Here is the proof. #1) F-3 to F-5 tornadoes have been less frequent in recent years. See the graph from NOAA below.
#2) NOAA's Storm Prediction Center created a weekly climatology of where tornadoes have occurred in the the past. It was posted on their web site the day of the tornado. You'll recall the Moore tornado occurred on May 20. Below is SPC's map of where tornadoes, based on past climate, are expected to occur the week of May 20.
Where are the highest probabilities? Moore!
If a huge tornado occurred on May 20 in Modesto, Montreal, or Mexico City one might have a point about climate change. In reality, the Moore tornado is evidence the climate hasn't changed in the way IPCC "consensus" fans believe.