Has the earth experienced a general change in average overall rainfall over the past 150 years?
For a 2015 study in the Journal of Hydrology, scientists examined rainfall measurements "made at nearly 1,000 stations located in 114 countries" and found "no significant global precipitation change from 1850 to present." Previous studies had examined shorter timeframes and found rainfall 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 looking at the broadest possible range of evidence instead of cherry picking selected time periods or areas. Media outlets sometimes flout this tenet of honest science, as documented in the second link below.