Wednesday, July 12, 2017

The 97% consensus myth, back again

I have a news feed on Google that will flag articles for me.  This morning, it forwarded this article from the Weather Channel: "87 Percent of Americans Unaware There's Scientific Consensus on Climate Change."
Nearly 90 percent of Americans are unaware that there is a consensus within the scientific community that human-caused climate change is real and threatens the planet, a new report says.
Here we go again: you just can't teach these rubes and climate deniers anything.  The Weather Channel article directs you to this IOPScience page and a technical article titled: "Quantifying the consensus on anthropogenic global warming in the scientific literature."  Here's the first part of the abstract (summary) for this paper:
We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11 944 climate abstracts from 1991–2011 matching the topics 'global climate change' or 'global warming'. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming.
So right from the get-go, we find that of all these papers reviewed, two-thirds do not take a position on AGW.  The report focuses on the one-third that do and, among them, we get our magic number of 97% consensus that mankind is warming the Earth.  You'd think a more honest assessment would say that 31.6% (32.6% * 97.1%) of the papers reviewed endorsed AGW, but that's not quite so dramatic as 97%.

Diving deeper into the paper, we further discover that the authors separated the AGW papers into a classification they called "level of endorsement."  These were "explicit endorsement with quantification," "explicit endorsement without quantification" and "implicit endorsement."  "Great!" I thought, since most of the dispute with those on the other side of the debate is that the quantification of mankind's effect on the environment is both difficult to estimate and critical to any kind of discussion regarding mitigation of AGW inputs.  In other words, if anthropogenic effects account for all of the warming, we have to consider the significant trade-offs of minimizing fossil fuels.  But if it only accounts for, say, 10% of observed warming, then we may want to consider whether adaptation to natural climate change is a better course of action.

So then "level of endorsement" is an important metric.  One, apparently, we're not allowed to see:
To simplify the analysis, ratings were consolidated into three groups: endorsements (including implicit and explicit; categories 1–3 in table 2), no position (category 4) and rejections (including implicit and explicit; categories 5–7).
Oh.  So the authors dumped everything into the same bin labeled "endorsements" whether they said "We're all gonna burn!" or "Maybe, I think possibly, man has some minor impact on warming."  One of the "endorsers" in this study was Dr. Roy Spencer, former senior scientist for climate studies at NASA.  In this Senate hearing, he expressed his surprise to be included in the group:



I think most people see through the hysteria of the 97% myth which purposely conflates some minor anthropomorphic contribution and global catastrophe.  Maybe they'd believe the hype when everybody in Washington decides to turn off the air conditioning.  You know, for Mother Earth.

14 comments:

Anonymous said...

From the technical article's opening paragraph:
"Our analysis indicates that the number of papers rejecting the consensus on AGW [anthropogenic global warming] is a vanishingly small proportion of the published research."

From the concluding paragraph:
"The narrative presented by some dissenters is that the scientific consensus is '...on the point of collapse' (Oddie 2012) while '...the number of scientific "heretics" is growing with each passing year' (Allègre et al 2012). A systematic, comprehensive review of the literature provides quantitative evidence countering this assertion. The number of papers rejecting AGW is a miniscule proportion of the published research, with the percentage slightly decreasing over time."

And from the article's middle:
"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."

This attempt at debunking is like insisting there's no true consensus that "Star Wars" is a financially successful movie series, because most articles about "Star Wars" don't discuss its financial success.

Eric said...

Nope. It's like saying: "rate the Star Wars movies on a scale from 1-10" and then reporting "97% of respondents reported a positive number."

As non-alarmist Roy Spencer noted, even he was in the "endorsement" bin because he believes there's a minor contribution from mankind. Duh: there's 7 billion mouth-breathers on the Earth.

Don't worry: the scientists checked their biases at the door. /sarc "Two sources of rating bias can be cited: first, given that the raters themselves endorsed the scientific consensus on AGW, they may have been more likely to classify papers as sharing that endorsement. Second, scientific reticence (Hansen 2007) or 'erring on the side of least drama' (ESLD; Brysse et al 2012) may have exerted an opposite effect by biasing raters towards a 'no position' classification."

Anonymous said...

For at least 1500 years, scientist's and those who selfishly decided to determine what was best for civilization knew for a fact that the Earth was the center of the universe. People who dared to disagree with the collective wisdom of those who "knew better" were ruined/killed/forced to recant.

Any argument based on "everybody knows/thinks this" is not worth a damn. 97 out of 100 people screaming 1+1=3 does not make it true.

Could it be true? Yes, but not because a shitload of people say so. But because facts, born out by dozens (and always continuing) of independent tests via the scientific method show it to be true.


Meltin' John said...

Hundreds, not dozens, of independent tests via the scientific method already exist.

But since this shitload of tests were done by a shitload of people and not celestial test fairies, it must be an argument not worth a damn. Especially since there's no difference between daring to disagree with global science in the year 2017 and daring to disagree with global science in the year 1017.

Anonymous said...

Hundreds, not dozens, of independent tests via the scientific method already exist.


Hundreds? Try thousands.

Eric said...

Thousands, eh? So the science must be SUPER settled by now, and you'll be able to tell me to the hundredth-percentile what portion of global warming is caused by fossil fuels.
Right? Right? Wrong.

Anonymous said...

Climate change is now and forever a matter of personal opinion, but the Social Security trust fund represents immovable and unyielding end times.

Eric said...

Predictions about climate change, despite the "settled science", have been wildly off-base. Predictions on the Social Security Trust Fund are a mathematical certainty.

Anonymous said...

Math that reflects policy can be adjusted. Tweaking the ozone layer is a little trickier.

Saying "settled science" in a sarcastic voice doesn't unsettle the science.

Eric said...

Well I'm always impressed by the Bill Nye brand of science which is "why do you want everybody to die?"

Anonymous said...

But not as impressed as you are with the college dropout/radio weatherman blogger.

Eric said...

He, at least, presents graphs and data to support his side of the argument.

Nye's bag of logical fallacies are "appeal to authority" and reductio ad absurdum.

Anonymous said...

Don't stop now! Keep your eye on what's important. If you can take down Bill Nye, you take down all of climate science.

And if that impossibly doesn't do the job, Al Gore rides planes and is boring and fat.

Eric said...

Al Gore who said there was a 75% chance of the polar ice caps melting by now?

(Checks polar ice caps). Still there.

Climate alarmists are never "wrong" though - they just miscalculated their timelines.