“The likely range of global temperature increase is 2.0–4.9 °C, with median 3.2 °C and a 5% (1%) chance that it will be less than 2 °C (1.5 °C).” reference 
“Earthly language serves two contradictory purposes: to facilitate thought and to prevent it.” Garrett Hardin
A good friend mentioned an interview of Trump supporters he’d read about. When asked what it would take to change their minds about President Trump they responded that Sean Hannity of FOX NEWS would have to change his mind; nobody else’s opinion mattered to them. My friend asked how do we know we are not thinking in exactly the same way except replacing Hannity with Paul Krugman or some other liberal pundit? I confessed I have always been worried about the same thing and have evolved a set of rules which I apply to new sources and information.
- Trust but verify. Whether we trust Hannity or Krugman or anyone else, we should always verify. I learned this as a fledgling firefighter in rookie school. We have all heard this advice.
- Always insist on references from your sources. Obviously, references help us verify. Without references, we can often still do this but it takes a lot more effort. I tend to avoid pundits who don’t provide references.
- There is such a thing as negative knowledge or as Mark Twain said “stuff we know for sure which just ain’t so.” This is Donald Rumsfeld’s fourth category which he famously left out. Economists and tech lovers think we have entered the Age Of Knowledge or Information as some sort of substitute for energy. But that simply doesn’t make sense. Humans have accumulated a considerable amount of perfectly useless knowledge and a considerable amount of knowledge which is simply wrong. All of this knowledge requires energy to store and even the merely useless knowledge displaces worthwhile knowledge. The cognitive scientist Thomas Landauer estimated  that the human brain can store about half a gigabyte of information. That is about a thousand times less than a typical laptop computer. We simply cannot afford to fill our brains with incorrect, false or negative knowledge.
- Develop filters against folly. Ecologist Garrett Hardin in his appropriately named book  reminds us that we are all literate; even those who cannot read and write use language. The problem is that evolution has supplied us with both a penchant to deceive and the skills to deceive [3, 4 and 5]. Hardin recommends numeracy and what he calls ecolacy . Numeracy does not mean we have to apply rigorous mathematics all the time. It is more about applying logic. Literacy is about storytelling, not logic. Another word for ecolacy is wisdom. The seat of wisdom in our brains is our frontal cortex but it takes a lot of energy to operate so we tend to be too lazy to actually engage it [6-7]. It is also the most recently evolved. Neuroscientist Robert Sapolsky tells us  that the “frontal cortex makes you do the harder thing when it is the right thing to do.”
- We don’t know everything and are prone to suffering Dunning-Kruger Effect. This simply means we overestimate our own expertise and knowledge [8-9]. And by the way Krugman and Hannity don’t know everything. Nobody is above requiring verification.
- Never assume. In rookie school, the first thing we were taught about fighting fire was “assume makes an ass of you and me.” Remember there are no stupid questions but human discourse overflows in stupid assumptions. Hardin calls these conversation stoppers .
- Be circumspect and discriminate. We do not have infinite time and cannot listen to and read everything every pundit ever said or wrote, nor are we under any obligation to do so.
- Science is what we do to keep from lying to ourselves as Richard Feynman reminded us. Collectively we do not know everything but our current scientific view of the world is really quite mature. The smart phone in your pocket and the discovery of human-caused climate change are evidence of that. The more science we know the better our filters against folly. Important to remember is that it is not the scientist or the pundit but the science.
- Gardiner and Tetlock tell us that superforecasters avoid ideology and never identify themselves by their beliefs. Ideology makes smart people stupid. In fact, the well-worn advice to think outside the box refers to thinking outside one’s world view, belief system or ideology. It does not mean thinking outside the laws of physics.
Note that many of these rules are commonsensical rules we all learn and at least notionally subscribe to but all too rarely apply: “trust but verify”, “assume makes an ass of you and me”, and “think outside the box”. The mistake most of us make is thinking merely literately or as Hardin says “trusting the merely eloquent.” Pretty words deceive us all too easily. This is why math and science are so important. The most important issue to consider is human-caused climate change, not only because it is existential [see reference 10 for example] but because in our society it is a clear-cut differentiator between people who may know how to think and people who are merely eloquent. It is the only issue which has been thoroughly researched and documented by humanity’s most knowledgeable experts and probed and tested by skeptics. We know it is true.
Getting back to my friend at the top of this article, he is right to be concerned about being deceived by pundits but his concern makes it unlikely that he will. He is also a radio frequency engineer like myself and knows some math and science, thus he has strong filters against folly. Many of my liberal friends get as goofy over Krugman as conservatives get over Hannity. While each readily sees the flaws in the other side’s thinking, nobody sees their own mistakes. A few years ago, my friend asked if I was following the debate between Krugman and economist Steve Keen over debt and if I understood it. I was indeed following their discussion and was reading a lot of economics to try to understand it. I was fact-checking both of them. My friend was doing the same thing. The important point here is that though notionally liberal, my friend and I both questioned Krugman and Keen, notionally liberal media experts and economists. Verification has a healthy element of curiosity. Deniers are generally incurious.
If we compare these three expert pundits, Hannity, Krugman and Keen, against scientific reality, we can avoid being deceived, even if we assume deception is not their goal. Hannity is a denier of human-caused climate change because of his conservative ideology (see 9). He has no science background and therefore suffers from Dunning-Kruger Effect (see 5). We know he does not know how to think properly and is a source of negative knowledge (see 3). It is not unreasonable to think that he might have less real knowledge than negative knowledge and might actually be net dumber than when he was born. This is why rule 7 is so important. Scanning his wiki page, we find that he is a merely eloquent and consummate source of misinformation and negative knowledge.
But what about Krugman and Keen? Krugman appears to not understand the importance of energy gradients to the human economy. Keen appears to get it but not quite. Hannity is completely out of his element here. But thermodynamics is a science which cannot be avoided if one is trying to understand the human condition or the human economy. Even if we do not understand debt, my friend and I know enough thermodynamics to knows when these three pundits are outside their respective comfort zones and are merely waxing eloquent. For Hannity, this is all the time. If you are not prepared to spend an awful lot of time fact checking him, he needs to be avoided (see 7). Krugman and Keen can be safely consumed with some reasonable caution. Of course, that is how I would recommend you consume my own column. My goal is to tell the truth free of any ideological bias (see 9), but of course I get things wrong (see 5), so can only guarantee verifiability (see 1 and 2). :+)
 T. K. Landauer, How much information do people remember? Some estimates of the Quantity of learning information in long-term memory, Cognitive Science 10(4):477-493.
 Garrett Hardin, Filters Against Folly
 Robert Trivers, The Folly of Fools, the logic of deception and self-deception in human life, Basic Books, 2011
 Michael Shermer, The Believing Brain, Times Books, 2011
 George Akerlof and Robert Shiller, Phishing for Phools, the economics of manipulation and deception, Princeton, 2015
 Robert Sapolsky, Behave, the biology of human’s at our best and worst, Penguin Press, 2017.
 Michael S. Gazzaniga, Who’s in Charge?: Free Will and the Science of the Brain 2011.
 Steven Sloman and Phillip Fernbach, The knowledge illusion, why we never think alone, Riverhead books, 2017.
 Dunning Kruger Effect, https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
 Adrian E. Raftery, Alec Zimmer, Dargan M. W. Frierson, Richard Startz & Peiran Liu, Less than 2 °C warming by 2100 unlikely Nature Climate Change (2017) doi:10.1038/nclimate3352, 31 July 2017