Has the earth experienced systemic changes in rainfall or droughts over the past 150 years?
Contrary to predictions from people who claimed that global warming would cause more droughts and floods, studies published by the International Journal of Climatology, the Hydrological Sciences Journal, the journal Theoretical and Applied Climatology, and the Journal of Hydrology all found no significant trends in rainfall or droughts over periods that extend back to as far as 150 years ago. Previous studies had examined shorter timeframes and found changes that were blamed on global warming, but the results were generally not statistically significant and "not entirely surprising given that precipitation varies considerably over time scales of decades." These facts drive home the importance of examining the broadest possible range of evidence instead of cherry picking data, time periods, or geographic areas. The second link below contains a video from Just Facts Academy about how to avoid that trap and conduct comprehensive research.