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.