The next time a JW brings up a natural disaster or severe weather event as proof of the last days, and they preface it by reciting a fact they heard on the news like, (just for the sake of example) 'It's the worst earthquake in 70 years' or 'the worst plague in 200' years', (you get the picture), then simply reply: "Oh, so that means that ____ years ago there was one that was worse, right?"
I did this twice. Both times got the same response:
*chirp-chirp-chirp*