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Politics : Formerly About Advanced Micro Devices -- Ignore unavailable to you. Want to Upgrade?

To: James Seagrove who wrote (1042628)	12/12/2017 6:39:21 AM
From: Mongo2116	Read Replies (3) \| Respond to of 1573924

an empty post from an empty HEAD

To: James Seagrove who wrote (1042628)

12/12/2017 11:17:48 AM

From: TideGlider

8 Recommendations

Recommended By
Bill
dave rose
James Seagrove
locogringo
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and 3 more members

Read Replies (3) | Respond to of 1573924

Climate Change Debate – Politics, False Consensus, Questionable Science & Some Questions

HT:DinoNavarre

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“Consensus is the business of politics. In science consensus is irrelevant. What is relevant is reproducible results.” – Michael Crichton

“97% of Scientists agree: #climate change is real, man-made and dangerous” – Barack Obama

The 97% Consensus figure came from a study of peer-reviewed papers by John Cook titled Quantifying the Consensus on Anthropogenic Global Warming in the Scientific Literature. While the 97% figure is widely quoted, the underlying methodology is less well known. Here is a quote from Mr. Cook himself:

“66.4% of abstracts expressed no position on AGW [Anthropogenic (man-made) Global Warming], 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.”

Give that quote a quick re-reading. Two-thirds of scientists expressed no opinion on human contribution to global warming. They were then excluded from the results. The remaining one-third was then taken to arrive at the 97% figure. This is how the first 97% rate of scientific agreement was arrived at. Cook then asked those scientists who had expressed no opinion or position to do so. About 15% of these scientists responded to Cook’s invitation (1,189 authors self-rated 2,142 papers) with the net result that 62.7% (1,342) of these second-round responders affirmed the global warming consensus question. 35.5% (761) of responders again stated they had no opinion. 1.8% (39) rejected the hypothesis. The responders who stated they held no opinion were once again excluded. So Cook took only those respondents who had answered in the affirmative (1,342) and the negative (39) and therefore again came up with 97.2%. Cooke started with 12,000 papers, excluded the vast majority of them as the authors refused to take a position, and ended up with 1,381 papers which he used to reach his 97% Consensus Figure. That equates to 11.5% of papers from the original starting number.

It gets worse. Note that there were 1,189 authors but 2,142 papers. Given that Cook excluded “no opinion” statements – from the 15% subset who actually responded – he was by definition double-counting authors who had generated multiple papers. Finally, the criteria by which Cook achieved his classifications was lacking in scientific clarity – or honesty. To be counted as affirming the global warming consensus question, scientists only needed to agree that “carbon dioxide is a greenhouse gas and that human activities have warmed the planet to some unspecified extent”. That’s it. If, as a scientist, you agreed that human activity had some portion – any portion – of responsibility for global warming you were included in the 97% consensus. I’m shocked the figure wasn’t 100%.

Needless to say, the much-touted figure of 97% is not only wildly over-stated – it is meaningless.

“There are three kinds of lies: lies, damned lies and statistics.” – Mark Twain