ignorance on what a survey does, unless there is a very good reason to doubt on the results, saying otherwise it is really reaching for an uncertainty that is not there, particularly when others also checked that a consensus was there.

The 97% consensus on global warming

This overwhelming consensus among climate experts is confirmed by an independent study that surveys all climate scientists who have publicly signed declarations supporting or rejecting the consensus. They find between 97% to 98% of climate experts support the consensus (Anderegg 2010). Moreover, they examine the number of publications by each scientist as a measure of expertise in climate science. They find the average number of publications by unconvinced scientists (eg - skeptics) is around half the number by scientists convinced by the evidence. Not only is there a vast difference in the number of convinced versus unconvinced scientists, there is also a considerable gap in expertise between the two groups.

And one should notice that you lost the bet, science based skeptics are not so inclined to go for the consensus, they remain a shrinking minority.

[Sailboat]

While the entire post this came from is just regurgitated talking points from the moneyed interests, I’ve decided to highlight this little beauty in particular:

@Zagzigger

These guys are paid to believe - if they show any dissent, they are thrown out - lose their grants, denied publication and so on.
They are what’s known as a “Community of Interest” - like Turkeys at Christmas time.

If there’s anyone who believes that academics and scientists are paid (by some interest group) to believe in something at a rate higher than the oil companies could pay them, please buy this here bridge from me. Making one’s reputation, and whatever money there might be, in science does not come from nodding in unison with everybody else. Scientists are always looking for something different to say, because saying something different is what makes their careers.

[Aji_de_Gallina]

@GIGObuster

And that shows that there is ignorance on what a survey does, unless there is a very good reason to doubt on the results, saying otherwise it is really reaching for an uncertainty that is not there, particularly when others also checked that a consensus was there.

The 97% consensus on global warming

And one should notice that you lost the bet, science based skeptics are not so inclined to go for the consensus, they remain a shrinking minority.

What ignorance? It is you denying the data.
Is there a very strong consensus among climate scietists? Yes, from 90 to 97%.
What is what they agree? Temperatures have risen from 1800 and humans play a significant role.

No mentioned in the consensus:
a) ammount of temperature rise past, present, and future
b) possible damages/benefits for temperature increase
c) accepting the levels of forcings
d) how to prevent damage/ increase benefit
e) cost-benefit analyses of what, if any, to do.

So, again, the consensus is about the bare-bones basic theory, not IPCC4.

Where in your link did I lose the bet?

[GIGObuster]

As pointed out, we know were that “97% of (climate) scientists agree with GW” that is indeed the bare bones of it, but the 97% also includes the A part, that is the human element.

That you do not like that there is plenty of support and other studies pointing at those levels of agreement is a different history.

[jovan]

@Aji_de_Gallina

So, again, the consensus is about the bare-bones basic theory, not IPCC4.

From the Anderegg study:

We compiled a database of 1,372 climate researchers and classified each researcher into two categories: convinced by the evidence (CE) for anthro- pogenic climate change (ACC) or unconvinced by the evidence (UE) for ACC. We defined CE researchers as those who signed statements broadly agreeing with or directly endorsing the primary tenets of the IPCC Fourth Assessment Report that it is “very likely” that anthropogenic greenhouse gases have been responsible for “most” of the “unequivocal” warming of the Earth’s average global temperature in the second half of the 20th century.

Again, going to primary sources, we have the brief paper by Doran and Zimmerman:

Results show that overall, 90% of par- ticipants answered “risen” to question 1 and 82% answered yes to question 2. In general, as the level of active research and specialization in climate science increases, so does agreement with the two primary questions (Figure 1). In our sur- vey, the most specialized and knowledge- able respondents (with regard to climate change) are those who listed climate sci- ence as their area of expertise and who also have published more than 50% of their recent peer-reviewed papers on the subject of climate change (79 individu-
als in total). Of these specialists, 96.2%
(76 of 79) answered “risen” to question 1 and 97.4% (75 of 77) answered yes to ques- tion 2.

“Question 1” vs. “question 2”:

1. When compared with pre-1800s lev- els, do you think that mean global tem- peratures have generally risen, fallen, or remained relatively constant?
2. Do you think human activity is a sig- nificant contributing factor in changing mean global temperatures?

These are the two main primary sources, and they both agree that ~97% of climate experts support the idea of AGW.

[Aji_de_Gallina]

@GIGObuster

As pointed out, we know were that “97% of (climate) scientists agree with GW” that is indeed the bare bones of it, but the 97% also includes the A part, that is the human element.

That you do not like that there is plenty of support and other studies pointing at those levels of agreement is a different history.

So 97% comprises 5% of the sample
90% includes all
I’ll tell you something, I’ll accept 100% agreeing if you accept that the agreement is ONLY about (as the paper your linked to says)

a) Temperatures have increased from 1800
b) Humans have played a significant role
(I wholeheartedly agree with both)

you also have to agree that the paper you quoted doesn’t mention:
a) ammount of temperature rise past, present, and future
b) possible damages/benefits for temperature increase
c) accepting the levels of forcings or its sign
d) how to prevent damage/ increase benefit
e) cost-benefit analyses of what, if any, to do.

[GIGObuster]

Meh, that is another history as mentioned, suffice to say the researchers have a reason to report on the 97% agreement level as it is supported by others.

And your bet referred to scientists that were skeptics, once again, the last cite showed that there is research from them that does not agree with the overwhelming consensus.

[Aji_de_Gallina]

@jovan

These are the two main primary sources, and they both agree that ~97% of climate experts support the idea of AGW.

Dorians says 97% comes from 80 guys, not the whole climate science community.

@GIGObuster

Meh, that is another history as mentioned, suffice to say the researchers have a reason to report on the 97% agreement level as it is supported by others.

And your bet referred to scientists that were skeptics, once again, the last cite showed that there is research from them that does not agree with the overwhelming consensus.

Nope, it doesn’t suffice, because it’s misleading to say “97% of climate scientists agree with GW/AGW/CGW/CAGW” when it’s actually “More than 90% of climate scientist agree with: Temperatures rose in the last 200 years, and humans are a significant part”.

I know the second one isn’t much of a slogan, but it’s the truth. And science is about the truth.

I’ll repeat that the consensus is **not **about:
a) ammount of temperature rise past, present, and future
b) possible damages/benefits for temperature increase
c) accepting the levels of forcings or its sign
d) how to prevent damage/ increase benefit
e) cost-benefit analyses of what, if any, to do.

Still nuthin’ on the bet, unless you expect me to watch GREENMAN6810 10 minute video or a 1-hour video. Can you get me, let’s say, 10 science-based skepics that deny that temepratures rose from 1800?

[space_loner]

@Exapno_Mapcase

I need to introduce you to tomh4040 in this thread. He starts by reviving the thread with post #53 in October and has kept it going ever since. He is a former believer in relativity who received enlightenment and now believes in aether theory. He can argue it freely and at length because he knows absolutely nothing about either relativity or aether theory.

The parallels are clear because of the remarks you’ve made in this thread. That the earth has been cooling since 1998 (1998 was an unusually high blip in an upward sawtooth graph that has since been exceeded anyway); that by using graphs with arbitrary start dates the warming effect vanishes (see the same graph using 1930 as a start date); that a letter to the editor trumps a peer-reviewed paper (as far as I can tell nobody has even bothered to respond to Bodenstein, possibly because as a pediatrician who backs up none of his claims he is not a credible information source); that “Climategate” proved … well anything at all (multiple independent investigations have vindicated the scientists involved).

As with tomh4040 it’s clear that you’ve merely switched from adhering to one side of an argument that you don’t understand to another side of the argument that you don’t understand. That’s clear because facts have meaning only in context. It is a fact that a letter to the editor was written and that a cut-off graph gives certain data. They are at best half-truths, and half-truths are deprecated because they serve no purpose except to further a cause by deliberately ripping a fact out of its context and presenting it as the full answer.

What neither of you seem to understand is that there may be a proper argument for aether theory or climate denial that you aren’t even approaching because neither of you knows enough about either science or these particular subjects to form a credible case. Individual facts are sufficient to refute theories, true, but only in a full context. Take the recent kerfluffle about faster-than-light neutrinos. That claim - properly presented as a possible if fascinating finding that needed more investigation - received the investigation. Scientists from all over the world tore into it trying to determine both whether the experiment had been run correctly and whether these results could fit into the large and deep body of previous findings. As it stands there is just enough evidence that tiny flaws in the apparatus that no outsider could possibly have known about were the cause of this anomaly that no scientist in the field will use them in the future. I’ll bet large sums of money that people who want relativity to be wrong will quote them forever, though.

If you don’t know when not to use a fact, then you don’t know enough about the argument to convince anyone. And that’s why science will survive your assault with its authority intact.

Slow clap

[GIGObuster]

@Aji_de_Gallina

Dorians says 97% comes from 80 guys, not the whole climate science community.

Keep showing all how an ignorant you are of how surveys work, there is no reason to assume that those levels of consensus are not there, specially when others did check too.