There is a new UN Intergovernmental Panel on Climate Change report. It contains nothing but bad news, of course. But I am busy with my real life; I have obligations to others; I have to feed myself and shower; I even go to the gym regularly. What to do? Just trust a hysterical sixteen-year-old? (Yes, I mean Greta.)

When someone or something claims that there is, has been, change in something I perceive might be important, I apply the following four quick tests. I do this to decide how much I must attention I should pay to the change news.

1 Source credibility

Not all sources are created equal. Some stink, some have a long record of being reliable. The Wall Street Journal is one of the latter. Almost all anonymous internet sources are not even sources. The National Enquirer will publish anything (although it has had a few remarkable scoops). Normal sixteen-year old girls are only credible when they pronounce on show biz stars or on something related to a skill they have personally acquired, such as piano or gymnastics.

2 Main text: description of process

I scrutinize the description at the heart of the announcement of change though only for a short time. Does the process described make sense? Is it derived in an intelligible way from a study, or studies, that conform to conventional scientific, or other scholarly standards? If no claim is made that they do, they don’t, ever. If there is such a claim, there can still be abuse but there will shortly be a denunciation, in most cases, at least.

3 Narrative around description

Most change descriptions not directly in a scholarly journal come wrapped up inside a narrative. The narrative is often more interesting than the findings to which they are supposed to be linked. That’s intentional but dangerous. Suppose your doctor carefully measures your heartbeat and records his observations. Suppose that then, he gives you a very good lecture on the faults of Social Security. However valid the latter is, it should gain no authority whatsoever from the impeccable measurement of you heartbeat. This is a crude example but people do this sort of things all the time. Do you think climate activist do?

I ask myself how tightly connected the narrative is to the straightforward description of the relevant change? Often the answer is: barely, sometimes: not at all.

4 Gauging critically the order of magnitude of change

Suppose I tell you that I have lost weight. (I could use that.) Courtesy requires that you congratulate me but rationality demands that you ask: How much? If my response is one ounce, you will tend to dismiss my announcement and you will be right. One ounce out of 220 lbs is like nothing. (That’s aside from the fact that it might actually be nothing, a measurement error.)

The mysterious issue of “statistical significance” (that I will resist going into here though I am tempted) is only indirectly related to this matter. A difference between before and after, for example, may be statistically significant but yet, completely unimportant.

The short Wall Street Journal piece (1) covering the publication of the report is rich in narrative and short on figures. (That’s usually the case with climate change announcements, I think.) On rare figure drew my attention:

In the past 140 years -covering most but not quite all of the Industrial Age – global surface temperatures have risen by one (unit) degree Celsius.

To give you a practical idea, that’s not enough of a rise to cause me to take off my cotton sweater, or even to unbutton the top of my shirt. If the temperature rose by only one C between 8 am and noon, I would think something was wrong with the weather! I can easily believe that at this rate, in another 1400 years, it will be ten degree centigrade (Celsius) warmer and, we will still be here. That’s unless something else, something much more likely, like an epidemic. wipes us out. (2) and (3).

As this example illustrates, it may often be wise too reverse the critical sequence described above. Why bother to assess the source credibility associated with an announced change, or the conformity of the description change process to good scientific practice, or check out the attachment of the surrounding narratives to the process in the description, why do all this if the measured change is too small to merit attention?

My more complete ruminations on climate change skepticism are in Liberty Unbound: “Climate Change Denier.”

Endnotes

1   “U.N. Panel Sees Threat to Ocean” – by Robert Lee Hotz, Wall Street Journal 9/26/19, P. A8.

2     I am well aware that this is a sort of arithmetic average. Surface temperature may have gone up more in some areas and less in others. They may have declined in some places. If the subject is dealt with, it will be in: Watts Up with That.

3      The WSJ accounts implies that the UN report is oddly concerned with fisheries. This is odd because fishermen have known forever that there are warm and cool patches at the same latitude in the oceans. They also know that those shift positions and that the positions of such warm and cool patches affect the movements of fish.