Talking with a climate-change denier.

A complete transcript of my Twitter DM conversation with a climate change denier, and my attempt to get him to explain what evidence would convince him (if it were found) that man-caused climate change was actually happening. My attempt did not succeed.

 

GregStevens Mar 12, 2:42pm I’d actually love to have a real discussion w/ you about all of this, re: Why you don’t believe in climate change.
(other person) Mar 12, 5:11pm I’m a physicist. While not an expert, I have followed atmospheric science and did some elementary analysis. The “hockey stick” intrigued me.
(other person) Mar 12, 5:13pm In the process I found a lot of junk science. The difficulty is proving a negative. Each piece of evidence has to be shown to be false.
(other person) Mar 12, 5:15pm There is NO evidence of man caused global warming! Now we’re riding on the notion that man is inherently evil.
GregStevens Mar 12, 9:07pm Is the “junk science” that you found the reason you believe there to be bias in the peer review process for this particular field?
(other person) Mar 12, 9:18pm No. Separate subject. Scientists actually conspired to keep contrary views out of the literature.
GregStevens Mar 12, 9:46pm Do you think they were doing it cynically, as a conscious manipulation? Or do you think they “believed” the contrary views were bad science?
GregStevens Mar 12, 9:47pm (I realize I’m just asking for your opinion/speculation here…. I’m curious about your view)
(other person) Mar 12, 9:50pm I suspect they believed their science. It is unethical to suppress contrary views though.
GregStevens Mar 12, 10:38pm It’s tough because science is a human endeavor. People are naturally more “picky” about views they disagree with. It happens in all fields.
(other person) Mar 12, 10:40pm Most of science is very objective. New ideas are aired if they have some basis.
(other person) Mar 12, 10:41pm The “hard sciences” are usually devoid of politics. The advantage working toward an objective truth.
GregStevens Mar 12, 10:41pm Q: is there an experiment or result you can imagine that, if found, would decisively demonstrate human-caused global warming?
GregStevens Mar 12, 10:42pm (i.e. can you imagine some such set of data that would change your mind?)
(other person) Mar 12, 10:43pm A warming that appeared to be above the trend set after the last mini-ice age would be a start.
GregStevens Mar 12, 10:52pm I assume you don’t trust inferences about rate of change over short intervals…
GregStevens Mar 12, 10:52pm So when you say “above the trend”, do you mean an actual greater mean global temperature for some extended interval?
(other person) Mar 12, 11:04pm No. The Earth has been warming at a fairly constant rate since last ice age. If that rate increased. Right now the rate is decreasing.
GregStevens Mar 13, 9:18am What MEASURE of rate increase would you accept as true? Some measures show the rate increasing, I assume you think those are bogus?
(other person) Mar 13, 9:42am The only obviously bogus thing I’ve seen is the hockey stick.
GregStevens Mar 13, 9:46am You have seen no other studies or data that have concluded that the mean temperature of the globe is warming right now?
(other person) Mar 13, 10:01am Of course I have. There are no valid studies I’m aware of that make a case for man caused global warming. We are warming since last ice age.
GregStevens Mar 13, 12:22pm I guess my question is this: what SPECIFIC data would you accept as convincing data?
GregStevens Mar 13, 12:23pm Do there exist ANY possible data sets, that are actually measurable, that COULD convince you? That’s another way of asking my question.
(other person) Mar 13, 1:46pm I’m a scientist. There are any number of things that could convince me there is man caused global warming. Or cooling for that matter.
GregStevens Mar 13, 2:02pm I understand; I’m not accusing or trying to “trap” you. But I’m sincerely asking: what’s an example?
GregStevens Mar 13, 2:04pm What is an example of a specific measured result that you feel would support the “man-made” part of the hypothesis?
GregStevens Mar 13, 2:04pm (I keep focusing on “specific” because I want to know what YOU think is a valid measure showing warming)
(other person) Mar 13, 2:32pm Sorry. I can’t help you.
GregStevens Mar 13, 2:34pm OK… my fear is that this is reminiscent of conversations I have with evolution deniers: they always say “I haven’t seen ENOUGH proof!” (cont)
GregStevens Mar 13, 2:34pm …but they are unwilling to ever specify what “enough” would actually be.
GregStevens Mar 13, 2:35pm Are you concerned at all that you are holding a position where a priority no possible data set will ever convince you?
(other person) Mar 13, 2:37pm Right now there is no EVIDENCE of man made global warming. I’m open minded. My concern is trillions $ spent based on bad info.
GregStevens Mar 13, 2:39pm Right. You say there is no evidence; some say there IS evidence. I’m asking what evidence YOU would consider valid. Just an example.
(other person) Mar 13, 2:51pm You’re not asking a legitimate question. If you’re aware of convincing evidence, let’s hear it.
GregStevens Mar 13, 3:14pm I’m not sure why my Q is not legit. If there exists NO data set that can possibly convince you of “not X” then your belief in X is faith…
GregStevens Mar 13, 3:15pm … not science. Right?
GregStevens Mar 13, 3:16pm It’s like those who say they don’t believe in evolution, but when asked “what evidence WOULD convince you of evolution?” there is none.
(other person) Mar 13, 3:43pm You’re way off base. It’s difficult to prove a negative and usually not worth while. Maybe there is man caused global warming.
(other person) Mar 13, 3:46pm But why would anybody believe it with no evidence? In fact when I looked it wasn’t even plausible.
GregStevens Mar 13, 3:46pm I’m honestly trying to understand. I’m not saying “prove there isn’t warming”; only asking for an example of what an empirical result …
GregStevens Mar 13, 3:48pm …would look like, that would convince you. I don’t think that is unreasonable: if your stance is “there is no proof!”, it’s valid to ask what WOULD be proof?
(other person) Mar 13, 3:49pm We’re done here. I’m not trying to convince you of anything.
GregStevens Mar 13, 3:50pm I’m trying to understand your position. If you do not want to discuss it, that is your right. Thanks for your time.

I have a big concern about this strategy of argument in the climate change debate. His position, on the surface, sounds very rational and scientific. The problem is, the criteria that he is setting up are never well-specified, and there is a real risk of the “moving goal-post”. No matter what evidence is presented, it will not meet the “threshold” because the person judging has already decided that nothing can meet the threshold.