Question for warmists: If CO2 causes floods and droughts, why did most of the top ten deadliest droughts and floods occur in the *first* half of the 20th century?

Top Ten Deadliest Floods « NOT A LOT OF PEOPLE KNOW THAT

As we noted with the list of droughts, most events were in the first half of the 20thC.

Ten Deadliest Droughts « NOT A LOT OF PEOPLE KNOW THAT

We are constantly told that climate change is making droughts worse. Yet the most recent event is 1983, and the deadliest droughts were in the first half of the 20thC.