Environment & Energy

OKIsItJustMe

(19,938 posts) Thu May 16, 2013, 10:15 AM May 2013

Study reveals scientific consensus on anthropogenic climate change

http://www.iop.org/news/13/may/page_60200.html

[font face=Serif][font size=5]Study reveals scientific consensus on anthropogenic climate change[/font]

16 May 2013 | Source: Environmental Research Letters

[font size=4]A comprehensive analysis of peer-reviewed articles on the topic of global warming and climate change has revealed an overwhelming consensus among scientists that recent warming is human-caused.[/font]

[font size=3]The study is the most comprehensive yet and identified 4000 summaries, otherwise known as abstracts, from papers published in the past 21 years that stated a position on the cause of recent global warming – 97 per cent of these endorsed the consensus that we are seeing man-made, or anthropogenic, global warming (AGW)

Led by John Cook at the University of Queensland, the study has been published today, Thursday 16 May, in IOP Publishing’s journal Environmental Research Letters.

The study went one step further, asking the authors of these papers to rate their entire paper using the same criteria. Over 2000 papers were rated and among those that discussed the cause of recent global warming, 97 per cent endorsed the consensus that it is caused by humans.

…[/font][/font]

http://dx.doi.org/10.1088/1748-9326/8/2/024024

8 replies

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Study reveals scientific consensus on anthropogenic climate change (Original Post) OKIsItJustMe May 2013 OP

K&R kristopher May 2013 #1

K&R - and bookmarked jpak May 2013 #2

The 3% DreamGypsy May 2013 #3

Perhaps I’m too cynical, but I question how many of the 3% are sincere OKIsItJustMe May 2013 #4

I have same question about sincerity. dixiegrrrrl May 2013 #5

Have you looked at the methodology and data in the paper? DreamGypsy May 2013 #6

Reading the paper, I feel the 97% needs a bit of a caveat lector OKIsItJustMe May 2013 #7

It could just be standard deviation. Jim Lane May 2013 #8

kristopher

(29,798 posts)

1. K&R

Reply to OKIsItJustMe (Original post)

Thu May 16, 2013, 10:24 AM

May 2013

jpak

(41,758 posts)

2. K&R - and bookmarked

Reply to OKIsItJustMe (Original post)

Thu May 16, 2013, 10:28 AM

May 2013

DreamGypsy

(2,252 posts)

3. The 3%

Reply to OKIsItJustMe (Original post)

Thu May 16, 2013, 10:46 AM

May 2013

More info and a video summarizing the findings of the study here: http://skepticalscience.com/

I like the pacman resemblance in this graphic -

Thanks for the post, OIIJM.

OKIsItJustMe

(19,938 posts)

4. Perhaps I’m too cynical, but I question how many of the 3% are sincere

Reply to DreamGypsy (Reply #3)

Thu May 16, 2013, 11:04 AM

May 2013

Additionally, I have this question: Since the 3% is a measure of papers published in the past 2 decades, and not the authors’ current opinions, how many of them have changed their minds since their papers were published.

dixiegrrrrl

(60,010 posts)

5. I have same question about sincerity.

Reply to OKIsItJustMe (Reply #4)

Thu May 16, 2013, 11:42 AM

May 2013

But also have some first hand experience.
There are a large number of Fox viewers in this state, esp. in the non-cities.
They tend to believe what Fox, and their ultra conservative ministers, and their pasty white demagogue Republican
Gov't people tell them.
Fox and the Bible....main sources of info.

DreamGypsy

(2,252 posts)

6. Have you looked at the methodology and data in the paper?

Reply to OKIsItJustMe (Reply #4)

Thu May 16, 2013, 12:46 PM

May 2013

The data is presented historically for the papers from 1991 to 2011, with graphs showing the percentages of No Position on AGW, Endorse AGW, and Reject AGW. The data is for two phases of the study: 1) a review of article abstracts by a group of independent raters of 11 944 papers written by 29 083 authors and published in 1980 journals, and 2) a self-review (by actual authors of the papers) where 2142 papers received self-ratings from 1189 authors (this serves an accuracy test for the independent review group).

The independent review and self-review findings show some significant differences in the early years, but converge with small margin of error to 97% for 2011.

So, the 97% number reflects data from 2 years ago and there is confirming evidence that the number reflects the authors' self assessments at the time (which albeit could have possibly changed in the intervening 2 years) with a clear trend of increasing endorsement of AGW over the period of the study.

The paper elucidates some sources of uncertainty in the study.

OKIsItJustMe

(19,938 posts)

7. Reading the paper, I feel the 97% needs a bit of a caveat lector

Reply to DreamGypsy (Reply #6)

Thu May 16, 2013, 03:37 PM

May 2013

http://iopscience.iop.org/1748-9326/8/2/024024/article

[font face=Serif][font size=5]Quantifying the consensus on anthropogenic global warming in the scientific literature[/font]

…

…

[font size=4]3.2. Endorsement percentages from self-ratings[/font]
[font size=3]We emailed 8547 authors an invitation to rate their own papers and received 1200 responses (a 14% response rate). After excluding papers that were not peer-reviewed, not climate-related or had no abstract, 2142 papers received self-ratings from 1189 authors. The self-rated levels of endorsement are shown in table 4. Among self-rated papers that stated a position on AGW, 97.2% endorsed the consensus. Among self-rated papers not expressing a position on AGW in the abstract, 53.8% were self-rated as endorsing the consensus. Among respondents who authored a paper expressing a view on AGW, 96.4% endorsed the consensus.

… The number of papers rejecting AGW is a miniscule proportion of the published research, with the percentage slightly decreasing over time. Among papers expressing a position on AGW, an overwhelming percentage (97.2% based on self-ratings, 97.1% based on abstract ratings) endorses the scientific consensus on AGW.

…[/font][/font]

66.4% of the papers (let’s call that 2/3’s) did not express a position on AGW (based on reading the abstract) of those, 53.8% were rated by their authors as supporting the consensus.

So, let’s say that accounts for 1/3 of the papers. (i.e. half of 2/3's)

The authors note this:

[font face=Serif][font size=3]Of note is the large proportion of abstracts that state no position on AGW. This result is expected in consensus situations where scientists '...generally focus their discussions on questions that are still disputed or unanswered rather than on matters about which everyone agrees' (Oreskes 2007, p 72). This explanation is also consistent with a description of consensus as a 'spiral trajectory' in which 'initially intense contestation generates rapid settlement and induces a spiral of new questions' (Shwed and Bearman 2010); the fundamental science of AGW is no longer controversial among the publishing science community and the remaining debate in the field has moved to other topics. This is supported by the fact that more than half of the self-rated endorsement papers did not express a position on AGW in their abstracts.[/font][/font]

Roughly 1/3 of the papers clearly expressed a position. Of those, 97%+ of them endorsed the scientific consensus (but the majority expressed no position on AGW.)

So, that leaves me with (about) 2/3’s of the papers being rated by their authors as endorsing the scientific consensus, a very few opposing the consensus, and (about) 1/3 neutral.

Jim Lane

(11,175 posts)

8. It could just be standard deviation.

Reply to OKIsItJustMe (Reply #4)

Fri May 17, 2013, 03:29 AM

May 2013

In some years, in some places (even in the Northern Hemisphere), April 15 is warmer than July 15. If sincere scientists take careful measurements of the temperature at multiple spots around City Hall at multiple times during the day, and compare them for the two days, a certain number of reports will conclude that from April to July there's a cooling trend.

Obviously, the studies included in this meta-analysis were much more complex. Nevertheless, they'd still be subject to the randomness of nature.

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