Doran and Zimmerman, 2009
A paper written by Maggie Kendall Zimmerman, a University of Illinois student, and her master’s thesis advisor, Peter Doran, was published in EOS.
They claimed “97% of climate scientists agree” that mean global temperatures have risen since before the 1800s, which is true, and that humans are a significant contributing factor, which is a guess, even if "significant" is better defined.
The researchers sent a two-minute online survey to 10,257 Earth scientists working for universities and government research agencies, generating 3,146 responses.
The two researchers started out by excluding thousands of scientists most likely to think that the Sun, or planetary movements, might have something to do with the climate on Earth.
They deliberately excluded:
-- solar scientists,
-- space scientists,
-- cosmologists,
-- physicists,
-- meteorologists, and
-- astronomers.
That left the 10,257 scientists in disciplines
such as geology, oceanography, paleontology, and geochemistry.
Note that only 5% of the respondents self-identified as climate scientists.
The survey asked two questions:
“Q1.
When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?
-- I would answer "risen", but caution the global average includes a high percentage of wild guesses, not just 100% actual measurements, and those actual measurements are so rough, and so often "adjusted", it's possible there was no warming in the 20th century before 1975.
(90% answered “risen” to question 1)
"Q2.
Do you think human activity is a significant contributing factor in changing mean global temperatures?”
-- I don't know what "significant" means, but I would answer "yes", because I believe it's possible humans have caused "warming", at least from faulty measurements and economic growth near land weather station thermometers (the urban heat island effect).
- Faulty measurements:
--- "Adjustments" to raw data,
---- Wild guesses of temperatures made for a large portion of the Earth's surface, where there are no weather stations, or there is missing temperature data from weather stations.
- Economic growth over time:
Building roads, parking lots, buildings, airport runways, etc. in the vicinity of land-based thermometers.
The authors get their fraudulent “97% of climate scientists believe” sound bite by focusing on only 79 scientists out of 3,146 responses!
They kept editing the responses until they got the "answer" they wanted.
The 79 scientists were those who listed climate science as their area of expertise, and who had published more than 50% of their recent peer-reviewed papers on the subject of climate change.
Most skeptics of man-made global warming, including me, would answer those two questions the same way as alarmists did.
Only 79 climate scientists is hardly a representative sample of scientific opinion.