“Be kind, for everyone you meet is fighting a hard battle” - Often attributed to Plato but likely from Ian McLaren (pseudonym of Reverend John Watson)

Saturday, July 05, 2014

It's all in the presentation

Graphic courtesy of NOAA
In the process of trying to understand the trajectory of our climate from a layperson's point of view, albeit one with at least a moderate level of sophistication with respect to basic physics and mathematics, I run across an awful lot of blogs. Some are hosted by actual climatologists, some are hosted by deeply interested people with extensive scientific knowledge but who are not climatologists, some are hosted by interested (and talented) amateurs. These bloggers are firmly convinced that mankind's emissions of carbon dioxide and other greenhouse gases present an imminent danger to our way of life.

There is an alternate universe of blogs from those who are either actually skeptical of any effects we may have on climate or who, for various reasons, write as if they are. Such writers range from those who are openly hostile to those who profess uncertainty. Again, these fall into groups. And again, these writers have vastly differing degrees of scientific sophistication, ranging from those whose career involves the study of climate (though skeptical professional climatologists are few in number) through, again, talented amateurs.

Some of those in the second group, however, are simply hacks. Such a one is the publisher of "Greenie Watch," published by John Ray, Ph.D., out of Brisbane Australia. His latest post discusses the charts one often sees that show global temperature anomalies. These numbers show the deviation from some reference value, typically a long-term average. Such a chart is at the top of this post.

Dr. Ray doesn't like these, and instead shows whole degrees Fahrenheit starting from zero (already questionable, since 0 degrees Fahrenheit has no significance). That results in this:

The point is, of course, that any trend in temperatures looks trivial in comparison to the distance from zero to the measured (calculated?) temperatures.

I thought I'd try something similar. Though I don't know anyone specific, I'd imagine that someone or another has developed a fever in the last 30 days. Let's plot such a person's temperature anomaly:

Woah. This guy had best see a doctor, stat! On the other hand, have a look at this:

I guess he was worried about nothing. And yet these two plots show precisely the same data, one in degrees Fahrenheit above or below 98.6, the other in Kelvins from absolute zero (a zero that, at least, does have some significance).

I may go back and refine these plots, they certainly aren't pretty (I'm working on coming to grips with Matlab and, while some of the manipulation is straightforward, the plotting features frustrate me). But they certainly get across the idea that, in many cases, it's quite straightforward to display data to suit one's agenda. I could almost say, to deceive.

1 comment:

Anonymous said...

What you describe is a very common problem, just like the media loves to overuse percentages.

If some extremely rare disease jumps from 1 case to 5, the media is quick to label this as a 400% increase, which is true, but delivers no context.