David Legates is a Professor at the University of Delaware who somewhere along the way managed to get a tenured position. I don't know what he teaches or if he's allowed to get anywhere near students - his profile gives not a clue. However he spends some of his time writing articles for climate conspiracy blogs. Today he's written an article for WUWT (archived here) where he's making wild and wrong claims about consensus studies. That is, about studies that show that almost all scientific papers that attribute a cause to global warming attribute it to human activity. David tells outright lies and also builds a few men of straw along the way.
971 in a thousand vs 20 in a thousand
Let's get the numbers from the Cook13 study. Did you know that Cook13 found that since 1991, there were less than 7 abstracts out of every thousand, that disputed humans are the main cause of global warming? That's not how it's presented in Cook13 though. In that paper they properly looked at the numbers only in the context of abstracts in which a position was expressed. In Cook13 the researchers categorised 4,014 papers that expressed a position on the cause of the current global warming.
Here are the results - if you're a gambler you might be interested:
- Human cause - 971 out of every thousand: the vast majority, 3896 of the 4014 abstracts or 97.1% attributed at least 50% of the warming to human activity
- Disputing human cause - less than 20 out of every thousand: only 78 of the 4014 abstracts or less than 2 out of every 100 disputed human activity as the predominant cause
- Uncertain cause - 10 out of every thousand: only 40 of the 4014 abstracts or only 1 out of every 100 showed that the authors were uncertain as to the predominant cause.
David Legates makes much of the fact that of the 11,944 abstracts categorised, 2/3 did not express a position on the predominant cause of global warming. That's like claiming that we aren't sure if germs can cause disease because not every paper on disease expresses a position on germ theory. If David wants to go there, then let's see how many out of the 11,944 abstracts disputed human activity. Out of all 11,944 abstract it's less than one in a hundred, only 0.65 out of every 100 papers (0.65%) that disputed human activity causes global warming.
David Legates has no excuse for lying
David also tells a lot of lies. For example he wrote: "...Cook and colleagues asserted that 97.1% endorsed their hypothesis that humans are the sole cause of recent global warming." No they didn't. What they were looking at wasn't any sole cause of recent global warming. The categories were based on 50% or more of global warming. It's attribution papers that have found that human activity is the cause of probably all the global warming since 1950 (and some of it prior to 1950).
Is David Legates a liar by nature? Can you believe anything he says on any subject? I wouldn't trust him as far as I could throw him, and it looks as if he's on the heavy side. How he's kept his job at the university is a quirk of the academic system no doubt.
In this case David has no excuse for telling lies. He can't claim that he didn't read the Cook13 paper, because he even coauthored a paper with the potty peer about it, which he got published in some obscure journal.
What David Legates won't admit to deniers
Thing is, as with almost all of the deniers' rants complaining about papers that look over the literature of climate change, David Legates:
- doesn't say what he thinks has caused the warming
- doesn't point out that over the past 20 years there were less than 20 in a thousand abstracts that disputed human activity as the main cause (and probably less today)
- doesn't do his own research to determine what proportion of scientific papers show that human activity is causing global warming vs disputing it
- doesn't say what he thinks is causing global warming.
David Legates draws on consensus to dispute the value of consensus
Here is some more illogic from David Legates. He draws on consensus to dispute the value of consensus:
Moreover, consensus and votes have no place in science. History is littered with theories that were long denied by “consensus” science and politics: plate tectonics, germ theory of disease, a geocentric universe. They all underscore how wrong consensus can be.How does David know about plate tectonics? Is he arguing that this is real despite few scientists supporting the notion, or is he arguing that it's real because there is a scientific consensus supported by lots of evidence?
How does he know that the germ theory of disease is real? It's not his subject area. So either he's arguing that it's real because there is a consensus or perhaps he's arguing it's real despite all the medicos saying it's nonsense.
As for him putting forward the geocentric universe in the same category as germ theory and plate tectonics - why does David Legates think that the Earth is the centre of the universe? That is not the scientific consensus. I'll leave that one for you to ponder.
Consensus has every place in scientific knowledge. Without consensus every piece of scientific research would have to start from scratch. There'd be no progress. No knowledge to build upon. (Before finding a genetic cause of a particular disability, every bit of research would first have to repeat scientific experiments to show that traits can be inherited, and how.)
David Legates' illogic on dangerous climate change
David's article has more contradictions. He wrote this strange inconsistent passage:
As for climate change being dangerous, this is pure hype based on little fact. Mile-high rivers of ice burying half of North America and Europe were disastrous for everything in their path, as they would be today. Likewise for the plummeting global temperatures that accompanied them. An era of more frequent and intense hurricanes would also be calamitous; but actual weather records do not show this.First he says that climate change being dangerous is "pure hype". Then to support his conjecture he gives examples of climate change that would be considered very dangerous to human civilisation were it to happen today. Does he read what he writes? Does he know that the "mile high rivers of ice" in the last glacial maximum happened when the global mean surface temperature was perhaps 3°C to 5°C cooler than pre-industrial? There is every reason to be concerned that a rise of 3°C to 5°C above pre-industrial will also have disastrous consequences.
Alarmism from David Legates
David Legates is an alarmist. He wrote a strawman, as if he ever cared for anything but his science denial:
It would be far more deadly to implement restrictive energy policies that condemn billions to continued life without affordable electricity – or to lower living standards in developed countries – in a vain attempt to control the world’s climate. In much of Europe, electricity prices have risen 50% or more over the past decade, leaving many unable to afford proper wintertime heat, and causing thousands to die.David provides no evidence that higher electricity prices have caused "thousands" to die. Nor does he mention the 70,000 who died in European heat waves this century.
Logic and simple arithmetic
I won't bother with the WUWT comments. They are all over the place. Instead I'll talk about how deniers typically fail logic. They want to have their cake and eat it too. Here's a logic question for you. If you were presented with 1,000 coloured blocks:-
- 500 red
- 383 blue
- 17 purple
- 97 white
- 1 black
- 1 mottled white and black
- 1 striped white and black.
For all the clever and not-so-clever people, you can answer the questions here, with some variations :) [Added by Sou after comments below.]
References and further reading
John Cook, Dana Nuccitelli, Sarah A Green, Mark Richardson, Bärbel Winkler, Rob Painting, Robert Way, Peter Jacobs and Andrew Skuce 2013 Quantifying the consensus on anthropogenic global warming in the scientific literature Environ. Res. Lett. 8 024024 doi:10.1088/1748-9326/8/2/024024 (open access)
Annan, J. D., and J. C. Hargreaves. "A new global reconstruction of temperature changes at the Last Glacial Maximum." Climate of the Past 9, no. 1 (2013): 367-376. doi:10.5194/cp-9-367-2013 (open access)
Summer heat wave arrives in Europe - article by Tom Tom Di Liberto at NOAA, July 2015
- Anthony Watts thinks it's April the first at WUWT! - September 2013
- Climatology Professor, David Legates, fails Climatology 101 at WUWT - October 2013
- The Evangelical Science Denier and the Alarmist Fundamentalist Religious Cult: The Cornwall Alliance - October 2013
- "Expert" David Legates tells US Senate Committee that CO2 is animal food - June 2014
- Cook et al Paper Confirms 97% Scientific Consensus - Prompting Silly Conspiracy Theories from Anthony Watts and WUWT - May 2013
- About that 97% - Not a "Great Moment" for WUWT - May 2013