People killed by lightning

As California has produced more almonds, fewer Americans have been killed by lightning, a correlation that raises the tantalizing possibility that almond orchards function as some kind of electromagnetic shield. They do not, but the coefficient is -0.880 across seventeen years, which is strong enough to make you feel briefly grateful for the Central Valley's contribution to both snack foods and storm safety. The almonds grow, the lightning relents, and the chart remains confident in a relationship between tree nuts and atmospheric electricity.

California almond production roughly doubled between 2006 and 2022, driven by export demand (particularly from China and India), favorable growing conditions, and agricultural investment. Lightning deaths declined from about 48 to 11 per year, driven by better weather alerts and the declining share of Americans working outdoors. Both trends are monotonic—one going up, one going down—which guarantees a strong negative correlation regardless of mechanism. The almonds are an agricultural commodity story, and the lightning deaths are a weather warning technology story. They share a direction across the same period, which is all it takes to produce a number that looks meaningful.

Seventeen years of almonds rising and lightning deaths declining is a textbook illustration of why correlation should never be mistaken for explanation. Both trends are real, important, and completely independent. The orchards bloom, the warnings ping, and the chart draws its line through both with the serenity of mathematics that does not care about logic. The almonds are innocent.