Read here. The IPCC Climategate scientists have predicted that global warming would increase the occurrence of floods on one hand, and on the other hand, warming would increase the frequency of droughts. As with most IPCC predictions, peer-reviewed research typically finds the IPCC predictions to be flops.
Scientists Korhonen and Kuusisto analyzed Finnish rivers and lakes to determine if IPCC prediction had validity.
"The authors write that "annual mean temperatures in Finland increased by about 0.7°C during the 20th century," citing Jylha et al. (2004), while noting that under such a warming regime, "both droughts and floods are expected to intensify," which is the claim of climate-alarmists the world over.....the peak of spring flow has become 1-8 days earlier per decade at over one-third of all studied sites." However, they say that "the magnitudes of spring high flow have not changed." On the other hand, low flows, in their words, "have increased at about half of the unregulated sites due to an increase in both winter and summer discharges." Nevertheless, they indicate that "statistically significant overall changes have not been observed in mean annual discharge."" [Johanna Korhonen and Esko Kuusisto 2010: Hydrology Research]
Additional flood-drought and peer-reviewed postings.