Guest Post by Willis Eschenbach
There’s a new survey out by the Pew Research Center folks that’s getting lots of press. Much of the coverage mentions the following claim that the claimed 97% consensus is real but it’s only 87%. The survey reports a:
• 37-percentage point gap over whether climate change is mostly caused by human activity – 87% of AAAS scientists say it is, while 50% of the public does.
So what’s not to like? Well, the first oddity of the study is that we have absolutely no guarantee that the scientists are … well … scientists.
The study was done “in collaboration with the American Association for the Advancement of Science (AAAS)”. Here’s the description from the Pew Center of the method used:
The survey of scientists was conducted online with a random sample of 3,748 U.S.-based members of the American Association for the Advancement of Science (AAAS) from September 11 to October 13, 2014. AAAS is the world’s largest general scientific society, and includes members from all scientific fields. Founded in 1848, AAAS publishes Science, one of the most widely circulated peer-reviewed scientific journals in the world. Membership in AAAS is open to all.
Sounds good … until you realize that not only is membership in AAAS “open to all”, but in addition anyone who subscribes to Science magazine is a member of AAAS … and for years Science magazine has been a strong supporter of the hypothesis that “climate change is mostly caused by human activity”, whatever that might mean.
So we are already dealing with a self-selected group of people, many of them not scientists, who read a magazine that for years has strongly supported the “anthropogenic global warming” (AGW) hypothesis.
But wait … it gets worse. For starters, you’d think that the Pew Research folks would have made a selection of scientists that weren’t subscribers to a magazine that has an axe to grind. And you’d also think that they would have picked … well … scientists.
But failing both of those, once the Pew Center folks had foolishly chosen to sample from AAAS members, surely they would make their own random selection of the AAAS membership? … well, think again. Their methods section cited above goes on to say:
A simple random sample of AAAS members was selected for participation by the staff of AAAS.
At this point, I’ve got to assume that the good folks at Pew have lost the plot entirely. They let the staff of the AAAS, a group which by and large seems to have swallowed the climate koolaid without demur, choose a “random sample” of which “scientists” the Pew folks would interview. Yeah, that’s the ticket, that inspires confidence …
And it gets worse yet, because the self-selection increases:
A total of 19,984 members were mailed a letter requesting participation in the survey.
And out of those, how many were actually sampled?
A total of 3,748 members completed the survey for an overall response rate of 18.8%.
Then there’s the matter of the poorly worded question. They asked if “climate change is mostly due to human activity”, with 87% of “scientists” saying yes versus 50% of citizens. I hate this kind of vague question, with no time frame on it, no definition of “climate change”, and no definition of “mostly”. For example, the IPCC defines “climate change” as being human caused … but under the general definition, the climate has been changing forever. This means that the well is poisoned before we even start. And what period of time are they talking about? The last ten years, during which there has been no statistically significant warming? The last century? The period since industrialization? And is 51% “mostly” or not? A vague question like that means nothing even if the rest of the survey had been handled perfectly.
I gotta say … I used to respect the Pew Research folks, and I’ve looked at their methods in other studies without finding much that seemed odd.
But this survey? On my planet, this one goes directly into the circular file … at the end of all of that, I gotta figure that their study is 87% horse feathers, and 13% unicorn-generated methane …
Best to all, and don’t believe everything you read.
AS ALWAYS: If you disagree with someone, please have the courtesy to QUOTE THE EXACT WORDS YOU DISAGREE WITH so that all of us can understand the exact nature of what you object to.
And in the interests of full disclosure, I am a member of AAAS … but somehow they didn’t ask my opinion. I figure my invitation got lost in the mail …