I was watching some excellent videos of recent Phoenix dust storms roll across the city. I started thinking about a joke story:
Scientists report that the number of Phoenix dust storms have likely increased substantially since 1990. Before that date, almost no cell phone videos exist of large dust storms in Phoenix. Today, one can find hundreds of such videos on Youtube, mostly from the last three or four years. Obviously we are seeing some sort of climate change
This would clearly be absurd -- there has been a change in measurement technology. No cell phone cameras existed before 1990. But equally absurd examples can be found every day.
- With the summer of the shark, an increase in frequency of media coverage of shark attacks was mistaken for an increase in frequency of shark attacks themselves.
- With tornadoes, improving detection of smaller twisters (e.g. by doppler radar and storm chasers) has been mistaken by many (cough Al Gore cough) for an increase in the frequency of tornadoes. In fact, all evidence points to declining tornado frequency
- With electrical grid disturbances, a trend was created solely by the government owner of the data making a push with power companies to provide more complete reporting.
- I have wondered whether the so-called cancer epidemic in India is real, or the results of better diagnosis and longer life spans
Postscript: I remember when I first saw one of these storms rolling towards me after I moved to Phoenix. Perhaps I should not have read Stephen King's The Mist, but I honestly wondered for a minute if I would live to regret not hopping in my car and racing to stay ahead of the wall coming towards me.
"Trend that is not a trend" is an occasional feature on this blog. I could probably write three stories a day on this topic if I wished. The media is filled with stories of supposed trends based on single data points or anecdotes rather than, you know, actual trend data. More stories of this type are here. It is not unusual to find that the trend data often support a trend in the opposite direction as claimed by media articles.